Merge pull request 'docs: Testing + rclone/SQL + docs index (#53)' (#64) from docs/w1-w3#53 into main

- Route HTTP helpers (getJSON/formRequest/deleteReq/postJSON/putJSON/
  multipart upload), Query and AuthenticateContext/ensureToken through the
  deterministic 429/502/503/504 retry (retryRaw), so the integration suite
  no longer fails on the shared openresty rate limit under parallel runs.
- Fix stale cmd/office/fetch integration test: loader.TaskFields was
  replaced by loader.DetailForm (broke go vet -tags=integration).
- Add unit tests for Transient/DoRetry.

.env.example

@@ -22,6 +22,47 @@ ONLYOFFICE_PROJECT_ID=33
 
 # oo mails uses ONLYOFFICE_URL/USER/PASS above (Workspace Mail addon).
 
+# deploy/docker-compose.rclone-webdav.yml — rclone FUSE mount of the oo-webdav
+# sidecar. Reuses ONLYOFFICE_USER and accepts ONLYOFFICE_PASSWORD (alias
+# ONLYOFFICE_PASS). Set ONLYOFFICE_WEBDAV_URL only if the sidecar is not on
+# the default docker bridge address. See docs/rclone-webdav.md.
+# ONLYOFFICE_WEBDAV_URL=http://172.17.0.1:8098/webdav
+
 # cmd/office TUI — optional Document Server for DOCX→HTML preview:
 # ONLYOFFICE_DOCS_URL=https://docs.example.com
 # ONLYOFFICE_DOCS_SECRET=
+
+# MinIO download fallback for the portal's stale AWS S3 consumer (older
+# Documents folders). When the portal redirects to amazonaws.com with access
+# key "minio" (403 InvalidAccessKeyId), files are fetched from the local MinIO
+# store instead. Without a key/secret the fallback is disabled.
+# MINIO_ENDPOINT=http://192.168.188.10:9000
+# MINIO_BUCKET=office
+# MINIO_ACCESS_KEY=
+# MINIO_SECRET_KEY=
+
+# oo search — direct Elasticsearch access for name + content search. ES lives
+# inside the OnlyOffice VM on localhost:9200; expose it with an SSH tunnel
+# (see docs/elasticsearch.md). ONLYOFFICE_ES_INDEX defaults to files_file.
+# ONLYOFFICE_ES_URL=http://127.0.0.1:9200
+# ONLYOFFICE_ES_INDEX=files_file
+# ONLYOFFICE_TENANT=
+
+# Read-only SQL file store over the Community Server database (see
+# docs/community-server-db.md). The live portal runs MySQL; ONLYOFFICE_DSN is
+# `user:pass@tcp(host:port)/onlyoffice?parseTime=true`, or a `postgres://` URL.
+# ONLYOFFICE_DSN=
+# ONLYOFFICE_PG_DRIVER=          # postgres | mysql (auto-detected from DSN)
+# ONLYOFFICE_PG_TENANT=1         # falls back to ONLYOFFICE_TENANT
+# Alternatively build a PostgreSQL DSN from parts:
+# ONLYOFFICE_PG_HOST=
+# ONLYOFFICE_PG_PORT=5432
+# ONLYOFFICE_PG_USER=
+# ONLYOFFICE_PG_PASSWORD=
+# ONLYOFFICE_PG_DBNAME=onlyoffice
+# ONLYOFFICE_PG_SSLMODE=disable
+
+# oo index / oo search --backend own — own full-text index for PDF/scans,
+# filled by `oo index` from internal/docpipe (pdftotext + OCR). Defaults to
+# oo_docs_text. Uses the same ONLYOFFICE_ES_URL.
+# ONLYOFFICE_ES_TEXT_INDEX=oo_docs_text

.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "0.17.0"
+  ".": "0.18.0"
 }

AGENTS.md

@@ -9,16 +9,18 @@ Canonical Go client for OnlyOffice Workspace (Projects + Calendar + CRM) and the
   - `request.go` — `Request`, `Query`, `Time`, `Token`, `MetaResponse`, `Permissions`.
   - `auth.go` — `Authenticate`, `AuthenticateContext`, `InvalidateToken`, `Auth`, token lifecycle.
   - `http.go` — transport + DRY response decoders (`ResponseArray`/`ResponseObject`/`postFormObject`/`putFormObject`/`deleteObject`).
-  - `projects.go`, `tasks.go`, `users.go`, `calendar.go`, `crm.go`, `files.go`, `mails.go`, `invoices.go` — typed / untyped domain methods. **`files.go`** — CRM opportunity upload plus **project/task Documents**. **`mails.go`** — OnlyOffice Workspace Mail. **`invoices.go`** — CRM invoices, PDF regen/cleanup, status. Association rules: [`docs/crm-associations.md`](docs/crm-associations.md).
+  - `projects.go`, `tasks.go`, `users.go`, `calendar.go`, `crm.go`, `files.go`, `files_webdav.go`, `files_stem.go`, `retry.go`, `mails.go`, `invoices.go` — typed / untyped domain methods. **`files.go`** — CRM opportunity upload plus **project/task Documents** (`UpdateFile`, `UploadToFolderReplacing`). **`files_webdav.go`** — Documents module by id (`ListDavFolder`, `MoveDavItems`/`CopyDavItems` with per-operation error surfacing, `ListFileOps`). **`retry.go`** — `DoRetry`: deterministic linear backoff (no jitter) on 429/502/503/504; every bulk tool routes API calls through it, and the HTTP transport + auth (`retryRaw`, `AuthenticateContext`) retry transient answers centrally. **`mails.go`** — OnlyOffice Workspace Mail. **`invoices.go`** — CRM invoices, PDF regen/cleanup, status. Association rules: [`docs/crm-associations.md`](docs/crm-associations.md).
+  - **Unified file client (epic #34) — `file_core.go`, `file_rest.go`, `file_dav.go`, `file_pg.go`, `file_es.go`, `file_es_text.go`, `file_text_index.go`, `file_facade.go`.** `file_core.go` — model (`Entry`, `Kind`) + `FileStore`/`Searcher`; `file_rest.go`/`file_dav.go` — REST/WebDAV adapters; `file_pg.go` — **read-only** SQL store (PostgreSQL/MySQL, `ErrReadOnly` on writes); `file_es.go` — OnlyOffice Elasticsearch searcher; `file_es_text.go`/`file_text_index.go` — own PDF/scan index (`oo_docs_text`, PDF attachments via pdfdetach); `file_facade.go` — `FileClient` with read/write/search order and transient fallback. Use `c.Files()` (facade), `c.FileStore("rest"|"dav"|"pg"|"sql")` or `c.SQLFileStore()`; contract and how to add a backend: [`docs/unified-file-client.md`](docs/unified-file-client.md).
   - Pure stdlib + `google/go-querystring`; no UI, no dotenv.
 - **CLI — `cmd/oo/` as `package main`.** Cobra wrapper that loads `.env` via `godotenv` at startup. **Subject-based command tree** mirroring [`tea`](https://gitea.com/gitea/tea):
   - `main.go` — entry point (docstring lists the command tree).
   - `common.go` — `rootCmd`, `newOO`, `printTable`/`printObject`, `--output table|json` flag.
-  - `calendar.go`, `projects.go`, `projects_files.go`, `tasks.go`, `tasks_files.go`, `users.go`, `contacts.go`, `opportunities.go`, `cases.go`, `crm_tasks.go`, `mails.go`, `invoices.go` — one file per subject (or per subject facet), each registers in `init()`.
+  - `calendar.go`, `projects.go`, `projects_files.go`, `tasks.go`, `tasks_files.go`, `users.go`, `contacts.go`, `opportunities.go`, `cases.go`, `crm.go`, `crm_tasks.go`, `catalog.go`, `docs.go`, `dav.go`, `search.go`, `index.go`, `mails.go`, `invoices.go` — one file per subject (or per subject facet), each registers in `init()`. `dav.go` exposes the Documents module by id (`oo dav ls|move|copy|mkdir|rename-file|rename-folder|download|fileops`); `search.go` runs `oo search QUERY` (name/content, `--backend oo|own`); `index.go` fills the own full-text index (`oo index folder|files`, see [`docs/unified-file-client.md`](docs/unified-file-client.md)).
   - CLI-only deps (`spf13/cobra`, `joho/godotenv`) stay out of the library.
 - **TUI — `cmd/office/` as `package main`.** Bubble Tea three-pane browser (module tree, selectable list, markdown preview). Reuses `cmd/internal/bootstrap` for env/auth and the root `onlyoffice` library for all API calls. UI logic in `cmd/office/ui/`; preview/formatting in `cmd/office/preview/`; list loaders in `cmd/office/fetch/`.
   - **List table (`DataTable`)** — `cmd/office/ui/table*.go`. Column layout policies live in `cmd/office/model/table_layout.go` (`TableFlexLayoutFor`); cell rendering uses the bubbles/table inline pattern in `table_render.go` (`renderTableCell`, `padANSIWidth`). See `.cursor/skills/office-tui-table/SKILL.md` before changing center-pane tables.
 - **Shared bootstrap — `cmd/internal/bootstrap/`.** `LoadEnv()` + `NewClient(ctx)` extracted from `oo`; both binaries import it.
+- **Bulk Documents tools — `cmd/ooscan/`, `cmd/pdfamount/`, `cmd/kontoblatt/`, `cmd/kontolink/`.** Single-purpose binaries (folder index, PDF amounts, Kontoblatt summary/linking). Pace requests, route API calls through `DoRetry`; usage in README.
 - **Personal ops tooling** (disk inventory, dossier→CRM sync, SearXNG) lives in private [`eSlider/oo-workspace`](https://git.produktor.io/eSlider/oo-workspace) (`oow`), not in this public tree.
 
 ## Rules
@@ -27,7 +29,7 @@ Canonical Go client for OnlyOffice Workspace (Projects + Calendar + CRM) and the
 - New endpoints go into the library first; CLI commands are thin wrappers.
 - Prefer `ResponseObject` / `postFormObject` / `putFormObject` / `deleteObject` over hand-rolled `json.Unmarshal(responseField(...))` blocks — they exist for DRY, use them.
 - Domain split is by file, **not** by subpackage. Don't introduce `internal/` or `pkg/*` subpackages inside the library — it flattens the `*Client` call surface for a reason.
-- CLI commands follow **subject → verb** structure (`oo <subject> <verb>`), never `oo <verb>-<subject>`. Add new commands to the existing subject file if one fits; create a new `cmd/oo/<subject>.go` for a genuinely new domain.
+- CLI commands follow **subject → verb** structure (`oo <subject> <verb>`), never `oo <verb>-<subject>`. Add new commands to the existing subject file if one fits; create a new `cmd/oo/<subject>.go` for a genuinely new domain. The subject→verb tree in `cmd/oo/main.go` and the README table are documentation — update them with the code.
 - **Documents for agents:** prefer Markdown in git; OnlyOffice UI is weak for `.md`/`.txt`. Use `oo docs put-md` (md→docx) and `oo docs put-txt` (txt→docx, preserves line breaks). All upload paths default to **upsert** by `stem|ext` (`--replace`, default true); `--no-replace` fails on conflict; `--allow-duplicate` opts into raw OO append. `oo projects files dedupe PROJECT_ID` reports/removes duplicate stem|ext copies (`--apply`, `--cross`; includes project root folder).
 - Every table output goes through `printTable(headers, rows)`; every single-object through `printObject(v)`. Do not `fmt.Println` rows ad-hoc or the `--output json` flag breaks for that command.
 - No secrets in the repo; use `.env` (gitignored). Commit `.env.example` only.
@@ -54,6 +56,7 @@ write `mux.HandleFunc("/api/2.0/...")` to emulate OnlyOffice, we write an
 
 ## Related
 
+- [`docs/README.md`](docs/README.md) — reference index (file client, ES, SQL, rclone).
 - [`eSlider/inventar`](https://git.produktor.io/eSlider/inventar) — ASR/ADR (see ASR-0008 Go library module conventions).
 - [`eSlider/inventar-sync`](https://git.produktor.io/eSlider/inventar-sync) — OnlyOffice → Gitea issue sync, consumes this library.
 - [`produktor.io/vidarr`](https://git.produktor.io/produktor.io/vidarr) — legacy consumer being migrated from `pkg/onlyoffice` to this module.

CHANGELOG.md

@@ -6,6 +6,23 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
 
+## [0.18.0](https://github.com/eSlider/go-onlyoffice/compare/v0.17.0...v0.18.0) (2026-09-04)
+
+
+### Features
+
+* **crm:** add UpdateContactName and CloseCRMTask helpers ([4d8af7a](https://github.com/eSlider/go-onlyoffice/commit/4d8af7a2fef1fcfd96ad913cefc6497e3389963b))
+
+
+### Bug Fixes
+
+* **crm:** deterministic sortBy=id in contact paged lists ([4d91726](https://github.com/eSlider/go-onlyoffice/commit/4d917261792203732ac739644c9c82124b2166eb))
+
+
+### Documentation
+
+* **funding:** eSlider support links (reverse-import GitHub e9c969a) ([d650a16](https://github.com/eSlider/go-onlyoffice/commit/d650a16a36037949505eb017c92bd3283e6e2f0f))
+
 ## [0.17.0](https://github.com/eSlider/go-onlyoffice/compare/v0.16.0...v0.17.0) (2026-08-31)
 
 

README.md

@@ -503,6 +503,29 @@ type Task struct {
 |---|---|
 | `GetUsers()` | List all users with profiles |
 
+### Documents Files
+
+| Method | Description |
+|---|---|
+| `ListDavFolder(ctx, id)` | List a Documents folder (`@root` for virtual sections) |
+| `ListDavSections(ctx)` | Virtual sections (Documents, Projects, …) |
+| `CreateDavFolder(ctx, parentID, title)` | Create a subfolder |
+| `RenameDavFolder(ctx, id, title)` / `RenameDavFile(ctx, id, title)` | Rename folder / file |
+| `DownloadFile(ctx, id, dst)` / `DownloadDavFile(ctx, id, w)` | Download file bytes |
+| `UploadDavFile(ctx, folderID, fileName, src)` | Upload from a reader |
+| `UploadToFolder(ctx, folderID, localPath)` | Upload a local file into a folder |
+| `UploadToFolderReplacing(ctx, folderID, localPath)` | Upsert by `stem\|ext`; returns replaced ids |
+| `UpdateFile(ctx, fileID, localPath)` | New version of an existing file (same id, no copy) |
+| `MoveDavItems(ctx, folderIDs, fileIDs, dest)` | Move (`resolveType=Skip`); per-operation errors surfaced, not silent nil |
+| `CopyDavItems(ctx, folderIDs, fileIDs, dest)` | Copy (`conflictResolveType=Skip`); errors surfaced |
+| `MoveFiles(ctx, destFolderID, fileIDs)` | Move with `resolveType=Skip` + `holdResult`; errors surfaced |
+| `ListFileOps(ctx)` | Active file operations (move/copy status polling) |
+| `FolderFiles(ctx, folderID)` | Flat file list of a folder (stem helpers) |
+| `DeleteFilesByStem(ctx, folderID, stem)` | Remove `stem\|ext` copies |
+| `DoRetry(ctx, policy, fn)` | Deterministic linear backoff (N·Base, no jitter) on 429/502/503/504 |
+| `DefaultRetryPolicy()` | 5 attempts, 1s·2s·3s·4s waits, 30s cap |
+| `Transient(err)` | True for retriable OnlyOffice answers |
+
 ### Helper Types
 
 | Type | Description |
@@ -622,6 +645,8 @@ oo docs convert ./note.docx               # → note.md
 oo docs ocr ./scan.jpg --md ./scan.md     # searchable PDF + markdown
 oo docs hocr ./scan.jpg --lang spa --md ./scan.hocr.md --yaml ./scan.yml
 oo docs put-md 7 ./OO-HONDA-7-INDEX.md --folder 490
+oo docs put-txt 7 ./notes.txt --folder 490
+oo docs put-xlsx 7 ./table.xlsx --folder 490
 oo docs as-md 2815 --to ./parte.md        # download OO file as MD (OCR if needed)
 oo docs as-md 307 --hocr --lang spa       # OO download via go-hocr structure
 oo projects files put-md 7 ./note.md      # alias
@@ -631,21 +656,117 @@ oo tasks files upload 208 ./notes.pdf
 oo tasks files detach 208 12345
 ```
 
+### Documents module (`oo dav`)
+
+Direct access to the Documents module by folder/file id — the same calls that
+back `oo-webdav` and the project/task file commands. `move` sends
+`resolveType=Skip` + `holdResult=true`: without those params the legacy
+`fileops/move` endpoint answers 200 without moving anything, and the library
+surfaces such per-operation errors instead of a silent nil
+(`MoveDavItems` / `CopyDavItems` / `MoveFiles`).
+
+```bash
+oo dav ls 659
+oo dav ls @root                       # virtual sections (Documents, Projects, …)
+oo dav mkdir 659 "2026 inbox"
+oo dav move 659 22881 22882           # DEST_FOLDER_ID FILE_ID…
+oo dav move 659 22881 --folders 670   # move folders along with files
+oo dav copy 659 22881
+oo dav rename-file 22881 invoice-v2.pdf
+oo dav rename-folder 671 o2-archive
+oo dav download 22881 --to ./copy.pdf # default path: ./<server title>
+oo dav fileops                        # active move/copy operations (status polling)
+```
+
+### Search and index (`oo search`, `oo index`)
+
+Full-text search over the Documents index. The REST endpoint
+`/api/2.0/files/@search/{query}` only searches file names in the database, so
+`oo search` talks to the OnlyOffice **Elasticsearch** directly (index
+`files_file`). Name search is default; `--content` also matches extracted
+document text (`document.attachment.content`, Office formats only).
+See [`docs/elasticsearch.md`](docs/elasticsearch.md) for the tunnel setup.
+
+```bash
+oo search "Rechnung"                          # names only
+oo search "Mahngebühr" --content              # names + document text
+oo search "Rechnung" --folder 649 --limit 50
+oo search "Rechnung" --json                   # shorthand for -o json
+```
+
+Requires `ONLYOFFICE_ES_URL` (plus optional `ONLYOFFICE_ES_INDEX`,
+`ONLYOFFICE_TENANT`).
+
+#### PDF/scans: own index (`oo index` + `--backend own`)
+
+The OnlyOffice index covers Office formats only, so PDFs (`S1019`-style invoice
+numbers) are not searchable by content. `oo index` extracts PDF text with
+`internal/docpipe` (pdftotext, OCR for scans) — including the text of embedded
+PDF attachments (`pdfdetach`: `<doc>.md`, `.xml`, covers the original/scan and
+ZUGFeRD e-invoice XML) — into a separate index (`ONLYOFFICE_ES_TEXT_INDEX`,
+default `oo_docs_text`); the OnlyOffice server and its index are **not**
+modified. Then search it with `--backend own`.
+
+```bash
+oo index folder 634 --recursive --exts pdf    # populate (idempotent upsert)
+oo index files 3576 3578                      # specific files
+oo index folder 634 --dry-run                 # plan only
+oo search "S1021" --content --backend own     # finds the PDF
+oo search "Rechnung" --backend own --folder 634 --json
+```
+
+See [`docs/elasticsearch.md`](docs/elasticsearch.md) for the decision and
+trade-offs.
+
+### Unified file client
+
+All file backends (REST, WebDAV, read-only SQL, Elasticsearch) sit behind one
+facade: `c.Files()` returns a `*FileClient` that also implements `FileStore`,
+so old call sites keep working. Pick a transport per call with
+`c.FileStore("rest"|"dav"|"pg"|"sql")` (SQL is read-only), open the SQL store
+with `c.SQLFileStore()`, or register a backend on the facade
+(`RegisterStore`/`RegisterSearcher`). Contract, model (`Entry`/`Kind`),
+fallback rules, env names and how to add a backend:
+[`docs/unified-file-client.md`](docs/unified-file-client.md).
+
+### Bulk tools (`cmd/`)
+
+Small single-purpose binaries for bulk Documents work. All of them pace
+requests and retry transient OnlyOffice answers (429/502/503/504) with a
+deterministic linear backoff — no jitter, same waits on every run
+(see `DoRetry` below). Build with `go build ./cmd/<tool>`.
+
+```bash
+ooscan 659                             # recursive index → TSV: file_id, folder_id, path, title
+ooscan 659 666 > oo-index.tsv          # several roots into one index
+pdfamount 671                          # "Zu zahlender Betrag" per PDF → TSV: file_id, title, amount
+kontoblatt 3906 ./kontoblatt.xlsx      # summary (Gegenkonto/Monat) uploaded next to source
+kontolink IN.xlsx oo-index.tsv OUT.xlsx [FILE_ID] [AMOUNTS_TSV]
+# kontolink writes DocEditor links into the Link column: Beleg → supplier+month
+# → amount+date (5th arg = pdfamount output); with FILE_ID it updates the
+# source file in place, else uploads an "(links)" copy next to it.
+```
+
 | Subject | Verbs |
 |---|---|
 | `calendar` | `list`, `events`, `add`, `delete` |
-| `projects` | `list`, `get`, `milestones`, `create`, `update`, `delete`, **`files`** (`list`, `upload`, `download`, `rename`, `delete`) |
+| `projects` | `list`, `get`, `milestones`, `milestone-create`, `create`, `update`, `delete`, `contacts` (`add`, `remove`), `link-authors`, `link-git`, **`files`** (`list`, `upload`, `download`, `rename`, `delete`, `dedupe`, `as-md`, `put-md`, `put-txt`, `put-xlsx`) |
 | `tasks` | `list`, `get`, `create`, `update`, `delete`, `subtask add`, **`files`** (`list`, `upload`, `detach`) |
 | `users` | `list`, `self` (alias: `oo whoami`) |
-| `contacts` | `list`, `get`, `delete`, `info-add`, `merge`, `dedupe-info` |
+| `contacts` | `list`, `get`, `delete`, `info-add`, `merge`, `dedupe-info`, `tags`, `tag-add`, `tag-create`, `tag-remove` |
 | `persons` | `list`, `create`, `delete`, `dedupe` |
 | `companies` | `list`, `create`, `delete`, `dedupe`, `dedupe-persons` |
-| `opportunities` | `list`, `get`, `create`, `delete`, `stages`, `member-add`, `dedupe`, `dedupe-members`, `fix-titles` |
+| `opportunities` | `list`, `get`, `create`, `update`, `delete`, `stages`, `member-add`, `dedupe`, `dedupe-members`, `fix-titles` |
 | `invoices` | `list`, `get`, `create`, `update`, `pdf`, `pdf-cleanup`, `status`, `delete`, `items …` |
 | `crm` | `cleanup` |
-| `mails` | `accounts`, `folders`, `list`, `get`, `draft`, `attach`, `draft-invoice`, `delete` |
+| `mails` | `accounts`, `folders`, `list`, `get`, `download-attachment`, `draft`, `attach`, `draft-invoice`, `send`, `delete` |
 | `cases` | `list`, `create`, `delete`, `member-add` |
-| `crm-tasks` | `list`, `create`, `delete`, `categories` |
+| `crm-tasks` | `list`, `create`, `delete`, `categories`, `reassign-self` |
+| `docs` | `tools`, `convert`, `optimize`, `ocr`, `hocr`, `as-md`, `put-md`, `put-txt`, `put-xlsx` |
+| `catalog` | `match`, `merge`, `apply`, `scan-contacts`, `scan-projects`, `scan-thunderbird` |
+| `dav` | `ls`, `move`, `copy`, `mkdir`, `rename-file`, `rename-folder`, `download`, `fileops` |
+| `search` | `QUERY` (`--content`, `--folder ID`, `--limit N`, `--backend oo\|own`, `--json`) |
+| `index` | `folder FOLDER_ID`, `files FILE_ID...` (`--recursive`, `--exts pdf`, `--limit N`, `--dry-run`) |
 
 The CLI reads only `.env` from the current working directory (godotenv is a
 CLI-only concern — the library itself never loads dotfiles).
@@ -878,9 +999,51 @@ oo projects files list 33
 | `ONLYOFFICE_CALENDAR_ID` | Default calendar id used when omitted (default `1`) |
 | `ONLYOFFICE_PROJECT_ID` | Default project id used when omitted (default `33`) |
 | `OO_URL`, `OO_USER`, `OO_PASS` | Optional CLI-only aliases for `ONLYOFFICE_*` |
+| `ONLYOFFICE_ES_URL` | Elasticsearch base URL (`oo search`, own index); see [`docs/elasticsearch.md`](docs/elasticsearch.md) |
+| `ONLYOFFICE_ES_INDEX` | OnlyOffice index (default `files_file`) |
+| `ONLYOFFICE_ES_TEXT_INDEX` | Own PDF/scan index (default `oo_docs_text`) |
+| `ONLYOFFICE_TENANT` | `tenantId` filter for ES/SQL (empty = all) |
+| `ONLYOFFICE_DSN` | Read-only SQL DSN (MySQL or `postgres://`); see [`docs/community-server-db.md`](docs/community-server-db.md) |
+| `ONLYOFFICE_PG_DRIVER`, `ONLYOFFICE_PG_TENANT`, `ONLYOFFICE_PG_HOST/_PORT/_USER/_PASSWORD/_DBNAME/_SSLMODE` | SQL store override / DSN by parts (PostgreSQL) |
+| `MINIO_ENDPOINT`, `MINIO_BUCKET`, `MINIO_ACCESS_KEY`, `MINIO_SECRET_KEY` | Object-store layout for SQL `Download` |
+| `ONLYOFFICE_WEBDAV_URL` | rclone WebDAV sidecar URL (default `http://172.17.0.1:8098/webdav`) |
 
 Mail and CRM cleanup are documented in [oo CLI use cases](#oo-cli-use-cases) above. Personal disk inventory / dossier sync lives in the private `oo-workspace` (`oow`) tooling.
 
+## Testing
+
+```bash
+go build ./... && go vet ./...
+go test ./...                 # unit — no network, no vendor mocks
+go test -race ./...
+go test -tags=integration ./...   # live OnlyOffice (skip without creds)
+```
+
+Unit tests are pure Go (parsers, encoders, conversions). Integration tests
+(`//go:build integration`) hit a live instance and **skip** cleanly when the
+env is missing, so `go test ./...` stays green offline. New endpoints ship with
+an integration test before merge (policy in [`AGENTS.md`](AGENTS.md)).
+
+Live runs need credentials (`ONLYOFFICE_URL`, `ONLYOFFICE_USER`,
+`ONLYOFFICE_PASS`) and, per backend:
+
+- **Elasticsearch** (`oo search`, own index) — ES lives on `127.0.0.1:9200`
+  inside the OnlyOffice VM; expose it over SSH
+  (`-L 9200:127.0.0.1:9200`) and set `ONLYOFFICE_ES_URL`
+  (see [`docs/elasticsearch.md`](docs/elasticsearch.md)).
+- **SQL backend** (`FileClient`, `SQLFileStore`) — MySQL on `127.0.0.1:3306`
+  in the same VM; tunnel `-L 3306:127.0.0.1:3306`, then set `ONLYOFFICE_DSN`
+  (see [`docs/community-server-db.md`](docs/community-server-db.md)).
+  `ONLYOFFICE_PG_TEST_FILE_ID` / `ONLYOFFICE_PG_TEST_FOLDER_ID` select a real
+  file for the REST cross-check; `MINIO_*` enable the download check.
+
+### rclone WebDAV mount
+
+`deploy/docker-compose.rclone-webdav.yml` mounts the Documents tree as a
+filesystem (compose, not systemd; container `rclone-webdav`) — read/write like
+a normal FS over the `oo-webdav` sidecar. Setup, smoke log and limitations:
+[`docs/rclone-webdav.md`](docs/rclone-webdav.md).
+
 ### CI / releases
 
 GitHub Actions (pattern from [`eSlider/go-config`](https://github.com/eSlider/go-config)):

auth.go

@@ -43,6 +43,11 @@ func (c *Client) Authenticate() error { return c.ensureToken() }
 // cached token is still valid it returns immediately; otherwise it performs
 // a POST to /api/2.0/authentication.json that is cancellable via ctx.
 //
+// Transient answers from the edge (openresty 429/502/503/504) are retried with
+// the same deterministic policy as every other request (see retry.go), because
+// the server rate-limits authentication and the integration suite otherwise
+// fails with a raw HTML 429 page.
+//
 // This is the recommended entry point for long-running syncs (cron,
 // watchers) because it guarantees that a stalled auth call will not block
 // the caller past its deadline.
@@ -50,6 +55,14 @@ func (c *Client) AuthenticateContext(ctx context.Context) error {
 	if c.tokenValid() {
 		return nil
 	}
+	return DoRetry(ctx, DefaultRetryPolicy(), func() error {
+		return c.authenticateOnce(ctx)
+	})
+}
+
+// authenticateOnce performs a single authentication POST. Callers must handle
+// retries; use AuthenticateContext.
+func (c *Client) authenticateOnce(ctx context.Context) error {
 	body, err := json.Marshal(c.credentials)
 	if err != nil {
 		return fmt.Errorf("marshal credentials: %w", err)
@@ -99,17 +112,13 @@ func (c *Client) tokenValid() bool {
 
 // ensureToken refreshes the authentication token when missing or expired.
 // Mirrors the logic inline in Query() but is safe to call from helpers that
-// bypass the typed Request abstraction.
+// bypass the typed Request abstraction. It shares AuthenticateContext so the
+// transient-retry policy applies to every code path.
 func (c *Client) ensureToken() error {
 	if c.tokenValid() {
 		return nil
 	}
-	tok, err := c.Auth(c.credentials)
+	return c.AuthenticateContext(context.Background())
-	if err != nil {
-		return err
-	}
-	c.token = tok
-	return nil
 }
 
 // authHeader returns the value for the Authorization header, ensuring a token.

client.go

@@ -14,6 +14,7 @@ import (
 	"net/http/cookiejar"
 	"os"
 	"strings"
+	"sync"
 )
 
 // Client of OnlyOffice API uses credentials to get a token and query the API
@@ -32,6 +33,9 @@ type Client struct {
 	defaults  Defaults // optional fallbacks for calendar/project IDs
 	selfID    string   // cached /api/2.0/people/@self id
 	noteCatID int      // cached CRM history category id for "note"
+
+	folderTitles   map[string]string // cached Documents folder id -> title (F9)
+	folderTitlesMu sync.Mutex
 }
 
 // NewClient returns a new Client backed by http.DefaultClient.

cmd/kontoblatt/main.go

@@ -0,0 +1,220 @@
+// Command kontoblatt builds a summary ("сводная таблица") of a Kontoblatt XLSX
+// (Datum, Gegenkonto, Buchungstext, Beleg, Soll, Haben, Bemerkung) and uploads
+// it back to the same OnlyOffice folder as the source file.
+//
+// Usage: kontoblatt <FILE_ID> <LOCAL_XLSX>
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+	"github.com/xuri/excelize/v2"
+)
+
+type agg struct {
+	count   int
+	soll    float64
+	haben   float64
+	reFehlt int
+}
+
+type rec struct {
+	date, month, konto, text string
+	soll, haben              float64
+	reFehlt                  bool
+}
+
+var dateRe = regexp.MustCompile(`^\d{2}\.\d{2}\.\d{4}$`)
+
+func parseAmount(s string) float64 {
+	s = strings.TrimSpace(s)
+	s = strings.ReplaceAll(s, "€", "")
+	s = strings.ReplaceAll(s, " ", "")
+	s = strings.ReplaceAll(s, ",", "") // German thousands separator
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return 0
+	}
+	v, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0
+	}
+	return v
+}
+
+func cell(row []string, i int) string {
+	if i < len(row) {
+		return strings.TrimSpace(row[i])
+	}
+	return ""
+}
+
+func main() {
+	if len(os.Args) < 3 {
+		fmt.Fprintln(os.Stderr, "usage: kontoblatt <FILE_ID> <LOCAL_XLSX>")
+		os.Exit(2)
+	}
+	fileID, path := os.Args[1], os.Args[2]
+	ctx := context.Background()
+
+	f, err := excelize.OpenFile(path)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	var recs []rec
+	for _, sh := range f.GetSheetList() {
+		rows, err := f.GetRows(sh)
+		if err != nil {
+			continue
+		}
+		for _, r := range rows {
+			d := cell(r, 0)
+			if !dateRe.MatchString(d) {
+				continue
+			}
+			text := cell(r, 2)
+			recs = append(recs, rec{
+				date:    d,
+				month:   d[3:10],
+				konto:   cell(r, 1),
+				text:    text,
+				soll:    parseAmount(cell(r, 4)),
+				haben:   parseAmount(cell(r, 5)),
+				reFehlt: strings.Contains(strings.ToUpper(text), "FEHLT"),
+			})
+		}
+	}
+
+	byKonto := map[string]*agg{}
+	byMonth := map[string]*agg{}
+	getK := func(k string) *agg {
+		if byKonto[k] == nil {
+			byKonto[k] = &agg{}
+		}
+		return byKonto[k]
+	}
+	getM := func(k string) *agg {
+		if byMonth[k] == nil {
+			byMonth[k] = &agg{}
+		}
+		return byMonth[k]
+	}
+	var tot agg
+	for _, r := range recs {
+		k := getK(r.konto)
+		k.count++
+		k.soll += r.soll
+		k.haben += r.haben
+		if r.reFehlt {
+			k.reFehlt++
+		}
+		m := getM(r.month)
+		m.count++
+		m.soll += r.soll
+		m.haben += r.haben
+		if r.reFehlt {
+			m.reFehlt++
+		}
+		tot.count++
+		tot.soll += r.soll
+		tot.haben += r.haben
+		if r.reFehlt {
+			tot.reFehlt++
+		}
+	}
+
+	out := excelize.NewFile()
+	defer out.Close()
+	writeSheet(out, "Nach Gegenkonto", "Gegenkonto", byKonto, tot)
+	writeSheet(out, "Nach Monat", "Monat", byMonth, tot)
+	outPath := "/tmp/opencode/kontoblatt-zusammenfassung.xlsx"
+	if err := out.SaveAs(outPath); err != nil {
+		panic(err)
+	}
+
+	// upload next to the source file
+	creds := onlyoffice.GetEnvironmentCredentials()
+	c := onlyoffice.NewClient(creds)
+	var src *onlyoffice.FileEntry
+	if derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+		var err error
+		src, err = c.GetFile(ctx, fileID)
+		return err
+	}); derr != nil {
+		panic(derr)
+	}
+	folder := ""
+	if src.FolderID != nil {
+		folder = src.FolderID.String()
+	}
+	title := ""
+	if src.Title != nil {
+		title = *src.Title
+	}
+	fmt.Printf("source: id=%s title=%q folder=%s\n", fileID, title, folder)
+
+	name := "Kontoblatt-1591-2025-Zusammenfassung.xlsx"
+	tmp := "/tmp/opencode/" + name
+	data, _ := os.ReadFile(outPath)
+	if err := os.WriteFile(tmp, data, 0o600); err != nil {
+		panic(err)
+	}
+	var entry *onlyoffice.FileEntry
+	if derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+		var err error
+		entry, _, err = c.UploadToFolderReplacing(ctx, folder, tmp)
+		return err
+	}); derr != nil {
+		panic(derr)
+	}
+	fmt.Printf("uploaded: %s -> folder %s (id %v)\n", name, folder, entry.ID)
+
+	// print the summary
+	printAgg("Nach Gegenkonto", byKonto, tot)
+	printAgg("Nach Monat", byMonth, tot)
+}
+
+func writeSheet(f *excelize.File, sheet, key string, m map[string]*agg, tot agg) {
+	f.NewSheet(sheet)
+	rows := [][]any{{key, "Anzahl", "Soll", "Haben", "Saldo", `davon "fehlt"`}}
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	for _, k := range keys {
+		a := m[k]
+		rows = append(rows, []any{k, a.count, a.soll, a.haben, a.soll - a.haben, a.reFehlt})
+	}
+	rows = append(rows, []any{"GESAMT", tot.count, tot.soll, tot.haben, tot.soll - tot.haben, tot.reFehlt})
+	for i, row := range rows {
+		for j, v := range row {
+			cellRef, _ := excelize.CoordinatesToCellName(j+1, i+1)
+			_ = f.SetCellValue(sheet, cellRef, v)
+		}
+	}
+}
+
+func printAgg(title string, m map[string]*agg, tot agg) {
+	fmt.Printf("\n== %s ==\n", title)
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	fmt.Printf("%-12s %6s %12s %12s %12s %7s\n", "key", "count", "soll", "haben", "saldo", "fehlt")
+	for _, k := range keys {
+		a := m[k]
+		fmt.Printf("%-12s %6d %12.2f %12.2f %12.2f %7d\n", k, a.count, a.soll, a.haben, a.soll-a.haben, a.reFehlt)
+	}
+	fmt.Printf("%-12s %6d %12.2f %12.2f %12.2f %7d\n", "GESAMT", tot.count, tot.soll, tot.haben, tot.soll-tot.haben, tot.reFehlt)
+}

cmd/kontolink/main.go

@@ -0,0 +1,478 @@
+// Command kontolink fills the "Link" column of a Kontoblatt ("ungeklärte
+// Posten") XLSX by matching each row to an OnlyOffice document.
+//
+// Strategy (deterministic, conservative — no LLM):
+//  1. Beleg token (letters/digits from the "Beleg" column) appears in the file
+//     title; among candidates prefer (a) the row's month, (b) real invoices over
+//     copies/dupes, and require the result to be unique;
+//  2. else supplier + row month + "rechnung", again unique.
+//
+// A file is linked at most once (rows already carrying a link are kept and their
+// file counts as used). Ambiguous rows are left UNLINKED for manual review.
+//
+// Usage: kontolink <IN_XLSX> <INDEX_TSV> <OUT_XLSX>
+package main
+
+import (
+	"context"
+
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+	"github.com/xuri/excelize/v2"
+)
+
+var (
+	dateRe = regexp.MustCompile(`^\d{2}\.\d{2}\.\d{4}$`)
+	nonAln = regexp.MustCompile(`[^0-9a-z]+`)
+	fileID = regexp.MustCompile(`fileid=(\d+)`)
+)
+
+func parseDay(s string) (time.Time, bool) {
+	t, err := time.Parse("02.01.2006", strings.TrimSpace(s))
+	return t, err == nil
+}
+
+func titleDay(title string) (time.Time, bool) {
+	if len(title) >= 10 {
+		if t, err := time.Parse("2006-01-02", title[:10]); err == nil {
+			return t, true
+		}
+	}
+	return time.Time{}, false
+}
+
+// nearest picks the candidate whose title date is closest to rd. Ties and
+// undated candidates (when >1) are rejected.
+func nearest(cands []entry, rd time.Time) (entry, bool) {
+	if len(cands) == 1 {
+		return cands[0], true
+	}
+	best, bestD, tie := -1, 0.0, false
+	for i, e := range cands {
+		td, ok := titleDay(e.title)
+		if !ok {
+			continue
+		}
+		d := td.Sub(rd).Hours() / 24
+		if d < 0 {
+			d = -d
+		}
+		if best < 0 || d < bestD {
+			best, bestD, tie = i, d, false
+		} else if d == bestD {
+			tie = true
+		}
+	}
+	if best < 0 || tie {
+		return entry{}, false
+	}
+	return cands[best], true
+}
+
+const linkPrefix = "https://office.pro-dukt.de/Products/Files/DocEditor.aspx?fileid="
+
+type entry struct {
+	id, path, title, norm string
+}
+
+func norm(s string) string { return nonAln.ReplaceAllString(strings.ToLower(s), "") }
+
+func main() {
+	if len(os.Args) < 4 {
+		fmt.Fprintln(os.Stderr, "usage: kontolink <IN_XLSX> <INDEX_TSV> <OUT_XLSX>")
+		os.Exit(2)
+	}
+	in, idxPath, out := os.Args[1], os.Args[2], os.Args[3]
+
+	idxRaw, err := os.ReadFile(idxPath)
+	if err != nil {
+		panic(err)
+	}
+	var entries []entry
+	for _, line := range strings.Split(string(idxRaw), "\n") {
+		parts := strings.Split(line, "\t")
+		if len(parts) < 4 || parts[0] == "" {
+			continue
+		}
+		entries = append(entries, entry{id: parts[0], path: parts[2], title: parts[3], norm: norm(parts[3])})
+	}
+
+	f, err := excelize.OpenFile(in)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	sheet := f.GetSheetList()[0]
+	rows, err := f.GetRows(sheet)
+	if err != nil {
+		panic(err)
+	}
+
+	// optional 5th arg: amounts TSV "file_id\ttitle\tamount" (see cmd/pdfamount)
+	var amts []amtEntry
+	if len(os.Args) >= 6 && os.Args[5] != "" {
+		amts = loadAmounts(os.Args[5])
+	}
+
+	used := map[string]bool{}
+	for _, r := range rows {
+		if m := fileID.FindStringSubmatch(cell(r, 7)); m != nil {
+			used[m[1]] = true
+		}
+	}
+
+	var linked, byBeleg, bySupplier, byAmount, unmatched, ambiguous int
+	for i, r := range rows {
+		if i == 0 || !dateRe.MatchString(cell(r, 0)) || strings.TrimSpace(cell(r, 7)) != "" {
+			continue
+		}
+		beleg := norm(cell(r, 3))
+		supplier := supplierNorm(cell(r, 2))
+		month := monthYear(cell(r, 0))
+		rd, _ := parseDay(cell(r, 0))
+
+		e, kind, ok := pick(entries, used, beleg, supplier, month, rd)
+		if !ok {
+			if ae, aok := amountPick(amts, used, supplier, rowAmount(r), rd); aok {
+				e, kind, ok = entry{id: ae.id, title: ae.title}, "amount", true
+			}
+		}
+		if !ok {
+			if beleg != "" {
+				ambiguous++
+			} else {
+				unmatched++
+			}
+			continue
+		}
+		ref, _ := excelize.CoordinatesToCellName(8, i+1)
+		if err := f.SetCellValue(sheet, ref, linkPrefix+e.id); err != nil {
+			panic(err)
+		}
+		used[e.id] = true
+		linked++
+		switch kind {
+		case "beleg":
+			byBeleg++
+		case "supplier":
+			bySupplier++
+		case "amount":
+			byAmount++
+		}
+		fmt.Printf("row %3d  %-30s -> %s  [%s]\n", i+1, cell(r, 2), e.title, kind)
+	}
+
+	if err := f.SaveAs(out); err != nil {
+		panic(err)
+	}
+	fmt.Printf("\nlinked=%d (beleg=%d, supplier=%d, amount=%d), ambiguous=%d, no-candidate=%d\n",
+		linked, byBeleg, bySupplier, byAmount, ambiguous, unmatched)
+
+	// Optional 4th arg: source OnlyOffice file id. Try to update it in place;
+	// if it is locked (OnlyOffice 500), upload a "(links)" copy next to it.
+	if len(os.Args) >= 5 && os.Args[4] != "" {
+		c := onlyoffice.NewClient(onlyoffice.GetEnvironmentCredentials())
+		ctx, cancel := context.WithTimeout(context.Background(), 120*time.Second)
+		defer cancel()
+		var src *onlyoffice.FileEntry
+		if derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+			var err error
+			src, err = c.GetFile(ctx, os.Args[4])
+			return err
+		}); derr != nil {
+			panic(derr)
+		}
+		folder, title := "", ""
+		if src.FolderID != nil {
+			folder = src.FolderID.String()
+		}
+		if src.Title != nil {
+			title = *src.Title
+		}
+		uderr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+			_, err := c.UpdateFile(ctx, os.Args[4], out)
+			return err
+		})
+		if uderr == nil {
+			fmt.Printf("updated file %s in place\n", os.Args[4])
+			return
+		}
+		fmt.Printf("in-place update failed (locked?); uploading a copy to folder %s\n", folder)
+		ext := filepath.Ext(title)
+		name := strings.TrimSuffix(title, ext) + " (links)" + ext
+		tmp := filepath.Join(os.TempDir(), name)
+		data, _ := os.ReadFile(out)
+		if err := os.WriteFile(tmp, data, 0o600); err != nil {
+			panic(err)
+		}
+		if derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+			_, _, err := c.UploadToFolderReplacing(ctx, folder, tmp)
+			return err
+		}); derr != nil {
+			panic(derr)
+		}
+		fmt.Printf("uploaded copy: %s -> folder %s\n", name, folder)
+	}
+}
+
+func cell(r []string, i int) string {
+	if i < len(r) {
+		return strings.TrimSpace(r[i])
+	}
+	return ""
+}
+
+func supplierNorm(s string) string {
+	s = strings.ToUpper(s)
+	if i := strings.Index(s, ","); i >= 0 {
+		s = s[:i]
+	}
+	for _, w := range []string{"RE FEHLT", "GS FEHLT", "WOFR", "WOFÜR"} {
+		s = strings.ReplaceAll(s, w, "")
+	}
+	return norm(s)
+}
+
+func monthYear(date string) string {
+	if len(date) == 10 {
+		return date[6:10] + "-" + date[3:5]
+	}
+	return ""
+}
+
+// pick returns an unused candidate. Beleg match wins; supplier+month is a
+// fallback. When several candidates qualify, the one closest in time to the row
+// date wins; a tie is rejected (ambiguous) rather than guessed.
+func pick(entries []entry, used map[string]bool, beleg, supplier, month string, rd time.Time) (entry, string, bool) {
+	free := func(e entry) bool { return !used[e.id] }
+
+	if len(beleg) >= 5 {
+		var inMonth []entry
+		for _, e := range entries {
+			if free(e) && belegMatches(e.norm, beleg) &&
+				(month == "" || strings.Contains(e.title, month)) {
+				inMonth = append(inMonth, e)
+			}
+		}
+		if supplier != "" {
+			var s []entry
+			for _, e := range inMonth {
+				if strings.Contains(e.norm, supplier) {
+					s = append(s, e)
+				}
+			}
+			if len(s) > 0 {
+				inMonth = s
+			}
+		}
+		inMonth = topRank(inMonth)
+		if e, ok := nearest(inMonth, rd); ok {
+			return e, "beleg", true
+		}
+		// A Beleg is present but no file carries it: do NOT fall back to a
+		// supplier guess (that links the wrong invoice).
+		return entry{}, "", false
+	}
+
+	if supplier != "" && month != "" {
+		var c []entry
+		for _, e := range entries {
+			if free(e) && strings.Contains(e.norm, supplier) &&
+				strings.Contains(e.title, month) && strings.Contains(e.norm, "rechnung") {
+				c = append(c, e)
+			}
+		}
+		c = topRank(c)
+		if e, ok := nearest(c, rd); ok {
+			return e, "supplier", true
+		}
+	}
+	return entry{}, "", false
+}
+
+// topRank keeps only the highest-ranked candidates (real invoice over copy /
+// dupe / op), so a tie with a duplicate does not mask the real file.
+func topRank(cands []entry) []entry {
+	if len(cands) < 2 {
+		return cands
+	}
+	best := 0
+	for _, e := range cands {
+		if rank(e) > best {
+			best = rank(e)
+		}
+	}
+	out := cands[:0]
+	for _, e := range cands {
+		if rank(e) == best {
+			out = append(out, e)
+		}
+	}
+	return out
+}
+
+func rank(e entry) int {
+	s := 0
+	if strings.Contains(e.path, "/2025") || strings.Contains(e.path, "/2024") {
+		s += 4
+	}
+	if strings.Contains(e.norm, "rechnung") {
+		s += 2
+	}
+	if strings.Contains(e.norm, "dupe") || strings.Contains(e.norm, "copy") ||
+		strings.Contains(e.norm, "op") {
+		s--
+	}
+	return s
+}
+
+// belegMatches reports whether a Beleg identifies the file: the whole normalized
+// Beleg appears, or (for long numeric Belege, e.g. "24/641393110") an 8-digit
+// window of its longest digit run appears.
+func belegMatches(titleNorm, beleg string) bool {
+	if strings.Contains(titleNorm, beleg) {
+		return true
+	}
+	run := longestDigitRun(beleg)
+	for i := 0; i+8 <= len(run); i++ {
+		if strings.Contains(titleNorm, run[i:i+8]) {
+			return true
+		}
+	}
+	return false
+}
+
+func longestDigitRun(s string) string {
+	var best, cur strings.Builder
+	for _, r := range s {
+		if r >= '0' && r <= '9' {
+			cur.WriteRune(r)
+			if cur.Len() > best.Len() {
+				best.Reset()
+				best.WriteString(cur.String())
+			}
+		} else {
+			cur.Reset()
+		}
+	}
+	return best.String()
+}
+
+type amtEntry struct {
+	id      string
+	title   string
+	norm    string
+	amount  float64
+	date    time.Time
+	hasDate bool
+}
+
+func loadAmounts(path string) []amtEntry {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil
+	}
+	var out []amtEntry
+	for _, line := range strings.Split(string(raw), "\n") {
+		p := strings.Split(line, "\t")
+		if len(p) < 3 {
+			continue
+		}
+		v, err := strconv.ParseFloat(strings.TrimSpace(p[2]), 64)
+		if err != nil {
+			continue
+		}
+		e := amtEntry{id: p[0], title: p[1], norm: norm(p[1]), amount: v}
+		if len(p[1]) >= 10 {
+			if t, err := time.Parse("2006-01-02", p[1][:10]); err == nil {
+				e.date, e.hasDate = t, true
+			}
+		}
+		out = append(out, e)
+	}
+	return out
+}
+
+func rowAmount(r []string) float64 {
+	if v := parseAmount(cell(r, 4)); v != 0 {
+		return v
+	}
+	return parseAmount(cell(r, 5))
+}
+
+func parseAmount(s string) float64 {
+	s = strings.ReplaceAll(s, "€", "")
+	s = strings.ReplaceAll(s, " ", "")
+	s = strings.ReplaceAll(s, ",", ".")
+	if s == "" {
+		return 0
+	}
+	v, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0
+	}
+	return v
+}
+
+// amountPick matches a row to an O2 invoice by amount + nearest date. Scoped to
+// Telefonica/O2 rows and O2 files, so it cannot cross-link other suppliers.
+func amountPick(amts []amtEntry, used map[string]bool, supplier string, amt float64, rd time.Time) (amtEntry, bool) {
+	if amt <= 0 || len(amts) == 0 {
+		return amtEntry{}, false
+	}
+	if !strings.Contains(supplier, "telefonica") && !strings.Contains(supplier, "o2") {
+		return amtEntry{}, false
+	}
+	var cands []amtEntry
+	for _, a := range amts {
+		if used[a.id] || !strings.Contains(a.norm, "o2") {
+			continue
+		}
+		d := a.amount - amt
+		if d < 0 {
+			d = -d
+		}
+		if d > 0.005 {
+			continue
+		}
+		if a.hasDate && !rd.IsZero() {
+			days := a.date.Sub(rd).Hours() / 24
+			if days < 0 {
+				days = -days
+			}
+			if days > 75 {
+				continue
+			}
+		}
+		cands = append(cands, a)
+	}
+	if len(cands) == 1 {
+		return cands[0], true
+	}
+	best, bestD, tie := -1, 0.0, false
+	for i, a := range cands {
+		if !a.hasDate {
+			continue
+		}
+		d := a.date.Sub(rd).Hours() / 24
+		if d < 0 {
+			d = -d
+		}
+		if best < 0 || d < bestD {
+			best, bestD, tie = i, d, false
+		} else if d == bestD {
+			tie = true
+		}
+	}
+	if best < 0 || tie {
+		return amtEntry{}, false
+	}
+	return cands[best], true
+}

cmd/office/fetch/list.go

@@ -17,6 +17,18 @@ const MailListPageSize = 25
 // Loader fetches list items for a menu subject using the OnlyOffice client.
 type Loader struct {
 	Client *onlyoffice.Client
+
+	// Files is the backend-agnostic file store used for file download, preview
+	// and delete. When nil it falls back to Client.FileStore(ProviderREST).
+	Files onlyoffice.FileStore
+}
+
+// fileStore returns the configured file store, defaulting to REST.
+func (l *Loader) fileStore() onlyoffice.FileStore {
+	if l.Files != nil {
+		return l.Files
+	}
+	return l.Client.FileStore(onlyoffice.ProviderREST)
 }
 
 // List returns items for the given list spec (nav leaf).
@@ -171,11 +183,7 @@ func (l *Loader) executeDelete(ctx context.Context, item model.Item) (string, er
 		}
 		return fmt.Sprintf("Deleted message %s", item.Title), nil
 	case model.KindFile:
-		id, err := strconv.Atoi(item.ID)
+		if err := l.fileStore().Delete(ctx, []string{item.ID}); err != nil {
-		if err != nil {
-			return "", err
-		}
-		if err := l.Client.DeleteFiles(ctx, []int{id}); err != nil {
 			return "", err
 		}
 		return fmt.Sprintf("Deleted file %s", item.Title), nil
@@ -199,7 +207,7 @@ func (l *Loader) executeDownload(ctx context.Context, item model.Item, destPath
 		return "", err
 	}
 	defer f.Close()
-	if _, err := l.Client.DownloadFile(ctx, item.ID, f); err != nil {
+	if _, err := l.fileStore().Download(ctx, item.ID, f); err != nil {
 		return "", err
 	}
 	return fmt.Sprintf("Downloaded to %s", destPath), nil

cmd/office/fetch/preview.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 
-	onlyoffice "github.com/eslider/go-onlyoffice"
 	"github.com/eslider/go-onlyoffice/cmd/office/model"
 	"github.com/eslider/go-onlyoffice/cmd/office/preview"
 )
@@ -30,13 +29,11 @@ func (l *Loader) filePreviewMarkdown(ctx context.Context, item model.Item) (stri
 		return "", fmt.Errorf("file id missing")
 	}
 	name := item.Title
-	if meta, err := l.Client.GetFile(ctx, item.ID); err == nil && meta != nil {
+	if e, err := l.fileStore().Stat(ctx, item.ID); err == nil && e.Title != "" {
-		if t := onlyoffice.FileEntryTitle(meta); t != "" {
+		name = e.Title
-			name = t
-		}
 	}
 	var buf bytes.Buffer
-	if _, err := l.Client.DownloadFile(ctx, item.ID, &buf); err != nil {
+	if _, err := l.fileStore().Download(ctx, item.ID, &buf); err != nil {
 		return "", err
 	}
 	return preview.FileBytesToMarkdown(name, buf.Bytes())

cmd/office/fetch/task_integration_test.go

@@ -4,7 +4,6 @@ package fetch_test
 
 import (
 	"context"
-	"os"
 	"testing"
 
 	"github.com/eslider/go-onlyoffice/cmd/office/model"
@@ -46,9 +45,6 @@ func TestIntegrationUpdateTaskTitleDescription(t *testing.T) {
 }
 
 func TestIntegrationTaskFieldsFromLiveAPI(t *testing.T) {
-	if os.Getenv("ONLYOFFICE_URL") == "" && os.Getenv("ONLYOFFICE_HOST") == "" {
-		t.Skip("ONLYOFFICE_URL not set")
-	}
 	loader, ctx := liveLoader(t)
 	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectTasks})
 	if err != nil {
@@ -57,12 +53,12 @@ func TestIntegrationTaskFieldsFromLiveAPI(t *testing.T) {
 	if len(items) == 0 {
 		t.Skip("no tasks")
 	}
-	title, desc, err := loader.TaskFields(ctx, items[0])
+	fields, err := loader.DetailForm(ctx, items[0])
 	if err != nil {
 		t.Fatal(err)
 	}
-	if title == "" {
+	if fields.Primary == "" {
 		t.Fatal("empty title")
 	}
-	_ = desc
+	_ = fields.Secondary
 }

cmd/oo/dav.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"time"
 
 	onlyoffice "github.com/eslider/go-onlyoffice"
 	"github.com/spf13/cobra"
@@ -12,8 +13,8 @@ func init() {
 	rootCmd.AddCommand(davCmd())
 }
 
-// davCmd exposes the Documents module through the same Dav calls that back
+// davCmd exposes the Documents module through the backend-agnostic FileStore
-// oo-webdav (ListDavFolder / MoveDavItems / CopyDavItems / DownloadDavFile).
+// (DAV backend). The underlying Dav calls are the oo-webdav proven path:
 // MoveDavItems sends resolveType=Skip + holdResult=true, which the legacy
 // fileops/move call without those params silently ignores (200 without move).
 func davCmd() *cobra.Command {
@@ -25,6 +26,7 @@ func davCmd() *cobra.Command {
 	cmd.AddCommand(davMoveCmd())
 	cmd.AddCommand(davCopyCmd())
 	cmd.AddCommand(davMkdirCmd())
+	cmd.AddCommand(davRemoveCmd())
 	cmd.AddCommand(davRenameFileCmd())
 	cmd.AddCommand(davRenameFolderCmd())
 	cmd.AddCommand(davDownloadCmd())
@@ -60,59 +62,46 @@ func davLsCmd() *cobra.Command {
 				printTable([]string{"id", "title", "filesCount", "foldersCount"}, rows)
 				return nil
 			}
-			l, err := c.ListDavFolder(ctx, args[0])
+			entries, err := c.FileStore(onlyoffice.ProviderDAV).List(ctx, args[0])
 			if err != nil {
 				return err
 			}
-			if outputFormat == "json" {
+			folders := make([]onlyoffice.Entry, 0, len(entries))
-				folders := make([]map[string]any, 0, len(l.Folders))
+			files := make([]onlyoffice.Entry, 0, len(entries))
-				for _, f := range l.Folders {
+			for _, e := range entries {
-					folders = append(folders, map[string]any{
+				if e.Kind == onlyoffice.Folder {
-						"id":           f.ID,
+					folders = append(folders, e)
-						"title":        f.Title,
+				} else {
-						"filesCount":   f.FilesCount,
+					files = append(files, e)
-						"foldersCount": f.FoldersCount,
-					})
 				}
-				files := make([]map[string]any, 0, len(l.Files))
-				for _, f := range l.Files {
-					files = append(files, map[string]any{
-						"id":      f.ID,
-						"title":   f.Title,
-						"size":    f.Size,
-						"updated": f.Updated,
-					})
-				}
-				printObject(map[string]any{"folders": folders, "files": files})
-				return nil
 			}
-			if len(l.Folders) > 0 {
+			frows := make([]map[string]any, 0, len(folders))
-				frows := make([]map[string]any, 0, len(l.Folders))
+			for _, f := range folders {
-				for _, f := range l.Folders {
+				frows = append(frows, map[string]any{
-					frows = append(frows, map[string]any{
+					"id":           f.ID,
-						"id":           f.ID,
+					"title":        f.Title,
-						"title":        f.Title,
+					"filesCount":   f.FilesCount,
-						"filesCount":   f.FilesCount,
+					"foldersCount": f.FoldersCount,
-						"foldersCount": f.FoldersCount,
+				})
-					})
-				}
-				if outputFormat == "table" {
-					fmt.Println("folders:")
-				}
-				printTable([]string{"id", "title", "filesCount", "foldersCount"}, frows)
 			}
-			rows := make([]map[string]any, 0, len(l.Files))
+			rows := make([]map[string]any, 0, len(files))
-			for _, f := range l.Files {
+			for _, f := range files {
 				rows = append(rows, map[string]any{
 					"id":      f.ID,
 					"title":   f.Title,
 					"size":    f.Size,
-					"updated": f.Updated,
+					"updated": entryUpdated(f),
 				})
 			}
-			if outputFormat == "table" {
+			if outputFormat == "json" {
-				fmt.Println("files:")
+				printObject(map[string]any{"folders": frows, "files": rows})
+				return nil
 			}
+			if len(frows) > 0 {
+				fmt.Println("folders:")
+				printTable([]string{"id", "title", "filesCount", "foldersCount"}, frows)
+			}
+			fmt.Println("files:")
 			printTable([]string{"id", "title", "size", "updated"}, rows)
 			return nil
 		},
@@ -120,6 +109,18 @@ func davLsCmd() *cobra.Command {
 	return cmd
 }
 
+// entryUpdated prefers the backend-native timestamp string so table/JSON output
+// round-trips what the API returned.
+func entryUpdated(e onlyoffice.Entry) string {
+	if e.Updated != "" {
+		return e.Updated
+	}
+	if e.Modified.IsZero() {
+		return ""
+	}
+	return e.Modified.Format(time.RFC3339)
+}
+
 func davMoveCmd() *cobra.Command {
 	var folderIDs []string
 	cmd := &cobra.Command{
@@ -131,7 +132,8 @@ func davMoveCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			if err := c.MoveDavItems(cmd.Context(), folderIDs, args[1:], args[0]); err != nil {
+			ids := append(append([]string{}, folderIDs...), args[1:]...)
+			if err := c.FileStore(onlyoffice.ProviderDAV).Move(cmd.Context(), ids, args[0]); err != nil {
 				return err
 			}
 			printObject(map[string]any{"moved_files": args[1:], "moved_folders": folderIDs, "dest": args[0]})
@@ -153,7 +155,8 @@ func davCopyCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			if err := c.CopyDavItems(cmd.Context(), folderIDs, args[1:], args[0]); err != nil {
+			ids := append(append([]string{}, folderIDs...), args[1:]...)
+			if err := c.FileStore(onlyoffice.ProviderDAV).Copy(cmd.Context(), ids, args[0]); err != nil {
 				return err
 			}
 			printObject(map[string]any{"copied_files": args[1:], "copied_folders": folderIDs, "dest": args[0]})
@@ -174,7 +177,7 @@ func davMkdirCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			f, err := c.CreateDavFolder(cmd.Context(), args[0], args[1])
+			f, err := c.FileStore(onlyoffice.ProviderDAV).CreateFolder(cmd.Context(), args[0], args[1])
 			if err != nil {
 				return err
 			}
@@ -184,6 +187,33 @@ func davMkdirCmd() *cobra.Command {
 	}
 }
 
+func davRemoveCmd() *cobra.Command {
+	var folderIDs []string
+	cmd := &cobra.Command{
+		Use:     "rm [FILE_ID...]",
+		Aliases: []string{"delete"},
+		Short:   "Permanently delete file(s) and/or folder(s) from Documents",
+		Args:    cobra.ArbitraryArgs,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if len(args) == 0 && len(folderIDs) == 0 {
+				return fmt.Errorf("dav rm: give at least one FILE_ID or --folders")
+			}
+			c, err := newOO(cmd)
+			if err != nil {
+				return err
+			}
+			ids := append(append([]string{}, args...), folderIDs...)
+			if err := c.FileStore(onlyoffice.ProviderDAV).Delete(cmd.Context(), ids); err != nil {
+				return err
+			}
+			printObject(map[string]any{"deleted_files": args, "deleted_folders": folderIDs})
+			return nil
+		},
+	}
+	cmd.Flags().StringSliceVar(&folderIDs, "folders", nil, "folder ids to delete")
+	return cmd
+}
+
 func davRenameFileCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "rename-file FILE_ID NEW_TITLE",
@@ -194,7 +224,7 @@ func davRenameFileCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			if err := c.RenameDavFile(cmd.Context(), args[0], args[1]); err != nil {
+			if err := c.FileStore(onlyoffice.ProviderDAV).Rename(cmd.Context(), args[0], args[1]); err != nil {
 				return err
 			}
 			printObject(map[string]any{"id": args[0], "title": args[1]})
@@ -213,7 +243,7 @@ func davRenameFolderCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			if err := c.RenameDavFolder(cmd.Context(), args[0], args[1]); err != nil {
+			if err := c.FileStore(onlyoffice.ProviderDAV).Rename(cmd.Context(), args[0], args[1]); err != nil {
 				return err
 			}
 			printObject(map[string]any{"id": args[0], "title": args[1]})
@@ -234,20 +264,21 @@ func davDownloadCmd() *cobra.Command {
 				return err
 			}
 			ctx := cmd.Context()
-			f, err := c.GetFile(ctx, args[0])
+			store := c.FileStore(onlyoffice.ProviderDAV)
+			e, err := store.Stat(ctx, args[0])
 			if err != nil {
 				return err
 			}
 			path := to
 			if path == "" {
-				path = onlyoffice.SafeLocalFileName(onlyoffice.FileEntryTitle(f))
+				path = onlyoffice.SafeLocalFileName(e.Title)
 			}
 			out, err := os.Create(path)
 			if err != nil {
 				return err
 			}
 			defer out.Close()
-			n, err := c.DownloadDavFile(ctx, args[0], out)
+			n, err := store.Download(ctx, args[0], out)
 			if err != nil {
 				_ = os.Remove(path)
 				return err

cmd/oo/index.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"strings"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(indexCmd())
+}
+
+// indexFlags are shared by the `oo index folder` and `oo index files` verbs.
+type indexFlags struct {
+	recursive bool
+	exts      string
+	limit     int
+	workers   int
+	lang      string
+	minChars  int
+	workDir   string
+	backend   string
+	dryRun    bool
+	asJSON    bool
+}
+
+// indexCmd populates the own full-text index (oo_docs_text) that makes PDF and
+// scanned content searchable. The OnlyOffice index is left untouched.
+func indexCmd() *cobra.Command {
+	f := &indexFlags{}
+	cmd := &cobra.Command{
+		Use:   "index",
+		Short: "Populate the own full-text index for PDF/scan content",
+		Long: "Index document text that the OnlyOffice Elasticsearch index does not\n" +
+			"cover (PDFs and scans) into a separate index (ONLYOFFICE_ES_TEXT_INDEX,\n" +
+			"default oo_docs_text). Text is extracted with docpipe (pdftotext, OCR)\n" +
+			"and the OnlyOffice server is never modified.\n\n" +
+			"Requires ONLYOFFICE_URL/USER/PASS (to download files) and ONLYOFFICE_ES_URL\n" +
+			"(to write the index). See docs/elasticsearch.md.",
+	}
+	cmd.PersistentFlags().BoolVar(&f.recursive, "recursive", false, "folder: descend into subfolders")
+	cmd.PersistentFlags().StringVar(&f.exts, "exts", "pdf", "comma-separated extensions to index")
+	cmd.PersistentFlags().IntVar(&f.limit, "limit", 0, "maximum number of files to index (0 = all)")
+	cmd.PersistentFlags().IntVar(&f.workers, "workers", 3, "parallel downloads/extractions")
+	cmd.PersistentFlags().StringVar(&f.lang, "lang", "deu+eng", "OCR language(s)")
+	cmd.PersistentFlags().IntVar(&f.minChars, "min-chars", 0, "text-layer threshold below which OCR runs")
+	cmd.PersistentFlags().StringVar(&f.workDir, "work-dir", "", "temp dir for downloads (default: system temp)")
+	cmd.PersistentFlags().StringVar(&f.backend, "backend", "rest", "file backend: rest|dav")
+	cmd.PersistentFlags().BoolVar(&f.dryRun, "dry-run", false, "list what would be indexed, without changes")
+	cmd.PersistentFlags().BoolVar(&f.asJSON, "json", false, "shorthand for --output json")
+
+	cmd.AddCommand(indexFolderCmd(f), indexFilesCmd(f))
+	return cmd
+}
+
+func indexFolderCmd(f *indexFlags) *cobra.Command {
+	return &cobra.Command{
+		Use:   "folder FOLDER_ID",
+		Short: "Index every matching file in a Documents folder",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runIndex(cmd, f, args[0], nil)
+		},
+	}
+}
+
+func indexFilesCmd(f *indexFlags) *cobra.Command {
+	return &cobra.Command{
+		Use:   "files FILE_ID...",
+		Short: "Index specific Documents files",
+		Args:  cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runIndex(cmd, f, "", args)
+		},
+	}
+}
+
+func runIndex(cmd *cobra.Command, f *indexFlags, folderID string, ids []string) error {
+	if f.asJSON {
+		outputFormat = "json"
+	}
+	c, err := newOO(cmd)
+	if err != nil {
+		return err
+	}
+	idx, err := onlyoffice.NewESTextIndex(onlyoffice.ESTextConfigFromEnv())
+	if err != nil {
+		return err
+	}
+	ti := onlyoffice.NewTextIndexer(c.FileStore(f.backend), idx)
+	ti.WorkDir = f.workDir
+	opts := onlyoffice.IndexOptions{
+		Recursive:  f.recursive,
+		Extensions: splitList(f.exts),
+		Limit:      f.limit,
+		Lang:       f.lang,
+		MinChars:   f.minChars,
+		Workers:    f.workers,
+	}
+	ctx := cmd.Context()
+
+	if f.dryRun {
+		var entries []onlyoffice.Entry
+		if folderID != "" {
+			entries, err = ti.PlanFolder(ctx, folderID, opts)
+		} else {
+			entries, err = ti.PlanFiles(ctx, ids, opts)
+		}
+		if err != nil {
+			return err
+		}
+		rows := make([]map[string]any, 0, len(entries))
+		for _, e := range entries {
+			rows = append(rows, map[string]any{
+				"id":     e.ID,
+				"title":  e.Title,
+				"folder": e.ParentID,
+			})
+		}
+		printTable([]string{"id", "title", "folder"}, rows)
+		return nil
+	}
+
+	if err := ti.Ensure(ctx); err != nil {
+		return err
+	}
+	var res onlyoffice.IndexResult
+	if folderID != "" {
+		res, err = ti.IndexFolder(ctx, folderID, opts)
+	} else {
+		res, err = ti.IndexFiles(ctx, ids, opts)
+	}
+	if err != nil {
+		return err
+	}
+	printObject(map[string]any{
+		"index":   idx.Index(),
+		"scanned": res.Scanned,
+		"indexed": res.Indexed,
+		"skipped": res.Skipped,
+		"failed":  res.Failed,
+		"errors":  res.Errors,
+	})
+	return nil
+}
+
+// splitList parses a comma-separated flag value, dropping blanks.
+func splitList(s string) []string {
+	parts := strings.Split(s, ",")
+	out := make([]string, 0, len(parts))
+	for _, p := range parts {
+		if p = strings.TrimSpace(p); p != "" {
+			out = append(out, p)
+		}
+	}
+	return out
+}

cmd/oo/index_test.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestIndexCommandRegistered(t *testing.T) {
+	cmd, _, err := rootCmd.Find([]string{"index"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cmd.Name() != "index" {
+		t.Fatalf("index resolved to %q", cmd.Name())
+	}
+	for _, name := range []string{"exts", "limit", "workers", "lang", "min-chars", "work-dir", "backend", "dry-run", "recursive", "json"} {
+		if cmd.PersistentFlags().Lookup(name) == nil {
+			t.Errorf("index: missing --%s flag", name)
+		}
+	}
+	if cmd.PersistentFlags().Lookup("exts").DefValue != "pdf" {
+		t.Errorf("--exts default = %q, want pdf", cmd.PersistentFlags().Lookup("exts").DefValue)
+	}
+	for _, verb := range []string{"index folder", "index files"} {
+		sub, _, err := rootCmd.Find(strings.Fields(verb))
+		if err != nil {
+			t.Fatalf("%s: %v", verb, err)
+		}
+		if sub.Name() != strings.Fields(verb)[1] {
+			t.Errorf("%s resolved to %q", verb, sub.Name())
+		}
+	}
+}
+
+func TestIndexSearchBackendFlag(t *testing.T) {
+	cmd, _, err := rootCmd.Find([]string{"search"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cmd.Flags().Lookup("backend") == nil {
+		t.Fatal("search: missing --backend flag")
+	}
+	if cmd.Flags().Lookup("backend").DefValue != "oo" {
+		t.Errorf("--backend default = %q, want oo", cmd.Flags().Lookup("backend").DefValue)
+	}
+}
+
+func TestSplitList(t *testing.T) {
+	got := splitList(" pdf , .PDF, docx ,, ")
+	want := []string{"pdf", ".PDF", "docx"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("splitList = %v, want %v", got, want)
+	}
+}

cmd/oo/main.go

@@ -3,20 +3,23 @@
 // Command tree is subject-based (mirrors the library split and the `tea` CLI):
 //
 //	oo calendar      list | events | add | delete
-//	oo projects      list | get | milestones | create | update | delete | files (list|upload|download|rename|delete|as-md|put-md)
+//	oo projects      list | get | milestones | milestone-create | create | update | delete | contacts (add|remove) | link-authors | link-git | files (list|upload|download|rename|delete|dedupe|as-md|put-md|put-txt|put-xlsx)
 //	oo tasks         list | get | create | update | delete | subtask add | files (list|upload|detach)
 //	oo users         list | self            (alias: oo whoami)
-//	oo contacts      list | get | delete | info-add | merge | dedupe-info
+//	oo contacts      list | get | delete | info-add | merge | dedupe-info | tags | tag-add | tag-create | tag-remove
 //	oo persons       list | create | delete | dedupe
 //	oo companies     list | create | delete | dedupe | dedupe-persons
-//	oo opportunities list | get | create | delete | stages | member-add | dedupe | dedupe-members | fix-titles
+//	oo opportunities list | get | create | update | delete | stages | member-add | dedupe | dedupe-members | fix-titles
 //	oo cases         list | create | delete | member-add
-//	oo crm-tasks     list | create | delete | categories
+//	oo crm-tasks     list | create | delete | categories | reassign-self
 //	oo crm           cleanup
-//	oo mails         accounts | folders | list | get | download-attachment | draft | attach | draft-invoice | delete
+//	oo mails         accounts | folders | list | get | download-attachment | draft | attach | draft-invoice | send | delete
 //	oo invoices      list | get | create | update | pdf | pdf-cleanup | status | delete | items …
-//	oo docs          tools | convert | ocr | as-md | put-md
+//	oo docs          tools | convert | optimize | ocr | hocr | as-md | put-md | put-txt | put-xlsx
+//	oo catalog       match | merge | apply | scan-contacts | scan-projects | scan-thunderbird
 //	oo dav           ls | move | copy | mkdir | rename-file | rename-folder | download | fileops
+//	oo search        QUERY [--content] [--folder ID] [--limit N] [--backend oo|own] [--json]
+//	oo index         folder FOLDER_ID | files FILE_ID... [--recursive] [--exts pdf] [--dry-run]
 //
 // CRM association rules: docs/crm-associations.md
 //

cmd/oo/projects_files.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strconv"
 	"time"
 
@@ -159,20 +160,22 @@ func prjFilesDownloadCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			f, err := c.GetFile(cmd.Context(), args[0])
+			ctx := cmd.Context()
+			store := c.Files()
+			e, err := store.Stat(ctx, args[0])
 			if err != nil {
 				return err
 			}
 			path := to
 			if path == "" {
-				path = onlyoffice.SafeLocalFileName(onlyoffice.FileEntryTitle(f))
+				path = onlyoffice.SafeLocalFileName(e.Title)
 			}
 			out, err := os.Create(path)
 			if err != nil {
 				return err
 			}
 			defer out.Close()
-			n, err := c.DownloadFile(cmd.Context(), args[0], out)
+			n, err := store.Download(ctx, args[0], out)
 			if err != nil {
 				_ = os.Remove(path)
 				return err
@@ -199,11 +202,16 @@ func prjFilesRenameCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			entry, err := c.RenameFile(cmd.Context(), args[0], args[1])
+			store := c.Files()
+			if err := store.Rename(cmd.Context(), args[0], args[1]); err != nil {
+				return err
+			}
+			entry, err := store.Stat(cmd.Context(), args[0])
 			if err != nil {
 				return err
 			}
-			printObject(fileEntryToMap(entry))
+			entry.Title = args[1]
+			printObject(entryToMap(entry))
 			return nil
 		},
 	}
@@ -228,7 +236,7 @@ func prjFilesDeleteCmd() *cobra.Command {
 				}
 				ids = append(ids, id)
 			}
-			if err := c.DeleteFiles(cmd.Context(), ids); err != nil {
+			if err := c.Files().Delete(cmd.Context(), args); err != nil {
 				return err
 			}
 			printObject(map[string]any{"deleted": ids})
@@ -317,6 +325,29 @@ func fileEntryToMap(f *onlyoffice.FileEntry) map[string]any {
 	return m
 }
 
+// entryToMap renders a canonical Entry with the same keys as fileEntryToMap.
+func entryToMap(e onlyoffice.Entry) map[string]any {
+	m := map[string]any{
+		"id":            e.ID,
+		"title":         e.Title,
+		"fileExst":      filepath.Ext(e.Title),
+		"contentLength": contentLengthString(e.Size),
+	}
+	if e.Updated != "" {
+		m["updated"] = e.Updated
+	} else if !e.Modified.IsZero() {
+		m["updated"] = e.Modified.Format(time.RFC3339)
+	}
+	return m
+}
+
+func contentLengthString(n int64) string {
+	if n <= 0 {
+		return ""
+	}
+	return strconv.FormatInt(n, 10)
+}
+
 func fileIDStr(f *onlyoffice.FileEntry) string {
 	if f == nil || f.ID == nil {
 		return ""

cmd/oo/search.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+	"github.com/eslider/go-onlyoffice/cmd/internal/bootstrap"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(searchCmd())
+}
+
+// searchCmd queries the OnlyOffice document index through the file facade. The
+// REST /api/2.0/files/@search endpoint only searches file names in the database;
+// content search needs Elasticsearch (see docs/elasticsearch.md).
+func searchCmd() *cobra.Command {
+	var (
+		content   bool
+		folder    string
+		limit     int
+		backend   string
+		asJSON    bool
+		substring bool
+	)
+	cmd := &cobra.Command{
+		Use:   "search QUERY...",
+		Short: "Full-text search over documents by name, optionally by content (Elasticsearch)",
+		Long: "Search the OnlyOffice Documents index.\n\n" +
+			"By default only file names are matched. With --content the query also\n" +
+			"matches extracted document text (document.attachment.content); this covers\n" +
+			"Office formats (docx/xlsx/pptx) and is slower.\n\n" +
+			"--backend own queries the separate index populated by `oo index`\n" +
+			"(ONLYOFFICE_ES_TEXT_INDEX, default oo_docs_text) instead, which also holds\n" +
+			"PDFs and scans (see docs/elasticsearch.md).\n\n" +
+			"Requires ONLYOFFICE_ES_URL (and optionally ONLYOFFICE_ES_INDEX,\n" +
+			"ONLYOFFICE_TENANT). See docs/elasticsearch.md for the tunnel setup.",
+		Args: cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if asJSON {
+				outputFormat = "json"
+			}
+			bootstrap.LoadEnv()
+			c := onlyoffice.NewClient(onlyoffice.GetEnvironmentCredentials())
+			var (
+				searcher onlyoffice.Searcher
+				err      error
+			)
+			switch strings.ToLower(strings.TrimSpace(backend)) {
+			case "", "oo", "elasticsearch":
+				searcher, err = c.Files().Search()
+			case "own", "es-text":
+				searcher, err = onlyoffice.NewESTextIndex(onlyoffice.ESTextConfigFromEnv())
+			default:
+				return fmt.Errorf("unknown search backend %q (want oo|own)", backend)
+			}
+			if err != nil {
+				return err
+			}
+			hits, err := searcher.Search(cmd.Context(), onlyoffice.SearchQuery{
+				Text:      strings.Join(args, " "),
+				InContent: content,
+				FolderID:  folder,
+				Limit:     limit,
+				Substring: substring,
+			})
+			if err != nil {
+				return err
+			}
+			rows := make([]map[string]any, 0, len(hits))
+			for _, h := range hits {
+				folderPath := h.Path
+				if len(folderPath) == 0 && h.ParentID != "" {
+					folderPath = []string{h.ParentID}
+				}
+				rows = append(rows, map[string]any{
+					"path":      c.UniquePath(cmd.Context(), folderPath, h.Title),
+					"id":        h.ID,
+					"title":     h.Title,
+					"folder":    h.ParentID,
+					"score":     h.Score,
+					"highlight": h.Highlight,
+				})
+			}
+			if outputFormat == "json" {
+				printJSON(rows)
+				return nil
+			}
+			printTable([]string{"path", "id", "title", "folder", "score", "highlight"}, rows)
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&content, "content", false, "also match extracted document content")
+	cmd.Flags().BoolVar(&substring, "substring", false, "case-insensitive *term* title match; multiple QUERY args are ANDed")
+	cmd.Flags().StringVar(&folder, "folder", "", "limit to a Documents folder id (matches the folder subtree)")
+	cmd.Flags().IntVar(&limit, "limit", 20, "maximum number of results")
+	cmd.Flags().StringVar(&backend, "backend", "oo", "index to query: oo (OnlyOffice) | own (oo index)")
+	cmd.Flags().BoolVar(&asJSON, "json", false, "shorthand for --output json")
+	return cmd
+}

cmd/oo/search_test.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func TestSearchCommandRegisteredWithFlags(t *testing.T) {
+	cmd, _, err := rootCmd.Find([]string{"search"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cmd.Name() != "search" {
+		t.Fatalf("search resolved to %q", cmd.Name())
+	}
+	for _, name := range []string{"content", "folder", "limit", "json"} {
+		if cmd.Flags().Lookup(name) == nil {
+			t.Errorf("search: missing --%s flag", name)
+		}
+	}
+	if got := cmd.Flags().Lookup("limit").DefValue; got != "20" {
+		t.Errorf("--limit default = %q, want 20", got)
+	}
+}
+
+func TestSearchWithoutESURLIsClearError(t *testing.T) {
+	clearEnv(t, "ONLYOFFICE_ES_URL", "ONLYOFFICE_ES_INDEX", "ONLYOFFICE_TENANT")
+	errBuf := &bytes.Buffer{}
+	rootCmd.SetErr(errBuf)
+	rootCmd.SetOut(&bytes.Buffer{})
+	rootCmd.SetArgs([]string{"search", "Rechnung"})
+	t.Cleanup(func() {
+		rootCmd.SetArgs(nil)
+		rootCmd.SetOut(nil)
+		rootCmd.SetErr(nil)
+	})
+
+	err := rootCmd.Execute()
+	if err == nil {
+		t.Fatal("expected error without ONLYOFFICE_ES_URL")
+	}
+	if !strings.Contains(err.Error(), "ONLYOFFICE_ES_URL") {
+		t.Fatalf("error %q missing ONLYOFFICE_ES_URL", err.Error())
+	}
+}

cmd/ooscan/main.go

@@ -0,0 +1,50 @@
+// Command ooscan recursively lists OnlyOffice Documents folders into a TSV
+// index: file_id, folder_id, path, title.
+//
+// Usage: ooscan <FOLDER_ID> [<FOLDER_ID>...]
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"time"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+)
+
+func main() {
+	ctx := context.Background()
+	c := onlyoffice.NewClient(onlyoffice.GetEnvironmentCredentials())
+	seen := map[string]bool{}
+	for _, root := range os.Args[1:] {
+		walk(ctx, c, root, "", 0, seen)
+	}
+}
+
+func walk(ctx context.Context, c *onlyoffice.Client, folderID, path string, depth int, seen map[string]bool) {
+	if depth > 8 || seen[folderID] {
+		return
+	}
+	seen[folderID] = true
+	// Throttle: OnlyOffice rate-limits (429) and the host must not be flooded.
+	time.Sleep(350 * time.Millisecond)
+	ctx, cancel := context.WithTimeout(ctx, 60*time.Second)
+	defer cancel()
+	var l *onlyoffice.DavListing
+	derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+		var err error
+		l, err = c.ListDavFolder(ctx, folderID)
+		return err
+	})
+	if derr != nil {
+		fmt.Fprintf(os.Stderr, "list %s (%s): %v\n", path, folderID, derr)
+		return
+	}
+	for _, f := range l.Files {
+		fmt.Printf("%s\t%s\t%s\t%s\n", f.ID, folderID, path, f.Title)
+	}
+	for _, sub := range l.Folders {
+		walk(ctx, c, sub.ID, path+"/"+sub.Title, depth+1, seen)
+	}
+}

cmd/pdfamount/main.go

@@ -0,0 +1,308 @@
+// Command pdfamount walks a Documents folder, downloads matching PDFs and
+// extracts the payable amount, printing "file_id\ttitle\tamount".
+//
+// Usage: pdfamount <FOLDER_ID> [TITLE_FILTER_REGEX]
+package main
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	onlyoffice "github.com/eslider/go-onlyoffice"
+)
+
+// amountPat is the amount capture shared by every amount regex.
+const amountPat = `([0-9]+(?:[.,][0-9]+)*)`
+
+// amountRE builds "<label> [optional (comment)] [: -] <number>".
+func amountRE(label string) *regexp.Regexp {
+	return regexp.MustCompile(
+		`(?i)\b` + regexp.QuoteMeta(label) + `\b\s*(?:\([^)]*\))?\s*[:\-]?\s*` + amountPat)
+}
+
+// amountRes lists the payable-amount patterns in strict priority order: the
+// first pattern with a usable amount wins, and a lower-priority label can never
+// override a higher-priority one ("zu zahlender betrag" > "rechnungsbetrag" >
+// "rechnungsendbetrag" > "gesamtbetrag" > "gesamtsumme (inkl. steuern)").
+//
+// "gesamtbetrag" and "gesamtsumme" are not in the original set but are the real
+// labels on Diashop invoices ("Gesamtsumme (inkl. Steuern)"). The inclusive
+// variant is matched before a plain "gesamtsumme". Everything after those
+// primary labels is the broader fallback set, consulted only when no primary
+// label yields an amount. Within one pattern the last usable amount is taken,
+// because totals usually come last.
+var amountRes = []*regexp.Regexp{
+	amountRE("zu zahlender betrag"),
+	amountRE("rechnungsbetrag"),
+	amountRE("rechnungsendbetrag"),
+	amountRE("gesamtbetrag"),
+	regexp.MustCompile(`(?i)\bgesamtsumme\b\s*\(\s*inkl\.?\s*steuern\s*\)\s*[:\-]?\s*` + amountPat),
+	amountRE("gesamtsumme"),
+	amountRE("endbetrag"),
+	amountRE("zahlbetrag"),
+	amountRE("bruttobetrag"),
+	amountRE("betrag"),
+	amountRE("total"),
+	amountRE("summe"),
+}
+
+// taxLineRe marks a line whose number is a tax rate/percentage: an explicit
+// percent sign or a VAT/tax keyword. "Steuern" (plural, as in "inkl. Steuern")
+// is handled separately so the inclusive total stays usable.
+var taxLineRe = regexp.MustCompile(`(?i)%|\bMwSt\b|\bUSt\b|\bProzent\b`)
+
+// steuerRe finds "Steuer"/"Umsatzsteuer" etc. RE2 has no lookahead, so the
+// plural "Steuern" is excluded in isTaxLine.
+var steuerRe = regexp.MustCompile(`(?i)steuer`)
+
+// percentAfterRe detects a percent sign directly after a number (spaces ok).
+var percentAfterRe = regexp.MustCompile(`^\s*%`)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, "usage: pdfamount <FOLDER_ID> [TITLE_FILTER_REGEX]")
+		os.Exit(2)
+	}
+	folder := os.Args[1]
+	filter := regexp.MustCompile(`(?i)rechnung`)
+	if len(os.Args) >= 3 {
+		filter = regexp.MustCompile(os.Args[2])
+	}
+	ctx := context.Background()
+	c := onlyoffice.NewClient(onlyoffice.GetEnvironmentCredentials())
+
+	files := listAll(ctx, c, folder)
+	for _, f := range files {
+		if !filter.MatchString(f.title) {
+			continue
+		}
+		if !strings.HasSuffix(strings.ToLower(f.title), ".pdf") {
+			continue
+		}
+		amount, err := pdfAmount(ctx, c, f.id)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s: %v\n", f.title, err)
+			continue
+		}
+		if amount == "" {
+			continue
+		}
+		fmt.Printf("%s\t%s\t%s\n", f.id, f.title, amount)
+	}
+}
+
+type file struct{ id, title string }
+
+func listAll(ctx context.Context, c *onlyoffice.Client, folder string) []file {
+	seen := map[string]bool{}
+	var out []file
+	var walk func(string)
+	walk = func(id string) {
+		if seen[id] {
+			return
+		}
+		seen[id] = true
+		time.Sleep(300 * time.Millisecond)
+		l, err := c.ListDavFolder(ctx, id)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "list %s: %v\n", id, err)
+			return
+		}
+		for _, f := range l.Files {
+			out = append(out, file{f.ID, f.Title})
+		}
+		for _, sub := range l.Folders {
+			walk(sub.ID)
+		}
+	}
+	walk(folder)
+	return out
+}
+
+func pdfAmount(ctx context.Context, c *onlyoffice.Client, id string) (string, error) {
+	time.Sleep(time.Second)
+	tmp, err := os.CreateTemp("", "pdf-*.pdf")
+	if err != nil {
+		return "", err
+	}
+	defer os.Remove(tmp.Name())
+	derr := onlyoffice.DoRetry(ctx, onlyoffice.DefaultRetryPolicy(), func() error {
+		_ = tmp.Truncate(0)
+		_, _ = tmp.Seek(0, 0)
+		_, err := c.DownloadFile(ctx, id, tmp)
+		return err
+	})
+	if derr != nil {
+		tmp.Close()
+		return "", derr
+	}
+	tmp.Close()
+	var buf bytes.Buffer
+	cmd := exec.CommandContext(ctx, "pdftotext", "-layout", tmp.Name(), "-")
+	cmd.Stdout = &buf
+	if err := cmd.Run(); err != nil {
+		return "", err
+	}
+	return extractAmount(buf.String()), nil
+}
+
+// extractAmount returns the normalised ("1234.56") payable amount found in
+// text, or "" if no usable amount matches.
+//
+// DKV invoices are special-cased first: they repeat a per-vehicle "TOTAL:" line
+// and carry the real total only in the "Gesamtsummenaufstellung" section.
+func extractAmount(text string) string {
+	if v, ok := dkvGrandTotal(text); ok {
+		return v
+	}
+	for _, re := range amountRes {
+		if v, ok := lastUsableAmount(text, re); ok {
+			return v
+		}
+	}
+	return ""
+}
+
+// dkvGrandTotal extracts the total of a DKV "Gesamtsummenaufstellung" section.
+//
+// Rule: DKV invoices repeat a per-vehicle "TOTAL:" line, so the last TOTAL is
+// not the invoice total. When a "Gesamtsummenaufstellung" section exists, its
+// total wins over every "TOTAL:" line: the first amount after the "»" marker,
+// or, if there is none, the last amount in the section. The section ends at the
+// page break (form feed) or end of text.
+func dkvGrandTotal(text string) (string, bool) {
+	idx := strings.Index(strings.ToLower(text), "gesamtsummenaufstellung")
+	if idx < 0 {
+		return "", false
+	}
+	section := text[idx:]
+	if ff := strings.IndexByte(section, '\f'); ff >= 0 {
+		section = section[:ff]
+	}
+	if m := strings.Index(section, "»"); m >= 0 {
+		if v, ok := firstAmount(section[m:]); ok {
+			return v, true
+		}
+	}
+	return lastAmount(section)
+}
+
+// lastUsableAmount returns the last amount matched by re that is not a tax rate
+// or percentage. Within one label the last usable amount wins.
+func lastUsableAmount(text string, re *regexp.Regexp) (string, bool) {
+	ms := re.FindAllStringSubmatchIndex(text, -1)
+	for i := len(ms) - 1; i >= 0; i-- {
+		m := ms[i]
+		if isTaxRate(text, m[2], m[3]) {
+			continue
+		}
+		if v, ok := normalizeAmount(text[m[2]:m[3]]); ok {
+			return v, true
+		}
+	}
+	return "", false
+}
+
+// isTaxRate reports whether the number at text[start:end] is a tax rate or a
+// percentage instead of a payable amount. A candidate is rejected when the
+// token right after the number is "%" or the number's line carries a percent
+// sign or a tax keyword. Rejecting is deliberate: office matching treats a
+// known-but-different amount as a hard disqualifier, so an empty result is
+// safer than the VAT rate.
+func isTaxRate(text string, start, end int) bool {
+	if percentAfterRe.MatchString(text[end:]) {
+		return true
+	}
+	lineStart := strings.LastIndexByte(text[:start], '\n') + 1
+	line := text[lineStart:]
+	if n := strings.IndexByte(text[end:], '\n'); n >= 0 {
+		line = text[lineStart : end+n]
+	}
+	return isTaxLine(line)
+}
+
+// isTaxLine reports whether a line looks like a tax rate rather than a payable
+// amount. "Steuern" is treated as a qualifier ("inkl. Steuern"), not a rate.
+func isTaxLine(line string) bool {
+	if taxLineRe.MatchString(line) {
+		return true
+	}
+	for _, loc := range steuerRe.FindAllStringIndex(line, -1) {
+		if loc[1] >= len(line) || (line[loc[1]] != 'n' && line[loc[1]] != 'N') {
+			return true
+		}
+	}
+	return false
+}
+
+// numberRe finds bare numbers (with optional thousands/decimal separators).
+var numberRe = regexp.MustCompile(`[0-9]+(?:[.,][0-9]+)*`)
+
+func firstAmount(s string) (string, bool) {
+	for _, m := range numberRe.FindAllString(s, -1) {
+		if v, ok := normalizeAmount(m); ok {
+			return v, true
+		}
+	}
+	return "", false
+}
+
+func lastAmount(s string) (string, bool) {
+	ms := numberRe.FindAllString(s, -1)
+	for i := len(ms) - 1; i >= 0; i-- {
+		if v, ok := normalizeAmount(ms[i]); ok {
+			return v, true
+		}
+	}
+	return "", false
+}
+
+// normalizeAmount turns "1.234,56" (DE), "1,234.56" (EN) or "1234.56" into
+// "1234.56". The rightmost separator is decimal only when followed by one or
+// two digits; otherwise every separator is a thousands separator.
+func normalizeAmount(s string) (string, bool) {
+	last := -1
+	for i := 0; i < len(s); i++ {
+		if s[i] == '.' || s[i] == ',' {
+			last = i
+		}
+	}
+	var dec byte
+	if last >= 0 {
+		digits := 0
+		for i := last + 1; i < len(s); i++ {
+			if s[i] < '0' || s[i] > '9' {
+				return "", false
+			}
+			digits++
+		}
+		if digits == 1 || digits == 2 {
+			dec = s[last]
+		}
+	}
+	var b strings.Builder
+	for i := 0; i < len(s); i++ {
+		switch c := s[i]; {
+		case c >= '0' && c <= '9':
+			b.WriteByte(c)
+		case (c == '.' || c == ',') && c == dec:
+			b.WriteByte('.')
+		case c == '.' || c == ',':
+			// thousands separator
+		default:
+			return "", false
+		}
+	}
+	v, err := strconv.ParseFloat(b.String(), 64)
+	if err != nil {
+		return "", false
+	}
+	return strconv.FormatFloat(v, 'f', 2, 64), true
+}

cmd/pdfamount/main_test.go

@@ -0,0 +1,175 @@
+package main
+
+import "testing"
+
+func TestExtractAmount(t *testing.T) {
+	tests := []struct {
+		name, text, want string
+	}{
+		{
+			name: "rechnungsbetrag de format",
+			text: "Rechnungsbetrag: 1.234,56 €",
+			want: "1234.56",
+		},
+		{
+			name: "rechnungsbetrag en thousands and dot",
+			text: "Rechnungsbetrag: 1,234.56",
+			want: "1234.56",
+		},
+		{
+			name: "rechnungsbetrag plain dot",
+			text: "Rechnungsbetrag: 1234.56",
+			want: "1234.56",
+		},
+		{
+			name: "rechnungsbetrag de comma only",
+			text: "Rechnungsbetrag: 1234,56",
+			want: "1234.56",
+		},
+		{
+			name: "currency suffix eur",
+			text: "Rechnungsbetrag: 1.234,56 EUR",
+			want: "1234.56",
+		},
+		{
+			name: "zu zahlender betrag wins over rechnungsbetrag",
+			text: "Zu zahlender Betrag: 10,00\nRechnungsbetrag: 99,00",
+			want: "10.00",
+		},
+		{
+			name: "rechnungsbetrag wins over endbetrag",
+			text: "Endbetrag: 20,00\nRechnungsbetrag: 30,00",
+			want: "30.00",
+		},
+		{
+			name: "bruttobetrag wins over bare betrag",
+			text: "Bruttobetrag: 50,00\nBetrag: 10,00",
+			want: "50.00",
+		},
+		{
+			name: "gesamtbetrag wins over bare betrag",
+			text: "Gesamtbetrag: 80,00\nBetrag: 10,00",
+			want: "80.00",
+		},
+		{
+			name: "last occurrence of same label wins",
+			text: "Rechnungsbetrag: 10,00\nRechnungsbetrag: 20,00",
+			want: "20.00",
+		},
+		{
+			name: "endbetrag fallback",
+			text: "Endbetrag: 42,00",
+			want: "42.00",
+		},
+		{
+			name: "zahlbetrag fallback without colon",
+			text: "Zahlbetrag 7,50 €",
+			want: "7.50",
+		},
+		{
+			name: "rechnungsendbetrag beats endbetrag",
+			text: "Rechnungsendbetrag: 12,00\nEndbetrag: 13,00",
+			want: "12.00",
+		},
+		{
+			name: "dkv style total line",
+			text: "Kundenbezogene Daten\n» TOTAL: 123,45 100,00 23,45 123,45\n",
+			want: "123.45",
+		},
+		{
+			name: "dkv gesamtsummenaufstellung grand total after marker",
+			text: "» TOTAL: 111,11 100,00 11,11 111,11\n" +
+				"» TOTAL: 222,22 200,00 22,22 222,22\n" +
+				"Gesamtsummenaufstellung\n" +
+				"Netto 240,00\n" +
+				"MwSt 47,25\n" +
+				"» 287,25\n",
+			want: "287.25",
+		},
+		{
+			name: "dkv gesamtsummenaufstellung total on next line",
+			text: "» TOTAL: 111,11\nGesamtsummenaufstellung\n»\n287,25\n",
+			want: "287.25",
+		},
+		{
+			name: "tax rate with percent sign is not an amount",
+			text: "Betrag: 19,00 % MwSt",
+			want: "",
+		},
+		{
+			name: "mehrwertsteuer rate is not an amount",
+			text: "Gesamtsumme: 19,00% MwSt",
+			want: "",
+		},
+		{
+			name: "steuer word on the number line rejects it",
+			text: "Betrag: 2,83 Steuer",
+			want: "",
+		},
+		{
+			name: "rejected primary falls back to a usable label",
+			text: "Gesamtsumme: 19,00 % MwSt\nEndbetrag: 42,00",
+			want: "42.00",
+		},
+		{
+			name: "labeled zu zahlender betrag beats unlabeled larger number",
+			text: "unlabeled 999,99\nZu zahlender Betrag: 10,00",
+			want: "10.00",
+		},
+		{
+			name: "labeled zu zahlender betrag beats lower label larger number",
+			text: "Endbetrag: 999,99\nZu zahlender Betrag: 10,00",
+			want: "10.00",
+		},
+		{
+			name: "diashop style gesamtsumme with comment",
+			text: "Zwischensumme\n12,34 €\nZwischensumme\n12,34 €\nVersand & Bearbeitung\n4,95 €\nGesamtsumme (inkl. Steuern)\n17,29 €\n",
+			want: "17.29",
+		},
+		{
+			name: "diashop picks inclusive total last",
+			text: "Gesamtsumme (exkl. Steuern)\n12,34 €\nGesamtsumme (inkl. Steuern)\n17,29 €",
+			want: "17.29",
+		},
+		{
+			name: "no label",
+			text: "some text without any amount label 12,34",
+			want: "",
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := extractAmount(tc.text); got != tc.want {
+				t.Fatalf("extractAmount()=%q want %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestNormalizeAmount(t *testing.T) {
+	tests := []struct {
+		in   string
+		want string
+		ok   bool
+	}{
+		{"1.234,56", "1234.56", true},
+		{"1,234.56", "1234.56", true},
+		{"1234.56", "1234.56", true},
+		{"1234,56", "1234.56", true},
+		{"1.234.567,89", "1234567.89", true},
+		{"1,234,567.89", "1234567.89", true},
+		{"1.234", "1234.00", true},
+		{"12,5", "12.50", true},
+		{"12", "12.00", true},
+		{"", "0.00", false},
+	}
+	for _, tc := range tests {
+		got, ok := normalizeAmount(tc.in)
+		if ok != tc.ok {
+			t.Fatalf("normalizeAmount(%q) ok=%v want %v", tc.in, ok, tc.ok)
+		}
+		if ok && got != tc.want {
+			t.Fatalf("normalizeAmount(%q)=%q want %q", tc.in, got, tc.want)
+		}
+	}
+}

deploy/docker-compose.rclone-webdav.yml

@@ -0,0 +1,70 @@
+# rclone WebDAV mount of the oo-webdav sidecar (OnlyOffice Documents).
+#
+# The sidecar publishes the portal's WebDAV tree on the docker bridge
+# (http://172.17.0.1:8098, prefix /webdav). rclone mounts it inside this
+# container as a normal filesystem.
+#
+# Credentials are OnlyOffice portal credentials (the same the `oo` CLI uses).
+# Export them before `docker compose up`, e.g.
+#   set -a; . .secrets/oo.env; set +a
+# or copy .env.example to .env and fill it. Only names live in git.
+#
+#   docker compose -f deploy/docker-compose.rclone-webdav.yml up -d
+#   docker exec rclone-webdav ls /mnt/onlyoffice
+#   docker compose -f deploy/docker-compose.rclone-webdav.yml down
+#
+# The mount point is the named volume `onlyoffice-mnt`; join it from another
+# container with `external_volumes` to read the tree without the API.
+name: rclone-webdav
+
+services:
+  rclone-webdav:
+    image: rclone/rclone:latest
+    container_name: rclone-webdav
+    restart: unless-stopped
+    # rclone mount needs FUSE. The remote is defined on the fly via flags for
+    # the mount; the same credentials are written to an rclone config so that
+    # `docker exec rclone-webdav rclone ls webdav:` works without flags.
+    entrypoint: ["/bin/sh", "-c"]
+    command:
+      - |
+        set -eu
+        : "$${ONLYOFFICE_USER:?ONLYOFFICE_USER is required}"
+        : "$${ONLYOFFICE_PASSWORD:?ONLYOFFICE_PASSWORD is required}"
+        obscured=$$(rclone obscure "$${ONLYOFFICE_PASSWORD}")
+        mkdir -p /config/rclone
+        cat > /config/rclone/rclone.conf <<EOF
+        [webdav]
+        type = webdav
+        url = $${ONLYOFFICE_WEBDAV_URL}
+        vendor = other
+        user = $${ONLYOFFICE_USER}
+        pass = $${obscured}
+        EOF
+        exec rclone mount :webdav: /mnt/onlyoffice \
+          --webdav-url "$${ONLYOFFICE_WEBDAV_URL}" \
+          --webdav-user "$${ONLYOFFICE_USER}" \
+          --webdav-pass "$${obscured}" \
+          --vfs-cache-mode writes \
+          --cache-dir /cache \
+          --dir-cache-time 1m \
+          --allow-other \
+          --allow-non-empty
+    environment:
+      ONLYOFFICE_USER: ${ONLYOFFICE_USER:?ONLYOFFICE_USER is required}
+      ONLYOFFICE_PASSWORD: ${ONLYOFFICE_PASSWORD:-${ONLYOFFICE_PASS:?ONLYOFFICE_PASSWORD is required}}
+      ONLYOFFICE_WEBDAV_URL: ${ONLYOFFICE_WEBDAV_URL:-http://172.17.0.1:8098/webdav}
+    cap_add:
+      - SYS_ADMIN
+    devices:
+      - /dev/fuse
+    # Ubuntu hosts run AppArmor; FUSE mounts need it unconfined.
+    security_opt:
+      - apparmor:unconfined
+    volumes:
+      - onlyoffice-mnt:/mnt/onlyoffice
+      - rclone-cache:/cache
+
+volumes:
+  onlyoffice-mnt:
+  rclone-cache:

docs/README.md

@@ -0,0 +1,25 @@
+---
+type: reference
+status: current
+related:
+  - README.md
+---
+
+# go-onlyoffice — docs
+
+Индекс справочников. Общее — [README.md](../README.md), правила — [AGENTS.md](../AGENTS.md).
+
+## Файлы
+- [unified-file-client.md](unified-file-client.md) — единый файловый клиент:
+  `Entry`/`FileStore`/`FileClient`, бэкенды REST/DAV/SQL/ES, env, как добавить
+  бэкенд.
+- [community-server-db.md](community-server-db.md) — read-only SQL-бэкенд
+  (MySQL/PostgreSQL): схема, SSH-туннель, DSN, MinIO download.
+- [elasticsearch.md](elasticsearch.md) — поиск: индекс OnlyOffice `files_file`
+  и свой `oo_docs_text` (PDF/сканы), туннель.
+- [rclone-webdav.md](rclone-webdav.md) — rclone-монтирование Documents
+  (`deploy/docker-compose.rclone-webdav.yml`), smoke, ограничения.
+- [crm-associations.md](crm-associations.md) — правила ассоциаций CRM.
+
+## Тесты
+Команды и туннели — раздел Testing в [README.md](../README.md#testing).

docs/community-server-db.md

@@ -0,0 +1,179 @@
+---
+type: reference
+status: current
+related:
+  - README.md
+  - file_pg.go
+  - docs/elasticsearch.md
+---
+
+# Community Server DB — прямой SQL-доступ (read-only)
+
+## Что это
+
+Бэкенд `pgStore` (`file_pg.go`) читает файлы и папки **напрямую из БД
+Community Server**, без HTTP-слоя. Реализует `FileStore` (`List`/`Stat`/
+`Download`) и `Searcher` по имени. Запись запрещена: все write-методы
+возвращают `ErrReadOnly`.
+
+## Что за БД (research, live)
+
+Проверено на VM `onlyoffice-v2` (SSH `127.0.0.1:32`):
+
+- Community Server работает на **MySQL 8.0**, не на PostgreSQL.
+  - Хост: `127.0.0.1:3306` внутри VM, база `onlyoffice`.
+  - Конфиг: `/etc/onlyoffice/communityserver/appsettings.production.json`,
+    `providerName: MySql.Data.MySqlClient`.
+  - Таблицы: `files_file`, `files_folder`, `files_folder_tree`,
+    `files_security`, тенанты — `tenants_tenants` (не `tenants`).
+- PostgreSQL 16 в той же VM — **наш** контур (`edw_docs`, роли `edw`/`edw_ro`,
+  office-assistant), к OnlyOffice отношения не имеет. `files_file` в PG нет.
+- Портал хранит файлы в **S3/MinIO** (DiscStorage только для мелочи).
+  Бакет `office`, объект — по ключу (см. ниже).
+
+Вывод: бэкенд назван по issue «PostgreSQL», но живой источник — MySQL.
+`database/sql` + драйвер по DSN: `mysql` для MySQL, `pgx` для PostgreSQL.
+`Name()` возвращает фактический движок (`mysql` или `postgres`).
+
+## Схема
+
+`files_file` — одна строка **на версию** (PK `tenant_id, id, version`):
+
+| поле | смысл |
+|------|-------|
+| `id` | id файла (тот же, что в REST/ES) |
+| `version` | номер версии этой строки |
+| `version_group` | номер версии |
+| `current_version` | `1` = текущая версия, `0` = старая |
+| `folder_id` | id родительской папки |
+| `title` | имя файла с расширением |
+| `content_length` | размер в байтах |
+| `create_on`, `modified_on` | даты (UTC, без зоны) |
+| `tenant_id` | тенант (портал) |
+
+`files_folder`: `id`, `parent_id`, `title`, `create_on`, `modified_on`,
+`tenant_id`. `files_folder_tree`: `folder_id`, `parent_id`, `level` — готовое
+дерево, пока не используется.
+
+Текущую строку файла берём по `current_version = 1`.
+
+## Доступ (SSH-туннель)
+
+MySQL слушает только `127.0.0.1:3306` внутри VM. Снаружи — SSH-туннель
+(SSH в VM открыт как `127.0.0.1:32`):
+
+```bash
+ssh -f -N -o ControlMaster=no -o ControlPath=none \
+    -p 32 -i ~/.ssh/id_ed25519 \
+    -L 3306:127.0.0.1:3306 root@127.0.0.1
+
+# MySQL DSN затем:
+# root:<pw>@tcp(127.0.0.1:3306)/onlyoffice?parseTime=true
+```
+
+Любой свободный локальный порт подойдёт (напр. `13306`); тогда тот же порт —
+в DSN. `-o ControlMaster=no -o ControlPath=none` обязательны: иначе forward
+уходит в persistent master из `~/.ssh/config`.
+
+Креды MySQL — в конфиге Community Server внутри VM:
+`/etc/onlyoffice/communityserver/appsettings.production.json` →
+`ConnectionStrings.connectionString` (поля `User ID`, `Password`), база
+`onlyoffice`. В самом MySQL-контейнере (`onlyoffice-mysql-server`) база пустая;
+рабочий сервер — host-mysqld на `127.0.0.1:3306` (207 таблиц). Не печатать
+пароль.
+
+## Переменные
+
+| env | default | смысл |
+|-----|---------|-------|
+| `ONLYOFFICE_DSN` | — | DSN драйвера (MySQL `...@tcp(...)/...` или `postgres://...`) |
+| `ONLYOFFICE_PG_DRIVER` | авто | `postgres` или `mysql`; иначе по форме DSN |
+| `ONLYOFFICE_PG_TENANT` | `ONLYOFFICE_TENANT` | фильтр `tenant_id` (пусто = все) |
+| `ONLYOFFICE_PG_HOST/PORT/USER/PASSWORD/DBNAME/SSLMODE` | — | собрать PG DSN, если `ONLYOFFICE_DSN` пуст |
+
+Имена — в [`.env.example`](../.env.example). Секретов нет.
+
+## Использование
+
+Напрямую: `NewPGStore(PGConfigFromEnv())`.
+
+Через фасад (эпик #34): SQL-стор регистрируется на `FileClient`. После этого
+`Read()` и все чтения (`Stat`/`List`) идут в БД, `Write()` остаётся REST/DAV.
+
+```go
+c := onlyoffice.NewClient(onlyoffice.GetEnvironmentCredentials())
+
+sql, err := c.SQLFileStore()            // открыть из env; caller закрывает
+if err != nil { /* нет DSN / нет связи */ }
+if closer, ok := sql.(interface{ Close() error }); ok { defer closer.Close() }
+
+f := c.Files()
+f.RegisterStore(onlyoffice.ProviderPG, sql)
+e, _ := f.Stat(ctx, "19423")            // e.Provider == "mysql" — ответил SQL
+```
+
+`Client.FileStore("pg"|"sql"|"postgres"|"mysql")` тоже отдаёт SQL-стор
+(открывает из env). Если DSN нет/битый — возвращается не `nil`, а заглушка,
+чей метод отдаёт ошибку открытия; ошибку как таковую даёт `SQLFileStore()`.
+Различить бэкенд в ответе можно по `Entry.Provider` (`mysql` у SQL, `rest` у
+REST).
+
+## Download (MinIO)
+
+`Download` не ходит в REST. Ключ объекта собирается из строки `files_file`:
+
+```
+00/00/<tenant>/files/folder_<shard>/file_<id>/v<version>/content.<ext>
+shard = (id/1000 + 1) * 1000
+```
+
+`shard` — не `folder_id`, а следующая тысяча над `id` (файл 3727 →
+`folder_4000`). Проверено live по бакету `office`.
+
+Стриминг переиспользует `downloadMinioObject` из `storage_fallback.go`
+(та же подпись SigV4 и `MINIO_*`), без дублирования.
+
+Ограничение: схема валидна только для файлов, лежащих в **MinIO/S3** (старые
+папки). Файлы в **Disc**-хранилище портала (`Data/Products/Files/...`, новые
+папки) по этому ключу недоступны — `Download` вернёт `404`. Если
+`MINIO_ACCESS_KEY`/`MINIO_SECRET_KEY` не заданы, `Download` вернёт явную
+ошибку; `Stat`/`List`/`Search` работают и без них.
+
+## Тесты
+
+```bash
+go test ./...                              # unit: rebind, csObjectKey, маппинг
+go test -race ./...
+
+# integration (нужен DSN; skip без него)
+ONLYOFFICE_DSN='root:<pw>@tcp(127.0.0.1:3306)/onlyoffice?parseTime=true' \
+ONLYOFFICE_PG_TENANT=1 \
+ONLYOFFICE_PG_TEST_FILE_ID=19423 \
+ONLYOFFICE_PG_TEST_FOLDER_ID=676 \
+  go test -tags=integration -run 'TestIntegrationPGStore|TestIntegrationSQLFacade' -v ./...
+
+# плюс MINIO_* для сверки Download с REST (иначе этот шаг skip)
+MINIO_ENDPOINT=http://127.0.0.1:9000 MINIO_BUCKET=office \
+MINIO_ACCESS_KEY=... MINIO_SECRET_KEY=... \
+  go test -tags=integration -run TestIntegrationPGStore -v ./...
+```
+
+- `TestIntegrationPGStore` — `Stat`/`List`/`Download` SQL против REST и
+  `ErrReadOnly` у write-методов.
+- `TestIntegrationSQLFacade` — SQL-стор, зарегистрированный на фасаде, реально
+  обслуживает чтения: `Read().Name()` = SQL-бэкенд, `Entry.Provider == "mysql"`
+  (у REST — `"rest"`), сверка `Stat`/`List` с REST, и прямой
+  `Client.FileStore("pg")`.
+
+Без `ONLYOFFICE_DSN` оба теста делают чистый `skip`.
+
+## Грабли
+
+- MySQL хранит `datetime` без зоны; `parseTime=true` (ставится автоматически)
+  читает их как UTC. REST отдаёт `+02:00` — сравнивать моменты, не строки.
+- `GetFile` (REST) не отдаёт `contentLength` — размер сверять с `Stat` SQL.
+- Один файл = много строк `files_file` (по версиям). Без `current_version = 1`
+  получите дубликаты.
+- `folder_id` не входит в ключ MinIO; ключ считает `shard` от `id`.
+- Searcher SQL ищет только по имени (`LIKE`). Контент — Elasticsearch
+  ([elasticsearch.md](elasticsearch.md)).

docs/elasticsearch.md

@@ -0,0 +1,255 @@
+---
+type: reference
+status: current
+related:
+  - README.md
+  - file_es.go
+---
+
+# Elasticsearch — полнотекстовый поиск OnlyOffice
+
+## Что это
+
+Полнотекстовый поиск OnlyOffice Workspace работает на **Elasticsearch**.
+Клиент на сервере — NEST. Индекс — имя таблицы.
+
+Для файлов индекс `files_file`:
+
+| поле | тип | смысл |
+|------|-----|-------|
+| `id` | integer | id файла (тот же, что в REST/Documents) |
+| `title` | text (`whitespacecustom`) | имя файла |
+| `tenantId` | integer | тенант (портал) |
+| `folders` | nested | список папок: `folderId` (строка), `id`, `tenantId` |
+| `document.attachment.content` | text (`document`) | извлеченный текст (ingest-attachment) |
+| `document.attachment.content_type` | text | MIME |
+
+Важно:
+- Живой сервер — **Elasticsearch 7.16.3**, кластер `elasticsearch`.
+- REST `GET /api/2.0/files/@search/{query}` ищет **только по имени в БД**
+  (`fileDao.Search`), ES не задействует. Для поиска по содержимому нужен
+  прямой ES — это и делает `oo search`.
+- `title` analyzer `whitespacecustom` режет по пробелам и lower-case. Полное
+  имя файла — один токен (`Rechnung-4711.pdf`), поэтому поиск по имени ищет
+  слово целиком, а не подстроку.
+- `document.attachment.content` заполняется **только для Office-форматов**
+  (docx / xlsx / pptx). У PDF/txt, залитых через API, контент не извлекается.
+- Индексация асинхронная (TeamLabSvc) — файл появляется в ES не мгновенно.
+
+## Доступ
+
+ES слушает `127.0.0.1:9200` **внутри** VM OnlyOffice. Снаружи порт закрыт,
+SSH в VM открыт на хосте как `127.0.0.1:32` (контейнер `onlyoffice-v2`,
+QEMU). Схема — SSH-туннель.
+
+```bash
+# из корня go-onlyoffice (ключ и хост — как в infra-доках)
+ssh -f -N -o ControlMaster=no -o ControlPath=none \
+    -p 32 -i ~/.ssh/id_ed25519 \
+    -L 9200:127.0.0.1:9200 root@127.0.0.1
+
+curl -s http://127.0.0.1:9200/ | head            # tagline + version
+curl -s 'http://127.0.0.1:9200/_cat/indices?h=index,docs.count'
+```
+
+`-o ControlMaster=no -o ControlPath=none` обязательны: иначе forward уходит
+в persistent master-соединение из `~/.ssh/config` и порт остаётся занят.
+
+Проверить, что туннель жив:
+
+```bash
+curl -s http://127.0.0.1:9200/files_file/_count
+```
+
+## Переменные
+
+| env | default | смысл |
+|-----|---------|-------|
+| `ONLYOFFICE_ES_URL` | — (обязателен) | `scheme://host:port` ES |
+| `ONLYOFFICE_ES_INDEX` | `files_file` | индекс |
+| `ONLYOFFICE_TENANT` | пусто (все) | фильтр `tenantId` |
+
+Имена — в [`.env.example`](../.env.example). Секретов нет: ES без пароля.
+
+## CLI
+
+```bash
+ONLYOFFICE_ES_URL=http://127.0.0.1:9200 oo search "Rechnung"
+ONLYOFFICE_ES_URL=http://127.0.0.1:9200 oo search "Mahngebühr" --content
+oo search "Rechnung" --folder 649 --limit 50 --json
+```
+
+Флаги: `--content` (искать и по тексту), `--folder ID` (папка
+`folders.folderId`), `--limit N` (по умолчанию 20, максимум 200),
+`--json` = `-o json`.
+
+## Библиотека
+
+`file_es.go` — `ESSearcher` (`Name() = "elasticsearch"`), прямой ES REST на
+stdlib `net/http`:
+
+```go
+es, _ := onlyoffice.NewESSearcher(onlyoffice.ESConfigFromEnv())
+hits, _ := es.Search(ctx, onlyoffice.SearchQuery{
+    Text: "Rechnung", InContent: true, Limit: 20,
+})
+```
+
+Запрос: `multi_match` по `title^2` (+ `document.attachment.content` при
+`InContent`), фильтры `tenantId` и `folders.folderId`, `_source`
+id/title/folders, `highlight` для фрагмента. Ответ → `[]SearchHit` (модель из
+эпика #34; пока объявлена в `file_es.go`, переедет в `file_core.go` с F1 #35).
+
+## Тесты
+
+```bash
+# unit — чистые builders/парсеры, без сети
+go test ./ -run ES
+
+# integration — нужен ONLYOFFICE_ES_URL (+ креды REST для залива)
+set -a; . .env; set +a
+ONLYOFFICE_ES_URL=http://127.0.0.1:9200 ONLYOFFICE_TENANT=1 \
+  go test -tags=integration -run TestIntegrationESSearch -v .
+```
+
+Интеграционный тест заливает временный xlsx (в имени и в ячейке — уникальные
+токены), ждёт индексации, проверяет поиск по имени и по содержимому, затем
+удаляет проект.
+
+## Грабли
+
+- `locale`/версия ES: 7.16.3, `_search` совместим с REST 7.x.
+- ES без auth и слушает только localhost — туннель обязателен.
+- Фильтр `tenantId` сузит выдачу; без него видны документы всех тенантов.
+- Поиск по содержимому PDF в индексе OnlyOffice не работает (для PDF нет
+  `attachment.content`) — только Office-форматы. Решение для PDF — свой индекс
+  `oo_docs_text` (F6 #42), см. ниже.
+
+# PDF и сканы — свой индекс (F6 #42)
+
+## Проблема
+
+`oo search --content "S1019"` не находил номер внутри PDF-счёта: в индексе
+OnlyOffice PDF лежит только по имени.
+
+## Почему PDF исключён (исходники CommunityServer)
+
+Разобрано в `ONLYOFFICE/CommunityServer`:
+
+- `web/core/ASC.Web.Core/Files/FileUtility.cs` — `CanIndex(fileName)` читает
+  серверную настройку `files.index.formats` (в `web/studio/ASC.Web.Studio/web.appsettings.config`
+  значение по умолчанию `".pptx|.xlsx|.docx"`).
+- `web/studio/ASC.Web.Studio/Products/Files/Core/Search/FilesWrapper.cs` —
+  `GetDocumentStream*` возвращает `null`, если `!FileUtility.CanIndex(Title)`,
+  файл зашифрован или больше `MaxFileSize`.
+- `module/ASC.ElasticSearch/Core/WrapperWithDoc.cs` + mapping в `Wrapper.cs` —
+  маппинг `document.attachment.content` и ingest-pipeline `attachments`
+  формат-агностичны: они распарсят любой поток.
+
+Вывод: PDF исключён **только настройкой** `files.index.formats`; жёсткого
+ограничения на формат в коде нет.
+
+## Варианты и решение
+
+| # | Вариант | Оценка |
+|---|---------|--------|
+| a | Включить `.pdf` в `files.index.formats` + reindex | Правка сервера OO; настройка может потеряться при обновлении; полный reindex 39k док-в; Tika **не OCR** — сканы без текстового слоя дадут пустой контент. Отклонён без решения PO. |
+| b | Server-side ingest/attachment для PDF | По факту то же, что (a): сервер кормит поток только для `CanIndex`. |
+| c | **Свой индекс** `oo_docs_text`, наполняемый `internal/docpipe` | **Выбран.** Сервер OO не трогаем; детерминированно; работает OCR для сканов; независимо от обновлений OO; любые форматы; фильтры папка/тип. |
+| d | Локальный поиск без индекса | Отклонён как основной: качаем и извлекаем на каждый запрос, нет выдачи/ранжирования/highlight. |
+
+Итог: **вариант c**. Индекс OnlyOffice (`files_file`) не изменяется; наш
+индекс живёт рядом.
+
+## Устройство
+
+- `file_es_text.go` — `ESTextIndex` (`Name() = "es-text"`):
+  `Ensure` (создаёт индекс с явным маппингом), `Put` (bulk, `refresh`),
+  `Delete` (по `id`), `Search` (`multi_match` по `title^2` + `content`,
+  фильтры `folder`/`ext`, highlight).
+- `file_text_index.go` — `TextIndexer`: листает папки (`FileStore.List`),
+  качает файлы (`FileStore.Download`), извлекает текст через
+  `internal/docpipe` (`pdftotext`, для сканов — `ocrmypdf`/`tesseract`),
+  пишет в `TextIndex`. Пул воркеров (по умолчанию 3).
+- CLI: `oo index folder|files` наполняет индекс; `oo search --backend own`
+  ищет по нему.
+
+### Встроенные вложения PDF
+
+Оцифрованные PDF несут вложения (`<doc>.md` — текст/таблицы скана,
+`<doc>.yaml`/`.json` — метаданные, `.xml` — EN 16931 CII eRechnung,
+`factur-x.xml` у ZUGFeRD; см. `office-assistant/docs/reference/document-metadata.md`).
+`TextIndexer` обходит их: `pdfdetach -list` перечисляет, `-save` сохраняет,
+каждое вложение проходит штатный `docpipe.ToMarkdown` (PDF/картинки → OCR,
+`.md`/`.txt` — как есть). Форматы, которые docpipe не конвертирует
+(`.xml`/`.html` — снимаются теги; `.json`/`.csv` — как текст), извлекаются
+текстом; нечитаемые — пропускаются.
+
+Текст склеивается: тело, затем по секции на вложение с маркером
+`[attachment: <имя>]` (функция `docpipe.JoinWithAttachments`). Индекс — тот же
+`file_id`, upsert идемпотентен. Нет вложений или pdfdetach/формат нечитаем —
+индексируется тело (без падения).
+
+Поля `oo_docs_text`:
+
+| поле | тип | смысл |
+|------|-----|-------|
+| `id` | keyword | id файла Documents |
+| `title` | text (+`.keyword`) | имя файла |
+| `folder` | keyword | id папки |
+| `ext` | keyword | расширение |
+| `content` | text | извлечённый текст (pdftotext/OCR) |
+
+## CLI
+
+```bash
+set -a; . .env; set +a          # ONLYOFFICE_URL/USER/PASS + ONLYOFFICE_ES_URL
+oo index folder 634             # PDF в папке 634
+oo index folder 634 --recursive --exts pdf,png --limit 100
+oo index files 3576 3578        # точечно
+oo index folder 634 --dry-run   # показать план, ничего не менять
+
+oo search "S1021" --content --backend own
+oo search "S1021" --backend own --folder 634 --json
+```
+
+`--backend` у `oo search`: `oo` (по умолчанию, индекс OnlyOffice) или `own`
+(наш `ONLYOFFICE_ES_TEXT_INDEX`).
+
+## Переменные (дополнение)
+
+| env | default | смысл |
+|-----|---------|-------|
+| `ONLYOFFICE_ES_TEXT_INDEX` | `oo_docs_text` | индекс своего конвейера |
+
+`ONLYOFFICE_ES_URL` — общий для обоих индексов.
+
+## Тесты
+
+```bash
+go test -run 'ESText|TextIndexer|Index' ./ ./cmd/oo/        # unit, без сети
+ONLYOFFICE_ES_URL=http://127.0.0.1:9200 \
+  go test -tags=integration -run TestIntegrationESTextIndex -v .
+```
+
+Интеграционный тест создаёт временный индекс, наполняет, ищет по контенту,
+проверяет фильтры и удаление, затем удаляет индекс;
+`TestIntegrationESTextIndexPDFAttachment` индексирует
+`testdata/pdf-with-attachment.pdf` реальным конвейером (pdfdetach + pdftotext)
+и ищет токен, лежащий только во вложении. Unit-тесты используют
+fake-store/fake-extractor и не требуют pdftotext/OCR (парсер списка, склейка
+`JoinWithAttachments`, снятие тегов `xmlToText` — чистые).
+
+## Грабли
+
+- Наполнение — ручное (`oo index`); после изменения/добавления PDF повтори.
+  Повтор идемпотентен (upsert по id файла).
+- В индексе ищется только то, что проиндексировано; `oo index` качает каждый
+  файл и (для сканов) гоняет OCR — это медленно, отсюда `--limit`/`--exts`.
+- `folder` фильтруется как id папки, а не как путь.
+- Дубликаты (напр. `S1055.pdf` и `2026-08-20-S1055-…`) дадут несколько строк —
+  это ожидаемо, дедуп — на стороне потребителя.
+- Вложения: нужен `pdfdetach` (poppler); если его нет — индексируется только
+  тело. Вложенный PDF/картинка с плохим текстовым слоем проходит OCR, это
+  медленно. `.json`-метаданные (CuraSoft) индексируются как текст и могут
+  добавить шумовых токенов.

docs/rclone-webdav.md

@@ -0,0 +1,109 @@
+---
+type: reference
+status: current
+related:
+  - deploy/docker-compose.rclone-webdav.yml
+  - docs/unified-file-client.md
+---
+
+# rclone WebDAV mount — OnlyOffice Documents как файловая ФС
+
+`deploy/docker-compose.rclone-webdav.yml` монтирует WebDAV-дерево OnlyOffice
+через `rclone`. Не systemd, только compose. Контейнер — `rclone-webdav`.
+
+## Что монтируется
+
+- Источник — сайдкар `oo-webdav` (`ghcr.io/eslider/oo-webdav`).
+- Адрес — `http://172.17.0.1:8098`, префикс `/webdav`.
+- Basic-auth — креды портала OnlyOffice (те же, что у `oo`).
+- Корень — `Dokumente der Projekte/…` (папка `Fibu EDL` внутри).
+
+## Конфиг
+
+- Образ — `rclone/rclone`.
+- Remote — on-the-fly `:webdav:` плюс флаги `--webdav-url`, `--webdav-user`,
+  `--webdav-pass`.
+- На старте контейнер пишет `/config/rclone/rclone.conf` (`[webdav]`), чтобы
+  `rclone ls webdav:` внутри контейнера работал без флагов.
+- `ONLYOFFICE_PASSWORD` — plain; rclone сам зовёт `rclone obscure`.
+- Флаги mount: `--vfs-cache-mode writes`, `--cache-dir /cache`,
+  `--dir-cache-time 1m`, `--allow-other`, `--allow-non-empty`.
+- FUSE: `cap_add: [SYS_ADMIN]`, `devices: [/dev/fuse]`,
+  `security_opt: apparmor:unconfined`.
+- Тома: `onlyoffice-mnt` → `/mnt/onlyoffice`, `rclone-cache` → `/cache`.
+
+### env (только имена)
+
+| Переменная | Значение |
+|------------|----------|
+| `ONLYOFFICE_USER` | пользователь портала |
+| `ONLYOFFICE_PASSWORD` | пароль портала (алиас `ONLYOFFICE_PASS`) |
+| `ONLYOFFICE_WEBDAV_URL` | по умолчанию `http://172.17.0.1:8098/webdav` |
+
+## Команды
+
+```bash
+# креды (или .env рядом с compose)
+set -a; . .secrets/oo.env; set +a
+
+docker compose -f deploy/docker-compose.rclone-webdav.yml up -d
+docker compose -f deploy/docker-compose.rclone-webdav.yml ps
+docker compose -f deploy/docker-compose.rclone-webdav.yml down
+
+# дерево
+docker exec rclone-webdav rclone ls webdav:
+docker exec rclone-webdav rclone lsf webdav:
+
+# содержимое точки монтирования
+docker exec rclone-webdav ls /mnt/onlyoffice
+
+# чтение/запись как обычная ФС
+docker exec rclone-webdav cat "/mnt/onlyoffice/Meine Dokumente/x.txt"
+```
+
+## Smoke (проверено 2026-09-16)
+
+```text
+$ docker exec rclone-webdav rclone ls webdav:
+  5357109 Meine Dokumente/ONLYOFFICE-Audiobeispiel.mp3
+    44805 Meine Dokumente/ONLYOFFICE-Beispiel-Tabellenblatt.xlsx
+    58988 Meine Dokumente/ONLYOFFICE-Beispieldokument.docx
+  ...
+
+$ TS=20260916-212459
+$ docker exec rclone-webdav sh -c "printf 'rclone-webdav round-trip $TS\n' \
+    > '/mnt/onlyoffice/Meine Dokumente/rclone-smoke-$TS/hello.txt'"
+# ждём появления на сервере (host HTTP, мимо монтирования):
+GET /webdav/Meine%20Dokumente/rclone-smoke-$TS/hello.txt -> 200 (через 7s)
+server bytes: rclone-webdav round-trip 20260916-212459
+# читаем обратно через монтирование:
+mount read: rclone-webdav round-trip 20260916-212459
+MATCH: yes
+
+$ docker exec rclone-webdav rm -f \
+    "/mnt/onlyoffice/Meine Dokumente/rclone-smoke-$TS/hello.txt"
+GET /webdav/Meine%20Dokumente/rclone-smoke-$TS/hello.txt -> 404 (через 1s)
+
+# пустой каталог: rmdir через монтирование на сервер не доходит,
+# удаляем напрямую:
+$ docker exec rclone-webdav rclone rmdir "webdav:Meine Dokumente/rclone-smoke-$TS"
+PROPFIND rclone-smoke-20260916-212459/ -> 404
+no rclone-smoke leftovers
+```
+
+Вывод: запись → чтение → удаление файла подтверждены. Файл удалён.
+
+## Ограничения
+
+- Нужен FUSE: `SYS_ADMIN` + `/dev/fuse`. На хосте без FUSE не поедет.
+- Сайдкар слушает docker-bridge `172.17.0.1:8098`, публично не выставлен.
+  Только localhost/локальные контейнеры.
+- Запись идёт через VFS write-back (по умолчанию ~5s). Перед проверкой
+  «файл на сервере» опрашивать сервер, не доверять сразу после `write`.
+- `rmdir` через монтирование НЕ доходит до `oo-webdav` (пустой каталог
+  остаётся на сервере). Удалять каталоги напрямую:
+  `rclone rmdir webdav:<path>` или `rclone purge webdav:<path>`.
+- VFS-кэш растёт в томе `rclone-cache`; ограничить `--vfs-cache-max-size`.
+- Блокировок между редактором OnlyOffice и монтированием нет. Не редактировать
+  один и тот же файл одновременно.
+- Данные не шифруются на диске хоста в `rclone-cache` (том Docker).

docs/unified-file-client.md

@@ -0,0 +1,205 @@
+---
+type: reference
+status: current
+related:
+  - README.md
+  - file_core.go
+  - file_facade.go
+  - docs/elasticsearch.md
+  - docs/community-server-db.md
+---
+
+# Unified file client — контракт файловых бэкендов
+
+## Что это
+
+Один файловый клиент на все бэкенды (эпик #34). Модель и интерфейсы —
+`file_core.go`. Фасад `FileClient` — `file_facade.go`. Бэкенды:
+REST, WebDAV, SQL (PostgreSQL/MySQL), Elasticsearch. Правило одно:
+код зовёт `c.Files()` и не знает про транспорт.
+
+## Модель
+
+- `Kind` — `File` (0) или `Folder` (1).
+- `Entry` — бэкенд-независимая строка: `ID`, `ParentID`, `Title`, `Kind`,
+  `Size`, `MIME`, `Created`, `Modified`, `Updated` (сырая строка API),
+  `Version`, `Provider`, `FilesCount`/`FoldersCount` (папки).
+  Чего бэкенд не даёт — остаётся в нуле.
+- `SearchQuery` — `Text`, `InContent`, `FolderID`, `Extensions`, `Limit`.
+- `SearchHit` — `Entry` + `Score`, `Highlight`, `Path`.
+
+## Интерфейсы
+
+`FileStore` — операции с файлами:
+
+```go
+type FileStore interface {
+    Name() string
+    List(ctx, parentID) ([]Entry, error)
+    Stat(ctx, id) (Entry, error)
+    CreateFolder(ctx, parentID, title) (Entry, error)
+    Upload(ctx, parentID, title, r) (Entry, error)
+    Download(ctx, id, w) (int64, error)
+    Move(ctx, ids, parentID) error
+    Copy(ctx, ids, parentID) error
+    Rename(ctx, id, title) error
+    Delete(ctx, ids) error
+}
+```
+
+`Searcher` — поиск (необязательный):
+
+```go
+type Searcher interface {
+    Search(ctx, q SearchQuery) ([]SearchHit, error)
+    Name() string
+}
+```
+
+`TextIndex` (`file_es_text.go`) — свой индекс: `Put`, `Delete`, `Search`,
+`Name`. `ESTextIndex` реализует и `Searcher`, и `TextIndex`.
+
+## Бэкенды
+
+| бэкенд | провайдер | файл | что умеет |
+|--------|-----------|------|-----------|
+| REST | `rest` | `file_rest.go` | read + write, Documents API |
+| WebDAV | `dav` | `file_dav.go` | read + write, Documents fileops |
+| SQL | `postgres` / `mysql` | `file_pg.go` | **read-only** |
+| OnlyOffice ES | `elasticsearch` | `file_es.go` | поиск (имя + контент Office) |
+| свой ES-индекс | `es-text` | `file_es_text.go` | поиск + запись (PDF/сканы) |
+
+- REST: `Stat` знает только файлы; папки — через `List`.
+- WebDAV: `Move`/`Copy`/`Delete` сперва `Stat`-ят id (папка/файл), потом зовут
+  fileops.
+- SQL: `List`/`Stat`/`Download`/`Search` (по имени). Все write-методы →
+  `ErrReadOnly`. `Download` идёт в S3/MinIO по layout портала.
+- OnlyOffice ES: индекс `files_file`, контент только для docx/xlsx/pptx.
+- Свой ES: индекс `oo_docs_text`, контент из `internal/docpipe`, в т.ч.
+  встроенные PDF-вложения.
+
+## Фасад `FileClient`
+
+`c.Files()` → `*FileClient`. Он же реализует `FileStore`, старый код
+компилируется.
+
+- `Read()` — первый зарегистрированный из `readOrder`:
+  `postgres` → `mysql` → `rest` → `dav`.
+- `Write()` — первый из `writeOrder`: `rest` → `dav`. SQL не пишет.
+- `Search()` — первый из `searchOrder`: `elasticsearch`. Нет бэкенда →
+  ошибка (`ONLYOFFICE_ES_URL`).
+- `RegisterStore(name, s)` / `RegisterSearcher(name, s)` — добавить бэкенд.
+
+Fallback:
+
+- `List`/`Stat` идут по `readOrder`; переходят к следующему только на
+  transient-ошибке (429/502/503/504). Иначе ошибка финальная.
+- `Download` **без** fallback: часть байтов уже в `w`, второй бэкенд допишет.
+- Запись (`CreateFolder`/`Upload`/`Move`/`Copy`/`Rename`/`Delete`) — только
+  `Write()`, без fallback.
+
+`newFileClient` сам кладёт `rest` и `dav`; ES-поиск — если задан
+`ONLYOFFICE_ES_URL`. SQL-стор регистрирует вызывающий: фасад создаётся на
+каждый `c.Files()`, регистрируй на том же экземпляре.
+
+```go
+sql, err := c.SQLFileStore()                     // открыть из env (ONLYOFFICE_DSN)
+if err != nil { /* нет DSN */ }
+if closer, ok := sql.(interface{ Close() error }); ok { defer closer.Close() }
+
+f := c.Files()
+f.RegisterStore(onlyoffice.ProviderPG, sql)      // или sql.Name() == "mysql"
+e, _ := f.Stat(ctx, "19423")                     // e.Provider == "mysql"
+entries, _ := f.List(ctx, "676")                 // пойдёт в SQL
+```
+
+`Client.FileStore("pg"|"sql"|"postgres"|"mysql")` — одноразовый доступ к
+SQL-стору без фасада: открывает из env; при ошибке возвращает заглушку,
+которая отдаёт ошибку открытия на каждом вызове (не `nil`). `SQLFileStore()`
+— тот же открыватель, но с ошибкой. Отвечавший бэкенд видно по
+`Entry.Provider` (`mysql` / `postgres` у SQL, `rest` у REST).
+
+## CLI
+
+```bash
+# поиск: --backend oo (индекс OnlyOffice) | own (свой oo_docs_text)
+oo search "Rechnung"
+oo search "Mahngebühr" --content
+oo search "S1021" --content --backend own --folder 634 --limit 50 --json
+
+# наполнение своего индекса (PDF/сканы, idempotent upsert по file id)
+oo index folder 634
+oo index folder 634 --recursive --exts pdf,png --limit 100
+oo index files 3576 3578
+oo index folder 634 --dry-run
+```
+
+`oo index` флаги: `--recursive`, `--exts` (default `pdf`), `--limit`,
+`--workers` (3), `--lang` (`deu+eng`), `--min-chars`, `--work-dir`,
+`--backend rest|dav`, `--dry-run`, `--json`.
+
+Библиотека:
+
+```go
+idx, _ := onlyoffice.NewESTextIndex(onlyoffice.ESTextConfigFromEnv())
+ti := onlyoffice.NewTextIndexer(store, idx)   // store = FileStore
+res, _ := ti.IndexFolder(ctx, "634", onlyoffice.IndexOptions{Recursive: true})
+```
+
+## Env (только имена)
+
+| env | default | кто читает |
+|-----|---------|------------|
+| `ONLYOFFICE_ES_URL` | — | ES (оба индекса), обязателен |
+| `ONLYOFFICE_ES_INDEX` | `files_file` | индекс OnlyOffice |
+| `ONLYOFFICE_ES_TEXT_INDEX` | `oo_docs_text` | свой индекс |
+| `ONLYOFFICE_TENANT` | пусто | фильтр `tenantId` |
+| `ONLYOFFICE_DSN` | — | SQL DSN (MySQL/PostgreSQL) |
+| `ONLYOFFICE_PG_DRIVER` | auto | `postgres` / `mysql` |
+| `ONLYOFFICE_PG_TENANT` | `ONLYOFFICE_TENANT` | SQL tenant |
+| `ONLYOFFICE_PG_HOST` `_PORT` `_USER` `_PASSWORD` `_DBNAME` `_SSLMODE` | — | DSN по частям |
+| `MINIO_ENDPOINT` `MINIO_BUCKET` `MINIO_ACCESS_KEY` `MINIO_SECRET_KEY` | — | download SQL-стора |
+| `OO_URL` `OO_USER` `OO_PASS` | — | CLI-алиасы |
+
+Имена — в [`.env.example`](../.env.example). Секретов в репо нет.
+
+## Ограничения
+
+- OnlyOffice ES: контент только Office-форматов. PDF — только по имени.
+  Встроенные вложения PDF сервер не индексирует.
+- Свой индекс `oo_docs_text`: покрывает PDF/сканы и вложения (pdfdetach), но
+  наполняется вручную (`oo index`) и идемпотентен. Фильтр `folder` — id папки,
+  не путь. Дубли дают несколько строк — дедуп на потребителе.
+- SQL: read-only. `InContent` игнорируется (только имя). Download — через
+  MinIO-схему, не HTTP.
+- ES: без auth, слушает localhost внутри VM — нужен SSH-туннель
+  (см. [elasticsearch.md](elasticsearch.md)).
+- `oo index` качает каждый файл и для сканов гоняет OCR — медленно; отсюда
+  `--limit` и `--exts`. Нужен `pdfdetach` (poppler); без него — только тело PDF.
+
+## Как добавить бэкенд
+
+1. Файл `file_<name>.go`. Реализуй `FileStore` (`Name` + 9 методов). Нужен
+   поиск — добавь `Searcher`; нужна запись своего индекса — `TextIndex`.
+2. Добавь const провайдера рядом с `ProviderREST`/`ProviderDAV`.
+3. Зарегистрируй: в `newFileClient` или снаружи через
+   `RegisterStore`/`RegisterSearcher`.
+4. Внеси имя в `readOrder` / `writeOrder` / `searchOrder`.
+5. Есть CLI-команда — добавь значение в `--backend`.
+6. Тесты: unit (чистые builders/парсеры, без сети) + интеграционный
+   (`//go:build integration`, skip без кред).
+
+## Тесты
+
+```bash
+go test ./...                                  # unit, без сети
+go test -tags=integration ./...                # live (креды в .env)
+go test ./ -run 'FileStore|Facade|ESText|PG'
+```
+
+## См. также
+
+- [README.md](README.md) — индекс справочников.
+- [elasticsearch.md](elasticsearch.md) — индекс OnlyOffice и свой `oo_docs_text`.
+- [community-server-db.md](community-server-db.md) — SQL-стор и схема БД.
+- [rclone-webdav.md](rclone-webdav.md) — монтирование Documents как ФС.

file_core.go

@@ -0,0 +1,262 @@
+package onlyoffice
+
+// Canonical file model and the backend-agnostic store interface. REST
+// (files.go), WebDAV (files_webdav.go) and future backends (PostgreSQL,
+// Elasticsearch) implement FileStore/Searcher so callers stop depending on a
+// concrete transport. This file holds only types and pure conversions — no IO.
+
+import (
+	"context"
+	"io"
+	"mime"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Kind distinguishes files from folders in the canonical model.
+type Kind int
+
+const (
+	File Kind = iota
+	Folder
+)
+
+// String renders the kind for logs and table output.
+func (k Kind) String() string {
+	switch k {
+	case File:
+		return "file"
+	case Folder:
+		return "folder"
+	default:
+		return "unknown"
+	}
+}
+
+// Provider names for the FileStore adapters.
+const (
+	ProviderREST = "rest"
+	ProviderDAV  = "dav"
+)
+
+// Entry is the backend-independent representation of a document or folder.
+// Fields that a backend cannot supply stay at their zero value.
+type Entry struct {
+	ID       string
+	ParentID string
+	Title    string
+	Kind     Kind
+	Size     int64
+	MIME     string
+	Created  time.Time
+	Modified time.Time
+	// Updated is the backend-native timestamp string, when the backend exposes
+	// one. It lets list output round-trip the API value; Modified is the
+	// parsed form for logic.
+	Updated  string
+	Version  int
+	Provider string
+
+	// Folder-only counters. Zero for files and for backends that do not
+	// report them.
+	FilesCount   int
+	FoldersCount int
+}
+
+// FileStore is the operation surface every file backend implements.
+type FileStore interface {
+	Name() string
+	List(ctx context.Context, parentID string) ([]Entry, error)
+	Stat(ctx context.Context, id string) (Entry, error)
+	CreateFolder(ctx context.Context, parentID, title string) (Entry, error)
+	Upload(ctx context.Context, parentID, title string, r io.Reader) (Entry, error)
+	Download(ctx context.Context, id string, w io.Writer) (int64, error)
+	Move(ctx context.Context, ids []string, parentID string) error
+	Copy(ctx context.Context, ids []string, parentID string) error
+	Rename(ctx context.Context, id, title string) error
+	Delete(ctx context.Context, ids []string) error
+}
+
+// SearchQuery narrows a Searcher request. InContent asks the backend to match
+// document bodies, not just titles. Substring switches title matching from the
+// analyzer's whole-token match to a case-insensitive "*term*" wildcard and ANDs
+// every whitespace-separated term (e.g. "rechnung 2025").
+type SearchQuery struct {
+	Text       string
+	InContent  bool
+	FolderID   string
+	Extensions []string
+	Limit      int
+	Substring  bool
+}
+
+// SearchHit is one Searcher result: the matching entry plus backend-specific
+// ranking metadata.
+type SearchHit struct {
+	Entry
+	Score     float64
+	Highlight string
+	Path      []string
+}
+
+// Searcher is the optional content/name search surface. Only some backends
+// (for example Elasticsearch) provide it.
+type Searcher interface {
+	Search(ctx context.Context, q SearchQuery) ([]SearchHit, error)
+	Name() string
+}
+
+// FileStore returns the adapter for a backend name: ProviderREST (default),
+// ProviderDAV (alias "webdav") or the read-only SQL store (ProviderPG,
+// ProviderMySQL and the aliases "pg"/"sql"). The SQL store is opened from the
+// environment (ONLYOFFICE_DSN / ONLYOFFICE_PG_*); when it cannot be opened the
+// returned store surfaces that error on every operation instead of returning
+// nil. Use SQLFileStore when the open error itself is needed. Unknown or empty
+// names select the REST backend. The composed facade (backend
+// selection/fallback) lives on FileClient in file_facade.go.
+func (c *Client) FileStore(backend string) FileStore {
+	switch strings.ToLower(strings.TrimSpace(backend)) {
+	case ProviderDAV, "webdav":
+		return &davStore{c: c}
+	case ProviderPG, ProviderMySQL, "pg", "sql":
+		s, err := c.SQLFileStore()
+		if err != nil {
+			return &errStore{name: strings.ToLower(strings.TrimSpace(backend)), err: err}
+		}
+		return s
+	default:
+		return &restStore{c: c}
+	}
+}
+
+// errStore is the FileStore placeholder returned when a backend cannot be
+// opened (for example SQL without a DSN). Every operation returns the recorded
+// error instead of panicking on a nil interface.
+type errStore struct {
+	name string
+	err  error
+}
+
+func (s *errStore) Name() string { return s.name }
+
+func (s *errStore) List(context.Context, string) ([]Entry, error) { return nil, s.err }
+
+func (s *errStore) Stat(context.Context, string) (Entry, error) { return Entry{}, s.err }
+
+func (s *errStore) CreateFolder(context.Context, string, string) (Entry, error) {
+	return Entry{}, s.err
+}
+
+func (s *errStore) Upload(context.Context, string, string, io.Reader) (Entry, error) {
+	return Entry{}, s.err
+}
+
+func (s *errStore) Download(context.Context, string, io.Writer) (int64, error) {
+	return 0, s.err
+}
+
+func (s *errStore) Move(context.Context, []string, string) error { return s.err }
+
+func (s *errStore) Copy(context.Context, []string, string) error { return s.err }
+
+func (s *errStore) Rename(context.Context, string, string) error { return s.err }
+
+func (s *errStore) Delete(context.Context, []string) error { return s.err }
+
+// Files returns the composed file facade. The returned *FileClient implements
+// FileStore, so callers that used Files() as the plain REST store keep working.
+func (c *Client) Files() *FileClient { return c.newFileClient() }
+
+// retryStoreOp runs one store operation under the shared deterministic
+// transient-error policy (429/502/503/504).
+func retryStoreOp(ctx context.Context, fn func() error) error {
+	return DoRetry(ctx, DefaultRetryPolicy(), fn)
+}
+
+// FileEntryToEntry converts a Files-module file row to the canonical model.
+func FileEntryToEntry(f *FileEntry, provider string) Entry {
+	e := Entry{Kind: File, Provider: provider}
+	if f == nil {
+		return e
+	}
+	if f.ID != nil {
+		e.ID = f.ID.String()
+	}
+	e.ParentID = FileFolderID(f)
+	if f.Title != nil {
+		e.Title = *f.Title
+	}
+	if f.ContentLength != nil {
+		e.Size = parseContentLength(*f.ContentLength)
+	}
+	exst := ""
+	if f.FileExst != nil {
+		exst = *f.FileExst
+	}
+	e.MIME = mimeForTitle(e.Title, exst)
+	if f.Updated != nil {
+		e.Modified = *f.Updated
+		e.Updated = f.Updated.Format(time.RFC3339)
+	}
+	return e
+}
+
+// DavFileToEntry converts a WebDAV file row to the canonical model.
+func DavFileToEntry(f DavFile, provider string) Entry {
+	return Entry{
+		ID:       f.ID,
+		Title:    f.Title,
+		Kind:     File,
+		Size:     f.Size,
+		MIME:     mimeForTitle(f.Title, ""),
+		Modified: f.ModTime(),
+		Updated:  f.Updated,
+		Provider: provider,
+	}
+}
+
+// DavFolderToEntry converts a WebDAV folder row to the canonical model.
+func DavFolderToEntry(f DavFolder, provider string) Entry {
+	return Entry{
+		ID:           f.ID,
+		ParentID:     f.ParentID,
+		Title:        f.Title,
+		Kind:         Folder,
+		Modified:     f.ModTime(),
+		Updated:      f.Updated,
+		Provider:     provider,
+		FilesCount:   f.FilesCount,
+		FoldersCount: f.FoldersCount,
+	}
+}
+
+// parseContentLength reads the leading integer of an OnlyOffice contentLength
+// string (the API sometimes appends a unit, e.g. "12345 b").
+func parseContentLength(s string) int64 {
+	fields := strings.Fields(s)
+	if len(fields) == 0 {
+		return 0
+	}
+	n, err := strconv.ParseInt(fields[0], 10, 64)
+	if err != nil {
+		return 0
+	}
+	return n
+}
+
+// mimeForTitle derives a MIME type from an explicit extension or the title.
+func mimeForTitle(title, exst string) string {
+	ext := strings.TrimSpace(exst)
+	if ext == "" {
+		ext = filepath.Ext(title)
+	}
+	if ext == "" {
+		return ""
+	}
+	if !strings.HasPrefix(ext, ".") {
+		ext = "." + ext
+	}
+	return mime.TypeByExtension(strings.ToLower(ext))
+}

file_core_test.go

@@ -0,0 +1,193 @@
+package onlyoffice
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestFileEntryToEntry(t *testing.T) {
+	id := json.Number("42")
+	title := "invoice.pdf"
+	exst := ".pdf"
+	size := "12345"
+	parent := json.Number("7")
+	updated := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	f := &FileEntry{
+		ID:            &id,
+		Title:         &title,
+		FileExst:      &exst,
+		ContentLength: &size,
+		FolderID:      &parent,
+		Updated:       &updated,
+	}
+
+	e := FileEntryToEntry(f, ProviderREST)
+	if e.ID != "42" {
+		t.Errorf("ID = %q, want 42", e.ID)
+	}
+	if e.ParentID != "7" {
+		t.Errorf("ParentID = %q, want 7", e.ParentID)
+	}
+	if e.Title != title {
+		t.Errorf("Title = %q, want %q", e.Title, title)
+	}
+	if e.Kind != File {
+		t.Errorf("Kind = %v, want file", e.Kind)
+	}
+	if e.Size != 12345 {
+		t.Errorf("Size = %d, want 12345", e.Size)
+	}
+	if e.MIME != "application/pdf" {
+		t.Errorf("MIME = %q, want application/pdf", e.MIME)
+	}
+	if !e.Modified.Equal(updated) {
+		t.Errorf("Modified = %v, want %v", e.Modified, updated)
+	}
+	if e.Provider != ProviderREST {
+		t.Errorf("Provider = %q, want %q", e.Provider, ProviderREST)
+	}
+}
+
+func TestFileEntryToEntryNil(t *testing.T) {
+	e := FileEntryToEntry(nil, ProviderDAV)
+	if e.Kind != File {
+		t.Errorf("Kind = %v, want file", e.Kind)
+	}
+	if e.ID != "" || e.Title != "" {
+		t.Errorf("nil entry should be empty: %+v", e)
+	}
+	if e.Provider != ProviderDAV {
+		t.Errorf("Provider = %q, want %q", e.Provider, ProviderDAV)
+	}
+}
+
+func TestFileEntryToEntrySizeFormats(t *testing.T) {
+	cases := map[string]int64{
+		"12345":   12345,
+		"12345 b": 12345,
+		"0":       0,
+		"":        0,
+		"notanum": 0,
+	}
+	for in, want := range cases {
+		got := parseContentLength(in)
+		if got != want {
+			t.Errorf("parseContentLength(%q) = %d, want %d", in, got, want)
+		}
+	}
+}
+
+func TestDavFileToEntry(t *testing.T) {
+	f := DavFile{
+		ID:      "9",
+		Title:   "note.txt",
+		Size:    10,
+		Updated: "2026-01-02T03:04:05.0000000+01:00",
+	}
+	e := DavFileToEntry(f, ProviderDAV)
+	if e.ID != "9" || e.Title != "note.txt" {
+		t.Errorf("identity mismatch: %+v", e)
+	}
+	if e.Kind != File {
+		t.Errorf("Kind = %v, want file", e.Kind)
+	}
+	if e.Size != 10 {
+		t.Errorf("Size = %d, want 10", e.Size)
+	}
+	if !strings.HasPrefix(e.MIME, "text/plain") {
+		t.Errorf("MIME = %q, want text/plain*", e.MIME)
+	}
+	if e.Modified.IsZero() {
+		t.Error("Modified not parsed")
+	}
+	if e.Provider != ProviderDAV {
+		t.Errorf("Provider = %q, want %q", e.Provider, ProviderDAV)
+	}
+}
+
+func TestDavFolderToEntry(t *testing.T) {
+	f := DavFolder{
+		ID:       "5",
+		Title:    "inbox",
+		ParentID: "1",
+		Updated:  "2026-01-02T03:04:05.0000000+01:00",
+	}
+	e := DavFolderToEntry(f, ProviderDAV)
+	if e.ID != "5" || e.Title != "inbox" || e.ParentID != "1" {
+		t.Errorf("identity mismatch: %+v", e)
+	}
+	if e.Kind != Folder {
+		t.Errorf("Kind = %v, want folder", e.Kind)
+	}
+	if e.MIME != "" {
+		t.Errorf("folder MIME = %q, want empty", e.MIME)
+	}
+	if e.Modified.IsZero() {
+		t.Error("Modified not parsed")
+	}
+}
+
+func TestEntriesFromFolderMap(t *testing.T) {
+	m := map[string]any{
+		"files": []any{
+			map[string]any{"id": float64(42), "title": "a.pdf", "pureContentLength": float64(7)},
+		},
+		"folders": []any{
+			map[string]any{"id": float64(7), "title": "sub", "parentId": float64(1)},
+		},
+	}
+	entries, err := entriesFromFolderMap(m, ProviderREST)
+	if err != nil {
+		t.Fatalf("entriesFromFolderMap: %v", err)
+	}
+	if len(entries) != 2 {
+		t.Fatalf("got %d entries, want 2: %+v", len(entries), entries)
+	}
+	byID := map[string]Entry{}
+	for _, e := range entries {
+		byID[e.ID] = e
+	}
+	if got := byID["42"]; got.Kind != File || got.Size != 7 || got.Title != "a.pdf" {
+		t.Errorf("file entry = %+v", got)
+	}
+	if got := byID["7"]; got.Kind != Folder || got.ParentID != "1" || got.Title != "sub" {
+		t.Errorf("folder entry = %+v", got)
+	}
+}
+
+func TestEntriesFromFolderMapNil(t *testing.T) {
+	entries, err := entriesFromFolderMap(nil, ProviderREST)
+	if err != nil || entries != nil {
+		t.Fatalf("got %v, %v; want nil, nil", entries, err)
+	}
+}
+
+func TestKindString(t *testing.T) {
+	if File.String() != "file" || Folder.String() != "folder" {
+		t.Errorf("kind strings: %q %q", File.String(), Folder.String())
+	}
+	if Kind(9).String() != "unknown" {
+		t.Errorf("unknown kind = %q", Kind(9).String())
+	}
+}
+
+func TestClientFileStoreSelection(t *testing.T) {
+	c := NewClient(Credentials{})
+	if got := c.FileStore(ProviderDAV).Name(); got != ProviderDAV {
+		t.Errorf("FileStore(dav).Name() = %q", got)
+	}
+	if got := c.FileStore("webdav").Name(); got != ProviderDAV {
+		t.Errorf("FileStore(webdav).Name() = %q", got)
+	}
+	if got := c.FileStore(ProviderREST).Name(); got != ProviderREST {
+		t.Errorf("FileStore(rest).Name() = %q", got)
+	}
+	if got := c.FileStore("").Name(); got != ProviderREST {
+		t.Errorf("FileStore(\"\").Name() = %q", got)
+	}
+	if got := c.Files().Name(); got != ProviderREST {
+		t.Errorf("Files().Name() = %q", got)
+	}
+}

file_dav.go

@@ -0,0 +1,189 @@
+package onlyoffice
+
+// davStore implements FileStore on top of the Documents/WebDAV methods in
+// files_webdav.go. The Documents fileops calls need folder and file ids
+// separated, so ids are classified through Stat before move/copy/rename/delete.
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+)
+
+// davStore is a FileStore over the WebDAV-oriented Documents API.
+type davStore struct{ c *Client }
+
+// Name reports the backend name.
+func (s *davStore) Name() string { return ProviderDAV }
+
+// List returns the files and folders directly below parentID.
+func (s *davStore) List(ctx context.Context, parentID string) ([]Entry, error) {
+	var out []Entry
+	err := retryStoreOp(ctx, func() error {
+		l, err := s.c.ListDavFolder(ctx, parentID)
+		if err != nil {
+			return err
+		}
+		entries := make([]Entry, 0, len(l.Folders)+len(l.Files))
+		for _, f := range l.Folders {
+			entries = append(entries, DavFolderToEntry(f, ProviderDAV))
+		}
+		for _, f := range l.Files {
+			entries = append(entries, DavFileToEntry(f, ProviderDAV))
+		}
+		out = entries
+		return nil
+	})
+	return out, err
+}
+
+// Stat resolves a folder or file entry by id. A folder answers ListDavFolder
+// with its own metadata in Current; otherwise the file metadata API is used.
+func (s *davStore) Stat(ctx context.Context, id string) (Entry, error) {
+	return s.stat(ctx, id)
+}
+
+// CreateFolder creates a subfolder under parentID.
+func (s *davStore) CreateFolder(ctx context.Context, parentID, title string) (Entry, error) {
+	var out Entry
+	err := retryStoreOp(ctx, func() error {
+		f, err := s.c.CreateDavFolder(ctx, parentID, title)
+		if err != nil {
+			return err
+		}
+		if f == nil {
+			return fmt.Errorf("onlyoffice: dav store: empty create-folder response")
+		}
+		out = DavFolderToEntry(*f, ProviderDAV)
+		return nil
+	})
+	return out, err
+}
+
+// Upload streams r into parentID as title. The reader is buffered once so a
+// retry re-sends the same bytes instead of an exhausted stream.
+func (s *davStore) Upload(ctx context.Context, parentID, title string, r io.Reader) (Entry, error) {
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return Entry{}, err
+	}
+	var out Entry
+	err = retryStoreOp(ctx, func() error {
+		f, err := s.c.UploadDavFile(ctx, parentID, title, bytes.NewReader(data))
+		if err != nil {
+			return err
+		}
+		if f == nil {
+			return fmt.Errorf("onlyoffice: dav store: empty upload response")
+		}
+		out = DavFileToEntry(*f, ProviderDAV)
+		return nil
+	})
+	return out, err
+}
+
+// Download streams the file bytes into w.
+func (s *davStore) Download(ctx context.Context, id string, w io.Writer) (int64, error) {
+	var n int64
+	err := retryStoreOp(ctx, func() error {
+		var e error
+		n, e = s.c.DownloadDavFile(ctx, id, w)
+		return e
+	})
+	return n, err
+}
+
+// Move moves ids into parentID, splitting folders from files.
+func (s *davStore) Move(ctx context.Context, ids []string, parentID string) error {
+	folders, files, err := s.split(ctx, ids)
+	if err != nil {
+		return err
+	}
+	if len(folders) == 0 && len(files) == 0 {
+		return nil
+	}
+	return retryStoreOp(ctx, func() error {
+		return s.c.MoveDavItems(ctx, folders, files, parentID)
+	})
+}
+
+// Copy copies ids into parentID, splitting folders from files.
+func (s *davStore) Copy(ctx context.Context, ids []string, parentID string) error {
+	folders, files, err := s.split(ctx, ids)
+	if err != nil {
+		return err
+	}
+	if len(folders) == 0 && len(files) == 0 {
+		return nil
+	}
+	return retryStoreOp(ctx, func() error {
+		return s.c.CopyDavItems(ctx, folders, files, parentID)
+	})
+}
+
+// Rename renames a folder or file.
+func (s *davStore) Rename(ctx context.Context, id, title string) error {
+	e, err := s.stat(ctx, id)
+	if err != nil {
+		return err
+	}
+	return retryStoreOp(ctx, func() error {
+		if e.Kind == Folder {
+			return s.c.RenameDavFolder(ctx, id, title)
+		}
+		return s.c.RenameDavFile(ctx, id, title)
+	})
+}
+
+// Delete removes ids, splitting folders from files.
+func (s *davStore) Delete(ctx context.Context, ids []string) error {
+	folders, files, err := s.split(ctx, ids)
+	if err != nil {
+		return err
+	}
+	if len(folders) == 0 && len(files) == 0 {
+		return nil
+	}
+	return retryStoreOp(ctx, func() error {
+		return s.c.DeleteDavItems(ctx, folders, files)
+	})
+}
+
+// stat resolves a single id to a folder or file Entry.
+func (s *davStore) stat(ctx context.Context, id string) (Entry, error) {
+	var out Entry
+	err := retryStoreOp(ctx, func() error {
+		if l, err := s.c.ListDavFolder(ctx, id); err == nil {
+			if l != nil && l.Current.ID != "" && l.Current.ID == id {
+				out = DavFolderToEntry(l.Current, ProviderDAV)
+				return nil
+			}
+		} else if Transient(err) {
+			return err
+		}
+		f, err := s.c.GetFile(ctx, id)
+		if err != nil {
+			return err
+		}
+		out = FileEntryToEntry(f, ProviderDAV)
+		return nil
+	})
+	return out, err
+}
+
+// split classifies ids into folder and file id lists.
+func (s *davStore) split(ctx context.Context, ids []string) (folders, files []string, err error) {
+	for _, id := range ids {
+		e, err := s.stat(ctx, id)
+		if err != nil {
+			return nil, nil, err
+		}
+		if e.Kind == Folder {
+			folders = append(folders, id)
+		} else {
+			files = append(files, id)
+		}
+	}
+	return folders, files, nil
+}

file_es.go

@@ -0,0 +1,325 @@
+package onlyoffice
+
+// Elasticsearch backend of the unified file client (epic #34, F3 #37).
+//
+// OnlyOffice full-text search runs on Elasticsearch (index `files_file`, NEST
+// client on the server). The REST endpoint GET /api/2.0/files/@search/{query}
+// only searches file names in the database, so content search needs a direct
+// ES query. The live server is Elasticsearch 7.16.3; the request shape below
+// is plain REST and stays stdlib-only, matching the repo's no-extra-deps rule.
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// The canonical model (Kind, Entry, SearchQuery, SearchHit, Searcher) lives in
+// file_core.go (F1 #35).
+
+const (
+	defaultESIndex    = "files_file"
+	defaultESLimit    = 20
+	maxESLimit        = 1000
+	maxESResponseSize = 8 << 20
+)
+
+// ESConfig configures the direct Elasticsearch searcher.
+type ESConfig struct {
+	URL    string // scheme://host:port of the ES HTTP endpoint
+	Index  string // index name, default files_file
+	Tenant string // tenantId filter, empty means all tenants
+}
+
+// ESConfigFromEnv reads ONLYOFFICE_ES_URL, ONLYOFFICE_ES_INDEX (default
+// files_file) and ONLYOFFICE_TENANT. The library never loads dotfiles — the
+// CLI does that.
+func ESConfigFromEnv() ESConfig {
+	return ESConfig{
+		URL:    strings.TrimRight(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL")), "/"),
+		Index:  firstNonEmpty(os.Getenv("ONLYOFFICE_ES_INDEX"), defaultESIndex),
+		Tenant: strings.TrimSpace(os.Getenv("ONLYOFFICE_TENANT")),
+	}
+}
+
+// ESSearcher queries OnlyOffice's Elasticsearch index directly for file name
+// and document content.
+type ESSearcher struct {
+	cfg  ESConfig
+	http *http.Client
+}
+
+// NewESSearcher returns a searcher for the OnlyOffice Elasticsearch index.
+// The URL is required; an empty index falls back to files_file.
+func NewESSearcher(cfg ESConfig) (*ESSearcher, error) {
+	if strings.TrimSpace(cfg.URL) == "" {
+		return nil, fmt.Errorf("onlyoffice: elasticsearch URL is empty (set ONLYOFFICE_ES_URL)")
+	}
+	cfg.URL = strings.TrimRight(cfg.URL, "/")
+	if cfg.Index == "" {
+		cfg.Index = defaultESIndex
+	}
+	return &ESSearcher{cfg: cfg, http: &http.Client{Timeout: 30 * time.Second}}, nil
+}
+
+// Name implements Searcher.
+func (s *ESSearcher) Name() string { return "elasticsearch" }
+
+// Search runs a multi_match over title (and, when q.InContent is set,
+// document.attachment.content), filtered by tenant and optional folder.
+func (s *ESSearcher) Search(ctx context.Context, q SearchQuery) ([]SearchHit, error) {
+	q.Text = strings.TrimSpace(q.Text)
+	if q.Text == "" {
+		return nil, fmt.Errorf("onlyoffice: empty search query")
+	}
+	body, err := json.Marshal(esSearchRequest(q, s.cfg.Tenant))
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: build elasticsearch query: %w", err)
+	}
+	endpoint := s.cfg.URL + "/" + s.cfg.Index + "/_search"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+	resp, err := s.http.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: elasticsearch search: %w", err)
+	}
+	defer resp.Body.Close()
+	raw, err := io.ReadAll(io.LimitReader(resp.Body, maxESResponseSize))
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("onlyoffice: elasticsearch search: %d %s", resp.StatusCode, truncate(string(raw), 400))
+	}
+	return parseESSearchResponse(raw)
+}
+
+// esSearchRequest builds the ES query body. Pure, so it is unit-tested.
+func esSearchRequest(q SearchQuery, tenant string) esRequest {
+	limit := q.Limit
+	if limit <= 0 {
+		limit = defaultESLimit
+	}
+	if limit > maxESLimit {
+		limit = maxESLimit
+	}
+	fields := []string{"title^2"}
+	if q.InContent {
+		fields = append(fields, "document.attachment.content")
+	}
+	var must []esClause
+	if q.Substring {
+		for _, term := range strings.Fields(strings.ToLower(q.Text)) {
+			if term = escapeWildcard(term); term != "" {
+				must = append(must, esClause{Wildcard: map[string]any{"title": "*" + term + "*"}})
+			}
+		}
+	}
+	if len(must) == 0 {
+		must = []esClause{{MultiMatch: &esMultiMatch{Query: q.Text, Fields: fields}}}
+	}
+
+	var filter []esClause
+	if t := strings.TrimSpace(tenant); t != "" {
+		filter = append(filter, esClause{Term: map[string]any{"tenantId": numericOrString(t)}})
+	}
+	if f := strings.TrimSpace(q.FolderID); f != "" {
+		// folders is an ES nested field; a plain term on folders.folderId would
+		// not match. The stored Folders list holds every ancestor id, so
+		// filtering by a project root id scopes to its whole subtree.
+		filter = append(filter, esClause{Nested: &esNested{
+			Path:  "folders",
+			Query: esNestedTerm{Term: map[string]any{"folders.folderId": f}},
+		}})
+	}
+	for _, ext := range normalizeExtensions(q.Extensions) {
+		filter = append(filter, esClause{Wildcard: map[string]any{"title": "*." + ext}})
+	}
+
+	highlightFields := map[string]struct{}{"title": {}}
+	if q.InContent {
+		highlightFields["document.attachment.content"] = struct{}{}
+	}
+	return esRequest{
+		Size:      limit,
+		Source:    []string{"id", "title", "folders"},
+		Query:     esQuery{Bool: esBool{Must: must, Filter: filter}},
+		Highlight: esHighlight{PreTags: []string{"<em>"}, PostTags: []string{"</em>"}, Fields: highlightFields},
+	}
+}
+
+// normalizeExtensions lowercases, trims leading dots and drops empties.
+func normalizeExtensions(exts []string) []string {
+	out := make([]string, 0, len(exts))
+	seen := map[string]bool{}
+	for _, e := range exts {
+		e = strings.ToLower(strings.TrimSpace(strings.TrimPrefix(strings.TrimSpace(e), ".")))
+		if e == "" || seen[e] {
+			continue
+		}
+		seen[e] = true
+		out = append(out, e)
+	}
+	return out
+}
+
+// numericOrString keeps an integer-looking filter value numeric (tenantId is
+// a long) and leaves anything else as a string (folderId is a text token).
+func numericOrString(s string) any {
+	if n, err := strconv.ParseInt(s, 10, 64); err == nil {
+		return n
+	}
+	return s
+}
+
+// esRequest is the subset of the ES query DSL this client emits.
+type esRequest struct {
+	Size      int         `json:"size"`
+	Source    []string    `json:"_source"`
+	Query     esQuery     `json:"query"`
+	Highlight esHighlight `json:"highlight"`
+}
+
+type esQuery struct {
+	Bool esBool `json:"bool"`
+}
+
+type esBool struct {
+	Must   []esClause `json:"must,omitempty"`
+	Filter []esClause `json:"filter,omitempty"`
+}
+
+type esClause struct {
+	MultiMatch *esMultiMatch  `json:"multi_match,omitempty"`
+	Term       map[string]any `json:"term,omitempty"`
+	Terms      map[string]any `json:"terms,omitempty"`
+	Wildcard   map[string]any `json:"wildcard,omitempty"`
+	Nested     *esNested      `json:"nested,omitempty"`
+}
+
+type esNested struct {
+	Path  string       `json:"path"`
+	Query esNestedTerm `json:"query"`
+}
+
+type esNestedTerm struct {
+	Term map[string]any `json:"term,omitempty"`
+}
+
+// escapeWildcard strips ES wildcard metacharacters from a user term so a query
+// cannot inject wildcard syntax. Pure, so it is unit-tested.
+func escapeWildcard(s string) string {
+	return strings.NewReplacer("*", "", "?", "", `\`, "").Replace(s)
+}
+
+type esMultiMatch struct {
+	Query  string   `json:"query"`
+	Fields []string `json:"fields"`
+}
+
+type esHighlight struct {
+	PreTags  []string            `json:"pre_tags,omitempty"`
+	PostTags []string            `json:"post_tags,omitempty"`
+	Fields   map[string]struct{} `json:"fields"`
+}
+
+// esResponse is the subset of an ES search response we consume.
+type esResponse struct {
+	Took int `json:"took"`
+	Hits struct {
+		Total struct {
+			Value    int    `json:"value"`
+			Relation string `json:"relation"`
+		} `json:"total"`
+		Hits []esResponseHit `json:"hits"`
+	} `json:"hits"`
+}
+
+type esResponseHit struct {
+	ID     string  `json:"_id"`
+	Score  float64 `json:"_score"`
+	Source struct {
+		ID      int    `json:"id"`
+		Title   string `json:"title"`
+		Folders []struct {
+			FolderID string `json:"folderId"`
+			ID       int    `json:"id"`
+		} `json:"folders"`
+	} `json:"_source"`
+	Highlight map[string][]string `json:"highlight"`
+}
+
+// parseESSearchResponse converts an ES search response into SearchHit values.
+// Pure, so it is unit-tested.
+func parseESSearchResponse(raw []byte) ([]SearchHit, error) {
+	var r esResponse
+	if err := json.Unmarshal(raw, &r); err != nil {
+		return nil, fmt.Errorf("onlyoffice: decode elasticsearch response: %w", err)
+	}
+	hits := make([]SearchHit, 0, len(r.Hits.Hits))
+	for _, h := range r.Hits.Hits {
+		id := strconv.Itoa(h.Source.ID)
+		if h.Source.ID == 0 {
+			id = h.ID
+		}
+		// Folders is the ancestor breadcrumb in root → leaf order, so the last
+		// entry is the immediate parent (the previous "first" value was the
+		// project root, which made every result look like it lived in #522).
+		var parent string
+		path := make([]string, 0, len(h.Source.Folders))
+		for _, f := range h.Source.Folders {
+			if strings.TrimSpace(f.FolderID) == "" {
+				continue
+			}
+			path = append(path, f.FolderID)
+		}
+		if len(path) > 0 {
+			parent = path[len(path)-1]
+		}
+		hits = append(hits, SearchHit{
+			Entry: Entry{
+				ID:       id,
+				ParentID: parent,
+				Title:    h.Source.Title,
+				Kind:     File,
+				Provider: "elasticsearch",
+			},
+			Score:     h.Score,
+			Highlight: esHighlightText(h.Highlight),
+			Path:      path,
+		})
+	}
+	return hits, nil
+}
+
+var esHighlightTag = regexp.MustCompile(`</?em[^>]*>`)
+
+// esHighlightText flattens a highlight map into one plain-text snippet,
+// preferring the content fragment over the title. It covers both the
+// OnlyOffice content field and the own-index "content" field.
+func esHighlightText(hl map[string][]string) string {
+	for _, key := range []string{"document.attachment.content", "content", "title"} {
+		frags := hl[key]
+		if len(frags) == 0 {
+			continue
+		}
+		clean := make([]string, 0, len(frags))
+		for _, f := range frags {
+			clean = append(clean, esHighlightTag.ReplaceAllString(f, ""))
+		}
+		return strings.Join(clean, " … ")
+	}
+	return ""
+}

file_es_integration_test.go

@@ -0,0 +1,226 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/xuri/excelize/v2"
+)
+
+// Default known fixtures for TestIntegrationESFacadeUsesES on the live index.
+const (
+	defaultESTestQuery     = "Rechnung_986-2025.pdf"
+	defaultESTestSubstring = "rechnung 2025"
+	defaultESTestFolder    = "522"
+)
+
+// TestIntegrationESFacadeUsesES proves that the public search path — `oo search`
+// and Client.Files().Search() — really runs against the OnlyOffice
+// Elasticsearch backend and not the REST @search endpoint, which only looks at
+// file names in the database and is not a Searcher at all (see
+// docs/elasticsearch.md). It pins the concrete backend and checks that a known
+// document comes back with a non-empty id and folder path.
+//
+// Requires ONLYOFFICE_ES_URL only — the query never touches the REST API, so no
+// OnlyOffice credentials are needed. Skips when it is missing. The fixture is
+// overridable with ONLYOFFICE_ES_TEST_QUERY, ONLYOFFICE_ES_TEST_TITLE,
+// ONLYOFFICE_ES_TEST_SUBSTRING and ONLYOFFICE_ES_TEST_FOLDER.
+func TestIntegrationESFacadeUsesES(t *testing.T) {
+	esURL := strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL"))
+	if esURL == "" {
+		t.Skip("ONLYOFFICE_ES_URL not set — skipping Elasticsearch integration test")
+	}
+	query := firstNonEmpty(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_TEST_QUERY")), defaultESTestQuery)
+	wantTitle := firstNonEmpty(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_TEST_TITLE")), query)
+	substring := firstNonEmpty(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_TEST_SUBSTRING")), defaultESTestSubstring)
+	folder := firstNonEmpty(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_TEST_FOLDER")), defaultESTestFolder)
+
+	c := NewClient(Credentials{})
+	searcher, err := c.Files().Search()
+	if err != nil {
+		t.Fatalf("Files().Search(): %v", err)
+	}
+	if got := searcher.Name(); got != ProviderES {
+		t.Fatalf("searcher.Name() = %q, want %q (REST @search is not a Searcher)", got, ProviderES)
+	}
+	if _, ok := searcher.(*ESSearcher); !ok {
+		t.Fatalf("searcher = %T, want *ESSearcher (ES backend, not REST)", searcher)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	// Known file name: multi_match over title, as `oo search <file>` does.
+	start := time.Now()
+	hits, err := searcher.Search(ctx, SearchQuery{Text: query, Limit: 20})
+	if err != nil {
+		t.Fatalf("Search(%q): %v", query, err)
+	}
+	t.Logf("ES facade query %q: %d hits in %s", query, len(hits), time.Since(start))
+
+	known := findHitByTitle(hits, wantTitle)
+	if known == nil {
+		t.Fatalf("query %q returned %d hits, none titled %q", query, len(hits), wantTitle)
+	}
+	if strings.TrimSpace(known.ID) == "" {
+		t.Errorf("hit %q has empty id", known.Title)
+	}
+	if len(known.Path) == 0 {
+		t.Errorf("hit %q has empty path", known.Title)
+	}
+	if known.Provider != ProviderES {
+		t.Errorf("hit provider = %q, want %q", known.Provider, ProviderES)
+	}
+
+	// Substring + folder subtree, as `oo search <terms> --substring --folder N`
+	// does: wildcard terms ANDed together, scoped to the folder's subtree.
+	start = time.Now()
+	subHits, err := searcher.Search(ctx, SearchQuery{Text: substring, Substring: true, FolderID: folder, Limit: 200})
+	if err != nil {
+		t.Fatalf("substring Search(%q, folder %s): %v", substring, folder, err)
+	}
+	t.Logf("ES facade substring %q folder %s: %d hits in %s", substring, folder, len(subHits), time.Since(start))
+	if len(subHits) == 0 {
+		t.Fatalf("substring query %q in folder %s returned no hits", substring, folder)
+	}
+	if findHitByTitle(subHits, wantTitle) == nil {
+		t.Errorf("substring query %q in folder %s did not return %q", substring, folder, wantTitle)
+	}
+}
+
+// findHitByTitle returns the first hit whose title matches, case-insensitively.
+func findHitByTitle(hits []SearchHit, title string) *SearchHit {
+	for i := range hits {
+		if strings.EqualFold(strings.TrimSpace(hits[i].Title), title) {
+			return &hits[i]
+		}
+	}
+	return nil
+}
+
+// TestIntegrationESSearch uploads a throwaway workbook and verifies that the
+// direct Elasticsearch search finds it by file name and by content.
+//
+// The content index (document.attachment.content) is only populated for Office
+// formats (docx/xlsx/pptx), so the fixture is an xlsx whose cell carries a
+// unique token. Requires ONLYOFFICE_ES_URL (a reachable ES endpoint — in the
+// current setup a tunnel to the ES inside the OnlyOffice VM, see
+// docs/elasticsearch.md) plus the regular REST credentials for the upload.
+// Skips when either is missing.
+func TestIntegrationESSearch(t *testing.T) {
+	esURL := strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL"))
+	if esURL == "" {
+		t.Skip("ONLYOFFICE_ES_URL not set — skipping Elasticsearch integration test")
+	}
+	c := liveClient(t)
+	t.Cleanup(func() { cleanupTestProjects(t, c) })
+
+	stamp := time.Now().UTC().Format("20060102-150405")
+	nameToken := "goesname" + stamp
+	contentToken := "goescontent" + stamp
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+
+	project, err := c.CreateProject(NewProjectRequest{
+		Title:       testProjectPrefix + "es-" + stamp,
+		Description: "go-onlyoffice elasticsearch integration",
+	})
+	if err != nil {
+		t.Fatalf("CreateProject: %v", err)
+	}
+	if project.ID == nil {
+		t.Fatal("created project without id")
+	}
+	pid := strconv.Itoa(*project.ID)
+
+	title := nameToken + ".xlsx"
+	localPath := filepath.Join(t.TempDir(), title)
+	book := excelize.NewFile()
+	if err := book.SetCellValue("Sheet1", "A1", "OnlyOffice Elasticsearch content fixture "+contentToken); err != nil {
+		t.Fatalf("SetCellValue: %v", err)
+	}
+	if err := book.SaveAs(localPath); err != nil {
+		t.Fatalf("SaveAs: %v", err)
+	}
+
+	entry, err := c.UploadProjectFile(ctx, pid, localPath)
+	if err != nil {
+		t.Fatalf("UploadProjectFile: %v", err)
+	}
+	fileID := strconv.Itoa(int(FileEntryNumericID(entry)))
+	if fileID == "0" {
+		t.Fatalf("upload returned no file id: %+v", entry)
+	}
+
+	es, err := NewESSearcher(ESConfig{
+		URL:    esURL,
+		Index:  os.Getenv("ONLYOFFICE_ES_INDEX"),
+		Tenant: os.Getenv("ONLYOFFICE_TENANT"),
+	})
+	if err != nil {
+		t.Fatalf("NewESSearcher: %v", err)
+	}
+
+	// Indexing is asynchronous on the server; poll until the file shows up.
+	// The server's title analyzer splits on whitespace, so the name query is
+	// the full file name token (including extension), as a user would type it.
+	nameHit := waitForHit(t, ctx, es, SearchQuery{Text: title}, fileID)
+	if nameHit.Title != title {
+		t.Errorf("name hit title = %q, want %q", nameHit.Title, title)
+	}
+	contentHit := waitForHit(t, ctx, es, SearchQuery{Text: contentToken, InContent: true}, fileID)
+	if contentHit.Highlight == "" {
+		t.Error("content hit has no highlight fragment")
+	}
+	if !strings.Contains(contentHit.Title, nameToken) {
+		t.Errorf("content hit title = %q, want the uploaded workbook", contentHit.Title)
+	}
+
+	// The content token is absent from the title, so a name-only search must
+	// not return the file — this proves the content field is really queried.
+	if hits := searchQuiet(t, es, SearchQuery{Text: contentToken}); len(hits) != 0 {
+		t.Errorf("name-only search for content token returned %d hits, want 0", len(hits))
+	}
+}
+
+// waitForHit polls ES until the file with fileID appears and returns that hit.
+func waitForHit(t *testing.T, ctx context.Context, s *ESSearcher, q SearchQuery, fileID string) SearchHit {
+	t.Helper()
+	var lastErr error
+	for {
+		hits, err := s.Search(ctx, q)
+		if err != nil {
+			lastErr = err
+		} else {
+			for _, h := range hits {
+				if h.ID == fileID {
+					return h
+				}
+			}
+		}
+		select {
+		case <-ctx.Done():
+			t.Fatalf("search %q: file %s not indexed in time (last err: %v)", q.Text, fileID, lastErr)
+		case <-time.After(3 * time.Second):
+		}
+	}
+}
+
+func searchQuiet(t *testing.T, s *ESSearcher, q SearchQuery) []SearchHit {
+	t.Helper()
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	hits, err := s.Search(ctx, q)
+	if err != nil {
+		t.Fatalf("Search(%q): %v", q.Text, err)
+	}
+	return hits
+}

file_es_test.go

@@ -0,0 +1,217 @@
+package onlyoffice
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+func TestESSearchRequestNameOnly(t *testing.T) {
+	got := esSearchRequest(SearchQuery{Text: "Rechnung"}, "1")
+	if got.Size != defaultESLimit {
+		t.Errorf("size = %d, want %d", got.Size, defaultESLimit)
+	}
+	if !reflect.DeepEqual(got.Source, []string{"id", "title", "folders"}) {
+		t.Errorf("_source = %v", got.Source)
+	}
+	if len(got.Query.Bool.Must) != 1 || got.Query.Bool.Must[0].MultiMatch == nil {
+		t.Fatalf("must = %+v, want one multi_match", got.Query.Bool.Must)
+	}
+	mm := got.Query.Bool.Must[0].MultiMatch
+	if mm.Query != "Rechnung" {
+		t.Errorf("query = %q", mm.Query)
+	}
+	if !reflect.DeepEqual(mm.Fields, []string{"title^2"}) {
+		t.Errorf("fields = %v, want title only", mm.Fields)
+	}
+	if _, ok := got.Highlight.Fields["document.attachment.content"]; ok {
+		t.Error("content highlight present without InContent")
+	}
+	if _, ok := got.Highlight.Fields["title"]; !ok {
+		t.Error("title highlight missing")
+	}
+	if len(got.Query.Bool.Filter) != 1 || got.Query.Bool.Filter[0].Term["tenantId"] != int64(1) {
+		t.Errorf("tenant filter = %+v, want numeric tenantId=1", got.Query.Bool.Filter)
+	}
+}
+
+func TestESSearchRequestContentFields(t *testing.T) {
+	got := esSearchRequest(SearchQuery{Text: "Mahnung", InContent: true}, "")
+	mm := got.Query.Bool.Must[0].MultiMatch
+	want := []string{"title^2", "document.attachment.content"}
+	if !reflect.DeepEqual(mm.Fields, want) {
+		t.Errorf("fields = %v, want %v", mm.Fields, want)
+	}
+	if _, ok := got.Highlight.Fields["document.attachment.content"]; !ok {
+		t.Error("content highlight missing with InContent")
+	}
+	if len(got.Query.Bool.Filter) != 0 {
+		t.Errorf("filter = %+v, want none without tenant/folder", got.Query.Bool.Filter)
+	}
+}
+
+func TestESSearchRequestFiltersAndLimit(t *testing.T) {
+	got := esSearchRequest(SearchQuery{
+		Text:       "Storchen",
+		FolderID:   "649",
+		Extensions: []string{".PDF", "pdf", "docx"},
+		Limit:      5000,
+	}, "42")
+	if got.Size != maxESLimit {
+		t.Errorf("size = %d, want cap %d", got.Size, maxESLimit)
+	}
+	var tenant, folder, wildcards int
+	for _, f := range got.Query.Bool.Filter {
+		switch {
+		case f.Term != nil && f.Term["tenantId"] != nil:
+			tenant++
+		case f.Nested != nil:
+			folder++
+			if f.Nested.Path != "folders" || f.Nested.Query.Term["folders.folderId"] != "649" {
+				t.Errorf("folder filter = %+v, want nested folders term 649", f.Nested)
+			}
+		case f.Wildcard != nil:
+			wildcards++
+		}
+	}
+	if tenant != 1 || folder != 1 {
+		t.Errorf("term filters tenant=%d folder=%d, want 1 each", tenant, folder)
+	}
+	if wildcards != 2 {
+		t.Errorf("wildcard filters = %d, want deduped PDF+docx", wildcards)
+	}
+}
+
+func TestESSearchRequestSubstringAndsTerms(t *testing.T) {
+	got := esSearchRequest(SearchQuery{Text: "Rechnung 2025", Substring: true, FolderID: "522"}, "")
+	if got.Query.Bool.Must[0].MultiMatch != nil {
+		t.Fatalf("substring must not use multi_match: %+v", got.Query.Bool.Must)
+	}
+	if len(got.Query.Bool.Must) != 2 {
+		t.Fatalf("must = %+v, want two ANDed wildcard terms", got.Query.Bool.Must)
+	}
+	want := []string{"*rechnung*", "*2025*"}
+	for i, m := range got.Query.Bool.Must {
+		if m.Wildcard == nil || m.Wildcard["title"] != want[i] {
+			t.Errorf("must[%d] = %+v, want title wildcard %q", i, m, want[i])
+		}
+	}
+	if len(got.Query.Bool.Filter) != 1 || got.Query.Bool.Filter[0].Nested == nil {
+		t.Errorf("folder filter = %+v, want nested", got.Query.Bool.Filter)
+	}
+}
+
+func TestEscapeWildcard(t *testing.T) {
+	cases := map[string]string{"*rechnung*": "rechnung", "a?b\\c": "abc", "plain": "plain"}
+	for in, want := range cases {
+		if got := escapeWildcard(in); got != want {
+			t.Errorf("escapeWildcard(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestESSearchRequestRejectsEmptyTextAtSearch(t *testing.T) {
+	s, err := NewESSearcher(ESConfig{URL: "http://localhost:9200"})
+	if err != nil {
+		t.Fatalf("NewESSearcher: %v", err)
+	}
+	if _, err := s.Search(t.Context(), SearchQuery{Text: "  "}); err == nil {
+		t.Error("empty query: want error")
+	}
+}
+
+func TestNewESSearcherRequiresURL(t *testing.T) {
+	if _, err := NewESSearcher(ESConfig{}); err == nil {
+		t.Error("empty URL: want error")
+	}
+	s, err := NewESSearcher(ESConfig{URL: "http://es:9200/"})
+	if err != nil {
+		t.Fatalf("NewESSearcher: %v", err)
+	}
+	if s.cfg.Index != defaultESIndex {
+		t.Errorf("index = %q, want %q", s.cfg.Index, defaultESIndex)
+	}
+	if s.cfg.URL != "http://es:9200" {
+		t.Errorf("url = %q, want trimmed", s.cfg.URL)
+	}
+	if s.Name() != "elasticsearch" {
+		t.Errorf("Name() = %q", s.Name())
+	}
+}
+
+func TestNormalizeExtensions(t *testing.T) {
+	got := normalizeExtensions([]string{" .PDF ", "pdf", "", "xlsx"})
+	want := []string{"pdf", "xlsx"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("normalizeExtensions = %v, want %v", got, want)
+	}
+}
+
+func TestParseESSearchResponse(t *testing.T) {
+	raw := []byte(`{
+	  "took": 12,
+	  "hits": {
+	    "total": {"value": 2, "relation": "eq"},
+	    "hits": [
+	      {
+	        "_id": "2395",
+	        "_score": 7.31,
+	        "_source": {"id": 2395, "title": "Rechnung-4711.pdf",
+	          "folders": [{"folderId": "438", "id": 0}, {"folderId": "11", "id": 0}]},
+	        "highlight": {
+	          "title": ["<em>Rechnung</em>-4711.pdf"],
+	          "document.attachment.content": ["… Zahlung der <em>Rechnung</em> …"]
+	        }
+	      },
+	      {
+	        "_id": "2318",
+	        "_score": 6.02,
+	        "_source": {"id": 2318, "title": "Mahnung.pdf", "folders": []},
+	        "highlight": {"title": ["<em>Mahnung</em>.pdf"]}
+	      }
+	    ]
+	  }
+	}`)
+	hits, err := parseESSearchResponse(raw)
+	if err != nil {
+		t.Fatalf("parseESSearchResponse: %v", err)
+	}
+	if len(hits) != 2 {
+		t.Fatalf("hits = %d, want 2", len(hits))
+	}
+	h0 := hits[0]
+	if h0.ID != "2395" || h0.Title != "Rechnung-4711.pdf" || h0.Kind != File {
+		t.Errorf("hit0 entry = %+v", h0.Entry)
+	}
+	// folders is root → leaf; the immediate parent is the last entry.
+	if h0.ParentID != "11" || !reflect.DeepEqual(h0.Path, []string{"438", "11"}) {
+		t.Errorf("hit0 path = %v parent = %q, want parent 11", h0.Path, h0.ParentID)
+	}
+	if h0.Score != 7.31 {
+		t.Errorf("hit0 score = %v", h0.Score)
+	}
+	if h0.Highlight != "… Zahlung der Rechnung …" {
+		t.Errorf("hit0 highlight = %q, want content fragment", h0.Highlight)
+	}
+	if hits[1].Highlight != "Mahnung.pdf" {
+		t.Errorf("hit1 highlight = %q, want title without tags", hits[1].Highlight)
+	}
+	if hits[1].ParentID != "" || len(hits[1].Path) != 0 {
+		t.Errorf("hit1 path = %v", hits[1].Path)
+	}
+}
+
+func TestESSearchRequestJSONShape(t *testing.T) {
+	got := esSearchRequest(SearchQuery{Text: "Rechnung", InContent: true}, "1")
+	b, err := json.Marshal(got)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	var back map[string]any
+	if err := json.Unmarshal(b, &back); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if _, ok := back["query"].(map[string]any)["bool"]; !ok {
+		t.Errorf("query.bool missing: %s", b)
+	}
+}

file_es_text.go

@@ -0,0 +1,336 @@
+package onlyoffice
+
+// Own full-text index (epic #34, F6 #42).
+//
+// The OnlyOffice Elasticsearch index (files_file) only holds extracted content
+// for Office formats. FileUtility.CanIndex gates extraction by the server
+// setting files.index.formats, whose default is ".pptx|.xlsx|.docx", so PDFs
+// are indexed by name only. Instead of patching the server (risky: lost on
+// upgrade, forces a full reindex) this file implements a second, independent
+// index (default oo_docs_text) that our own pipeline fills from
+// internal/docpipe (pdftotext + OCR). The OnlyOffice index is never touched.
+//
+// See docs/elasticsearch.md for the decision and the trade-offs.
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+)
+
+const defaultESTextIndex = "oo_docs_text"
+
+// ESTextConfig configures the own full-text index.
+type ESTextConfig struct {
+	URL    string // scheme://host:port of the ES HTTP endpoint
+	Index  string // index name, default oo_docs_text
+	Tenant string // reserved for future multi-tenant data; unused for now
+}
+
+// ESTextConfigFromEnv reads ONLYOFFICE_ES_URL and ONLYOFFICE_ES_TEXT_INDEX
+// (default oo_docs_text). The library never loads dotfiles — the CLI does that.
+func ESTextConfigFromEnv() ESTextConfig {
+	return ESTextConfig{
+		URL:    strings.TrimRight(strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL")), "/"),
+		Index:  firstNonEmpty(os.Getenv("ONLYOFFICE_ES_TEXT_INDEX"), defaultESTextIndex),
+		Tenant: strings.TrimSpace(os.Getenv("ONLYOFFICE_TENANT")),
+	}
+}
+
+// TextDoc is one document in the own full-text index. It is keyed by the
+// OnlyOffice file id so hits map straight back to Documents entries.
+type TextDoc struct {
+	ID       string `json:"id"`
+	Title    string `json:"title"`
+	FolderID string `json:"folder,omitempty"`
+	Ext      string `json:"ext,omitempty"`
+	Content  string `json:"content"`
+}
+
+// TextIndex is the storage/search surface for locally extracted document text.
+// It complements Searcher: ESSearcher reads OnlyOffice's index, ESTextIndex
+// reads ours.
+type TextIndex interface {
+	Put(ctx context.Context, docs []TextDoc) error
+	Delete(ctx context.Context, ids []string) error
+	Search(ctx context.Context, q SearchQuery) ([]SearchHit, error)
+	Name() string
+}
+
+// ESTextIndex is a TextIndex (and Searcher) over a dedicated Elasticsearch
+// index filled by TextIndexer.
+type ESTextIndex struct {
+	cfg  ESTextConfig
+	http *http.Client
+}
+
+var (
+	_ TextIndex = (*ESTextIndex)(nil)
+	_ Searcher  = (*ESTextIndex)(nil)
+)
+
+// NewESTextIndex returns a searcher/writer for the own full-text index. The URL
+// is required; an empty index falls back to oo_docs_text.
+func NewESTextIndex(cfg ESTextConfig) (*ESTextIndex, error) {
+	if strings.TrimSpace(cfg.URL) == "" {
+		return nil, fmt.Errorf("onlyoffice: elasticsearch URL is empty (set ONLYOFFICE_ES_URL)")
+	}
+	cfg.URL = strings.TrimRight(cfg.URL, "/")
+	if cfg.Index == "" {
+		cfg.Index = defaultESTextIndex
+	}
+	return &ESTextIndex{cfg: cfg, http: &http.Client{Timeout: 120 * time.Second}}, nil
+}
+
+// Name implements Searcher and TextIndex.
+func (x *ESTextIndex) Name() string { return "es-text" }
+
+// Index returns the configured index name.
+func (x *ESTextIndex) Index() string { return x.cfg.Index }
+
+// esTextMapping pins explicit types: content must stay a plain text field (no
+// keyword subfield) and folder/ext stay exact keywords for filters.
+const esTextMapping = `{
+  "mappings": {
+    "properties": {
+      "id":      {"type": "keyword"},
+      "title":   {"type": "text", "fields": {"keyword": {"type": "keyword", "ignore_above": 512}}},
+      "folder":  {"type": "keyword"},
+      "ext":     {"type": "keyword"},
+      "content": {"type": "text"}
+    }
+  }
+}`
+
+// Ensure creates the index with the explicit mapping. A missing index is
+// created; an already existing one is left untouched.
+func (x *ESTextIndex) Ensure(ctx context.Context) error {
+	status, raw, err := x.do(ctx, http.MethodPut, "/"+x.cfg.Index, []byte(esTextMapping), "application/json")
+	if err != nil {
+		return err
+	}
+	if status == http.StatusOK {
+		return nil
+	}
+	if status == http.StatusBadRequest && bytes.Contains(raw, []byte("resource_already_exists_exception")) {
+		return nil
+	}
+	return fmt.Errorf("onlyoffice: create text index %s: %d %s", x.cfg.Index, status, truncate(string(raw), 300))
+}
+
+// Put upserts documents via the bulk API and refreshes so they are immediately
+// searchable.
+func (x *ESTextIndex) Put(ctx context.Context, docs []TextDoc) error {
+	if len(docs) == 0 {
+		return nil
+	}
+	status, raw, err := x.do(ctx, http.MethodPost, "/"+x.cfg.Index+"/_bulk?refresh=true", esTextBulkBody(docs), "application/x-ndjson")
+	if err != nil {
+		return err
+	}
+	if status >= 400 {
+		return fmt.Errorf("onlyoffice: bulk index %s: %d %s", x.cfg.Index, status, truncate(string(raw), 400))
+	}
+	var res esBulkResponse
+	if err := json.Unmarshal(raw, &res); err != nil {
+		return fmt.Errorf("onlyoffice: decode bulk response: %w", err)
+	}
+	if !res.Errors {
+		return nil
+	}
+	return fmt.Errorf("onlyoffice: bulk index %s: %s", x.cfg.Index, res.firstError())
+}
+
+// Delete removes documents by OnlyOffice file id. A missing index means there
+// is nothing to delete.
+func (x *ESTextIndex) Delete(ctx context.Context, ids []string) error {
+	if len(ids) == 0 {
+		return nil
+	}
+	body, err := json.Marshal(map[string]any{"query": map[string]any{"terms": map[string]any{"id": ids}}})
+	if err != nil {
+		return err
+	}
+	status, raw, err := x.do(ctx, http.MethodPost, "/"+x.cfg.Index+"/_delete_by_query?refresh=true", body, "application/json")
+	if err != nil {
+		return err
+	}
+	if status == http.StatusNotFound {
+		return nil
+	}
+	if status >= 400 {
+		return fmt.Errorf("onlyoffice: delete from %s: %d %s", x.cfg.Index, status, truncate(string(raw), 400))
+	}
+	return nil
+}
+
+// Search runs a multi_match over title (boosted) and content, with optional
+// folder and extension filters. A missing index yields no hits, not an error.
+func (x *ESTextIndex) Search(ctx context.Context, q SearchQuery) ([]SearchHit, error) {
+	q.Text = strings.TrimSpace(q.Text)
+	if q.Text == "" {
+		return nil, fmt.Errorf("onlyoffice: empty search query")
+	}
+	body, err := json.Marshal(esTextSearchRequest(q))
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: build elasticsearch query: %w", err)
+	}
+	status, raw, err := x.do(ctx, http.MethodPost, "/"+x.cfg.Index+"/_search", body, "application/json")
+	if err != nil {
+		return nil, err
+	}
+	if status == http.StatusNotFound {
+		return nil, nil
+	}
+	if status >= 400 {
+		return nil, fmt.Errorf("onlyoffice: search %s: %d %s", x.cfg.Index, status, truncate(string(raw), 400))
+	}
+	return parseESTextResponse(raw)
+}
+
+// do sends one request and returns the status and body (bounded). The caller
+// decides which statuses are errors.
+func (x *ESTextIndex) do(ctx context.Context, method, path string, body []byte, contentType string) (int, []byte, error) {
+	var r io.Reader
+	if body != nil {
+		r = bytes.NewReader(body)
+	}
+	req, err := http.NewRequestWithContext(ctx, method, x.cfg.URL+path, r)
+	if err != nil {
+		return 0, nil, err
+	}
+	req.Header.Set("Accept", "application/json")
+	if contentType != "" {
+		req.Header.Set("Content-Type", contentType)
+	}
+	resp, err := x.http.Do(req)
+	if err != nil {
+		return 0, nil, fmt.Errorf("onlyoffice: elasticsearch %s: %w", method, err)
+	}
+	defer resp.Body.Close()
+	raw, err := io.ReadAll(io.LimitReader(resp.Body, maxESResponseSize))
+	if err != nil {
+		return resp.StatusCode, nil, err
+	}
+	return resp.StatusCode, raw, nil
+}
+
+// esTextBulkBody renders the NDJSON bulk payload. Pure, so it is unit-tested.
+func esTextBulkBody(docs []TextDoc) []byte {
+	var b bytes.Buffer
+	enc := json.NewEncoder(&b)
+	enc.SetEscapeHTML(false)
+	for _, d := range docs {
+		_ = enc.Encode(map[string]any{"index": map[string]any{"_id": d.ID}})
+		_ = enc.Encode(d)
+	}
+	return b.Bytes()
+}
+
+// esTextSearchRequest builds the own-index query. Pure, so it is unit-tested.
+func esTextSearchRequest(q SearchQuery) esRequest {
+	limit := q.Limit
+	if limit <= 0 {
+		limit = defaultESLimit
+	}
+	if limit > maxESLimit {
+		limit = maxESLimit
+	}
+	fields := []string{"title^2", "content"}
+	must := []esClause{{MultiMatch: &esMultiMatch{Query: q.Text, Fields: fields}}}
+
+	var filter []esClause
+	if f := strings.TrimSpace(q.FolderID); f != "" {
+		filter = append(filter, esClause{Term: map[string]any{"folder": f}})
+	}
+	if exts := normalizeExtensions(q.Extensions); len(exts) > 0 {
+		filter = append(filter, esClause{Terms: map[string]any{"ext": exts}})
+	}
+
+	return esRequest{
+		Size:      limit,
+		Source:    []string{"id", "title", "folder", "ext"},
+		Query:     esQuery{Bool: esBool{Must: must, Filter: filter}},
+		Highlight: esHighlight{PreTags: []string{"<em>"}, PostTags: []string{"</em>"}, Fields: map[string]struct{}{"title": {}, "content": {}}},
+	}
+}
+
+// esBulkResponse is the subset of an ES bulk response we consume.
+type esBulkResponse struct {
+	Errors bool `json:"errors"`
+	Items  []map[string]struct {
+		ID     string `json:"_id"`
+		Status int    `json:"status"`
+		Error  *struct {
+			Type   string `json:"type"`
+			Reason string `json:"reason"`
+		} `json:"error"`
+	} `json:"items"`
+}
+
+// firstError returns a compact description of the first failed bulk item.
+func (r esBulkResponse) firstError() string {
+	for _, item := range r.Items {
+		for op, res := range item {
+			if res.Error != nil {
+				return fmt.Sprintf("%s %s: %s %s", op, res.ID, res.Error.Type, res.Error.Reason)
+			}
+		}
+	}
+	return "unknown bulk error"
+}
+
+// esTextResponse is the subset of an own-index search response we consume.
+type esTextResponse struct {
+	Hits struct {
+		Total struct {
+			Value int `json:"value"`
+		} `json:"total"`
+		Hits []struct {
+			ID     string              `json:"_id"`
+			Score  float64             `json:"_score"`
+			Source TextDoc             `json:"_source"`
+			HL     map[string][]string `json:"highlight"`
+		} `json:"hits"`
+	} `json:"hits"`
+}
+
+// parseESTextResponse converts an own-index search response into SearchHit
+// values. Pure, so it is unit-tested.
+func parseESTextResponse(raw []byte) ([]SearchHit, error) {
+	var r esTextResponse
+	if err := json.Unmarshal(raw, &r); err != nil {
+		return nil, fmt.Errorf("onlyoffice: decode elasticsearch response: %w", err)
+	}
+	hits := make([]SearchHit, 0, len(r.Hits.Hits))
+	for _, h := range r.Hits.Hits {
+		id := h.Source.ID
+		if id == "" {
+			id = h.ID
+		}
+		parent := h.Source.FolderID
+		var path []string
+		if parent != "" {
+			path = []string{parent}
+		}
+		hits = append(hits, SearchHit{
+			Entry: Entry{
+				ID:       id,
+				ParentID: parent,
+				Title:    h.Source.Title,
+				Kind:     File,
+				Provider: "es-text",
+			},
+			Score:     h.Score,
+			Highlight: esHighlightText(h.HL),
+			Path:      path,
+		})
+	}
+	return hits, nil
+}

file_es_text_integration_test.go

@@ -0,0 +1,158 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"context"
+	"net/http"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/eslider/go-onlyoffice/internal/docpipe"
+)
+
+// TestIntegrationESTextIndex verifies the own full-text index end to end
+// against a live Elasticsearch: create the index with its mapping, index a
+// document, find it by content (and reject it via a folder filter and after
+// deletion), then drop the throwaway index.
+//
+// Requires ONLYOFFICE_ES_URL (a reachable ES endpoint — in the current setup a
+// tunnel to the ES inside the OnlyOffice VM, see docs/elasticsearch.md). It
+// does not need OnlyOffice credentials because no file is downloaded: the
+// TextIndexer write path is covered by unit tests with a fake extractor.
+func TestIntegrationESTextIndex(t *testing.T) {
+	esURL := strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL"))
+	if esURL == "" {
+		t.Skip("ONLYOFFICE_ES_URL not set — skipping Elasticsearch integration test")
+	}
+	stamp := time.Now().UTC().Format("20060102150405")
+	idx, err := NewESTextIndex(ESTextConfig{URL: esURL, Index: "oo_docs_text_it_" + stamp})
+	if err != nil {
+		t.Fatalf("NewESTextIndex: %v", err)
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+
+	t.Cleanup(func() {
+		cleanupCtx, done := context.WithTimeout(context.Background(), 30*time.Second)
+		defer done()
+		_, _, _ = idx.do(cleanupCtx, http.MethodDelete, "/"+idx.Index(), nil, "")
+	})
+
+	if err := idx.Ensure(ctx); err != nil {
+		t.Fatalf("Ensure: %v", err)
+	}
+	// Ensure is idempotent.
+	if err := idx.Ensure(ctx); err != nil {
+		t.Fatalf("Ensure (second): %v", err)
+	}
+
+	token := "gotes" + stamp
+	doc := TextDoc{
+		ID:       "3578",
+		Title:    "2026-07-28-S1021-Edelweiss-rechnung.pdf",
+		FolderID: "634",
+		Ext:      "pdf",
+		Content:  "Begleitzettel SGB XI — Rechnung " + token,
+	}
+	if err := idx.Put(ctx, []TextDoc{doc}); err != nil {
+		t.Fatalf("Put: %v", err)
+	}
+
+	hits, err := idx.Search(ctx, SearchQuery{Text: token})
+	if err != nil {
+		t.Fatalf("Search: %v", err)
+	}
+	if len(hits) != 1 || hits[0].ID != "3578" {
+		t.Fatalf("content search hits = %+v, want doc 3578", hits)
+	}
+	if !strings.Contains(hits[0].Highlight, token) {
+		t.Errorf("highlight = %q, want token", hits[0].Highlight)
+	}
+
+	if hits, err := idx.Search(ctx, SearchQuery{Text: token, FolderID: "999"}); err != nil {
+		t.Fatalf("Search with folder filter: %v", err)
+	} else if len(hits) != 0 {
+		t.Errorf("folder filter returned %d hits, want 0", len(hits))
+	}
+	if hits, err := idx.Search(ctx, SearchQuery{Text: token, Extensions: []string{"docx"}}); err != nil {
+		t.Fatalf("Search with ext filter: %v", err)
+	} else if len(hits) != 0 {
+		t.Errorf("ext filter returned %d hits, want 0", len(hits))
+	}
+
+	if err := idx.Delete(ctx, []string{"3578"}); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if hits, err := idx.Search(ctx, SearchQuery{Text: token}); err != nil {
+		t.Fatalf("Search after delete: %v", err)
+	} else if len(hits) != 0 {
+		t.Errorf("after delete search returned %d hits, want 0", len(hits))
+	}
+}
+
+// TestIntegrationESTextIndexPDFAttachment indexes testdata/pdf-with-attachment.pdf
+// through the real pipeline (TextIndexer + docpipe: pdfdetach + pdftotext) and
+// verifies that text living only in the embedded attachment is searchable.
+//
+// Requires ONLYOFFICE_ES_URL plus poppler (pdfdetach/pdftotext). No OnlyOffice
+// credentials are needed: a fixture FileStore serves the PDF bytes.
+func TestIntegrationESTextIndexPDFAttachment(t *testing.T) {
+	esURL := strings.TrimSpace(os.Getenv("ONLYOFFICE_ES_URL"))
+	if esURL == "" {
+		t.Skip("ONLYOFFICE_ES_URL not set — skipping Elasticsearch integration test")
+	}
+	if docpipe.LookPath().PDFDetach == "" {
+		t.Skip("pdfdetach not on PATH — skipping PDF attachment integration test")
+	}
+	pdf, err := os.ReadFile("testdata/pdf-with-attachment.pdf")
+	if err != nil {
+		t.Fatalf("read fixture: %v", err)
+	}
+
+	stamp := time.Now().UTC().Format("20060102150405")
+	idx, err := NewESTextIndex(ESTextConfig{URL: esURL, Index: "oo_docs_text_it_att_" + stamp})
+	if err != nil {
+		t.Fatalf("NewESTextIndex: %v", err)
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
+	defer cancel()
+	t.Cleanup(func() {
+		cleanupCtx, done := context.WithTimeout(context.Background(), 30*time.Second)
+		defer done()
+		_, _, _ = idx.do(cleanupCtx, http.MethodDelete, "/"+idx.Index(), nil, "")
+	})
+	if err := idx.Ensure(ctx); err != nil {
+		t.Fatalf("Ensure: %v", err)
+	}
+
+	store := &textFakeStore{files: map[string][]byte{"9001": pdf}}
+	ix := NewTextIndexer(store, idx)
+	res, err := ix.IndexEntries(ctx, []Entry{{ID: "9001", Title: "scan.pdf", ParentID: "777", Kind: File}}, IndexOptions{MinChars: 1})
+	if err != nil {
+		t.Fatalf("IndexEntries: %v", err)
+	}
+	if res.Indexed != 1 || res.Failed != 0 {
+		t.Fatalf("result = %+v, want one indexed doc", res)
+	}
+
+	// Token appears only inside the embedded goo-note.txt attachment.
+	hits, err := idx.Search(ctx, SearchQuery{Text: "gooattachmenttoken"})
+	if err != nil {
+		t.Fatalf("Search attachment token: %v", err)
+	}
+	if len(hits) != 1 || hits[0].ID != "9001" {
+		t.Fatalf("attachment-token hits = %+v, want doc 9001", hits)
+	}
+	if !strings.Contains(hits[0].Highlight, "gooattachmenttoken") {
+		t.Errorf("highlight = %q, want attachment token", hits[0].Highlight)
+	}
+	// Body text is indexed as before.
+	if hits, err := idx.Search(ctx, SearchQuery{Text: "goobodytoken"}); err != nil {
+		t.Fatalf("Search body token: %v", err)
+	} else if len(hits) != 1 {
+		t.Errorf("body-token hits = %d, want 1", len(hits))
+	}
+}

file_es_text_test.go

@@ -0,0 +1,275 @@
+package onlyoffice
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestESTextSearchRequestShape(t *testing.T) {
+	got := esTextSearchRequest(SearchQuery{
+		Text:       "S1021",
+		FolderID:   "634",
+		Extensions: []string{".PDF", "pdf"},
+		Limit:      5,
+	})
+	if got.Size != 5 {
+		t.Errorf("size = %d, want 5", got.Size)
+	}
+	mm := got.Query.Bool.Must[0].MultiMatch
+	if mm == nil || !reflect.DeepEqual(mm.Fields, []string{"title^2", "content"}) {
+		t.Fatalf("multi_match = %+v, want title^2 + content", mm)
+	}
+	if _, ok := got.Highlight.Fields["content"]; !ok {
+		t.Error("content highlight missing")
+	}
+	if _, ok := got.Highlight.Fields["title"]; !ok {
+		t.Error("title highlight missing")
+	}
+	var folder, exts int
+	for _, f := range got.Query.Bool.Filter {
+		switch {
+		case f.Term != nil && f.Term["folder"] != nil:
+			folder++
+			if f.Term["folder"] != "634" {
+				t.Errorf("folder term = %+v", f.Term)
+			}
+		case f.Terms != nil:
+			exts++
+			if !reflect.DeepEqual(f.Terms["ext"], []string{"pdf"}) {
+				t.Errorf("ext terms = %+v, want deduped pdf", f.Terms)
+			}
+		}
+	}
+	if folder != 1 || exts != 1 {
+		t.Errorf("filters folder=%d exts=%d, want 1 each", folder, exts)
+	}
+}
+
+func TestESTextBulkBody(t *testing.T) {
+	body := esTextBulkBody([]TextDoc{
+		{ID: "3578", Title: "S1021.pdf", FolderID: "634", Ext: "pdf", Content: "Begleitzettel <S1021> & mehr"},
+		{ID: "3579", Title: "S1023.pdf", Ext: "pdf", Content: "x"},
+	})
+	lines := strings.Split(strings.TrimRight(string(body), "\n"), "\n")
+	if len(lines) != 4 {
+		t.Fatalf("bulk body has %d lines, want 4:\n%s", len(lines), body)
+	}
+	if !strings.Contains(lines[0], `"index"`) || !strings.Contains(lines[0], `"_id":"3578"`) {
+		t.Errorf("action line = %q", lines[0])
+	}
+	if !strings.Contains(lines[1], `"content":"Begleitzettel <S1021> & mehr"`) {
+		t.Errorf("source line should keep HTML unescaped, got %q", lines[1])
+	}
+	if !strings.Contains(lines[2], `"_id":"3579"`) {
+		t.Errorf("second action line = %q", lines[2])
+	}
+}
+
+func TestParseESTextResponse(t *testing.T) {
+	raw := []byte(`{
+	  "hits": {
+	    "total": {"value": 1, "relation": "eq"},
+	    "hits": [
+	      {
+	        "_id": "3578",
+	        "_score": 3.21,
+	        "_source": {"id": "3578", "title": "2026-07-28-S1021-Edelweiss-rechnung.pdf", "folder": "634", "ext": "pdf"},
+	        "highlight": {"content": ["Begleitzettel … <em>S1021</em> …"]}
+	      }
+	    ]
+	  }
+	}`)
+	hits, err := parseESTextResponse(raw)
+	if err != nil {
+		t.Fatalf("parseESTextResponse: %v", err)
+	}
+	if len(hits) != 1 {
+		t.Fatalf("hits = %d, want 1", len(hits))
+	}
+	h := hits[0]
+	if h.ID != "3578" || h.Title != "2026-07-28-S1021-Edelweiss-rechnung.pdf" || h.Kind != File {
+		t.Errorf("entry = %+v", h.Entry)
+	}
+	if h.ParentID != "634" || !reflect.DeepEqual(h.Path, []string{"634"}) {
+		t.Errorf("path = %v parent = %q", h.Path, h.ParentID)
+	}
+	if h.Provider != "es-text" {
+		t.Errorf("provider = %q", h.Provider)
+	}
+	if h.Highlight != "Begleitzettel … S1021 …" {
+		t.Errorf("highlight = %q, want tags stripped", h.Highlight)
+	}
+}
+
+func TestNewESTextIndexDefaults(t *testing.T) {
+	if _, err := NewESTextIndex(ESTextConfig{}); err == nil {
+		t.Error("empty URL: want error")
+	}
+	x, err := NewESTextIndex(ESTextConfig{URL: "http://es:9200/"})
+	if err != nil {
+		t.Fatalf("NewESTextIndex: %v", err)
+	}
+	if x.Index() != defaultESTextIndex {
+		t.Errorf("index = %q, want %q", x.Index(), defaultESTextIndex)
+	}
+	if x.cfg.URL != "http://es:9200" {
+		t.Errorf("url = %q, want trimmed", x.cfg.URL)
+	}
+	if x.Name() != "es-text" {
+		t.Errorf("Name() = %q", x.Name())
+	}
+}
+
+func TestESTextConfigFromEnvIndexDefault(t *testing.T) {
+	t.Setenv("ONLYOFFICE_ES_URL", "http://es:9200/")
+	t.Setenv("ONLYOFFICE_ES_TEXT_INDEX", "")
+	cfg := ESTextConfigFromEnv()
+	if cfg.Index != defaultESTextIndex {
+		t.Errorf("index = %q, want %q", cfg.Index, defaultESTextIndex)
+	}
+}
+
+func TestTextIndexerIndexEntries(t *testing.T) {
+	store := &textFakeStore{
+		files: map[string][]byte{"1": []byte("PDFBYTES")},
+	}
+	idx := &textFakeIndex{}
+	ix := NewTextIndexer(store, idx)
+	ix.Extractor = textFakeExtractor{prefix: "TEXT "}
+
+	res, err := ix.IndexEntries(context.Background(), []Entry{
+		{ID: "1", Title: "Rechnung.PDF", ParentID: "649", Kind: File},
+		{ID: "2", Title: "Tabelle.xlsx", ParentID: "649", Kind: File},
+		{ID: "3", Title: "Unterordner", Kind: Folder},
+	}, IndexOptions{})
+	if err != nil {
+		t.Fatalf("IndexEntries: %v", err)
+	}
+	if res.Scanned != 3 || res.Indexed != 1 || res.Skipped != 2 || res.Failed != 0 {
+		t.Errorf("result = %+v, want scanned=3 indexed=1 skipped=2 failed=0", res)
+	}
+	if len(idx.docs) != 1 {
+		t.Fatalf("indexed docs = %d, want 1", len(idx.docs))
+	}
+	got := idx.docs[0]
+	want := TextDoc{ID: "1", Title: "Rechnung.PDF", FolderID: "649", Ext: "pdf", Content: "TEXT PDFBYTES"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("doc = %+v, want %+v", got, want)
+	}
+}
+
+func TestTextIndexerRecordsExtractionFailure(t *testing.T) {
+	store := &textFakeStore{files: map[string][]byte{"1": []byte("x")}}
+	idx := &textFakeIndex{}
+	ix := NewTextIndexer(store, idx)
+	ix.Extractor = textFailingExtractor{}
+
+	res, err := ix.IndexEntries(context.Background(), []Entry{{ID: "1", Title: "a.pdf", Kind: File}}, IndexOptions{})
+	if err != nil {
+		t.Fatalf("IndexEntries: %v", err)
+	}
+	if res.Indexed != 0 || res.Failed != 1 || len(res.Errors) != 1 {
+		t.Errorf("result = %+v, want one failure recorded", res)
+	}
+}
+
+func TestTextIndexerPlanFolder(t *testing.T) {
+	store := &textFakeStore{dirs: map[string][]Entry{
+		"root": {
+			{ID: "10", Title: "a.pdf", Kind: File},
+			{ID: "11", Title: "sub", Kind: Folder},
+		},
+		"11": {
+			{ID: "12", Title: "b.PDF", Kind: File},
+			{ID: "13", Title: "c.xlsx", Kind: File},
+		},
+	}}
+	ix := NewTextIndexer(store, &textFakeIndex{})
+
+	flat, err := ix.PlanFolder(context.Background(), "root", IndexOptions{})
+	if err != nil {
+		t.Fatalf("PlanFolder: %v", err)
+	}
+	if len(flat) != 1 || flat[0].ID != "10" {
+		t.Errorf("flat plan = %+v, want only a.pdf", flat)
+	}
+	deep, err := ix.PlanFolder(context.Background(), "root", IndexOptions{Recursive: true, Limit: 10})
+	if err != nil {
+		t.Fatalf("PlanFolder recursive: %v", err)
+	}
+	if len(deep) != 2 {
+		t.Errorf("recursive plan = %d entries, want 2", len(deep))
+	}
+}
+
+// --- fakes -----------------------------------------------------------------
+
+type textFakeStore struct {
+	dirs  map[string][]Entry
+	files map[string][]byte
+	stat  map[string]Entry
+}
+
+func (f *textFakeStore) Name() string { return "fake" }
+
+func (f *textFakeStore) List(_ context.Context, parentID string) ([]Entry, error) {
+	return f.dirs[parentID], nil
+}
+
+func (f *textFakeStore) Stat(_ context.Context, id string) (Entry, error) {
+	if e, ok := f.stat[id]; ok {
+		return e, nil
+	}
+	return Entry{}, fmt.Errorf("not found: %s", id)
+}
+
+func (f *textFakeStore) Download(_ context.Context, id string, w io.Writer) (int64, error) {
+	b, ok := f.files[id]
+	if !ok {
+		return 0, fmt.Errorf("no bytes for %s", id)
+	}
+	n, err := w.Write(b)
+	return int64(n), err
+}
+
+func (f *textFakeStore) CreateFolder(context.Context, string, string) (Entry, error) {
+	return Entry{}, nil
+}
+func (f *textFakeStore) Upload(context.Context, string, string, io.Reader) (Entry, error) {
+	return Entry{}, nil
+}
+func (f *textFakeStore) Move(context.Context, []string, string) error { return nil }
+func (f *textFakeStore) Copy(context.Context, []string, string) error { return nil }
+func (f *textFakeStore) Rename(context.Context, string, string) error { return nil }
+func (f *textFakeStore) Delete(context.Context, []string) error       { return nil }
+
+type textFakeIndex struct{ docs []TextDoc }
+
+func (f *textFakeIndex) Put(_ context.Context, docs []TextDoc) error {
+	f.docs = append(f.docs, docs...)
+	return nil
+}
+func (f *textFakeIndex) Delete(context.Context, []string) error                   { return nil }
+func (f *textFakeIndex) Search(context.Context, SearchQuery) ([]SearchHit, error) { return nil, nil }
+func (f *textFakeIndex) Name() string                                             { return "fake" }
+
+type textFakeExtractor struct{ prefix string }
+
+func (f textFakeExtractor) Extract(path, _, _ string, _ int) (string, error) {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return "", err
+	}
+	return f.prefix + string(b), nil
+}
+
+type textFailingExtractor struct{}
+
+func (textFailingExtractor) Extract(string, string, string, int) (string, error) {
+	return "", fmt.Errorf("boom")
+}

file_facade.go

@@ -0,0 +1,249 @@
+package onlyoffice
+
+// Single file client (epic #34, F4 #38). FileClient composes the registered
+// FileStore and Searcher backends and picks one per operation: REST/DAV for
+// writes, PostgreSQL (when registered) for fast reads, Elasticsearch for name
+// and content search. Client.Files returns the facade; it also implements
+// FileStore, so existing callers keep compiling.
+
+import (
+	"context"
+	"errors"
+	"io"
+	"strings"
+)
+
+// ProviderES is the composed Elasticsearch searcher. The SQL store owns
+// ProviderPG/ProviderMySQL (file_pg.go); the facade references ProviderPG in
+// readOrder.
+const ProviderES = "elasticsearch"
+
+var (
+	errNoReadBackend  = errors.New("onlyoffice: no file backend registered for reads")
+	errNoWriteBackend = errors.New("onlyoffice: no file backend registered for writes")
+	errNoSearcher     = errors.New("onlyoffice: no search backend registered (set ONLYOFFICE_ES_URL)")
+)
+
+// FileClient is the single entry point for file operations. It holds the
+// registered backends and the order in which each operation tries them.
+type FileClient struct {
+	stores    map[string]FileStore
+	searchers map[string]Searcher
+
+	readOrder   []string
+	writeOrder  []string
+	searchOrder []string
+}
+
+// newFileClient builds the facade over the built-in REST and DAV stores. The
+// Elasticsearch searcher is registered when ONLYOFFICE_ES_URL is set; the
+// missing-credential case is left to Search so read-only commands still work.
+func (c *Client) newFileClient() *FileClient {
+	f := &FileClient{
+		stores: map[string]FileStore{
+			ProviderREST: &restStore{c: c},
+			ProviderDAV:  &davStore{c: c},
+		},
+		searchers:   map[string]Searcher{},
+		readOrder:   []string{ProviderPG, ProviderMySQL, ProviderREST, ProviderDAV},
+		writeOrder:  []string{ProviderREST, ProviderDAV},
+		searchOrder: []string{ProviderES},
+	}
+	if cfg := ESConfigFromEnv(); cfg.URL != "" {
+		if es, err := NewESSearcher(cfg); err == nil {
+			f.searchers[ProviderES] = es
+		}
+	}
+	return f
+}
+
+// RegisterStore adds or replaces a named backend (for example the PostgreSQL
+// read store). The name is matched case-insensitively.
+func (f *FileClient) RegisterStore(name string, s FileStore) {
+	if f == nil || s == nil {
+		return
+	}
+	name = normalizeProvider(name)
+	if name == "" {
+		return
+	}
+	if f.stores == nil {
+		f.stores = map[string]FileStore{}
+	}
+	f.stores[name] = s
+}
+
+// RegisterSearcher adds or replaces a named search backend.
+func (f *FileClient) RegisterSearcher(name string, s Searcher) {
+	if f == nil || s == nil {
+		return
+	}
+	name = normalizeProvider(name)
+	if name == "" {
+		return
+	}
+	if f.searchers == nil {
+		f.searchers = map[string]Searcher{}
+	}
+	f.searchers[name] = s
+}
+
+// Read returns the preferred backend for reads: the SQL store (PostgreSQL or
+// MySQL) when registered, then REST, then WebDAV.
+func (f *FileClient) Read() FileStore { return f.firstStore(f.readOrder) }
+
+// Write returns the preferred backend for writes: REST, then WebDAV.
+func (f *FileClient) Write() FileStore { return f.firstStore(f.writeOrder) }
+
+// Search returns the preferred name/content searcher (Elasticsearch), or an
+// error when no search backend is configured.
+func (f *FileClient) Search() (Searcher, error) {
+	if f == nil {
+		return nil, errNoSearcher
+	}
+	for _, name := range f.searchOrder {
+		if s := f.searchers[normalizeProvider(name)]; s != nil {
+			return s, nil
+		}
+	}
+	return nil, errNoSearcher
+}
+
+// firstStore returns the first registered store in the order.
+func (f *FileClient) firstStore(order []string) FileStore {
+	if f == nil {
+		return nil
+	}
+	for _, name := range order {
+		if s := f.stores[normalizeProvider(name)]; s != nil {
+			return s
+		}
+	}
+	return nil
+}
+
+// orderedStores returns the registered stores in the order.
+func (f *FileClient) orderedStores(order []string) []FileStore {
+	if f == nil {
+		return nil
+	}
+	out := make([]FileStore, 0, len(order))
+	for _, name := range order {
+		if s := f.stores[normalizeProvider(name)]; s != nil {
+			out = append(out, s)
+		}
+	}
+	return out
+}
+
+func normalizeProvider(name string) string {
+	return strings.ToLower(strings.TrimSpace(name))
+}
+
+// Name implements FileStore and reports the preferred read backend.
+func (f *FileClient) Name() string {
+	if s := f.Read(); s != nil {
+		return s.Name()
+	}
+	return ""
+}
+
+// List reads from the preferred backend, falling back to the next read backend
+// only on a transient error (429/502/503/504).
+func (f *FileClient) List(ctx context.Context, parentID string) ([]Entry, error) {
+	return fallbackRead(ctx, f.orderedStores(f.readOrder), func(s FileStore) ([]Entry, error) {
+		return s.List(ctx, parentID)
+	})
+}
+
+// Stat reads from the preferred backend, with the same transient fallback.
+func (f *FileClient) Stat(ctx context.Context, id string) (Entry, error) {
+	return fallbackRead(ctx, f.orderedStores(f.readOrder), func(s FileStore) (Entry, error) {
+		return s.Stat(ctx, id)
+	})
+}
+
+// Download streams file bytes. It does not fall back: a failed attempt may have
+// already written partial bytes into w, so a second backend would append.
+func (f *FileClient) Download(ctx context.Context, id string, w io.Writer) (int64, error) {
+	s := f.Read()
+	if s == nil {
+		return 0, errNoReadBackend
+	}
+	return s.Download(ctx, id, w)
+}
+
+// CreateFolder writes to the preferred write backend.
+func (f *FileClient) CreateFolder(ctx context.Context, parentID, title string) (Entry, error) {
+	s := f.Write()
+	if s == nil {
+		return Entry{}, errNoWriteBackend
+	}
+	return s.CreateFolder(ctx, parentID, title)
+}
+
+// Upload writes to the preferred write backend.
+func (f *FileClient) Upload(ctx context.Context, parentID, title string, r io.Reader) (Entry, error) {
+	s := f.Write()
+	if s == nil {
+		return Entry{}, errNoWriteBackend
+	}
+	return s.Upload(ctx, parentID, title, r)
+}
+
+// Move writes to the preferred write backend.
+func (f *FileClient) Move(ctx context.Context, ids []string, parentID string) error {
+	s := f.Write()
+	if s == nil {
+		return errNoWriteBackend
+	}
+	return s.Move(ctx, ids, parentID)
+}
+
+// Copy writes to the preferred write backend.
+func (f *FileClient) Copy(ctx context.Context, ids []string, parentID string) error {
+	s := f.Write()
+	if s == nil {
+		return errNoWriteBackend
+	}
+	return s.Copy(ctx, ids, parentID)
+}
+
+// Rename writes to the preferred write backend.
+func (f *FileClient) Rename(ctx context.Context, id, title string) error {
+	s := f.Write()
+	if s == nil {
+		return errNoWriteBackend
+	}
+	return s.Rename(ctx, id, title)
+}
+
+// Delete writes to the preferred write backend.
+func (f *FileClient) Delete(ctx context.Context, ids []string) error {
+	s := f.Write()
+	if s == nil {
+		return errNoWriteBackend
+	}
+	return s.Delete(ctx, ids)
+}
+
+// fallbackRead runs op against each store in order, moving on only when the
+// error is transient. Non-transient errors (not found, forbidden) are final.
+func fallbackRead[T any](ctx context.Context, stores []FileStore, op func(FileStore) (T, error)) (T, error) {
+	var zero T
+	if len(stores) == 0 {
+		return zero, errNoReadBackend
+	}
+	var err error
+	for i, s := range stores {
+		var v T
+		v, err = op(s)
+		if err == nil {
+			return v, nil
+		}
+		if i == len(stores)-1 || !Transient(err) {
+			return zero, err
+		}
+	}
+	return zero, err
+}

file_facade_test.go

@@ -0,0 +1,268 @@
+package onlyoffice
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+	"testing"
+)
+
+// fakeStore is a FileStore test double; it records which backend served a call
+// and returns a canned result or error.
+type fakeStore struct {
+	name    string
+	entries []Entry
+	err     error
+	calls   *[]string
+}
+
+func (f *fakeStore) record(op string) {
+	if f.calls != nil {
+		*f.calls = append(*f.calls, op+":"+f.name)
+	}
+}
+
+func (f *fakeStore) Name() string { return f.name }
+
+func (f *fakeStore) List(_ context.Context, _ string) ([]Entry, error) {
+	f.record("list")
+	if f.err != nil {
+		return nil, f.err
+	}
+	return f.entries, nil
+}
+
+func (f *fakeStore) Stat(_ context.Context, id string) (Entry, error) {
+	f.record("stat")
+	if f.err != nil {
+		return Entry{}, f.err
+	}
+	return Entry{ID: id, Title: "t-" + f.name, Provider: f.name}, nil
+}
+
+func (f *fakeStore) CreateFolder(_ context.Context, _, title string) (Entry, error) {
+	f.record("mkdir")
+	if f.err != nil {
+		return Entry{}, f.err
+	}
+	return Entry{ID: "new", Title: title, Provider: f.name}, nil
+}
+
+func (f *fakeStore) Upload(_ context.Context, _, title string, _ io.Reader) (Entry, error) {
+	f.record("upload")
+	return Entry{ID: "up", Title: title, Provider: f.name}, f.err
+}
+
+func (f *fakeStore) Download(_ context.Context, _ string, _ io.Writer) (int64, error) {
+	f.record("download")
+	return 0, f.err
+}
+
+func (f *fakeStore) Move(_ context.Context, _ []string, _ string) error {
+	f.record("move")
+	return f.err
+}
+
+func (f *fakeStore) Copy(_ context.Context, _ []string, _ string) error {
+	f.record("copy")
+	return f.err
+}
+
+func (f *fakeStore) Rename(_ context.Context, _, _ string) error {
+	f.record("rename")
+	return f.err
+}
+
+func (f *fakeStore) Delete(_ context.Context, _ []string) error {
+	f.record("delete")
+	return f.err
+}
+
+type fakeSearcher struct{ name string }
+
+func (s *fakeSearcher) Name() string { return s.name }
+
+func (s *fakeSearcher) Search(_ context.Context, _ SearchQuery) ([]SearchHit, error) {
+	return []SearchHit{{Entry: Entry{Title: s.name}}}, nil
+}
+
+func newFacadeTestClient(stores map[string]FileStore, read, write []string) *FileClient {
+	return &FileClient{
+		stores:     stores,
+		searchers:  map[string]Searcher{},
+		readOrder:  read,
+		writeOrder: write,
+	}
+}
+
+// TestFileClientIsFileStore guarantees the facade can stand in for the
+// interface anywhere a plain FileStore is expected.
+func TestFileClientIsFileStore(t *testing.T) {
+	var _ FileStore = (*FileClient)(nil)
+}
+
+func TestClientFilesPrefersRESTForReadsAndWrites(t *testing.T) {
+	c := NewClient(Credentials{})
+	f := c.Files()
+	if got := f.Read().Name(); got != ProviderREST {
+		t.Errorf("Read().Name() = %q, want %q", got, ProviderREST)
+	}
+	if got := f.Write().Name(); got != ProviderREST {
+		t.Errorf("Write().Name() = %q, want %q", got, ProviderREST)
+	}
+	if got := f.Name(); got != ProviderREST {
+		t.Errorf("Name() = %q, want %q", got, ProviderREST)
+	}
+}
+
+func TestFileClientPostgresTakesReadPriority(t *testing.T) {
+	pg := &fakeStore{name: ProviderPG}
+	f := newFacadeTestClient(
+		map[string]FileStore{ProviderREST: &fakeStore{name: ProviderREST}, ProviderPG: pg},
+		[]string{ProviderPG, ProviderREST},
+		[]string{ProviderREST},
+	)
+	if got := f.Read().Name(); got != ProviderPG {
+		t.Errorf("Read().Name() = %q, want %q", got, ProviderPG)
+	}
+	if got := f.Write().Name(); got != ProviderREST {
+		t.Errorf("Write().Name() = %q, want %q (PG is read-only)", got, ProviderREST)
+	}
+}
+
+func TestFileClientRegisterStoreNormalizesName(t *testing.T) {
+	pg := &fakeStore{name: "pg"}
+	f := newFacadeTestClient(map[string]FileStore{}, []string{ProviderPG}, nil)
+	f.RegisterStore("  POSTGRES  ", pg)
+	if got := f.Read(); got != pg {
+		t.Fatalf("Read() = %v, want registered postgres store", got)
+	}
+	f.RegisterStore("", pg)
+	f.RegisterStore("pg", nil)
+}
+
+func TestFileClientReadFallsBackOnlyOnTransient(t *testing.T) {
+	var calls []string
+	primary := &fakeStore{name: "primary", err: fmt.Errorf("onlyoffice: list: 503 unavailable"), calls: &calls}
+	secondary := &fakeStore{name: "secondary", entries: []Entry{{ID: "1"}}, calls: &calls}
+	f := newFacadeTestClient(
+		map[string]FileStore{"primary": primary, "secondary": secondary},
+		[]string{"primary", "secondary"},
+		nil,
+	)
+	got, err := f.List(context.Background(), "root")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(got) != 1 || got[0].ID != "1" {
+		t.Fatalf("List() = %+v, want secondary entry", got)
+	}
+	want := []string{"list:primary", "list:secondary"}
+	if fmt.Sprint(calls) != fmt.Sprint(want) {
+		t.Fatalf("call order = %v, want %v", calls, want)
+	}
+}
+
+func TestFileClientReadStopsOnPermanentError(t *testing.T) {
+	var calls []string
+	primary := &fakeStore{name: "primary", err: errors.New("onlyoffice: not found"), calls: &calls}
+	secondary := &fakeStore{name: "secondary", entries: []Entry{{ID: "1"}}, calls: &calls}
+	f := newFacadeTestClient(
+		map[string]FileStore{"primary": primary, "secondary": secondary},
+		[]string{"primary", "secondary"},
+		nil,
+	)
+	if _, err := f.List(context.Background(), "root"); err == nil {
+		t.Fatal("expected permanent error to be returned")
+	}
+	if len(calls) != 1 || calls[0] != "list:primary" {
+		t.Fatalf("secondary backend must not run on a permanent error: %v", calls)
+	}
+}
+
+func TestFileClientWriteUsesWriteBackend(t *testing.T) {
+	var calls []string
+	rest := &fakeStore{name: ProviderREST, calls: &calls}
+	dav := &fakeStore{name: ProviderDAV, calls: &calls}
+	f := newFacadeTestClient(
+		map[string]FileStore{ProviderREST: rest, ProviderDAV: dav},
+		[]string{ProviderREST},
+		[]string{ProviderREST, ProviderDAV},
+	)
+	if _, err := f.CreateFolder(context.Background(), "p", "t"); err != nil {
+		t.Fatalf("CreateFolder: %v", err)
+	}
+	if _, err := f.Upload(context.Background(), "p", "t", nil); err != nil {
+		t.Fatalf("Upload: %v", err)
+	}
+	if len(calls) != 2 || calls[0] != "mkdir:rest" || calls[1] != "upload:rest" {
+		t.Fatalf("write calls = %v, want REST", calls)
+	}
+}
+
+func TestFileClientWriteWithoutBackend(t *testing.T) {
+	f := newFacadeTestClient(map[string]FileStore{}, nil, nil)
+	if err := f.Delete(context.Background(), []string{"1"}); !errors.Is(err, errNoWriteBackend) {
+		t.Fatalf("Delete err = %v, want errNoWriteBackend", err)
+	}
+	if _, err := f.List(context.Background(), "root"); !errors.Is(err, errNoReadBackend) {
+		t.Fatalf("List err = %v, want errNoReadBackend", err)
+	}
+}
+
+func TestNewFileClientReadOrderIncludesSQL(t *testing.T) {
+	f := NewClient(Credentials{}).newFileClient()
+	want := []string{ProviderPG, ProviderMySQL, ProviderREST, ProviderDAV}
+	if fmt.Sprint(f.readOrder) != fmt.Sprint(want) {
+		t.Fatalf("readOrder = %v, want %v", f.readOrder, want)
+	}
+}
+
+// TestClientFileStoreSQLRoutingWithoutDSN checks that the SQL backend names are
+// recognised and never yield nil: without a DSN the returned store surfaces the
+// open error on use.
+func TestClientFileStoreSQLRoutingWithoutDSN(t *testing.T) {
+	t.Setenv("ONLYOFFICE_DSN", "")
+	t.Setenv("ONLYOFFICE_PG_HOST", "")
+	c := NewClient(Credentials{})
+	for _, name := range []string{"pg", "sql", ProviderPG, ProviderMySQL} {
+		s := c.FileStore(name)
+		if s == nil {
+			t.Fatalf("FileStore(%q) = nil", name)
+		}
+		if _, err := s.Stat(context.Background(), "1"); err == nil {
+			t.Errorf("FileStore(%q).Stat without DSN: want error", name)
+		}
+	}
+}
+
+func TestFileClientMySQLStoreIsPreferredForReads(t *testing.T) {
+	mysql := &fakeStore{name: ProviderMySQL}
+	f := newFacadeTestClient(
+		map[string]FileStore{ProviderREST: &fakeStore{name: ProviderREST}, ProviderMySQL: mysql},
+		[]string{ProviderPG, ProviderMySQL, ProviderREST},
+		[]string{ProviderREST},
+	)
+	if got := f.Read().Name(); got != ProviderMySQL {
+		t.Errorf("Read().Name() = %q, want %q", got, ProviderMySQL)
+	}
+}
+
+func TestFileClientSearchSelection(t *testing.T) {
+	f := &FileClient{searchers: map[string]Searcher{}, searchOrder: []string{ProviderES}}
+	_, err := f.Search()
+	if err == nil || !strings.Contains(err.Error(), "ONLYOFFICE_ES_URL") {
+		t.Fatalf("Search without backend = %v, want ONLYOFFICE_ES_URL hint", err)
+	}
+	es := &fakeSearcher{name: "fake-es"}
+	f.RegisterSearcher(ProviderES, es)
+	got, err := f.Search()
+	if err != nil {
+		t.Fatalf("Search: %v", err)
+	}
+	if got.Name() != "fake-es" {
+		t.Fatalf("searcher = %q, want fake-es", got.Name())
+	}
+}

file_pg.go

@@ -0,0 +1,525 @@
+package onlyoffice
+
+// Read-only SQL backend of the unified file client (epic #34, F2 #36).
+//
+// The goal is to read files and folders straight from the Community Server
+// database, without the REST layer. Research on the live portal (VM
+// `onlyoffice-v2`) showed the server runs on **MySQL 8.0** (`files_file`,
+// `files_folder`, `files_folder_tree`, tenant `tenants_tenants`), not
+// PostgreSQL — see docs/community-server-db.md. The store below therefore
+// speaks `database/sql` and selects its driver from the DSN, so it works
+// against the live MySQL today and against PostgreSQL if the portal is ever
+// migrated. Every query is a SELECT; the write methods of FileStore return
+// ErrReadOnly.
+//
+// Downloads follow the portal's S3/MinIO object layout through the shared
+// MinIO helper in storage_fallback.go — no HTTP file endpoint is used.
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/go-sql-driver/mysql"
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+// Provider names for the SQL backend. ProviderPG is the value Name reports for
+// a PostgreSQL connection and ProviderMySQL for MySQL.
+const (
+	ProviderPG    = "postgres"
+	ProviderMySQL = "mysql"
+)
+
+// ErrReadOnly is returned by every FileStore write method of the SQL backend.
+var ErrReadOnly = errors.New("onlyoffice: sql file store is read-only")
+
+const (
+	pgConnectTimeout = 10 * time.Second
+	pgSearchLimit    = 50
+	pgSearchMaxLimit = 500
+)
+
+// PGConfig configures the read-only SQL store. DSN is a driver DSN:
+// `user:pass@tcp(host:port)/onlyoffice?parseTime=true` for MySQL or a
+// `postgres://` / libpq keyword string for PostgreSQL. Driver, when set,
+// forces the engine ("postgres" or "mysql"); otherwise it is detected from the
+// DSN. Tenant filters rows (empty means all tenants).
+type PGConfig struct {
+	DSN    string
+	Driver string
+	Tenant string
+}
+
+// PGConfigFromEnv reads ONLYOFFICE_DSN (or the ONLYOFFICE_PG_* parts),
+// ONLYOFFICE_PG_DRIVER and the tenant from ONLYOFFICE_PG_TENANT /
+// ONLYOFFICE_TENANT. The library never loads dotfiles — the CLI does that.
+func PGConfigFromEnv() PGConfig {
+	dsn := strings.TrimSpace(os.Getenv("ONLYOFFICE_DSN"))
+	if dsn == "" {
+		dsn = pgDSNFromParts()
+	}
+	return PGConfig{
+		DSN:    dsn,
+		Driver: strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_DRIVER")),
+		Tenant: firstNonEmpty(os.Getenv("ONLYOFFICE_PG_TENANT"), os.Getenv("ONLYOFFICE_TENANT")),
+	}
+}
+
+// pgDSNFromParts builds a libpq keyword DSN from ONLYOFFICE_PG_* variables.
+// It returns "" unless a host is set, which keeps the MySQL path (ONLYOFFICE_DSN)
+// the default.
+func pgDSNFromParts() string {
+	host := strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_HOST"))
+	if host == "" {
+		return ""
+	}
+	port := firstNonEmpty(os.Getenv("ONLYOFFICE_PG_PORT"), "5432")
+	dbname := firstNonEmpty(os.Getenv("ONLYOFFICE_PG_DBNAME"), "onlyoffice")
+	sslmode := firstNonEmpty(os.Getenv("ONLYOFFICE_PG_SSLMODE"), "disable")
+	return fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=%s",
+		host, port, os.Getenv("ONLYOFFICE_PG_USER"), os.Getenv("ONLYOFFICE_PG_PASSWORD"), dbname, sslmode)
+}
+
+// SQLFileStore opens the read-only SQL store from the environment
+// (PGConfigFromEnv: ONLYOFFICE_DSN or the ONLYOFFICE_PG_* parts). It is the
+// error-aware counterpart of Client.FileStore("pg"/"sql"), which returns an
+// errStore when the open fails. The caller owns the returned store and should
+// close it (the concrete type has a Close method).
+func (c *Client) SQLFileStore() (FileStore, error) {
+	return NewPGStore(PGConfigFromEnv())
+}
+
+// pgStore is a read-only FileStore/Searcher over the Community Server database.
+type pgStore struct {
+	db        *sql.DB
+	driver    string
+	tenantID  int64
+	hasTenant bool
+	http      *http.Client
+}
+
+var (
+	_ FileStore = (*pgStore)(nil)
+	_ Searcher  = (*pgStore)(nil)
+)
+
+// NewPGStore opens the database and verifies connectivity. It never writes.
+func NewPGStore(cfg PGConfig) (*pgStore, error) {
+	dsn := strings.TrimSpace(cfg.DSN)
+	if dsn == "" {
+		return nil, fmt.Errorf("onlyoffice: sql file store: empty DSN (set ONLYOFFICE_DSN)")
+	}
+	driver := pgDriver(dsn, cfg.Driver)
+	dsn, err := normalizeSQLDSN(driver, dsn)
+	if err != nil {
+		return nil, err
+	}
+	db, err := sql.Open(sqlDriverName(driver), dsn)
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: sql file store: open %s: %w", driver, err)
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), pgConnectTimeout)
+	defer cancel()
+	if err := db.PingContext(ctx); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("onlyoffice: sql file store: ping %s: %w", driver, err)
+	}
+	s := &pgStore{db: db, driver: driver, http: &http.Client{}}
+	if t := strings.TrimSpace(cfg.Tenant); t != "" {
+		n, err := strconv.ParseInt(t, 10, 64)
+		if err != nil {
+			db.Close()
+			return nil, fmt.Errorf("onlyoffice: sql file store: non-numeric tenant %q", t)
+		}
+		s.tenantID, s.hasTenant = n, true
+	}
+	return s, nil
+}
+
+// Close releases the database handle.
+func (s *pgStore) Close() error { return s.db.Close() }
+
+// Name implements FileStore and Searcher.
+func (s *pgStore) Name() string { return s.driver }
+
+// pgDriver resolves the engine: the explicit value wins, otherwise the DSN
+// shape decides. A leading postgres:// scheme or a libpq keyword DSN (which
+// always carries '=') selects PostgreSQL; anything else is MySQL.
+func pgDriver(dsn, explicit string) string {
+	switch strings.ToLower(strings.TrimSpace(explicit)) {
+	case ProviderPG, "pg", "postgresql", "pgx":
+		return ProviderPG
+	case ProviderMySQL, "mariadb":
+		return ProviderMySQL
+	}
+	l := strings.ToLower(strings.TrimSpace(dsn))
+	switch {
+	case strings.HasPrefix(l, "postgres://"), strings.HasPrefix(l, "postgresql://"):
+		return ProviderPG
+	case strings.HasPrefix(l, "mysql://"), strings.Contains(l, "@tcp("), strings.Contains(l, "@unix("):
+		return ProviderMySQL
+	case strings.Contains(l, "="):
+		return ProviderPG
+	default:
+		return ProviderMySQL
+	}
+}
+
+// sqlDriverName maps the engine to its registered database/sql driver.
+func sqlDriverName(driver string) string {
+	if driver == ProviderPG {
+		return "pgx"
+	}
+	return "mysql"
+}
+
+// normalizeSQLDSN converts a mysql:// URL to the go-sql-driver form and forces
+// parseTime so datetime columns scan into time.Time. PostgreSQL DSNs pass
+// through untouched.
+func normalizeSQLDSN(driver, dsn string) (string, error) {
+	if driver != ProviderMySQL {
+		return dsn, nil
+	}
+	if strings.HasPrefix(strings.ToLower(dsn), "mysql://") {
+		converted, err := mysqlDSNFromURL(dsn)
+		if err != nil {
+			return "", err
+		}
+		dsn = converted
+	}
+	cfg, err := mysql.ParseDSN(dsn)
+	if err != nil {
+		return "", fmt.Errorf("onlyoffice: sql file store: parse mysql DSN: %w", err)
+	}
+	cfg.ParseTime = true
+	return cfg.FormatDSN(), nil
+}
+
+// mysqlDSNFromURL turns mysql://user:pass@host:port/db into the driver DSN.
+func mysqlDSNFromURL(raw string) (string, error) {
+	u, err := url.Parse(raw)
+	if err != nil || u.Host == "" {
+		return "", fmt.Errorf("onlyoffice: sql file store: bad mysql URL %q", raw)
+	}
+	user := ""
+	if u.User != nil {
+		user = u.User.Username()
+		if p, ok := u.User.Password(); ok {
+			user += ":" + p
+		}
+	}
+	q := u.Query()
+	q.Set("parseTime", "true")
+	return fmt.Sprintf("%s@tcp(%s)/%s?%s", user, u.Host, strings.TrimPrefix(u.Path, "/"), q.Encode()), nil
+}
+
+// rebind rewrites '?' placeholders to PostgreSQL's $1..$n. MySQL keeps them.
+func rebind(query, driver string) string {
+	if driver != ProviderPG {
+		return query
+	}
+	var b strings.Builder
+	b.Grow(len(query) + 8)
+	n := 0
+	for _, r := range query {
+		if r == '?' {
+			n++
+			b.WriteByte('$')
+			b.WriteString(strconv.Itoa(n))
+			continue
+		}
+		b.WriteRune(r)
+	}
+	return b.String()
+}
+
+// List returns the folders and files directly below parentID, folders first.
+func (s *pgStore) List(ctx context.Context, parentID string) ([]Entry, error) {
+	pid, err := parseEntryID(parentID)
+	if err != nil {
+		return nil, err
+	}
+	folders, err := s.queryFolders(ctx, "parent_id = ?", pid)
+	if err != nil {
+		return nil, err
+	}
+	files, err := s.queryFiles(ctx, "folder_id = ? AND current_version = 1", pid)
+	if err != nil {
+		return nil, err
+	}
+	out := make([]Entry, 0, len(folders)+len(files))
+	for _, f := range folders {
+		out = append(out, folderRowToEntry(f, s.Name()))
+	}
+	for _, f := range files {
+		out = append(out, fileRowToEntry(f, s.Name()))
+	}
+	return out, nil
+}
+
+// Stat resolves a folder or file id to an Entry. Folders win when both id
+// spaces overlap (they never do on a real portal, but the lookup is cheap).
+func (s *pgStore) Stat(ctx context.Context, id string) (Entry, error) {
+	n, err := parseEntryID(id)
+	if err != nil {
+		return Entry{}, err
+	}
+	folders, err := s.queryFolders(ctx, "id = ?", n)
+	if err != nil {
+		return Entry{}, err
+	}
+	if len(folders) > 0 {
+		return folderRowToEntry(folders[0], s.Name()), nil
+	}
+	files, err := s.queryFiles(ctx, "id = ? AND current_version = 1", n)
+	if err != nil {
+		return Entry{}, err
+	}
+	if len(files) == 0 {
+		return Entry{}, fmt.Errorf("onlyoffice: sql file store: id %s not found", id)
+	}
+	return fileRowToEntry(files[0], s.Name()), nil
+}
+
+// Download streams the file's current version from the portal's S3/MinIO store.
+// The object key is reconstructed from the file id and version; the parent
+// folder id is not part of the key.
+func (s *pgStore) Download(ctx context.Context, id string, w io.Writer) (int64, error) {
+	n, err := parseEntryID(id)
+	if err != nil {
+		return 0, err
+	}
+	files, err := s.queryFiles(ctx, "id = ? AND current_version = 1", n)
+	if err != nil {
+		return 0, err
+	}
+	if len(files) == 0 {
+		return 0, fmt.Errorf("onlyoffice: sql file store: file %s not found", id)
+	}
+	f := files[0]
+	key := csObjectKey(s.tenantID, f.id, f.version, filepath.Ext(f.title))
+	return downloadMinioObject(ctx, s.http, key, w)
+}
+
+// CreateFolder is unavailable: the SQL backend is read-only.
+func (s *pgStore) CreateFolder(context.Context, string, string) (Entry, error) {
+	return Entry{}, ErrReadOnly
+}
+
+// Upload is unavailable: the SQL backend is read-only.
+func (s *pgStore) Upload(context.Context, string, string, io.Reader) (Entry, error) {
+	return Entry{}, ErrReadOnly
+}
+
+// Move is unavailable: the SQL backend is read-only.
+func (s *pgStore) Move(context.Context, []string, string) error { return ErrReadOnly }
+
+// Copy is unavailable: the SQL backend is read-only.
+func (s *pgStore) Copy(context.Context, []string, string) error { return ErrReadOnly }
+
+// Rename is unavailable: the SQL backend is read-only.
+func (s *pgStore) Rename(context.Context, string, string) error { return ErrReadOnly }
+
+// Delete is unavailable: the SQL backend is read-only.
+func (s *pgStore) Delete(context.Context, []string) error { return ErrReadOnly }
+
+// Search matches file titles by substring. Content search lives in the
+// Elasticsearch backend; q.InContent is ignored here.
+func (s *pgStore) Search(ctx context.Context, q SearchQuery) ([]SearchHit, error) {
+	text := strings.TrimSpace(q.Text)
+	if text == "" {
+		return nil, fmt.Errorf("onlyoffice: empty search query")
+	}
+	limit := q.Limit
+	if limit <= 0 {
+		limit = pgSearchLimit
+	}
+	if limit > pgSearchMaxLimit {
+		limit = pgSearchMaxLimit
+	}
+
+	where := "title LIKE ? AND current_version = 1"
+	args := []any{"%" + text + "%"}
+	if s.hasTenant {
+		where += " AND tenant_id = ?"
+		args = append(args, s.tenantID)
+	}
+	if fid := strings.TrimSpace(q.FolderID); fid != "" {
+		n, err := parseEntryID(fid)
+		if err != nil {
+			return nil, err
+		}
+		where += " AND folder_id = ?"
+		args = append(args, n)
+	}
+	for _, ext := range normalizeExtensions(q.Extensions) {
+		where += " AND LOWER(title) LIKE ?"
+		args = append(args, "%."+ext)
+	}
+	query := rebind(`SELECT id, folder_id, title, content_length, version, create_on, modified_on
+        FROM files_file WHERE `+where+` ORDER BY modified_on DESC, id DESC LIMIT ?`, s.driver)
+	args = append(args, limit)
+
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: sql search: %w", err)
+	}
+	defer rows.Close()
+	var hits []SearchHit
+	for rows.Next() {
+		f, err := scanFileRow(rows)
+		if err != nil {
+			return nil, err
+		}
+		hits = append(hits, SearchHit{Entry: fileRowToEntry(f, s.Name())})
+	}
+	return hits, rows.Err()
+}
+
+// queryFolders runs a folder SELECT with the tenant filter applied.
+func (s *pgStore) queryFolders(ctx context.Context, where string, arg any) ([]pgFolderRow, error) {
+	args := []any{arg}
+	if s.hasTenant {
+		where += " AND tenant_id = ?"
+		args = append(args, s.tenantID)
+	}
+	query := rebind(`SELECT id, parent_id, title, create_on, modified_on
+        FROM files_folder WHERE `+where+` ORDER BY title, id`, s.driver)
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: sql list folders: %w", err)
+	}
+	defer rows.Close()
+	var out []pgFolderRow
+	for rows.Next() {
+		var r pgFolderRow
+		if err := rows.Scan(&r.id, &r.parentID, &r.title, &r.created, &r.modified); err != nil {
+			return nil, fmt.Errorf("onlyoffice: sql folder row: %w", err)
+		}
+		out = append(out, r)
+	}
+	return out, rows.Err()
+}
+
+// queryFiles runs a file SELECT for the current version with the tenant filter.
+func (s *pgStore) queryFiles(ctx context.Context, where string, arg any) ([]pgFileRow, error) {
+	args := []any{arg}
+	if s.hasTenant {
+		where += " AND tenant_id = ?"
+		args = append(args, s.tenantID)
+	}
+	query := rebind(`SELECT id, folder_id, title, content_length, version, create_on, modified_on
+        FROM files_file WHERE `+where+` ORDER BY title, id`, s.driver)
+	rows, err := s.db.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("onlyoffice: sql list files: %w", err)
+	}
+	defer rows.Close()
+	var out []pgFileRow
+	for rows.Next() {
+		f, err := scanFileRow(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, f)
+	}
+	return out, rows.Err()
+}
+
+// pgFileRow is one current files_file row.
+type pgFileRow struct {
+	id       int64
+	folderID int64
+	title    string
+	size     int64
+	version  int
+	created  time.Time
+	modified time.Time
+}
+
+// pgFolderRow is one files_folder row.
+type pgFolderRow struct {
+	id       int64
+	parentID int64
+	title    string
+	created  time.Time
+	modified time.Time
+}
+
+// scanFileRow reads the canonical file column order.
+func scanFileRow(rows *sql.Rows) (pgFileRow, error) {
+	var f pgFileRow
+	if err := rows.Scan(&f.id, &f.folderID, &f.title, &f.size, &f.version, &f.created, &f.modified); err != nil {
+		return f, fmt.Errorf("onlyoffice: sql file row: %w", err)
+	}
+	return f, nil
+}
+
+// fileRowToEntry maps a files_file row to the canonical model.
+func fileRowToEntry(f pgFileRow, provider string) Entry {
+	return Entry{
+		ID:       strconv.FormatInt(f.id, 10),
+		ParentID: strconv.FormatInt(f.folderID, 10),
+		Title:    f.title,
+		Kind:     File,
+		Size:     f.size,
+		MIME:     mimeForTitle(f.title, ""),
+		Created:  f.created.UTC(),
+		Modified: f.modified.UTC(),
+		Version:  f.version,
+		Provider: provider,
+	}
+}
+
+// folderRowToEntry maps a files_folder row to the canonical model.
+func folderRowToEntry(f pgFolderRow, provider string) Entry {
+	return Entry{
+		ID:       strconv.FormatInt(f.id, 10),
+		ParentID: strconv.FormatInt(f.parentID, 10),
+		Title:    f.title,
+		Kind:     Folder,
+		Created:  f.created.UTC(),
+		Modified: f.modified.UTC(),
+		Provider: provider,
+	}
+}
+
+// csObjectKey reconstructs the object key the portal's S3 consumer uses:
+//
+//	00/00/<tenant>/files/folder_<shard>/file_<id>/v<version>/content.<ext>
+//
+// The shard is the next thousand above the file id (file 3727 -> folder_4000),
+// NOT the parent folder id — verified live against the MinIO bucket.
+func csObjectKey(tenant int64, fileID int64, version int, ext string) string {
+	shard := (fileID/1000 + 1) * 1000
+	ext = strings.TrimPrefix(strings.ToLower(strings.TrimSpace(ext)), ".")
+	if ext == "" {
+		ext = "bin"
+	}
+	if version < 1 {
+		version = 1
+	}
+	if tenant <= 0 {
+		tenant = 1
+	}
+	return fmt.Sprintf("00/00/%02d/files/folder_%d/file_%d/v%d/content.%s", tenant, shard, fileID, version, ext)
+}
+
+// parseEntryID parses a numeric OnlyOffice id or returns a store error.
+func parseEntryID(id string) (int64, error) {
+	n, err := strconv.ParseInt(strings.TrimSpace(id), 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("onlyoffice: sql file store: non-numeric id %q", id)
+	}
+	return n, nil
+}

file_pg_integration_test.go

@@ -0,0 +1,224 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+// TestIntegrationPGStore exercises the read-only SQL backend against the live
+// Community Server database and cross-checks list/stat/download with the REST
+// FileStore. It needs ONLYOFFICE_DSN plus the usual ONLYOFFICE_URL/USER/PASS;
+// ONLYOFFICE_PG_TEST_FILE_ID / ONLYOFFICE_PG_TEST_FOLDER_ID pick a real file
+// (a file reachable over REST too). Download streams from MinIO, so it also
+// needs MINIO_ACCESS_KEY/MINIO_SECRET_KEY.
+//
+// The live Community Server runs on MySQL; PostgreSQL is supported by the same
+// code path when the DSN says so.
+func TestIntegrationPGStore(t *testing.T) {
+	cfg := PGConfigFromEnv()
+	if strings.TrimSpace(cfg.DSN) == "" {
+		t.Skip("ONLYOFFICE_DSN not set — skipping SQL store integration test")
+	}
+	store, err := NewPGStore(cfg)
+	if err != nil {
+		t.Fatalf("NewPGStore: %v", err)
+	}
+	t.Cleanup(func() { _ = store.Close() })
+	t.Logf("sql store backend: %s", store.Name())
+	ctx := context.Background()
+
+	if err := testPGStoreReadOnly(ctx, store); err != nil {
+		t.Fatal(err)
+	}
+
+	fileID := strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_TEST_FILE_ID"))
+	folderID := strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_TEST_FOLDER_ID"))
+	if fileID == "" || folderID == "" {
+		t.Skip("ONLYOFFICE_PG_TEST_FILE_ID / ONLYOFFICE_PG_TEST_FOLDER_ID not set — skipping live comparison")
+	}
+
+	c := liveClient(t)
+	rest := c.Files()
+
+	dbFile, err := store.Stat(ctx, fileID)
+	if err != nil {
+		t.Fatalf("sql Stat(%s): %v", fileID, err)
+	}
+	restFile, err := rest.Stat(ctx, fileID)
+	if err != nil {
+		t.Fatalf("rest Stat(%s): %v", fileID, err)
+	}
+	if dbFile.Kind != File {
+		t.Errorf("sql kind = %v, want file", dbFile.Kind)
+	}
+	if dbFile.ID != restFile.ID || dbFile.Title != restFile.Title || dbFile.ParentID != restFile.ParentID {
+		t.Errorf("stat mismatch sql=%+v rest=%+v", dbFile, restFile)
+	}
+	// GetFile omits contentLength, so size is only comparable when REST has it.
+	if restFile.Size > 0 && dbFile.Size != restFile.Size {
+		t.Errorf("size sql=%d rest=%d", dbFile.Size, restFile.Size)
+	}
+	if d := dbFile.Modified.Sub(restFile.Modified); d > 2*time.Minute || d < -2*time.Minute {
+		t.Errorf("modified sql=%v rest=%v", dbFile.Modified, restFile.Modified)
+	}
+
+	list, err := store.List(ctx, folderID)
+	if err != nil {
+		t.Fatalf("sql List(%s): %v", folderID, err)
+	}
+	if entryByID(list, fileID) == nil {
+		t.Errorf("file %s not in sql List(%s)", fileID, folderID)
+	}
+
+	// Every file the REST layer can see in the folder must be in the SQL list
+	// (the SQL store sees more, so only assert this direction).
+	restList, err := rest.List(ctx, folderID)
+	if err != nil {
+		t.Fatalf("rest List(%s): %v", folderID, err)
+	}
+	dbIDs := make(map[string]bool, len(list))
+	for _, e := range list {
+		dbIDs[e.ID] = true
+	}
+	for _, e := range restList {
+		if e.Kind == File && !dbIDs[e.ID] {
+			t.Errorf("rest file %s (%q) missing from sql list", e.ID, e.Title)
+		}
+	}
+
+	// Download reads the object store, not the database, so it only runs with
+	// the MinIO credentials configured (the portal's S3 layout). Without them
+	// the DSN-only assertions above still prove the SQL reads.
+	if os.Getenv("MINIO_ACCESS_KEY") == "" || os.Getenv("MINIO_SECRET_KEY") == "" {
+		t.Log("MINIO_ACCESS_KEY/MINIO_SECRET_KEY not set — SQL download cross-check skipped")
+		return
+	}
+
+	var buf bytes.Buffer
+	n, err := store.Download(ctx, fileID, &buf)
+	if err != nil {
+		t.Fatalf("sql Download(%s): %v", fileID, err)
+	}
+	if n == 0 || n != dbFile.Size {
+		t.Errorf("sql Download = %d bytes, stat says %d", n, dbFile.Size)
+	}
+	var restBuf bytes.Buffer
+	rn, err := rest.Download(ctx, fileID, &restBuf)
+	if err != nil {
+		t.Fatalf("rest Download(%s): %v", fileID, err)
+	}
+	if rn != n || !bytes.Equal(restBuf.Bytes(), buf.Bytes()) {
+		t.Errorf("download mismatch sql=%d rest=%d bytes", n, rn)
+	}
+}
+
+// TestIntegrationSQLFacade proves that reads are served by the SQL store when
+// it is part of the file client, not by REST. It needs ONLYOFFICE_DSN plus
+// ONLYOFFICE_PG_TEST_FILE_ID / ONLYOFFICE_PG_TEST_FOLDER_ID and the usual REST
+// credentials (for the cross-check). Every Entry served by SQL carries
+// Provider "mysql"; REST entries carry "rest", so the provider is the proof of
+// which backend answered.
+func TestIntegrationSQLFacade(t *testing.T) {
+	cfg := PGConfigFromEnv()
+	if strings.TrimSpace(cfg.DSN) == "" {
+		t.Skip("ONLYOFFICE_DSN not set — skipping SQL facade integration test")
+	}
+	fileID := strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_TEST_FILE_ID"))
+	folderID := strings.TrimSpace(os.Getenv("ONLYOFFICE_PG_TEST_FOLDER_ID"))
+	if fileID == "" || folderID == "" {
+		t.Skip("ONLYOFFICE_PG_TEST_FILE_ID / ONLYOFFICE_PG_TEST_FOLDER_ID not set — skipping SQL facade integration test")
+	}
+	c := liveClient(t)
+	ctx := context.Background()
+
+	sqlStore, err := c.SQLFileStore()
+	if err != nil {
+		t.Fatalf("SQLFileStore: %v", err)
+	}
+	if closer, ok := sqlStore.(interface{ Close() error }); ok {
+		t.Cleanup(func() { _ = closer.Close() })
+	}
+	if sqlStore.Name() == ProviderREST {
+		t.Fatalf("SQLFileStore returned REST")
+	}
+
+	// Direct constructor: Client.FileStore("pg") must not be REST either.
+	direct := c.FileStore("pg")
+	if direct == nil || direct.Name() == ProviderREST {
+		t.Fatalf("FileStore(\"pg\") = %v, want SQL backend", direct)
+	}
+	if closer, ok := direct.(interface{ Close() error }); ok {
+		t.Cleanup(func() { _ = closer.Close() })
+	}
+
+	f := c.Files()
+	f.RegisterStore(ProviderPG, sqlStore)
+	if got := f.Read().Name(); got != sqlStore.Name() {
+		t.Fatalf("facade read backend = %q, want %q (SQL)", got, sqlStore.Name())
+	}
+
+	got, err := f.Stat(ctx, fileID)
+	if err != nil {
+		t.Fatalf("facade Stat(%s): %v", fileID, err)
+	}
+	if got.Provider != ProviderMySQL {
+		t.Errorf("facade Stat provider = %q, want %q (SQL, not REST)", got.Provider, ProviderMySQL)
+	}
+	want, err := c.FileStore(ProviderREST).Stat(ctx, fileID)
+	if err != nil {
+		t.Fatalf("rest Stat(%s): %v", fileID, err)
+	}
+	if got.ID != want.ID || got.Title != want.Title || got.ParentID != want.ParentID {
+		t.Errorf("facade SQL stat %+v != REST %+v", got, want)
+	}
+
+	list, err := f.List(ctx, folderID)
+	if err != nil {
+		t.Fatalf("facade List(%s): %v", folderID, err)
+	}
+	entry := entryByID(list, fileID)
+	if entry == nil {
+		t.Fatalf("file %s not in facade List(%s)", fileID, folderID)
+	}
+	if entry.Provider != ProviderMySQL {
+		t.Errorf("facade List provider = %q, want %q", entry.Provider, ProviderMySQL)
+	}
+
+	d, err := direct.Stat(ctx, fileID)
+	if err != nil {
+		t.Fatalf("FileStore(\"pg\").Stat(%s): %v", fileID, err)
+	}
+	if d.Provider != ProviderMySQL {
+		t.Errorf("FileStore(\"pg\") provider = %q, want %q", d.Provider, ProviderMySQL)
+	}
+}
+
+// testPGStoreReadOnly asserts that every write method returns ErrReadOnly.
+func testPGStoreReadOnly(ctx context.Context, s *pgStore) error {
+	if _, err := s.CreateFolder(ctx, "1", "x"); !errors.Is(err, ErrReadOnly) {
+		return errors.New("CreateFolder did not return ErrReadOnly")
+	}
+	if _, err := s.Upload(ctx, "1", "x", strings.NewReader("x")); !errors.Is(err, ErrReadOnly) {
+		return errors.New("Upload did not return ErrReadOnly")
+	}
+	if err := s.Move(ctx, []string{"1"}, "2"); !errors.Is(err, ErrReadOnly) {
+		return errors.New("Move did not return ErrReadOnly")
+	}
+	if err := s.Copy(ctx, []string{"1"}, "2"); !errors.Is(err, ErrReadOnly) {
+		return errors.New("Copy did not return ErrReadOnly")
+	}
+	if err := s.Rename(ctx, "1", "x"); !errors.Is(err, ErrReadOnly) {
+		return errors.New("Rename did not return ErrReadOnly")
+	}
+	if err := s.Delete(ctx, []string{"1"}); !errors.Is(err, ErrReadOnly) {
+		return errors.New("Delete did not return ErrReadOnly")
+	}
+	return nil
+}

file_pg_test.go

@@ -0,0 +1,165 @@
+package onlyoffice
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestRebind(t *testing.T) {
+	mysqlQuery := "SELECT id FROM files_file WHERE folder_id = ? AND title = ? LIMIT ?"
+	if got := rebind(mysqlQuery, ProviderMySQL); got != mysqlQuery {
+		t.Errorf("mysql query changed: %q", got)
+	}
+	want := "SELECT id FROM files_file WHERE folder_id = $1 AND title = $2 LIMIT $3"
+	if got := rebind(mysqlQuery, ProviderPG); got != want {
+		t.Errorf("rebind = %q, want %q", got, want)
+	}
+}
+
+func TestCSPObjectKey(t *testing.T) {
+	cases := []struct {
+		tenant  int64
+		fileID  int64
+		version int
+		ext     string
+		want    string
+	}{
+		{1, 2, 1, ".docx", "00/00/01/files/folder_1000/file_2/v1/content.docx"},
+		{1, 999, 1, ".pdf", "00/00/01/files/folder_1000/file_999/v1/content.pdf"},
+		{1, 1000, 1, ".xlsx", "00/00/01/files/folder_2000/file_1000/v1/content.xlsx"},
+		{1, 3727, 1, ".pdf", "00/00/01/files/folder_4000/file_3727/v1/content.pdf"},
+		{1, 22484, 1, ".PDF", "00/00/01/files/folder_23000/file_22484/v1/content.pdf"},
+		{1, 4, 6, "xlsx", "00/00/01/files/folder_1000/file_4/v6/content.xlsx"},
+		{0, 7, 0, "", "00/00/01/files/folder_1000/file_7/v1/content.bin"},
+		{2, 11, 3, ".doc", "00/00/02/files/folder_1000/file_11/v3/content.doc"},
+	}
+	for _, tc := range cases {
+		if got := csObjectKey(tc.tenant, tc.fileID, tc.version, tc.ext); got != tc.want {
+			t.Errorf("csObjectKey(%d,%d,%d,%q) = %q, want %q", tc.tenant, tc.fileID, tc.version, tc.ext, got, tc.want)
+		}
+	}
+}
+
+func TestPGDriverDetection(t *testing.T) {
+	cases := []struct {
+		dsn, explicit, want string
+	}{
+		{"postgres://u:p@h:5432/onlyoffice", "", ProviderPG},
+		{"postgresql://u:p@h/db", "", ProviderPG},
+		{"host=h user=u password=p dbname=onlyoffice sslmode=disable", "", ProviderPG},
+		{"root:secret@tcp(127.0.0.1:3306)/onlyoffice?parseTime=true", "", ProviderMySQL},
+		{"mysql://root:secret@127.0.0.1:3306/onlyoffice", "", ProviderMySQL},
+		{"root:secret@tcp(h:3306)/db", "postgres", ProviderPG},
+		{"postgres://u:p@h/db", "mysql", ProviderMySQL},
+	}
+	for _, tc := range cases {
+		if got := pgDriver(tc.dsn, tc.explicit); got != tc.want {
+			t.Errorf("pgDriver(%q, %q) = %q, want %q", tc.dsn, tc.explicit, got, tc.want)
+		}
+	}
+}
+
+func TestNormalizeSQLDSNMySQL(t *testing.T) {
+	got, err := normalizeSQLDSN(ProviderMySQL, "mysql://root:secret@127.0.0.1:3306/onlyoffice")
+	if err != nil {
+		t.Fatalf("normalizeSQLDSN: %v", err)
+	}
+	want := "root:secret@tcp(127.0.0.1:3306)/onlyoffice?parseTime=true"
+	if got != want {
+		t.Errorf("normalize = %q, want %q", got, want)
+	}
+
+	// A driver DSN keeps parseTime and gains it when missing.
+	got, err = normalizeSQLDSN(ProviderMySQL, "root:secret@tcp(127.0.0.1:3306)/onlyoffice")
+	if err != nil {
+		t.Fatalf("normalizeSQLDSN: %v", err)
+	}
+	if got != want {
+		t.Errorf("normalize = %q, want %q", got, want)
+	}
+}
+
+func TestFileRowToEntry(t *testing.T) {
+	created := time.Date(2026, 9, 12, 18, 0, 37, 0, time.UTC)
+	modified := time.Date(2026, 9, 13, 13, 50, 36, 0, time.UTC)
+	e := fileRowToEntry(pgFileRow{
+		id: 22484, folderID: 649, title: "Rechnung.pdf",
+		size: 123433, version: 2, created: created, modified: modified,
+	}, ProviderMySQL)
+	if e.ID != "22484" || e.ParentID != "649" {
+		t.Errorf("ids = %q/%q", e.ID, e.ParentID)
+	}
+	if e.Title != "Rechnung.pdf" || e.Kind != File {
+		t.Errorf("title/kind = %q/%v", e.Title, e.Kind)
+	}
+	if e.Size != 123433 || e.Version != 2 {
+		t.Errorf("size/version = %d/%d", e.Size, e.Version)
+	}
+	if e.MIME != "application/pdf" {
+		t.Errorf("mime = %q", e.MIME)
+	}
+	if !e.Created.Equal(created) || !e.Modified.Equal(modified) {
+		t.Errorf("times = %v/%v", e.Created, e.Modified)
+	}
+	if e.Provider != ProviderMySQL {
+		t.Errorf("provider = %q", e.Provider)
+	}
+}
+
+func TestFolderRowToEntry(t *testing.T) {
+	modified := time.Date(2026, 8, 1, 10, 30, 0, 0, time.UTC)
+	e := folderRowToEntry(pgFolderRow{id: 649, parentID: 647, title: "2025", modified: modified}, ProviderMySQL)
+	if e.ID != "649" || e.ParentID != "647" || e.Title != "2025" {
+		t.Errorf("folder = %+v", e)
+	}
+	if e.Kind != Folder {
+		t.Errorf("kind = %v, want folder", e.Kind)
+	}
+	if e.Size != 0 || e.MIME != "" {
+		t.Errorf("folder size/mime = %d/%q", e.Size, e.MIME)
+	}
+	if !e.Modified.Equal(modified) {
+		t.Errorf("modified = %v", e.Modified)
+	}
+}
+
+func TestPGStoreWriteMethodsReadOnly(t *testing.T) {
+	s := &pgStore{driver: ProviderPG}
+	ctx := context.Background()
+	if _, err := s.CreateFolder(ctx, "1", "x"); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("CreateFolder err = %v", err)
+	}
+	if _, err := s.Upload(ctx, "1", "x", nil); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("Upload err = %v", err)
+	}
+	if err := s.Move(ctx, nil, "1"); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("Move err = %v", err)
+	}
+	if err := s.Copy(ctx, nil, "1"); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("Copy err = %v", err)
+	}
+	if err := s.Rename(ctx, "1", "x"); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("Rename err = %v", err)
+	}
+	if err := s.Delete(ctx, nil); !errors.Is(err, ErrReadOnly) {
+		t.Errorf("Delete err = %v", err)
+	}
+}
+
+func TestPGStoreName(t *testing.T) {
+	if got := (&pgStore{driver: ProviderPG}).Name(); got != ProviderPG {
+		t.Errorf("Name = %q, want %q", got, ProviderPG)
+	}
+	if got := (&pgStore{driver: ProviderMySQL}).Name(); got != ProviderMySQL {
+		t.Errorf("Name = %q, want %q", got, ProviderMySQL)
+	}
+}
+
+func TestPGStoreStatRejectsNonNumeric(t *testing.T) {
+	s := &pgStore{driver: ProviderPG}
+	if _, err := s.Stat(context.Background(), "not-a-number"); err == nil {
+		t.Error("Stat accepted a non-numeric id")
+	}
+}

file_rest.go

@@ -0,0 +1,230 @@
+package onlyoffice
+
+// restStore implements FileStore on top of the REST Documents methods in
+// files.go. It is a thin adapter: no endpoint logic lives here, and every call
+// is wrapped in DoRetry.
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// restStore is a FileStore over the REST Documents API.
+type restStore struct{ c *Client }
+
+// Name reports the backend name.
+func (s *restStore) Name() string { return ProviderREST }
+
+// List returns the files and folders directly below parentID.
+func (s *restStore) List(ctx context.Context, parentID string) ([]Entry, error) {
+	var out []Entry
+	err := retryStoreOp(ctx, func() error {
+		raw, err := s.c.ListFolder(ctx, parentID)
+		if err != nil {
+			return err
+		}
+		entries, err := entriesFromFolderMap(raw, ProviderREST)
+		if err != nil {
+			return err
+		}
+		out = entries
+		return nil
+	})
+	return out, err
+}
+
+// Stat returns file metadata. The REST adapter resolves files only; folders
+// are listed by their parent (use List).
+func (s *restStore) Stat(ctx context.Context, id string) (Entry, error) {
+	var out Entry
+	err := retryStoreOp(ctx, func() error {
+		f, err := s.c.GetFile(ctx, id)
+		if err != nil {
+			return err
+		}
+		out = FileEntryToEntry(f, ProviderREST)
+		return nil
+	})
+	return out, err
+}
+
+// CreateFolder creates a subfolder under parentID.
+func (s *restStore) CreateFolder(ctx context.Context, parentID, title string) (Entry, error) {
+	var out Entry
+	err := retryStoreOp(ctx, func() error {
+		m, err := s.c.CreateFolder(ctx, parentID, title)
+		if err != nil {
+			return err
+		}
+		e, err := folderEntryFromMap(m, parentID, ProviderREST)
+		if err != nil {
+			return err
+		}
+		if e.ParentID == "" {
+			e.ParentID = parentID
+		}
+		if e.Title == "" {
+			e.Title = title
+		}
+		out = e
+		return nil
+	})
+	return out, err
+}
+
+// Upload streams r into parentID as title. UploadToFolder is path based, so
+// the reader is spooled to a temporary file first (ponytail: OnlyOffice
+// multipart upload buffers the whole body anyway).
+func (s *restStore) Upload(ctx context.Context, parentID, title string, r io.Reader) (Entry, error) {
+	dir, err := os.MkdirTemp("", "oo-rest-upload-")
+	if err != nil {
+		return Entry{}, err
+	}
+	defer os.RemoveAll(dir)
+
+	local := filepath.Join(dir, SafeLocalFileName(title))
+	f, err := os.Create(local)
+	if err != nil {
+		return Entry{}, err
+	}
+	if _, err := io.Copy(f, r); err != nil {
+		f.Close()
+		return Entry{}, err
+	}
+	if err := f.Close(); err != nil {
+		return Entry{}, err
+	}
+
+	var out Entry
+	err = retryStoreOp(ctx, func() error {
+		fe, err := s.c.UploadToFolder(ctx, parentID, local)
+		if err != nil {
+			return err
+		}
+		out = FileEntryToEntry(fe, ProviderREST)
+		return nil
+	})
+	return out, err
+}
+
+// Download streams the file bytes into w.
+func (s *restStore) Download(ctx context.Context, id string, w io.Writer) (int64, error) {
+	var n int64
+	err := retryStoreOp(ctx, func() error {
+		var e error
+		n, e = s.c.DownloadFile(ctx, id, w)
+		return e
+	})
+	return n, err
+}
+
+// Move moves file ids into parentID. The REST MoveFiles endpoint handles files
+// only; folder moves are not exposed by this adapter.
+func (s *restStore) Move(ctx context.Context, ids []string, parentID string) error {
+	dest, err := strconv.Atoi(strings.TrimSpace(parentID))
+	if err != nil {
+		return fmt.Errorf("onlyoffice: rest store: move: non-numeric destination folder id %q", parentID)
+	}
+	fileIDs, err := numericIDs(ids)
+	if err != nil {
+		return err
+	}
+	return retryStoreOp(ctx, func() error {
+		_, err := s.c.MoveFiles(ctx, dest, fileIDs)
+		return err
+	})
+}
+
+// Copy copies file ids into parentID. files.go has no copy method, so the
+// shared REST fileops copy endpoint (CopyDavItems) is used.
+func (s *restStore) Copy(ctx context.Context, ids []string, parentID string) error {
+	if len(ids) == 0 {
+		return nil
+	}
+	return retryStoreOp(ctx, func() error {
+		return s.c.CopyDavItems(ctx, nil, ids, parentID)
+	})
+}
+
+// Rename sets a new title (including extension) for a file.
+func (s *restStore) Rename(ctx context.Context, id, title string) error {
+	return retryStoreOp(ctx, func() error {
+		_, err := s.c.RenameFile(ctx, id, title)
+		return err
+	})
+}
+
+// Delete permanently deletes file ids.
+func (s *restStore) Delete(ctx context.Context, ids []string) error {
+	fileIDs, err := numericIDs(ids)
+	if err != nil {
+		return err
+	}
+	if len(fileIDs) == 0 {
+		return nil
+	}
+	return retryStoreOp(ctx, func() error {
+		return s.c.DeleteFiles(ctx, fileIDs)
+	})
+}
+
+// entriesFromFolderMap converts a ListFolder response map into canonical
+// entries, reusing the DavFile/DavFolder decoders for robust size handling.
+func entriesFromFolderMap(m map[string]any, provider string) ([]Entry, error) {
+	if m == nil {
+		return nil, nil
+	}
+	b, err := json.Marshal(m)
+	if err != nil {
+		return nil, err
+	}
+	var listing DavListing
+	if err := json.Unmarshal(b, &listing); err != nil {
+		return nil, err
+	}
+	out := make([]Entry, 0, len(listing.Folders)+len(listing.Files))
+	for _, f := range listing.Folders {
+		out = append(out, DavFolderToEntry(f, provider))
+	}
+	for _, f := range listing.Files {
+		out = append(out, DavFileToEntry(f, provider))
+	}
+	return out, nil
+}
+
+// folderEntryFromMap converts a CreateFolder response map into a folder Entry.
+func folderEntryFromMap(m map[string]any, parentID, provider string) (Entry, error) {
+	e := Entry{Kind: Folder, Provider: provider, ParentID: parentID}
+	if m == nil {
+		return e, nil
+	}
+	b, err := json.Marshal(m)
+	if err != nil {
+		return e, err
+	}
+	var f DavFolder
+	if err := json.Unmarshal(b, &f); err != nil {
+		return e, err
+	}
+	e = DavFolderToEntry(f, provider)
+	return e, nil
+}
+
+// numericIDs parses Documents numeric ids from strings.
+func numericIDs(ids []string) ([]int, error) {
+	out := make([]int, 0, len(ids))
+	for _, id := range ids {
+		n, err := strconv.Atoi(strings.TrimSpace(id))
+		if err != nil {
+			return nil, fmt.Errorf("onlyoffice: rest store: non-numeric id %q", id)
+		}
+		out = append(out, n)
+	}
+	return out, nil
+}

file_store_integration_test.go

@@ -0,0 +1,209 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"bytes"
+	"context"
+	"strconv"
+	"testing"
+	"time"
+)
+
+// TestIntegrationFileStores runs the same operation set (create folder, upload,
+// list, stat, download, move, copy, rename, delete) through the REST and DAV
+// FileStore adapters against a throwaway project Documents folder. Destructive
+// — only run against instances you own.
+//
+// The Documents fileops API is asynchronous: a move/copy/delete is accepted
+// immediately and becomes visible a moment later, so effects are polled.
+func TestIntegrationFileStores(t *testing.T) {
+	c := liveClient(t)
+	t.Cleanup(func() { cleanupTestProjects(t, c) })
+	ctx := context.Background()
+
+	suffix := time.Now().UTC().Format("20060102-150405")
+	project, err := c.CreateProject(NewProjectRequest{
+		Title:       testProjectPrefix + "store-" + suffix,
+		Description: "go-onlyoffice file store integration",
+	})
+	if err != nil {
+		t.Fatalf("CreateProject: %v", err)
+	}
+	if project.ID == nil {
+		t.Fatal("created project without id")
+	}
+	root, err := c.projectFolderID(ctx, strconv.Itoa(*project.ID))
+	if err != nil {
+		t.Fatalf("projectFolderID: %v", err)
+	}
+
+	for _, backend := range []string{ProviderREST, ProviderDAV} {
+		t.Run(backend, func(t *testing.T) {
+			testFileStoreOps(t, ctx, c, c.FileStore(backend), root, suffix)
+		})
+	}
+}
+
+func testFileStoreOps(t *testing.T, ctx context.Context, c *Client, store FileStore, root, suffix string) {
+	t.Helper()
+	content := []byte("file store " + store.Name() + " " + suffix + "\n")
+
+	src, err := store.CreateFolder(ctx, root, "fs-src-"+suffix)
+	if err != nil {
+		t.Fatalf("CreateFolder src: %v", err)
+	}
+	if src.Kind != Folder || src.ID == "" {
+		t.Fatalf("created src folder: %+v", src)
+	}
+	dst, err := store.CreateFolder(ctx, root, "fs-dst-"+suffix)
+	if err != nil {
+		t.Fatalf("CreateFolder dst: %v", err)
+	}
+	if dst.Kind != Folder || dst.ID == "" {
+		t.Fatalf("created dst folder: %+v", dst)
+	}
+	t.Cleanup(func() {
+		if err := c.DeleteDavItems(ctx, []string{src.ID, dst.ID}, nil); err != nil {
+			t.Logf("cleanup folders: %v", err)
+		}
+	})
+
+	up, err := store.Upload(ctx, src.ID, "doc-"+suffix+".txt", bytes.NewReader(content))
+	if err != nil {
+		t.Fatalf("Upload: %v", err)
+	}
+	if up.Kind != File || up.ID == "" {
+		t.Fatalf("uploaded entry: %+v", up)
+	}
+	if !waitEntry(ctx, store, src.ID, up.ID, 15*time.Second) {
+		t.Fatalf("uploaded %s not listed in src", up.ID)
+	}
+
+	st, err := store.Stat(ctx, up.ID)
+	if err != nil {
+		t.Fatalf("Stat: %v", err)
+	}
+	if st.ID != up.ID || st.Kind != File {
+		t.Fatalf("stat = %+v", st)
+	}
+
+	var buf bytes.Buffer
+	n, err := store.Download(ctx, up.ID, &buf)
+	if err != nil {
+		t.Fatalf("Download: %v", err)
+	}
+	if n != int64(len(content)) || !bytes.Equal(buf.Bytes(), content) {
+		t.Fatalf("download mismatch: got %d bytes %q want %d", n, buf.String(), len(content))
+	}
+
+	moveEventually(t, ctx, store, up.ID, dst.ID)
+	if !waitEntry(ctx, store, dst.ID, up.ID, 20*time.Second) {
+		t.Fatalf("moved file %s not in dst", up.ID)
+	}
+
+	if err := store.Copy(ctx, []string{up.ID}, src.ID); err != nil {
+		t.Fatalf("Copy: %v", err)
+	}
+	copied := waitOtherFile(ctx, store, src.ID, up.ID, 20*time.Second)
+	if copied == nil {
+		t.Fatalf("no copy found in src after Copy")
+	}
+
+	newTitle := "renamed-" + suffix + ".txt"
+	renameEventually(t, ctx, store, up.ID, newTitle)
+
+	if err := store.Delete(ctx, []string{up.ID, copied.ID}); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	if !waitNoEntry(ctx, store, dst.ID, up.ID, 20*time.Second) {
+		t.Fatalf("file %s still present in dst after delete", up.ID)
+	}
+	if !waitNoEntry(ctx, store, src.ID, copied.ID, 20*time.Second) {
+		t.Fatalf("copy %s still present in src after delete", copied.ID)
+	}
+}
+
+// moveEventually issues Move and retries while the operation is not visible yet
+// (the fileops API accepts asynchronously and occasionally rejects a move that
+// raced the just-finished upload).
+func moveEventually(t *testing.T, ctx context.Context, store FileStore, id, dstID string) {
+	t.Helper()
+	var lastErr error
+	for attempt := 0; attempt < 5; attempt++ {
+		if lastErr = store.Move(ctx, []string{id}, dstID); lastErr == nil {
+			if waitEntry(ctx, store, dstID, id, 6*time.Second) {
+				return
+			}
+		}
+		time.Sleep(time.Second)
+	}
+	t.Fatalf("Move %s -> %s: %v", id, dstID, lastErr)
+}
+
+func renameEventually(t *testing.T, ctx context.Context, store FileStore, id, title string) {
+	t.Helper()
+	var lastErr error
+	for attempt := 0; attempt < 5; attempt++ {
+		if lastErr = store.Rename(ctx, id, title); lastErr == nil {
+			if e, err := store.Stat(ctx, id); err == nil && e.Title == title {
+				return
+			}
+		}
+		time.Sleep(time.Second)
+	}
+	t.Fatalf("Rename %s -> %q: %v", id, title, lastErr)
+}
+
+func waitEntry(ctx context.Context, store FileStore, parentID, id string, d time.Duration) bool {
+	deadline := time.Now().Add(d)
+	for time.Now().Before(deadline) {
+		if list, err := store.List(ctx, parentID); err == nil && entryByID(list, id) != nil {
+			return true
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	return false
+}
+
+func waitNoEntry(ctx context.Context, store FileStore, parentID, id string, d time.Duration) bool {
+	deadline := time.Now().Add(d)
+	for time.Now().Before(deadline) {
+		if list, err := store.List(ctx, parentID); err == nil && entryByID(list, id) == nil {
+			return true
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	return false
+}
+
+func waitOtherFile(ctx context.Context, store FileStore, parentID, id string, d time.Duration) *Entry {
+	deadline := time.Now().Add(d)
+	for time.Now().Before(deadline) {
+		if list, err := store.List(ctx, parentID); err == nil {
+			if e := firstFileOtherThan(list, id); e != nil {
+				return e
+			}
+		}
+		time.Sleep(500 * time.Millisecond)
+	}
+	return nil
+}
+
+func entryByID(entries []Entry, id string) *Entry {
+	for i := range entries {
+		if entries[i].ID == id {
+			return &entries[i]
+		}
+	}
+	return nil
+}
+
+func firstFileOtherThan(entries []Entry, id string) *Entry {
+	for i := range entries {
+		if entries[i].Kind == File && entries[i].ID != id {
+			return &entries[i]
+		}
+	}
+	return nil
+}

file_text_index.go

@@ -0,0 +1,337 @@
+package onlyoffice
+
+// Text extraction pipeline for the own full-text index (epic #34, F6 #42).
+//
+// TextIndexer downloads stored documents, extracts text through docpipe
+// (pdftotext; OCR for scans) and writes the result to a TextIndex. For PDFs it
+// also indexes the text of embedded attachments (pdfdetach), so a scan filed
+// as an attachment is searchable too. It is the write side of ESTextIndex and
+// never touches the OnlyOffice server's own ES index.
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+
+	"github.com/eslider/go-onlyoffice/internal/docpipe"
+)
+
+// defaultTextIndexExts are the formats extracted by default. The OnlyOffice
+// index already covers docx/xlsx/pptx; F6 adds PDF.
+var defaultTextIndexExts = []string{"pdf"}
+
+const (
+	defaultTextIndexWorkers = 3
+	defaultTextIndexLang    = "deu+eng"
+	maxTextIndexErrors      = 20
+)
+
+// TextExtractor turns a local file into indexable plain text. The default uses
+// docpipe (pdftotext + OCR); tests inject a fake to stay offline.
+type TextExtractor interface {
+	Extract(path, workDir, lang string, minChars int) (string, error)
+}
+
+// docpipeExtractor is the production TextExtractor.
+type docpipeExtractor struct{ tools docpipe.Tools }
+
+// Extract renders the file as Markdown, OCRing PDFs/images with a weak text
+// layer first and appending the text of embedded PDF attachments
+// (docpipe.ToMarkdownWithAttachments).
+func (d docpipeExtractor) Extract(path, workDir, lang string, minChars int) (string, error) {
+	text, err := d.tools.ToMarkdownWithAttachments(path, workDir, lang, minChars)
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(text), nil
+}
+
+// IndexOptions controls a TextIndexer run.
+type IndexOptions struct {
+	Recursive  bool     // IndexFolder: descend into subfolders
+	Extensions []string // empty = defaultTextIndexExts (pdf)
+	Limit      int      // max files to index, 0 = all
+	Lang       string   // OCR language(s), default deu+eng
+	MinChars   int      // OCR threshold, default docpipe.DefaultMinTextChars
+	Workers    int      // parallel downloads/extractions, default 3
+}
+
+// IndexResult summarises a run.
+type IndexResult struct {
+	Scanned int
+	Indexed int
+	Skipped int
+	Failed  int
+	Errors  []string
+}
+
+// TextIndexer wires a FileStore, a TextIndex and an extractor together.
+type TextIndexer struct {
+	Store     FileStore
+	Index     TextIndex
+	Extractor TextExtractor // nil = local docpipe tools
+	WorkDir   string        // temp dir for downloads/extraction
+}
+
+// NewTextIndexer returns a TextIndexer over the given store and index.
+func NewTextIndexer(store FileStore, index TextIndex) *TextIndexer {
+	return &TextIndexer{Store: store, Index: index}
+}
+
+// textIndexEnsurer is implemented by indexes that can be created up front.
+type textIndexEnsurer interface {
+	Ensure(ctx context.Context) error
+}
+
+// Ensure creates the backing index when the TextIndex supports it.
+func (ix *TextIndexer) Ensure(ctx context.Context) error {
+	if e, ok := ix.Index.(textIndexEnsurer); ok {
+		return e.Ensure(ctx)
+	}
+	return nil
+}
+
+// IndexFiles stats the given file ids and indexes them.
+func (ix *TextIndexer) IndexFiles(ctx context.Context, ids []string, opts IndexOptions) (IndexResult, error) {
+	entries := make([]Entry, 0, len(ids))
+	for _, id := range ids {
+		e, err := ix.Store.Stat(ctx, id)
+		if err != nil {
+			return IndexResult{}, fmt.Errorf("onlyoffice: stat %s: %w", id, err)
+		}
+		entries = append(entries, e)
+	}
+	return ix.IndexEntries(ctx, entries, opts)
+}
+
+// IndexFolder lists a folder and indexes every matching file.
+func (ix *TextIndexer) IndexFolder(ctx context.Context, folderID string, opts IndexOptions) (IndexResult, error) {
+	entries, err := ix.collect(ctx, folderID, opts.Recursive)
+	if err != nil {
+		return IndexResult{}, err
+	}
+	return ix.IndexEntries(ctx, entries, opts)
+}
+
+// PlanFolder lists the files IndexFolder would process, without downloading or
+// extracting anything.
+func (ix *TextIndexer) PlanFolder(ctx context.Context, folderID string, opts IndexOptions) ([]Entry, error) {
+	entries, err := ix.collect(ctx, folderID, opts.Recursive)
+	if err != nil {
+		return nil, err
+	}
+	return selectEntries(entries, opts), nil
+}
+
+// PlanFiles stats the ids and returns those that would be indexed.
+func (ix *TextIndexer) PlanFiles(ctx context.Context, ids []string, opts IndexOptions) ([]Entry, error) {
+	entries := make([]Entry, 0, len(ids))
+	for _, id := range ids {
+		e, err := ix.Store.Stat(ctx, id)
+		if err != nil {
+			return nil, fmt.Errorf("onlyoffice: stat %s: %w", id, err)
+		}
+		entries = append(entries, e)
+	}
+	return selectEntries(entries, opts), nil
+}
+
+// IndexEntries extracts and indexes the given files (folders are ignored).
+func (ix *TextIndexer) IndexEntries(ctx context.Context, entries []Entry, opts IndexOptions) (IndexResult, error) {
+	opts = opts.withDefaults()
+	var res IndexResult
+	work := selectEntries(entries, opts)
+	res.Scanned = len(entries)
+	res.Skipped = len(entries) - len(work)
+	if len(work) == 0 {
+		return res, nil
+	}
+
+	workers := opts.Workers
+	if workers > len(work) {
+		workers = len(work)
+	}
+	if workers < 1 {
+		workers = 1
+	}
+
+	type outcome struct {
+		doc TextDoc
+		err error
+	}
+	jobs := make(chan Entry)
+	results := make(chan outcome, workers)
+	var wg sync.WaitGroup
+	for i := 0; i < workers; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for e := range jobs {
+				if err := ctx.Err(); err != nil {
+					results <- outcome{err: err}
+					continue
+				}
+				doc, err := ix.indexOne(ctx, e, opts)
+				results <- outcome{doc: doc, err: err}
+			}
+		}()
+	}
+	go func() {
+		defer close(jobs)
+		for _, e := range work {
+			select {
+			case jobs <- e:
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+	go func() {
+		wg.Wait()
+		close(results)
+	}()
+
+	var docs []TextDoc
+	for r := range results {
+		if r.err != nil {
+			res.Failed++
+			if len(res.Errors) < maxTextIndexErrors {
+				res.Errors = append(res.Errors, r.err.Error())
+			}
+			continue
+		}
+		docs = append(docs, r.doc)
+	}
+	if err := ctx.Err(); err != nil {
+		return res, err
+	}
+	if len(docs) > 0 {
+		if err := ix.Index.Put(ctx, docs); err != nil {
+			return res, fmt.Errorf("onlyoffice: index %d docs: %w", len(docs), err)
+		}
+		res.Indexed = len(docs)
+	}
+	return res, nil
+}
+
+// indexOne downloads and extracts a single file.
+func (ix *TextIndexer) indexOne(ctx context.Context, e Entry, opts IndexOptions) (TextDoc, error) {
+	ext := fileExt(e.Title)
+	dir := ix.WorkDir
+	if dir == "" {
+		dir = os.TempDir()
+	}
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return TextDoc{}, err
+	}
+	tmp, err := os.CreateTemp(dir, "ooidx-*."+ext)
+	if err != nil {
+		return TextDoc{}, err
+	}
+	tmpPath := tmp.Name()
+	defer os.Remove(tmpPath)
+
+	if _, err := ix.Store.Download(ctx, e.ID, tmp); err != nil {
+		tmp.Close()
+		return TextDoc{}, fmt.Errorf("download %s (%s): %w", e.ID, e.Title, err)
+	}
+	if err := tmp.Close(); err != nil {
+		return TextDoc{}, err
+	}
+	text, err := ix.extractor().Extract(tmpPath, dir, opts.Lang, opts.MinChars)
+	if err != nil {
+		return TextDoc{}, fmt.Errorf("extract %s: %w", e.Title, err)
+	}
+	return TextDoc{ID: e.ID, Title: e.Title, FolderID: e.ParentID, Ext: ext, Content: text}, nil
+}
+
+// collect lists files under folderID, breadth-first when recursive.
+func (ix *TextIndexer) collect(ctx context.Context, folderID string, recursive bool) ([]Entry, error) {
+	var files []Entry
+	queue := []string{folderID}
+	for len(queue) > 0 {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		id := queue[0]
+		queue = queue[1:]
+		entries, err := ix.Store.List(ctx, id)
+		if err != nil {
+			return nil, fmt.Errorf("onlyoffice: list folder %s: %w", id, err)
+		}
+		for _, e := range entries {
+			if e.Kind == Folder {
+				if recursive {
+					queue = append(queue, e.ID)
+				}
+				continue
+			}
+			if e.ParentID == "" {
+				e.ParentID = id
+			}
+			files = append(files, e)
+		}
+	}
+	return files, nil
+}
+
+// selectEntries filters files by extension and applies the limit.
+func selectEntries(entries []Entry, opts IndexOptions) []Entry {
+	allowed := extensionSet(opts.Extensions)
+	work := make([]Entry, 0, len(entries))
+	for _, e := range entries {
+		if e.Kind != File {
+			continue
+		}
+		if opts.Limit > 0 && len(work) >= opts.Limit {
+			break
+		}
+		if !allowed[fileExt(e.Title)] {
+			continue
+		}
+		work = append(work, e)
+	}
+	return work
+}
+
+// extensionSet normalises the extension allow-list (default: pdf).
+func extensionSet(exts []string) map[string]bool {
+	if len(exts) == 0 {
+		exts = defaultTextIndexExts
+	}
+	set := make(map[string]bool, len(exts))
+	for _, e := range normalizeExtensions(exts) {
+		set[e] = true
+	}
+	return set
+}
+
+// fileExt returns the lower-case extension without the dot.
+func fileExt(title string) string {
+	return strings.ToLower(strings.TrimPrefix(filepath.Ext(strings.TrimSpace(title)), "."))
+}
+
+// withDefaults fills zero-valued options.
+func (o IndexOptions) withDefaults() IndexOptions {
+	if o.Workers <= 0 {
+		o.Workers = defaultTextIndexWorkers
+	}
+	if o.MinChars <= 0 {
+		o.MinChars = docpipe.DefaultMinTextChars
+	}
+	if strings.TrimSpace(o.Lang) == "" {
+		o.Lang = defaultTextIndexLang
+	}
+	return o
+}
+
+// extractor returns the configured extractor or the local docpipe default.
+func (ix *TextIndexer) extractor() TextExtractor {
+	if ix.Extractor != nil {
+		return ix.Extractor
+	}
+	return docpipeExtractor{tools: docpipe.LookPath()}
+}

files.go

@@ -247,6 +247,8 @@ func (c *Client) UploadProjectFileReplacing(ctx context.Context, projectID, loca
 }
 
 // GetFile returns file metadata including viewUrl for download.
+//
+// Deprecated: use FileStore.Stat via Client.Files()/Client.FileStore.
 func (c *Client) GetFile(ctx context.Context, fileID string) (*FileEntry, error) {
 	if fileID == "" {
 		return nil, fmt.Errorf("file id is required")
@@ -260,6 +262,8 @@ func (c *Client) GetFile(ctx context.Context, fileID string) (*FileEntry, error)
 }
 
 // RenameFile sets a new title (including extension) for the file.
+//
+// Deprecated: use FileStore.Rename via Client.Files()/Client.FileStore.
 func (c *Client) RenameFile(ctx context.Context, fileID, newTitle string) (*FileEntry, error) {
 	if fileID == "" || newTitle == "" {
 		return nil, fmt.Errorf("file id and new title are required")
@@ -275,6 +279,8 @@ func (c *Client) RenameFile(ctx context.Context, fileID, newTitle string) (*File
 // DeleteFiles permanently deletes files by numeric id (Documents module).
 // Uses per-file DELETE (DeleteDavItems); fileops/delete returns 200 on some
 // portals (e.g. produktor.io) without removing the file.
+//
+// Deprecated: use FileStore.Delete via Client.Files()/Client.FileStore.
 func (c *Client) DeleteFiles(ctx context.Context, fileIDs []int) error {
 	if len(fileIDs) == 0 {
 		return fmt.Errorf("no file ids to delete")
@@ -288,6 +294,8 @@ func (c *Client) DeleteFiles(ctx context.Context, fileIDs []int) error {
 
 // ListFolder returns the Documents module listing for a folder id
 // (GET /api/2.0/files/{folderId}).
+//
+// Deprecated: use FileStore.List via Client.Files()/Client.FileStore.
 func (c *Client) ListFolder(ctx context.Context, folderID string) (map[string]any, error) {
 	if folderID == "" {
 		return nil, fmt.Errorf("folder id is required")
@@ -313,6 +321,8 @@ func (c *Client) CreateFolder(ctx context.Context, parentFolderID, title string)
 }
 
 // MoveFiles moves file ids into destFolderID (Documents fileops/move).
+//
+// Deprecated: use FileStore.Move via Client.Files()/Client.FileStore.
 func (c *Client) MoveFiles(ctx context.Context, destFolderID int, fileIDs []int) (map[string]any, error) {
 	if destFolderID == 0 || len(fileIDs) == 0 {
 		return nil, fmt.Errorf("dest folder and file ids are required")
@@ -324,22 +334,27 @@ func (c *Client) MoveFiles(ctx context.Context, destFolderID int, fileIDs []int)
 		"resolveType":  "Skip",
 		"holdResult":   true,
 	}
-	out, err := c.putJSONObject(ctx, "/api/2.0/files/fileops/move.json", body)
+	// fileops/move answers an operations envelope (like MoveDavItems), not a
+	// single object, so parse the raw body before unwrapping and surface any
+	// per-operation error. Unwrapping first (putJSONObject) made fileopsError
+	// look for a "response" key that was already stripped.
+	raw, err := c.putJSON(ctx, "/api/2.0/files/fileops/move", body)
 	if err != nil {
-		out, err = c.putJSONObject(ctx, "/api/2.0/files/fileops/move", body)
+		raw, err = c.putJSON(ctx, "/api/2.0/files/fileops/move.json", body)
-	}
+		if err != nil {
-	if err != nil {
+			return nil, err
-		return nil, err
-	}
-	if raw, merr := json.Marshal(out); merr == nil {
-		if ferr := fileopsError(raw); ferr != nil {
-			return nil, ferr
 		}
 	}
-	return out, err
+	if ferr := fileopsError(raw); ferr != nil {
+		return nil, ferr
+	}
+	out, _ := unmarshalResponseObject(raw)
+	return out, nil
 }
 
 // UploadToFolder uploads a local file into an arbitrary Documents folder id.
+//
+// Deprecated: use FileStore.Upload via Client.Files()/Client.FileStore.
 func (c *Client) UploadToFolder(ctx context.Context, folderID, localPath string) (*FileEntry, error) {
 	if folderID == "" || localPath == "" {
 		return nil, fmt.Errorf("folder id and local path are required")
@@ -358,20 +373,31 @@ func (c *Client) UploadToFolder(ctx context.Context, folderID, localPath string)
 
 // UpdateFile uploads a new version of an existing file (same id, name and
 // folder). It does not delete and does not create a second file.
+//
+// The Documents API method is PUT /api/2.0/files/{id}/update; POST is kept as
+// a fallback for older servers. The path is tried with and without .json.
 func (c *Client) UpdateFile(ctx context.Context, fileID, localPath string) (*FileEntry, error) {
 	if fileID == "" || localPath == "" {
 		return nil, fmt.Errorf("file id and local path are required")
 	}
-	uploadPath := fmt.Sprintf("/api/2.0/files/%s/update", url.PathEscape(fileID))
+	base := fmt.Sprintf("/api/2.0/files/%s/update", url.PathEscape(fileID))
-	raw, err := c.uploadMultipart(ctx, uploadPath, "file", localPath)
+	attempts := []struct {
-	if err != nil {
+		method, path string
-		uploadPath = fmt.Sprintf("/api/2.0/files/%s/update.json", url.PathEscape(fileID))
+	}{
-		raw, err = c.uploadMultipart(ctx, uploadPath, "file", localPath)
+		{http.MethodPut, base},
-		if err != nil {
+		{http.MethodPut, base + ".json"},
-			return nil, err
+		{http.MethodPost, base},
-		}
+		{http.MethodPost, base + ".json"},
 	}
-	return decodeResponseFileEntry(raw)
+	var lastErr error
+	for _, a := range attempts {
+		raw, err := c.uploadMultipartMethod(ctx, a.method, a.path, "file", localPath)
+		if err == nil {
+			return decodeResponseFileEntry(raw)
+		}
+		lastErr = err
+	}
+	return nil, lastErr
 }
 
 // FileFolderID returns the parent folder id string for a file entry, if known.
@@ -383,36 +409,17 @@ func FileFolderID(f *FileEntry) string {
 }
 
 // DownloadFile streams file bytes from the file's viewUrl using the same auth
-// as API calls. Writes into dst.
+// as API calls. Writes into dst. When the portal serves the file from its stale
+// AWS S3 consumer, the bytes are fetched from the local MinIO store instead
+// (see storage_fallback.go).
+//
+// Deprecated: use FileStore.Download via Client.Files()/Client.FileStore.
 func (c *Client) DownloadFile(ctx context.Context, fileID string, dst io.Writer) (int64, error) {
 	f, err := c.GetFile(ctx, fileID)
 	if err != nil {
 		return 0, err
 	}
-	if f.ViewURL == nil || *f.ViewURL == "" {
+	return c.downloadFileEntry(ctx, f, dst)
-		return 0, fmt.Errorf("file %s has no viewUrl", fileID)
-	}
-	downloadURL := c.resolveAPIURL(*f.ViewURL)
-	auth, err := c.authHeader()
-	if err != nil {
-		return 0, err
-	}
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, downloadURL, nil)
-	if err != nil {
-		return 0, err
-	}
-	req.Header.Set("Authorization", auth)
-	resp, err := c.client.Do(req)
-	if err != nil {
-		return 0, err
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode >= 400 {
-		b, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
-		return 0, fmt.Errorf("GET viewUrl: %d %s", resp.StatusCode, truncate(string(b), 400))
-	}
-	n, err := io.Copy(dst, resp.Body)
-	return n, err
 }
 
 func (c *Client) resolveAPIURL(ref string) string {

files_path.go

@@ -0,0 +1,79 @@
+package onlyoffice
+
+// Human-readable folder paths for search results (F9). The OnlyOffice ES
+// index stores only ancestor folder ids; titles live in the Documents tree, so
+// resolving a path costs one GET /api/2.0/files/{id} per distinct folder,
+// cached on the client. Folders that cannot be listed (e.g. a section root)
+// fall back to their id, so a path is always produced.
+
+import (
+	"context"
+	"strings"
+)
+
+// FolderTitle returns the title of a Documents folder id, cached on the client.
+// An empty id yields an empty title. Unknown/unlistable ids (section roots)
+// return ("", nil) so callers can fall back to the id.
+func (c *Client) FolderTitle(ctx context.Context, folderID string) (string, error) {
+	folderID = strings.TrimSpace(folderID)
+	if folderID == "" {
+		return "", nil
+	}
+	c.folderTitlesMu.Lock()
+	if c.folderTitles != nil {
+		if t, ok := c.folderTitles[folderID]; ok {
+			c.folderTitlesMu.Unlock()
+			return t, nil
+		}
+	}
+	c.folderTitlesMu.Unlock()
+
+	title := ""
+	out, err := c.ListFolder(ctx, folderID)
+	if err == nil {
+		if cur, ok := out["current"].(map[string]any); ok {
+			if s, ok := cur["title"].(string); ok {
+				title = strings.TrimSpace(s)
+			}
+		}
+	}
+
+	c.folderTitlesMu.Lock()
+	if c.folderTitles == nil {
+		c.folderTitles = map[string]string{}
+	}
+	c.folderTitles[folderID] = title
+	c.folderTitlesMu.Unlock()
+	return title, nil
+}
+
+// FolderPath resolves an ancestor folder id chain (root → leaf, as the ES
+// backend reports it) into folder titles, falling back to the id when a title
+// cannot be read. The result never fails on a single lookup: only the whole
+// call honours ctx cancellation.
+func (c *Client) FolderPath(ctx context.Context, ids []string) []string {
+	out := make([]string, 0, len(ids))
+	for _, id := range ids {
+		if err := ctx.Err(); err != nil {
+			break
+		}
+		title, err := c.FolderTitle(ctx, id)
+		if err != nil || title == "" {
+			title = id
+		}
+		out = append(out, title)
+	}
+	return out
+}
+
+// UniquePath builds a stable, human-readable, unique path for a result: the
+// resolved folder chain plus the file title. "." separates nothing — the
+// segments are joined with "/", matching the Documents breadcrumb the web UI
+// shows.
+func (c *Client) UniquePath(ctx context.Context, folderPath []string, title string) string {
+	parts := c.FolderPath(ctx, folderPath)
+	if t := strings.TrimSpace(title); t != "" {
+		parts = append(parts, t)
+	}
+	return strings.Join(parts, "/")
+}

files_path_integration_test.go

@@ -0,0 +1,35 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"context"
+	"strings"
+	"testing"
+)
+
+// TestIntegrationFolderPath resolves the real Fibu EDL folder chain
+// (project root 522 → Eingangsrechnungen 647 → 2025 649) to titles.
+func TestIntegrationFolderPath(t *testing.T) {
+	creds := GetEnvironmentCredentials()
+	if strings.TrimSpace(creds.Url) == "" || strings.TrimSpace(creds.User) == "" {
+		t.Skip("no ONLYOFFICE_URL/USER credentials")
+	}
+	c := NewClient(creds)
+	ctx := context.Background()
+
+	path := c.FolderPath(ctx, []string{"522", "647", "649"})
+	if len(path) != 3 {
+		t.Fatalf("FolderPath returned %v, want 3 segments", path)
+	}
+	for i, seg := range path {
+		if strings.TrimSpace(seg) == "" {
+			t.Errorf("segment %d empty: %v", i, path)
+		}
+	}
+	full := c.UniquePath(ctx, []string{"522", "647", "649"}, "Rechnung-x.pdf")
+	if !strings.HasSuffix(full, "Rechnung-x.pdf") || !strings.Contains(full, "/") {
+		t.Errorf("UniquePath = %q, want a slash-joined path ending in the file", full)
+	}
+	t.Logf("path=%v full=%q", path, full)
+}

files_webdav.go

@@ -52,6 +52,8 @@ type DavListing struct {
 
 // ListDavFolder returns the contents of a folder by id, which may be a
 // symbolic root such as "@my". For "@root" use ListDavSections.
+//
+// Deprecated: use FileStore.List via Client.Files()/Client.FileStore.
 func (c *Client) ListDavFolder(ctx context.Context, id string) (*DavListing, error) {
 	raw, err := c.getJSON(ctx, "/api/2.0/files/"+url.PathEscape(id))
 	if err != nil {
@@ -111,6 +113,8 @@ func (c *Client) ListDavSections(ctx context.Context) ([]DavFolder, error) {
 }
 
 // CreateDavFolder creates a folder titled title inside parentID.
+//
+// Deprecated: use FileStore.CreateFolder via Client.Files()/Client.FileStore.
 func (c *Client) CreateDavFolder(ctx context.Context, parentID, title string) (*DavFolder, error) {
 	raw, err := c.postJSON(ctx, "/api/2.0/files/folder/"+url.PathEscape(parentID),
 		map[string]string{"title": title})
@@ -130,6 +134,8 @@ func (c *Client) CreateDavFolder(ctx context.Context, parentID, title string) (*
 }
 
 // RenameDavFolder renames a folder.
+//
+// Deprecated: use FileStore.Rename via Client.Files()/Client.FileStore.
 func (c *Client) RenameDavFolder(ctx context.Context, id, title string) error {
 	_, err := c.putJSON(ctx, "/api/2.0/files/folder/"+url.PathEscape(id),
 		map[string]string{"title": title})
@@ -137,6 +143,8 @@ func (c *Client) RenameDavFolder(ctx context.Context, id, title string) error {
 }
 
 // RenameDavFile renames a file (title includes the extension).
+//
+// Deprecated: use FileStore.Rename via Client.Files()/Client.FileStore.
 func (c *Client) RenameDavFile(ctx context.Context, id, title string) error {
 	_, err := c.putJSON(ctx, "/api/2.0/files/file/"+url.PathEscape(id),
 		map[string]string{"title": title})
@@ -147,6 +155,8 @@ func (c *Client) RenameDavFile(ctx context.Context, id, title string) error {
 // The fileops API answers 200 with per-operation error strings even when
 // nothing moves (e.g. missing permission), so the response is parsed and the
 // first operation error is returned instead of a silent nil.
+//
+// Deprecated: use FileStore.Move via Client.Files()/Client.FileStore.
 func (c *Client) MoveDavItems(ctx context.Context, folderIDs, fileIDs []string, destFolderID string) error {
 	raw, err := c.putJSON(ctx, "/api/2.0/files/fileops/move", map[string]any{
 		"folderIds":    nums(folderIDs),
@@ -163,6 +173,8 @@ func (c *Client) MoveDavItems(ctx context.Context, folderIDs, fileIDs []string,
 
 // CopyDavItems copies the given folders and/or files into destFolderID.
 // Per-operation errors are surfaced like in MoveDavItems.
+//
+// Deprecated: use FileStore.Copy via Client.Files()/Client.FileStore.
 func (c *Client) CopyDavItems(ctx context.Context, folderIDs, fileIDs []string, destFolderID string) error {
 	raw, err := c.putJSON(ctx, "/api/2.0/files/fileops/copy", map[string]any{
 		"folderIds":           nums(folderIDs),
@@ -226,6 +238,8 @@ func fileopsError(raw json.RawMessage) error {
 }
 
 // DeleteDavItems deletes the given folders and/or files.
+//
+// Deprecated: use FileStore.Delete via Client.Files()/Client.FileStore.
 func (c *Client) DeleteDavItems(ctx context.Context, folderIDs, fileIDs []string) error {
 	body := map[string]any{"DeleteAfter": true, "Immediately": true}
 	for _, id := range folderIDs {
@@ -242,6 +256,8 @@ func (c *Client) DeleteDavItems(ctx context.Context, folderIDs, fileIDs []string
 }
 
 // UploadDavFile uploads src (fileName) into folderID, streaming from src.
+//
+// Deprecated: use FileStore.Upload via Client.Files()/Client.FileStore.
 func (c *Client) UploadDavFile(ctx context.Context, folderID, fileName string, src io.Reader) (*DavFile, error) {
 	raw, err := c.uploadReader(ctx, "/api/2.0/files/"+url.PathEscape(folderID)+"/upload", "file", fileName, src)
 	if err != nil {
@@ -259,34 +275,12 @@ func (c *Client) UploadDavFile(ctx context.Context, folderID, fileName string, s
 	return env.Response, nil
 }
 
-// DownloadDavFile streams the file identified by id to w, returning bytes copied.
+// DownloadDavFile streams the file identified by id to w, returning bytes
+// copied. It shares the MinIO stale-S3 fallback with DownloadFile.
+//
+// Deprecated: use FileStore.Download via Client.Files()/Client.FileStore.
 func (c *Client) DownloadDavFile(ctx context.Context, id string, w io.Writer) (int64, error) {
-	file, err := c.GetFile(ctx, id)
+	return c.DownloadFile(ctx, id, w)
-	if err != nil {
-		return 0, err
-	}
-	if file.ViewURL == nil || *file.ViewURL == "" {
-		return 0, fmt.Errorf("onlyoffice: file %s has no viewUrl", id)
-	}
-	u := c.resolveAPIURL(*file.ViewURL)
-	auth, err := c.authHeader()
-	if err != nil {
-		return 0, err
-	}
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
-	if err != nil {
-		return 0, err
-	}
-	req.Header.Set("Authorization", auth)
-	resp, err := c.client.Do(req)
-	if err != nil {
-		return 0, err
-	}
-	defer resp.Body.Close()
-	if resp.StatusCode >= 400 {
-		return 0, fmt.Errorf("onlyoffice: download: %d", resp.StatusCode)
-	}
-	return io.Copy(w, resp.Body)
 }
 
 // --- internal helpers -------------------------------------------------------
@@ -434,12 +428,12 @@ func (f *DavFolder) UnmarshalJSON(b []byte) error {
 // UnmarshalJSON decodes a file row, capturing size and timestamps.
 func (f *DavFile) UnmarshalJSON(b []byte) error {
 	var raw struct {
-		ID        *json.Number `json:"id"`
+		ID       *json.Number `json:"id"`
-		Title     *string      `json:"title"`
+		Title    *string      `json:"title"`
-		PureSize  *int64       `json:"pureContentLength"`
+		PureSize *int64       `json:"pureContentLength"`
-		SizeStr   *string      `json:"contentLength"`
+		SizeStr  *string      `json:"contentLength"`
-		Updated   *string      `json:"updated"`
+		Updated  *string      `json:"updated"`
-		ViewURL   *string      `json:"viewUrl"`
+		ViewURL  *string      `json:"viewUrl"`
 	}
 	if err := json.Unmarshal(b, &raw); err != nil {
 		return err

go.mod

@@ -4,6 +4,7 @@ go 1.25.0
 
 require (
 	github.com/JohannesKaufmann/html-to-markdown/v2 v2.5.2
+	github.com/aws/aws-sdk-go-v2 v1.41.1
 	github.com/charmbracelet/bubbles v0.18.0
 	github.com/charmbracelet/bubbletea v0.25.0
 	github.com/charmbracelet/glamour v0.8.0
@@ -12,7 +13,9 @@ require (
 	github.com/emersion/go-vcard v0.0.0-20260618161152-d854b7e0e2d3
 	github.com/eslider/go-hocr v0.2.2-0.20260827163626-8ff01582b002
 	github.com/eslider/go-xls/v2 v2.1.0
+	github.com/go-sql-driver/mysql v1.10.1
 	github.com/google/go-querystring v1.2.0
+	github.com/jackc/pgx/v5 v5.11.0
 	github.com/joho/godotenv v1.5.1
 	github.com/mattn/go-runewidth v0.0.15
 	github.com/muesli/termenv v0.16.0
@@ -23,9 +26,11 @@ require (
 )
 
 require (
+	filippo.io/edwards25519 v1.2.0 // indirect
 	github.com/JohannesKaufmann/dom v0.3.1 // indirect
 	github.com/alecthomas/chroma/v2 v2.14.0 // indirect
 	github.com/atotto/clipboard v0.1.4 // indirect
+	github.com/aws/smithy-go v1.24.0 // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81 // indirect
@@ -34,6 +39,10 @@ require (
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/css v1.0.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	github.com/kr/text v0.2.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.24 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
@@ -46,6 +55,7 @@ require (
 	github.com/richardlehane/mscfb v1.0.7 // indirect
 	github.com/richardlehane/msoleps v1.0.6 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
+	github.com/rogpeppe/go-internal v1.16.0 // indirect
 	github.com/spf13/pflag v1.0.9 // indirect
 	github.com/tiendc/go-deepcopy v1.7.2 // indirect
 	github.com/xuri/efp v0.0.1 // indirect

go.sum

@@ -1,3 +1,5 @@
+filippo.io/edwards25519 v1.2.0 h1:crnVqOiS4jqYleHd9vaKZ+HKtHfllngJIiOpNpoJsjo=
+filippo.io/edwards25519 v1.2.0/go.mod h1:xzAOLCNug/yB62zG1bQ8uziwrIqIuxhctzJT18Q77mc=
 github.com/JohannesKaufmann/dom v0.3.1 h1:J16l9JAHWgkFPR3VIPbQ1gvS0cWab6laK1q7PFL3qh0=
 github.com/JohannesKaufmann/dom v0.3.1/go.mod h1:BZPkf8ZeYrBgABjwJn9iiKt8aiCtkxpHkevms+Yp2DE=
 github.com/JohannesKaufmann/html-to-markdown/v2 v2.5.2 h1:XFJZFWESIWlUEHHjzBuv8RvrtCWnSGlimEX17ysSDb8=
@@ -10,6 +12,10 @@ github.com/alecthomas/repr v0.4.0 h1:GhI2A8MACjfegCPVq9f1FLvIBS+DrQ2KQBFZP1iFzXc
 github.com/alecthomas/repr v0.4.0/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
 github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z4=
 github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
+github.com/aws/aws-sdk-go-v2 v1.41.1 h1:ABlyEARCDLN034NhxlRUSZr4l71mh+T5KAeGh6cerhU=
+github.com/aws/aws-sdk-go-v2 v1.41.1/go.mod h1:MayyLB8y+buD9hZqkCW3kX1AKq07Y5pXxtgB+rRFhz0=
+github.com/aws/smithy-go v1.24.0 h1:LpilSUItNPFr1eY85RYgTIg5eIEPtvFbskaFcmmIUnk=
+github.com/aws/smithy-go v1.24.0/go.mod h1:LEj2LM3rBRQJxPZTB4KuzZkaZYnZPnvgIhb4pu07mx0=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
 github.com/aymanbagabas/go-udiff v0.2.0 h1:TK0fH4MteXUDspT88n8CKzvK0X9O2xu9yQjWpi6yML8=
@@ -31,6 +37,8 @@ github.com/charmbracelet/x/exp/golden v0.0.0-20240715153702-9ba8adf781c4/go.mod
 github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81 h1:q2hJAaP1k2wIvVRd/hEHD7lacgqrCPS+k8g1MndzfWY=
 github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81/go.mod h1:YynlIjWYF8myEu6sdkwKIvGQq+cOckRm6So2avqoYAk=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dlclark/regexp2 v1.11.0 h1:G/nrcoOa7ZXlpoa/91N3X7mM3r8eIlMBBJZvsz/mxKI=
@@ -43,6 +51,8 @@ github.com/eslider/go-hocr v0.2.2-0.20260827163626-8ff01582b002 h1:LOFxQG4mxvlH7
 github.com/eslider/go-hocr v0.2.2-0.20260827163626-8ff01582b002/go.mod h1:fIgfH/E1j3rU8du4X4+7mxTD0GPtPQibTzytgitdJWU=
 github.com/eslider/go-xls/v2 v2.1.0 h1:HszWKqYQbXxACmAXXWdMsfNl1NDBfGVBnJUPtyUHQ7A=
 github.com/eslider/go-xls/v2 v2.1.0/go.mod h1:xgxO6JrfuBr9jGUB+0z5l/yDmFFZ5diGk0ATGihxlMU=
+github.com/go-sql-driver/mysql v1.10.1 h1:arlSnNLq6a5yxGxV7qg9lF4j0C+KwD6NbQyKr9QL6ME=
+github.com/go-sql-driver/mysql v1.10.1/go.mod h1:M+cqaI7+xxXGG9swrdeUIoPG3Y3KCkF0pZej+SK+nWk=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/go-querystring v1.2.0 h1:yhqkPbu2/OH+V9BfpCVPZkNmUXhb2gBxJArfhIxNtP0=
@@ -59,8 +69,20 @@ github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUq
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.11.0 h1:IzBBtyK9AHqf98cctWFifYSci2hgQR/cd56wB4p+ogg=
+github.com/jackc/pgx/v5 v5.11.0/go.mod h1:mal1tBGAFfLHvZzaYh77YS/eC6IX9OWbRV1QIIM0Jn4=
+github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/lucasb-eyer/go-colorful v1.4.0 h1:UtrWVfLdarDgc44HcS7pYloGHJUjHV/4FwW4TvVgFr4=
 github.com/lucasb-eyer/go-colorful v1.4.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-isatty v0.0.24 h1:tGZZoVgT/KiqK1c8ocVLeDS8BSWMRd47J3Lbz7vsReI=
@@ -94,6 +116,8 @@ github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJ
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
+github.com/rogpeppe/go-internal v1.16.0 h1:O9DK+vNMDVGLr2BeZqmpLeMjiMNkuXfcqntWbZV6S5g=
+github.com/rogpeppe/go-internal v1.16.0/go.mod h1:DrUVZyrJU+txYW5/1kwtXQSMFio52ZOxX7yM1VHvnxs=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sebdah/goldie/v2 v2.8.0 h1:dZb9wR8q5++oplmEiJT+U/5KyotVD+HNGCAc5gNr8rc=
 github.com/sebdah/goldie/v2 v2.8.0/go.mod h1:oZ9fp0+se1eapSRjfYbsV/0Hqhbuu3bJVvKI/NNtssI=
@@ -103,6 +127,9 @@ github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
 github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
 github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
 github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/tiendc/go-deepcopy v1.7.2 h1:Ut2yYR7W9tWjTQitganoIue4UGxZwCcJy3orjrrIj44=
@@ -138,8 +165,10 @@ golang.org/x/text v0.38.0 h1:sXmwo9DwP3OK9EZ7PqAdaooSGozfl/3a6/xJcbzPRhE=
 golang.org/x/text v0.38.0/go.mod h1:YXZt3QhHUKYT53r2lLKFIVi6Ao1jdzrTR/KQ09qyxF4=
 golang.org/x/tools v0.47.0 h1:7Kn5x/d1svx/PzryTsqeoZN4TZwqeH5pGWjefhLi/1Q=
 golang.org/x/tools v0.47.0/go.mod h1:dFHnyTvFWY212G+h7ZY4Vsp/K3U4/7W9TyVaAul8uCA=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 modernc.org/cc/v4 v4.29.1 h1:MKgdCV3WykTSPqpVrnxdEDS0HEd2FHpKZDzxzU5LyeI=

http.go

@@ -144,8 +144,13 @@ func unmarshalResponseObject(raw json.RawMessage) (map[string]any, error) {
 	}
 }
 
-// getJSON issues an authenticated GET and returns the raw response body.
+// getJSON issues an authenticated GET and returns the raw response body,
+// retrying transient answers (see retryRaw).
 func (c *Client) getJSON(ctx context.Context, path string) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) { return c.getJSONOnce(ctx, path) })
+}
+
+func (c *Client) getJSONOnce(ctx context.Context, path string) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -187,6 +192,12 @@ func (c *Client) deleteForm(ctx context.Context, path string, fields url.Values)
 }
 
 func (c *Client) formRequest(ctx context.Context, method, path string, fields url.Values) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) {
+		return c.formRequestOnce(ctx, method, path, fields)
+	})
+}
+
+func (c *Client) formRequestOnce(ctx context.Context, method, path string, fields url.Values) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -215,6 +226,10 @@ func (c *Client) formRequest(ctx context.Context, method, path string, fields ur
 
 // deleteReq issues an authenticated DELETE.
 func (c *Client) deleteReq(ctx context.Context, path string) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) { return c.deleteReqOnce(ctx, path) })
+}
+
+func (c *Client) deleteReqOnce(ctx context.Context, path string) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -260,6 +275,10 @@ func (c *Client) postJSONObject(ctx context.Context, path string, body any) (map
 
 // postJSON issues an authenticated POST with application/json body.
 func (c *Client) postJSON(ctx context.Context, path string, body any) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) { return c.postJSONOnce(ctx, path, body) })
+}
+
+func (c *Client) postJSONOnce(ctx context.Context, path string, body any) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -303,6 +322,10 @@ func (c *Client) postJSON(ctx context.Context, path string, body any) (json.RawM
 
 // putJSON issues an authenticated PUT with application/json body.
 func (c *Client) putJSON(ctx context.Context, path string, body any) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) { return c.putJSONOnce(ctx, path, body) })
+}
+
+func (c *Client) putJSONOnce(ctx context.Context, path string, body any) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -346,6 +369,21 @@ func (c *Client) putJSON(ctx context.Context, path string, body any) (json.RawMe
 
 // uploadMultipart posts a single file to path under the given form field name.
 func (c *Client) uploadMultipart(ctx context.Context, path, fieldName, filePath string) (json.RawMessage, error) {
+	return c.uploadMultipartMethod(ctx, http.MethodPost, path, fieldName, filePath)
+}
+
+// uploadMultipartMethod sends a single-file multipart request with the given
+// HTTP method. The OnlyOffice Documents API needs PUT for /update (a new
+// version) and POST for /upload (a new file); sending POST to /update answers
+// 500 on current servers. The file is re-opened per attempt, so transient
+// answers are retried like every other request.
+func (c *Client) uploadMultipartMethod(ctx context.Context, method, path, fieldName, filePath string) (json.RawMessage, error) {
+	return retryRaw(ctx, func() (json.RawMessage, error) {
+		return c.uploadMultipartOnce(ctx, method, path, fieldName, filePath)
+	})
+}
+
+func (c *Client) uploadMultipartOnce(ctx context.Context, method, path, fieldName, filePath string) (json.RawMessage, error) {
 	auth, err := c.authHeader()
 	if err != nil {
 		return nil, err
@@ -368,7 +406,7 @@ func (c *Client) uploadMultipart(ctx context.Context, path, fieldName, filePath
 	if err := mw.Close(); err != nil {
 		return nil, err
 	}
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL()+path, &buf)
+	req, err := http.NewRequestWithContext(ctx, method, c.baseURL()+path, &buf)
 	if err != nil {
 		return nil, err
 	}

internal/docpipe/docpipe.go

@@ -5,6 +5,7 @@
 //   - pandoc     — md↔docx
 //   - ocrmypdf   — OCR into a searchable PDF
 //   - pdftotext  — extract text layer
+//   - pdfdetach  — list/save embedded PDF attachments
 //   - tesseract  — OCR single images when ocrmypdf is unsuitable
 //   - ghostscript (gs) — PDF rewrite/optimize via PostScript (pdfwrite)
 package docpipe
@@ -26,6 +27,7 @@ type Tools struct {
 	Pandoc      string
 	OCRMyPDF    string
 	PDFToText   string
+	PDFDetach   string
 	Tesseract   string
 	Ghostscript string
 }
@@ -44,6 +46,7 @@ func LookPath() Tools {
 		Pandoc:      find("pandoc"),
 		OCRMyPDF:    find("ocrmypdf"),
 		PDFToText:   find("pdftotext"),
+		PDFDetach:   find("pdfdetach"),
 		Tesseract:   find("tesseract"),
 		Ghostscript: find("gs", "ghostscript"),
 	}

internal/docpipe/pdfattach.go

@@ -0,0 +1,278 @@
+package docpipe
+
+// Embedded PDF attachments (F6 #42). Digitised invoices often carry the
+// original scan as a PDF attachment; the searchable body may hold only a
+// summary. pdfdetach (poppler) lists/saves them; each saved attachment is run
+// through the normal docpipe extraction (pdftotext/OCR).
+
+import (
+	"bytes"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// PDFAttachment is one embedded file in a PDF.
+type PDFAttachment struct {
+	Index int    // 1-based number as `pdfdetach -list` reports it
+	Name  string // embedded file name
+}
+
+// AttachmentText is the extracted text of one embedded attachment.
+type AttachmentText struct {
+	Name string
+	Text string
+}
+
+// parseAttachmentList parses `pdfdetach -list` output. The first line is a
+// count ("N embedded files"); every following line is "<index>: <name>".
+// Pure, so it is unit-tested.
+func parseAttachmentList(out string) []PDFAttachment {
+	var atts []PDFAttachment
+	for _, line := range strings.Split(out, "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		colon := strings.Index(line, ":")
+		if colon <= 0 {
+			continue
+		}
+		n, err := strconv.Atoi(strings.TrimSpace(line[:colon]))
+		if err != nil {
+			continue
+		}
+		name := strings.TrimSpace(line[colon+1:])
+		if name == "" {
+			continue
+		}
+		atts = append(atts, PDFAttachment{Index: n, Name: name})
+	}
+	return atts
+}
+
+// safeAttachmentName strips directories and leading dots so a hostile
+// attachment name cannot escape the extraction directory.
+func safeAttachmentName(name string) string {
+	name = strings.ReplaceAll(strings.TrimSpace(name), "\\", "/")
+	name = filepath.Base(name)
+	name = strings.TrimLeft(name, ".")
+	if name == "" || name == "." || name == "/" {
+		return ""
+	}
+	return name
+}
+
+// JoinWithAttachments appends attachment text to the document body, each
+// section preceded by an "[attachment: <name>]" marker so a search hit shows
+// its source. Empty attachments are skipped. Pure, so it is unit-tested.
+func JoinWithAttachments(body string, atts []AttachmentText) string {
+	var b strings.Builder
+	b.WriteString(strings.TrimRight(body, "\n"))
+	for _, a := range atts {
+		text := strings.TrimSpace(a.Text)
+		if text == "" {
+			continue
+		}
+		b.WriteString("\n\n[attachment: ")
+		b.WriteString(a.Name)
+		b.WriteString("]\n\n")
+		b.WriteString(text)
+	}
+	return b.String()
+}
+
+// ListAttachments returns the embedded files of a PDF. A PDF without
+// attachments yields an empty slice and no error.
+func (t Tools) ListAttachments(pdfPath string) ([]PDFAttachment, error) {
+	if t.PDFDetach == "" {
+		return nil, fmt.Errorf("pdfdetach not found on PATH")
+	}
+	cmd := exec.Command(t.PDFDetach, "-list", pdfPath)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("pdfdetach -list %s: %w (%s)", filepath.Base(pdfPath), err, strings.TrimSpace(stderr.String()))
+	}
+	return parseAttachmentList(string(out)), nil
+}
+
+// SaveAttachment writes the n-th embedded file (1-based) to outPath.
+func (t Tools) SaveAttachment(pdfPath string, index int, outPath string) error {
+	if t.PDFDetach == "" {
+		return fmt.Errorf("pdfdetach not found on PATH")
+	}
+	if strings.TrimSpace(outPath) == "" {
+		return fmt.Errorf("output path required")
+	}
+	if err := EnsureDir(outPath); err != nil {
+		return err
+	}
+	cmd := exec.Command(t.PDFDetach, "-save", strconv.Itoa(index), "-o", outPath, pdfPath)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("pdfdetach -save %d: %w (%s)", index, err, strings.TrimSpace(stderr.String()))
+	}
+	return nil
+}
+
+// ToMarkdownWithAttachments extracts the file as ToMarkdown does, then — for
+// PDFs — appends the text of every embedded attachment under an
+// "[attachment: <name>]" marker. Attachment failures are non-fatal: the body
+// is returned unchanged.
+func (t Tools) ToMarkdownWithAttachments(path, workDir, lang string, minChars int) (string, error) {
+	res, err := t.ToMarkdown(path, workDir, lang, minChars)
+	if err != nil {
+		return "", err
+	}
+	if Ext(path) != ".pdf" {
+		return res.Markdown, nil
+	}
+	atts, err := t.attachmentTexts(path, workDir, lang, minChars)
+	if err != nil {
+		return res.Markdown, nil
+	}
+	return JoinWithAttachments(res.Markdown, atts), nil
+}
+
+// attachmentTexts saves and extracts every embedded attachment, skipping the
+// ones that cannot be read. It returns an error only when the attachment list
+// itself cannot be obtained.
+func (t Tools) attachmentTexts(pdfPath, workDir, lang string, minChars int) ([]AttachmentText, error) {
+	list, err := t.ListAttachments(pdfPath)
+	if err != nil || len(list) == 0 {
+		return nil, err
+	}
+	if workDir == "" {
+		workDir = os.TempDir()
+	}
+	dir := filepath.Join(workDir, "att-"+trimExt(filepath.Base(pdfPath)))
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, err
+	}
+	defer os.RemoveAll(dir)
+
+	out := make([]AttachmentText, 0, len(list))
+	for _, a := range list {
+		name := safeAttachmentName(a.Name)
+		if name == "" {
+			continue
+		}
+		saved := filepath.Join(dir, fmt.Sprintf("%d-%s", a.Index, name))
+		if err := t.SaveAttachment(pdfPath, a.Index, saved); err != nil {
+			continue
+		}
+		text, err := t.attachmentMarkdown(saved, dir, lang, minChars)
+		if err != nil {
+			continue
+		}
+		out = append(out, AttachmentText{Name: a.Name, Text: text})
+	}
+	return out, nil
+}
+
+// attachmentMarkdown extracts a saved attachment with the regular pipeline.
+// Structured attachments that docpipe does not convert (e-invoice XML,
+// CuraSoft JSON, CSV/HTML) fall back to their text content, so the embedded
+// original is still searchable. Other unreadable formats return an error and
+// the caller skips them.
+func (t Tools) attachmentMarkdown(path, workDir, lang string, minChars int) (string, error) {
+	if res, err := t.ToMarkdown(path, workDir, lang, minChars); err == nil {
+		return res.Markdown, nil
+	}
+	switch Ext(path) {
+	case ".xml", ".html", ".htm":
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			return "", err
+		}
+		return xmlToText(raw), nil
+	case ".json", ".csv", ".yaml", ".yml", ".toml", ".txt", ".md", ".markdown":
+		raw, err := os.ReadFile(path)
+		if err != nil {
+			return "", err
+		}
+		return string(raw), nil
+	default:
+		return textFallback(path)
+	}
+}
+
+// textFallback reads an attachment of an unknown or missing extension as plain
+// text when it looks textual (valid UTF-8, mostly printable runes). Binary
+// payloads (images, archives, NUL-padded blobs) are rejected with an error so
+// the caller skips them instead of poisoning the index. Classified digitised
+// PDFs (Scanner-*.ocr.pdf) carry .yaml/.md attachments; some exporters omit the
+// extension, which this covers.
+func textFallback(path string) (string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	raw, err := io.ReadAll(io.LimitReader(f, 1<<20))
+	if err != nil {
+		return "", err
+	}
+	if !utf8.Valid(raw) {
+		return "", fmt.Errorf("unsupported attachment type %q", Ext(path))
+	}
+	if !mostlyPrintable(raw) {
+		return "", fmt.Errorf("unsupported attachment type %q", Ext(path))
+	}
+	return string(raw), nil
+}
+
+// mostlyPrintable reports whether at least 90% of the runes are printable text
+// (newlines, carriage returns and tabs count as text). Pure, so it is tested.
+func mostlyPrintable(b []byte) bool {
+	if len(b) == 0 {
+		return false
+	}
+	printable, total := 0, 0
+	for _, r := range string(b) {
+		if r == utf8.RuneError {
+			continue
+		}
+		total++
+		if unicode.IsPrint(r) || r == '\n' || r == '\r' || r == '\t' {
+			printable++
+		}
+	}
+	return total > 0 && printable*10 >= total*9
+}
+
+// xmlToText returns the character data of an XML/HTML document: element text
+// values with decoded entities, one per line. Used for invoice XML (EN 16931
+// CII / ZUGFeRD) and HTML attachments. Pure, so it is unit-tested.
+func xmlToText(raw []byte) string {
+	dec := xml.NewDecoder(bytes.NewReader(raw))
+	dec.Strict = false
+	var b strings.Builder
+	for {
+		tok, err := dec.Token()
+		if err != nil {
+			break
+		}
+		cd, ok := tok.(xml.CharData)
+		if !ok {
+			continue
+		}
+		s := strings.TrimSpace(string(cd))
+		if s == "" {
+			continue
+		}
+		b.WriteString(s)
+		b.WriteByte('\n')
+	}
+	return b.String()
+}

internal/docpipe/pdfattach_test.go

@@ -0,0 +1,189 @@
+package docpipe
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestParseAttachmentList(t *testing.T) {
+	out := "2 embedded files\n1: original.pdf\n2: scan_001.png\n"
+	got := parseAttachmentList(out)
+	want := []PDFAttachment{{Index: 1, Name: "original.pdf"}, {Index: 2, Name: "scan_001.png"}}
+	if len(got) != len(want) {
+		t.Fatalf("got %+v, want %+v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Errorf("att[%d] = %+v, want %+v", i, got[i], want[i])
+		}
+	}
+}
+
+func TestParseAttachmentListEmptyAndMalformed(t *testing.T) {
+	for _, in := range []string{"", "0 embedded files\n", "garbage\n\n  \n"} {
+		if got := parseAttachmentList(in); len(got) != 0 {
+			t.Errorf("parseAttachmentList(%q) = %+v, want empty", in, got)
+		}
+	}
+}
+
+func TestSafeAttachmentName(t *testing.T) {
+	cases := map[string]string{
+		"note.txt":            "note.txt",
+		"../../evil.pdf":      "evil.pdf",
+		`..\..\evil.pdf`:      "evil.pdf",
+		"/abs/scan_001.pdf":   "scan_001.pdf",
+		".hidden":             "hidden",
+		"  spaced name.txt  ": "spaced name.txt",
+		"..":                  "",
+		"":                    "",
+	}
+	for in, want := range cases {
+		if got := safeAttachmentName(in); got != want {
+			t.Errorf("safeAttachmentName(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestJoinWithAttachments(t *testing.T) {
+	body := "# scan.pdf\n\nbody token\n"
+	atts := []AttachmentText{
+		{Name: "original.pdf", Text: "  original token  "},
+		{Name: "empty.txt", Text: "   "},
+	}
+	got := JoinWithAttachments(body, atts)
+	if !strings.Contains(got, "body token") {
+		t.Errorf("body text lost: %q", got)
+	}
+	if !strings.Contains(got, "[attachment: original.pdf]") {
+		t.Errorf("marker missing: %q", got)
+	}
+	if !strings.Contains(got, "original token") {
+		t.Errorf("attachment text missing: %q", got)
+	}
+	if strings.Contains(got, "empty.txt") {
+		t.Errorf("empty attachment must be skipped: %q", got)
+	}
+}
+
+func TestJoinWithAttachmentsNoAttachments(t *testing.T) {
+	got := JoinWithAttachments("# a.pdf\n\ntext\n\n", nil)
+	if got != "# a.pdf\n\ntext" {
+		t.Errorf("got %q, want trimmed body only", got)
+	}
+}
+
+func TestListAttachmentsWithoutTool(t *testing.T) {
+	if _, err := (Tools{}).ListAttachments("x.pdf"); err == nil || !strings.Contains(err.Error(), "pdfdetach") {
+		t.Fatalf("want pdfdetach error, got %v", err)
+	}
+}
+
+// TestToMarkdownWithAttachmentsFixture exercises the real pdfdetach + pdftotext
+// pipeline on testdata/pdf-with-attachment.pdf (body token + embedded
+// goo-note.txt). Skips when poppler is not installed.
+func TestToMarkdownWithAttachmentsFixture(t *testing.T) {
+	tools := LookPath()
+	if tools.PDFDetach == "" || tools.PDFToText == "" {
+		t.Skip("pdfdetach/pdftotext not on PATH — skipping attachment extraction test")
+	}
+	fixture := filepath.Join("..", "..", "testdata", "pdf-with-attachment.pdf")
+	got, err := tools.ToMarkdownWithAttachments(fixture, t.TempDir(), "eng", 1)
+	if err != nil {
+		t.Fatalf("ToMarkdownWithAttachments: %v", err)
+	}
+	for _, want := range []string{"goobodytoken", "[attachment: goo-note.txt]", "gooattachmenttoken"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("result missing %q:\n%s", want, got)
+		}
+	}
+}
+
+func TestXMLToText(t *testing.T) {
+	raw := []byte(`<?xml version="1.0" encoding="UTF-8"?>
+<rsm:CrossIndustryInvoice><rsm:ExchangedDocument>
+<ram:ID>S1063</ram:ID></rsm:ExchangedDocument>
+<ram:Name>Edelweiss &amp; Co</ram:Name><ram:GrandTotalAmount>42.00</ram:GrandTotalAmount>
+</rsm:CrossIndustryInvoice>`)
+	got := xmlToText(raw)
+	for _, want := range []string{"S1063", "Edelweiss & Co", "42.00"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("xmlToText missing %q:\n%s", want, got)
+		}
+	}
+	if strings.ContainsAny(got, "<>") {
+		t.Errorf("xmlToText left markup: %q", got)
+	}
+}
+
+// TestAttachmentMarkdownFallback verifies structured attachments that docpipe
+// cannot convert are still reduced to searchable text, and unknown binary
+// formats error (so the caller skips them).
+func TestAttachmentMarkdownFallback(t *testing.T) {
+	dir := t.TempDir()
+	xmlPath := filepath.Join(dir, "factur-x.xml")
+	if err := os.WriteFile(xmlPath, []byte(`<Invoice><Number>S1063</Number></Invoice>`), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	got, err := (Tools{}).attachmentMarkdown(xmlPath, dir, "", 0)
+	if err != nil {
+		t.Fatalf("attachmentMarkdown(xml): %v", err)
+	}
+	if !strings.Contains(got, "S1063") {
+		t.Errorf("xml attachment text = %q, want S1063", got)
+	}
+
+	// Classified digitised PDFs (Scanner-*.ocr.pdf) carry .yaml metadata.
+	yamlPath := filepath.Join(dir, "Scanner-123-003.ocr.yaml")
+	if err := os.WriteFile(yamlPath, []byte("document:\n  type: Rechnung\nnumber: S1063\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	gotYAML, err := (Tools{}).attachmentMarkdown(yamlPath, dir, "", 0)
+	if err != nil {
+		t.Fatalf("attachmentMarkdown(yaml): %v", err)
+	}
+	if !strings.Contains(gotYAML, "S1063") {
+		t.Errorf("yaml attachment text = %q, want S1063", gotYAML)
+	}
+
+	// Extensionless textual attachment falls back to raw text.
+	noExt := filepath.Join(dir, "attachment")
+	if err := os.WriteFile(noExt, []byte("plain attachment token goonoext"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	gotNoExt, err := (Tools{}).attachmentMarkdown(noExt, dir, "", 0)
+	if err != nil {
+		t.Fatalf("attachmentMarkdown(no extension): %v", err)
+	}
+	if !strings.Contains(gotNoExt, "goonoext") {
+		t.Errorf("extensionless attachment text = %q, want goonoext", gotNoExt)
+	}
+
+	binPath := filepath.Join(dir, "data.bin")
+	if err := os.WriteFile(binPath, []byte{0, 1, 2, 3}, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := (Tools{}).attachmentMarkdown(binPath, dir, "", 0); err == nil {
+		t.Error("unsupported attachment: want error, got nil")
+	}
+}
+
+// TestToMarkdownWithAttachmentsPlainPDF ensures a PDF without attachments
+// returns just the body (pdfdetach prints "0 embedded files").
+func TestToMarkdownWithAttachmentsPlainPDF(t *testing.T) {
+	tools := LookPath()
+	if tools.PDFDetach == "" || tools.PDFToText == "" {
+		t.Skip("pdfdetach/pdftotext not on PATH")
+	}
+	// The fixture itself is a PDF with one attachment; strip it by extracting
+	// the body only through ToMarkdown and compare JoinWithAttachments(nil).
+	res, err := tools.ToMarkdown(filepath.Join("..", "..", "testdata", "pdf-with-attachment.pdf"), t.TempDir(), "eng", 1)
+	if err != nil {
+		t.Fatalf("ToMarkdown: %v", err)
+	}
+	if strings.Contains(res.Markdown, "gooattachmenttoken") {
+		t.Fatalf("body must not contain attachment text: %q", res.Markdown)
+	}
+}

request.go

@@ -8,6 +8,7 @@ package onlyoffice
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -49,6 +50,12 @@ func (r Request) GetMethod() string {
 //   - If request.NoAuth is true then no token is fetched — the caller is
 //     responsible for authenticating requests (used internally by Auth()).
 func (c *Client) Query(request Request, result interface{}) error {
+	return DoRetry(context.Background(), DefaultRetryPolicy(), func() error {
+		return c.queryOnce(request, result)
+	})
+}
+
+func (c *Client) queryOnce(request Request, result interface{}) error {
 	url := c.credentials.Url + request.Uri
 
 	if request.Params != nil {
@@ -90,10 +97,17 @@ func (c *Client) Query(request Request, result interface{}) error {
 	}
 	defer resp.Body.Close()
 
+	raw, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	if resp.StatusCode >= 400 {
+		return fmt.Errorf("%s %s: %d %s", request.GetMethod(), request.Uri, resp.StatusCode, truncate(string(raw), 400))
+	}
 	if result == nil {
 		return nil
 	}
-	return json.NewDecoder(resp.Body).Decode(result)
+	return json.Unmarshal(raw, result)
 }
 
 // requestBodyReader normalises Query() body input into an io.Reader.

retry.go

@@ -0,0 +1,74 @@
+package onlyoffice
+
+import (
+	"context"
+	"encoding/json"
+	"regexp"
+	"time"
+)
+
+// RetryPolicy controls deterministic retries against OnlyOffice: fixed linear
+// backoff without jitter, so repeated runs wait exactly the same schedule.
+// OnlyOffice throttles bulk reads/writes with 429 (and occasional 502/503/504
+// from openresty), so every bulk tool routes API calls through DoRetry.
+type RetryPolicy struct {
+	Attempts int           // total attempts, including the first try
+	Base     time.Duration // wait before retry N is N*Base
+	Max      time.Duration // per-wait cap
+}
+
+// DefaultRetryPolicy retries up to 5 times with 1s, 2s, 3s, 4s waits.
+func DefaultRetryPolicy() RetryPolicy {
+	return RetryPolicy{Attempts: 5, Base: time.Second, Max: 30 * time.Second}
+}
+
+var transientRe = regexp.MustCompile(`:\s*(429|502|503|504)\b`)
+
+// Transient reports whether err looks like a transient OnlyOffice answer
+// (an HTTP 429/502/503/504 surfaced as "...: <code> ...").
+func Transient(err error) bool {
+	if err == nil {
+		return false
+	}
+	return transientRe.MatchString(err.Error())
+}
+
+// DoRetry runs fn until it succeeds, fails non-transiently, or attempts run
+// out. Waits are deterministic: N*Base capped at Max, no jitter.
+func DoRetry(ctx context.Context, p RetryPolicy, fn func() error) error {
+	if p.Attempts < 1 {
+		p.Attempts = 1
+	}
+	var err error
+	for attempt := 1; attempt <= p.Attempts; attempt++ {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		if err = fn(); err == nil || !Transient(err) || attempt == p.Attempts {
+			return err
+		}
+		wait := time.Duration(attempt) * p.Base
+		if wait > p.Max {
+			wait = p.Max
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-time.After(wait):
+		}
+	}
+	return err
+}
+
+// retryRaw runs a transport attempt under the default transient-retry policy
+// and returns its raw payload. All HTTP helpers and Query() go through it, so
+// an openresty 429/502/503/504 is retried exactly like every bulk tool.
+func retryRaw(ctx context.Context, fn func() (json.RawMessage, error)) (json.RawMessage, error) {
+	var raw json.RawMessage
+	err := DoRetry(ctx, DefaultRetryPolicy(), func() error {
+		var e error
+		raw, e = fn()
+		return e
+	})
+	return raw, err
+}

retry_test.go

@@ -0,0 +1,88 @@
+package onlyoffice
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestTransient(t *testing.T) {
+	cases := []struct {
+		err  error
+		want bool
+	}{
+		{nil, false},
+		{errors.New("boom"), false},
+		{errors.New("GET /api/2.0/files/1.json: 429 Too Many Requests"), true},
+		{errors.New("auth: 502 bad gateway"), true},
+		{errors.New("POST /x: 503 service unavailable"), true},
+		{errors.New("PUT /x: 504 gateway timeout"), true},
+		{errors.New("GET /x: 404 not found"), false},
+		{errors.New("GET /x: 4290 not a code"), false},
+	}
+	for _, c := range cases {
+		if got := Transient(c.err); got != c.want {
+			t.Errorf("Transient(%v) = %v, want %v", c.err, got, c.want)
+		}
+	}
+}
+
+func TestDoRetryRetriesTransientThenSucceeds(t *testing.T) {
+	p := RetryPolicy{Attempts: 5, Base: time.Millisecond, Max: 5 * time.Millisecond}
+	attempts := 0
+	err := DoRetry(context.Background(), p, func() error {
+		attempts++
+		if attempts < 3 {
+			return errors.New("GET /x: 429 Too Many Requests")
+		}
+		return nil
+	})
+	if err != nil {
+		t.Fatalf("DoRetry: %v", err)
+	}
+	if attempts != 3 {
+		t.Fatalf("attempts = %d, want 3", attempts)
+	}
+}
+
+func TestDoRetryStopsOnPermanentError(t *testing.T) {
+	p := RetryPolicy{Attempts: 5, Base: time.Millisecond, Max: time.Millisecond}
+	attempts := 0
+	err := DoRetry(context.Background(), p, func() error {
+		attempts++
+		return errors.New("GET /x: 404 not found")
+	})
+	if err == nil {
+		t.Fatal("want error")
+	}
+	if attempts != 1 {
+		t.Fatalf("attempts = %d, want 1", attempts)
+	}
+}
+
+func TestDoRetryExhaustsAttemptsOnPersistentTransient(t *testing.T) {
+	p := RetryPolicy{Attempts: 3, Base: time.Millisecond, Max: time.Millisecond}
+	attempts := 0
+	err := DoRetry(context.Background(), p, func() error {
+		attempts++
+		return errors.New("GET /x: 429 Too Many Requests")
+	})
+	if !Transient(err) {
+		t.Fatalf("want transient error, got %v", err)
+	}
+	if attempts != 3 {
+		t.Fatalf("attempts = %d, want 3", attempts)
+	}
+}
+
+func TestDoRetryHonoursContextCancellation(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	err := DoRetry(ctx, RetryPolicy{Attempts: 3, Base: time.Millisecond, Max: time.Millisecond}, func() error {
+		return errors.New("GET /x: 429 Too Many Requests")
+	})
+	if !errors.Is(err, context.Canceled) {
+		t.Fatalf("want context.Canceled, got %v", err)
+	}
+}

storage_fallback.go

@@ -0,0 +1,207 @@
+package onlyoffice
+
+// MinIO download fallback for the portal's stale AWS S3 consumer.
+//
+// On the Fibu EDL portal some older Documents files live in S3/MinIO, but the
+// portal's storage consumer still points at s3.us-east-1.amazonaws.com with
+// access key "minio". Downloads of those files answer 403 InvalidAccessKeyId.
+// The bytes are present in the local MinIO store under a deterministic object
+// key, so the client retries the GET there.
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/aws"
+	"github.com/aws/aws-sdk-go-v2/aws/signer/v4"
+)
+
+const (
+	defaultMinioEndpoint = "http://192.168.188.10:9000"
+	defaultMinioBucket   = "office"
+	minioRegion          = "us-east-1"
+)
+
+// minioObjectKey is the fallback object key layout the portal's S3 consumer
+// writes for Documents files: 00/00/01/files/folder_<folderId>/file_<fileId>/v1/content.pdf.
+// Prefer minioObjectKeyFromURL: the portal stores all files below its storage
+// root folder, which is not the API folderId returned by GetFile.
+func minioObjectKey(fileID, folderID string) string {
+	return "00/00/01/files/folder_" + folderID + "/file_" + fileID + "/v1/content.pdf"
+}
+
+// minioObjectKeyFromURL extracts the object key from an S3 download URL. Path
+// style URLs (bucket as first path segment) have that segment removed; virtual
+// host style URLs are returned as-is. This is authoritative: the portal signs
+// the exact key, so no folder-id guessing is needed.
+func minioObjectKeyFromURL(rawURL, bucket string) (string, bool) {
+	u, err := url.Parse(strings.TrimSpace(rawURL))
+	if err != nil || u.Path == "" {
+		return "", false
+	}
+	segs := strings.Split(strings.Trim(u.Path, "/"), "/")
+	// Path-style URLs carry the bucket as leading segment; the portal's S3
+	// consumer can emit it twice (serviceurl already includes the bucket), so
+	// strip every leading segment equal to the bucket.
+	for len(segs) > 0 && bucket != "" && segs[0] == bucket {
+		segs = segs[1:]
+	}
+	if len(segs) == 0 {
+		return "", false
+	}
+	for _, s := range segs {
+		if s == "" || s == "." || s == ".." {
+			return "", false
+		}
+	}
+	return strings.Join(segs, "/"), true
+}
+
+// isStaleS3Redirect reports whether a download landed on the portal's stale AWS
+// S3 consumer. Such responses either carry an S3 InvalidAccessKeyId XML body or
+// point at amazonaws.com with the "minio" access key id in the query.
+func isStaleS3Redirect(rawURL string, body []byte) bool {
+	if strings.Contains(strings.ToLower(string(body)), "invalidaccesskeyid") {
+		return true
+	}
+	u, err := url.Parse(strings.TrimSpace(rawURL))
+	if err != nil || u.Host == "" {
+		return false
+	}
+	host := strings.ToLower(u.Host)
+	if !strings.Contains(host, "amazonaws.com") {
+		return false
+	}
+	q := strings.ToLower(u.RawQuery)
+	return strings.Contains(q, "accesskeyid=minio") || strings.Contains(q, "x-amz-credential=minio")
+}
+
+// minioConfig is the runtime configuration for the local MinIO fallback.
+type minioConfig struct {
+	Endpoint  string
+	Bucket    string
+	AccessKey string
+	SecretKey string
+}
+
+// loadMinioConfig reads the fallback configuration from the environment.
+// Secrets are never defaulted; without access/secret keys the fallback is off.
+func loadMinioConfig() minioConfig {
+	return minioConfig{
+		Endpoint:  strings.TrimRight(firstNonEmpty(os.Getenv("MINIO_ENDPOINT"), defaultMinioEndpoint), "/"),
+		Bucket:    firstNonEmpty(os.Getenv("MINIO_BUCKET"), defaultMinioBucket),
+		AccessKey: os.Getenv("MINIO_ACCESS_KEY"),
+		SecretKey: os.Getenv("MINIO_SECRET_KEY"),
+	}
+}
+
+// downloadFileEntry downloads f's bytes to dst. It transparently falls back to
+// the local MinIO store when the portal redirects the download to its stale AWS
+// S3 consumer.
+func (c *Client) downloadFileEntry(ctx context.Context, f *FileEntry, dst io.Writer) (int64, error) {
+	if f == nil {
+		return 0, fmt.Errorf("onlyoffice: download: nil file entry")
+	}
+	if f.ViewURL == nil || *f.ViewURL == "" {
+		return 0, fmt.Errorf("onlyoffice: file has no viewUrl")
+	}
+	downloadURL := c.resolveAPIURL(*f.ViewURL)
+	auth, err := c.authHeader()
+	if err != nil {
+		return 0, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, downloadURL, nil)
+	if err != nil {
+		return 0, err
+	}
+	req.Header.Set("Authorization", auth)
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return 0, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode >= 400 {
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		finalURL := downloadURL
+		if resp.Request != nil && resp.Request.URL != nil {
+			finalURL = resp.Request.URL.String()
+		}
+		if isStaleS3Redirect(finalURL, b) {
+			key, ok := minioObjectKeyFromURL(finalURL, loadMinioConfig().Bucket)
+			if !ok {
+				fileID := ""
+				if f.ID != nil {
+					fileID = f.ID.String()
+				}
+				key = minioObjectKey(fileID, FileFolderID(f))
+			}
+			n, merr := c.downloadFromMinio(ctx, key, dst)
+			if merr == nil {
+				return n, nil
+			}
+			return 0, fmt.Errorf("GET viewUrl: %d (stale S3) and minio fallback: %w", resp.StatusCode, merr)
+		}
+		return 0, fmt.Errorf("GET viewUrl: %d %s", resp.StatusCode, truncate(string(b), 400))
+	}
+	return io.Copy(dst, resp.Body)
+}
+
+// downloadFromMinio streams objectKey from the configured MinIO bucket.
+func (c *Client) downloadFromMinio(ctx context.Context, objectKey string, dst io.Writer) (int64, error) {
+	return downloadMinioObject(ctx, c.client, objectKey, dst)
+}
+
+// downloadMinioObject streams objectKey from the configured MinIO bucket using
+// hc. It is the shared implementation behind (*Client).downloadFromMinio and
+// the read-only SQL store (file_pg.go), which has no *Client.
+func downloadMinioObject(ctx context.Context, hc *http.Client, objectKey string, dst io.Writer) (int64, error) {
+	if objectKey == "" {
+		return 0, fmt.Errorf("onlyoffice: minio fallback: empty object key")
+	}
+	cfg := loadMinioConfig()
+	if cfg.AccessKey == "" || cfg.SecretKey == "" {
+		return 0, fmt.Errorf("onlyoffice: minio fallback: MINIO_ACCESS_KEY/MINIO_SECRET_KEY not set")
+	}
+	base, err := url.Parse(cfg.Endpoint)
+	if err != nil || base.Host == "" {
+		return 0, fmt.Errorf("onlyoffice: minio fallback: bad MINIO_ENDPOINT %q", cfg.Endpoint)
+	}
+	u := *base
+	u.Path = "/" + cfg.Bucket + "/" + objectKey
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return 0, err
+	}
+	if err := signMinioRequest(ctx, cfg, req); err != nil {
+		return 0, err
+	}
+	resp, err := hc.Do(req)
+	if err != nil {
+		return 0, fmt.Errorf("onlyoffice: minio fallback: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
+		return 0, fmt.Errorf("onlyoffice: minio fallback: %d %s", resp.StatusCode, truncate(string(b), 300))
+	}
+	return io.Copy(dst, resp.Body)
+}
+
+// signMinioRequest signs req with AWS Signature V4 for the S3 service.
+func signMinioRequest(ctx context.Context, cfg minioConfig, req *http.Request) error {
+	sum := sha256.Sum256(nil)
+	creds := aws.Credentials{AccessKeyID: cfg.AccessKey, SecretAccessKey: cfg.SecretKey}
+	if err := v4.NewSigner().SignHTTP(ctx, creds, req, hex.EncodeToString(sum[:]), "s3", minioRegion, time.Now()); err != nil {
+		return fmt.Errorf("onlyoffice: minio fallback: sign: %w", err)
+	}
+	return nil
+}

storage_fallback_integration_test.go

@@ -0,0 +1,45 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"context"
+	"io"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+// TestIntegrationMinioFallback downloads known stale-S3 files through the local
+// MinIO fallback. Requires ONLYOFFICE_URL/USER/PASS (as all integration tests),
+// MINIO_ACCESS_KEY/MINIO_SECRET_KEY and MINIO_TEST_FILE_IDS="3785,3859,3666";
+// skips when any of those are missing.
+func TestIntegrationMinioFallback(t *testing.T) {
+	if os.Getenv("MINIO_ACCESS_KEY") == "" || os.Getenv("MINIO_SECRET_KEY") == "" {
+		t.Skip("MINIO_ACCESS_KEY/MINIO_SECRET_KEY not set — skipping integration test")
+	}
+	raw := strings.TrimSpace(os.Getenv("MINIO_TEST_FILE_IDS"))
+	if raw == "" {
+		t.Skip("MINIO_TEST_FILE_IDS not set — skipping integration test")
+	}
+	c := liveClient(t)
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+	for _, id := range strings.Split(raw, ",") {
+		id = strings.TrimSpace(id)
+		if id == "" {
+			continue
+		}
+		n, err := c.DownloadFile(ctx, id, io.Discard)
+		if err != nil {
+			t.Errorf("DownloadFile(%s): %v", id, err)
+			continue
+		}
+		if n == 0 {
+			t.Errorf("DownloadFile(%s): 0 bytes", id)
+		} else {
+			t.Logf("DownloadFile(%s): %d bytes", id, n)
+		}
+	}
+}

storage_fallback_test.go

@@ -0,0 +1,219 @@
+package onlyoffice
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestMinioObjectKey(t *testing.T) {
+	cases := []struct {
+		fileID   string
+		folderID string
+		want     string
+	}{
+		{"3785", "652", "00/00/01/files/folder_652/file_3785/v1/content.pdf"},
+		{"1", "2", "00/00/01/files/folder_2/file_1/v1/content.pdf"},
+		{"3666", "4000", "00/00/01/files/folder_4000/file_3666/v1/content.pdf"},
+	}
+	for _, tc := range cases {
+		if got := minioObjectKey(tc.fileID, tc.folderID); got != tc.want {
+			t.Errorf("minioObjectKey(%q, %q) = %q, want %q", tc.fileID, tc.folderID, got, tc.want)
+		}
+	}
+}
+
+func TestMinioObjectKeyFromURL(t *testing.T) {
+	cases := []struct {
+		name   string
+		url    string
+		bucket string
+		want   string
+		ok     bool
+	}{
+		{
+			name:   "path style drops bucket segment",
+			url:    "https://s3.us-east-1.amazonaws.com/office/00/00/01/files/folder_4000/file_3785/v1/content.pdf?AWSAccessKeyId=minio",
+			bucket: "office",
+			want:   "00/00/01/files/folder_4000/file_3785/v1/content.pdf",
+			ok:     true,
+		},
+		{
+			name:   "doubled bucket segment (portal serviceurl includes bucket)",
+			url:    "https://s3.us-east-1.amazonaws.com/office/office/00/00/01/files/folder_4000/file_3785/v1/content.pdf?AWSAccessKeyId=minio",
+			bucket: "office",
+			want:   "00/00/01/files/folder_4000/file_3785/v1/content.pdf",
+			ok:     true,
+		},
+		{
+			name:   "virtual host style keeps path",
+			url:    "https://office.s3.us-east-1.amazonaws.com/00/00/01/files/folder_4000/file_3785/v1/content.pdf",
+			bucket: "office",
+			want:   "00/00/01/files/folder_4000/file_3785/v1/content.pdf",
+			ok:     true,
+		},
+		{
+			name:   "foreign first segment kept",
+			url:    "https://example.com/other/file_1/v1/content.pdf",
+			bucket: "office",
+			want:   "other/file_1/v1/content.pdf",
+			ok:     true,
+		},
+		{name: "empty path", url: "https://example.com", bucket: "office", ok: false},
+		{name: "traversal", url: "https://example.com/office/../etc/passwd", bucket: "office", ok: false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := minioObjectKeyFromURL(tc.url, tc.bucket)
+			if ok != tc.ok || got != tc.want {
+				t.Errorf("minioObjectKeyFromURL(%q, %q) = (%q, %v), want (%q, %v)", tc.url, tc.bucket, got, ok, tc.want, tc.ok)
+			}
+		})
+	}
+}
+
+func TestIsStaleS3Redirect(t *testing.T) {
+	cases := []struct {
+		name string
+		url  string
+		body []byte
+		want bool
+	}{
+		{
+			name: "aws redirect with minio access key",
+			url:  "https://s3.us-east-1.amazonaws.com/office/x/file_1?AWSAccessKeyId=minio&Expires=1",
+			want: true,
+		},
+		{
+			name: "aws redirect with minio x-amz-credential",
+			url:  "https://office.s3.us-east-1.amazonaws.com/00/00/01/files/folder_1/file_1?X-Amz-Credential=minio%2F20260914",
+			want: true,
+		},
+		{
+			name: "invalid access key xml body",
+			url:  "https://portal.internal/download/1",
+			body: []byte(`<?xml version="1.0"?><Error><Code>InvalidAccessKeyId</Code><AWSAccessKeyId>minio</AWSAccessKeyId></Error>`),
+			want: true,
+		},
+		{
+			name: "regular pdf from portal",
+			url:  "https://portal.internal/download/1",
+			body: []byte("%PDF-1.7 data"),
+			want: false,
+		},
+		{
+			name: "aws redirect with foreign key",
+			url:  "https://s3.us-east-1.amazonaws.com/office/x?AWSAccessKeyId=other",
+			want: false,
+		},
+		{
+			name: "amazonaws in path but foreign host",
+			url:  "https://example.com/amazonaws.com/file?AWSAccessKeyId=minio",
+			want: false,
+		},
+		{
+			name: "empty",
+			want: false,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := isStaleS3Redirect(tc.url, tc.body); got != tc.want {
+				t.Errorf("isStaleS3Redirect(%q, %q) = %v, want %v", tc.url, tc.body, got, tc.want)
+			}
+		})
+	}
+}
+
+const staleS3Body = `<?xml version="1.0" encoding="UTF-8"?>` +
+	`<Error><Code>InvalidAccessKeyId</Code>` +
+	`<Message>The AWS Access Key Id you provided does not exist in our records.</Message>` +
+	`<AWSAccessKeyId>minio</AWSAccessKeyId></Error>`
+
+func TestDownloadFileMinioFallback(t *testing.T) {
+	const payload = "PDFDATA-3785"
+
+	portal := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/2.0/files/file/3785.json":
+			w.Header().Set("Content-Type", "application/json")
+			io.WriteString(w, `{"response":{"id":3785,"title":"04.pdf","folderId":655,"viewUrl":"/download/3785"}}`)
+		case "/download/3785":
+			http.Redirect(w, r, "/office/00/00/01/files/folder_4000/file_3785/v1/content.pdf?AWSAccessKeyId=minio", http.StatusTemporaryRedirect)
+		case "/office/00/00/01/files/folder_4000/file_3785/v1/content.pdf":
+			w.WriteHeader(http.StatusForbidden)
+			io.WriteString(w, staleS3Body)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer portal.Close()
+
+	var minioPath, minioAuth string
+	minio := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		minioPath, minioAuth = r.URL.Path, r.Header.Get("Authorization")
+		io.WriteString(w, payload)
+	}))
+	defer minio.Close()
+
+	t.Setenv("MINIO_ENDPOINT", minio.URL)
+	t.Setenv("MINIO_BUCKET", "office")
+	t.Setenv("MINIO_ACCESS_KEY", "testkey")
+	t.Setenv("MINIO_SECRET_KEY", "testsecret")
+
+	c := &Client{
+		client:      portal.Client(),
+		credentials: &Credentials{Url: portal.URL},
+		token:       &Token{Value: "Bearer test", Expires: Time(time.Now().Add(time.Hour))},
+	}
+
+	var buf bytes.Buffer
+	n, err := c.DownloadFile(context.Background(), "3785", &buf)
+	if err != nil {
+		t.Fatalf("DownloadFile: %v", err)
+	}
+	if n != int64(len(payload)) || buf.String() != payload {
+		t.Fatalf("got %d bytes %q, want %d bytes %q", n, buf.String(), len(payload), payload)
+	}
+	if want := "/office/00/00/01/files/folder_4000/file_3785/v1/content.pdf"; minioPath != want {
+		t.Errorf("minio path = %q, want %q", minioPath, want)
+	}
+	if !strings.HasPrefix(minioAuth, "AWS4-HMAC-SHA256") {
+		t.Errorf("minio request not SigV4-signed; Authorization=%q", minioAuth)
+	}
+}
+
+func TestDownloadFileMinioFallbackWithoutCreds(t *testing.T) {
+	portal := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/2.0/files/file/3785.json":
+			io.WriteString(w, `{"response":{"id":3785,"folderId":652,"viewUrl":"/download/3785"}}`)
+		default:
+			w.WriteHeader(http.StatusForbidden)
+			io.WriteString(w, staleS3Body)
+		}
+	}))
+	defer portal.Close()
+
+	t.Setenv("MINIO_ACCESS_KEY", "")
+	t.Setenv("MINIO_SECRET_KEY", "")
+
+	c := &Client{
+		client:      portal.Client(),
+		credentials: &Credentials{Url: portal.URL},
+		token:       &Token{Value: "Bearer test", Expires: Time(time.Now().Add(time.Hour))},
+	}
+
+	_, err := c.DownloadFile(context.Background(), "3785", io.Discard)
+	if err == nil {
+		t.Fatal("expected error without minio credentials")
+	}
+	if !strings.Contains(err.Error(), "MINIO_ACCESS_KEY/MINIO_SECRET_KEY not set") {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}

testdata/pdf-with-attachment.pdf

@@ -0,0 +1,114 @@
+%PDF-1.7
+%Çì�¢
+%%Invocation: gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite ? ? ?
+5 0 obj
+<</Length 6 0 R/Filter /FlateDecode>>
+stream
+xœ-ŠA
+ƒ0÷ÿoÙnìO7q]èZ*ÿ�IˆmJ½½M
+³f7
+\¨6‘žfRÿŠ*ñºõª…8:g}‡f†Dºø”ÞiØsúØ	ÝôÝ;炱(Ùn.ly]ìUFz
+½~Aë øendstream
+endobj
+6 0 obj
+110
+endobj
+4 0 obj
+<</Type/Page/MediaBox [0 0 612 792]
+/Rotate 0/Parent 3 0 R
+/Resources<</ProcSet[/PDF /Text]
+/Font 8 0 R
+>>
+/Contents 5 0 R
+>>
+endobj
+3 0 obj
+<< /Type /Pages /Kids [
+4 0 R
+] /Count 1
+>>
+endobj
+1 0 obj
+<</Type /Catalog /Pages 3 0 R
+/Metadata 9 0 R
+>>
+endobj
+8 0 obj
+<</R7
+7 0 R>>
+endobj
+7 0 obj
+<</BaseFont/Helvetica/Type/Font
+/Subtype/Type1>>
+endobj
+9 0 obj
+<</Type/Metadata
+/Subtype/XML/Length 1173>>stream
+<?xpacket begin='' id='W5M0MpCehiHzreSzNTczkc9d'?>
+<?adobe-xap-filters esc="CRLF"?>
+<x:xmpmeta xmlns:x='adobe:ns:meta/' x:xmptk='XMP toolkit 2.9.1-13, framework 1.6'>
+<rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#' xmlns:iX='http://ns.adobe.com/iX/1.0/'>
+<rdf:Description rdf:about="" xmlns:pdf='http://ns.adobe.com/pdf/1.3/' pdf:Producer='GPL Ghostscript 10.02.1'/>
+<rdf:Description rdf:about="" xmlns:xmp='http://ns.adobe.com/xap/1.0/'><xmp:ModifyDate>2026-09-16T17:29:12Z</xmp:ModifyDate>
+<xmp:CreateDate>2026-09-16T17:29:12Z</xmp:CreateDate>
+<xmp:CreatorTool>UnknownApplication</xmp:CreatorTool></rdf:Description>
+<rdf:Description rdf:about="" xmlns:xapMM='http://ns.adobe.com/xap/1.0/mm/' xapMM:DocumentID='uuid:ae8d7575-ea10-11fc-0000-3a98742e0b71'/>
+<rdf:Description rdf:about="" xmlns:dc='http://purl.org/dc/elements/1.1/' dc:format='application/pdf'><dc:title><rdf:Alt><rdf:li xml:lang='x-default'>Untitled</rdf:li></rdf:Alt></dc:title></rdf:Description>
+</rdf:RDF>
+</x:xmpmeta>
+                                                                        
+                                                                        
+<?xpacket end='w'?>
+endstream
+endobj
+2 0 obj
+<</Producer(GPL Ghostscript 10.02.1)
+/CreationDate(D:20260916172912Z00'00')
+/ModDate(D:20260916172912Z00'00')>>endobj
+xref
+0 10
+0000000000 65535 f 
+0000000476 00000 n 
+0000001882 00000 n 
+0000000417 00000 n 
+0000000276 00000 n 
+0000000077 00000 n 
+0000000257 00000 n 
+0000000569 00000 n 
+0000000540 00000 n 
+0000000633 00000 n 
+trailer
+<< /Size 10 /Root 1 0 R /Info 2 0 R
+/ID [<5A562476FBF11852133AA873452909F9><5A562476FBF11852133AA873452909F9>]
+>>
+startxref
+2008
+%%EOF
+1 0 obj
+<</Type /Catalog /Pages 3 0 R /Metadata 9 0 R /Names <</EmbeddedFiles 12 0 R >> >> 
+endobj
+10 0 obj
+<</Length 44 /Params <</Size 44 >> >> stream
+gooattachmenttoken embedded attachment text
+
+endstream
+
+endobj
+11 0 obj
+<</Type /Filespec /UF <feff0067006f006f002d006e006f00740065002e007400780074> /EF <</F 10 0 R >> >> 
+endobj
+12 0 obj
+<</Names [<feff0067006f006f002d006e006f00740065002e007400780074> 11 0 R ] >> 
+endobj
+xref
+0 2
+0000000002 65535 f
+0000002361 00000 n
+10 3
+0000002463 00000 n
+0000002586 00000 n
+0000002705 00000 n
+trailer
+<</Size 13 /ID [(ZV$vûñR:¨sE\)	ù) (P…õrˆ‚ Åð¡Ï) ] /Root 1 0 R /Prev 2008 /Info 2 0 R >> 
+startxref
+2802