diff --git a/.env.example b/.env.example
index bfcff31..d5f5b5e 100644
--- a/.env.example
+++ b/.env.example
@@ -34,3 +34,10 @@ ONLYOFFICE_PROJECT_ID=33
 # 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=
diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 7b51ca0..5e39b94 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.17.0"
+  ".": "0.18.0"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8deea41..ed506c5 100644
--- a/CHANGELOG.md
+++ b/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)
 
 
diff --git a/README.md b/README.md
index 50870c4..1458a5f 100644
--- a/README.md
+++ b/README.md
@@ -678,6 +678,25 @@ oo dav download 22881 --to ./copy.pdf # default path: ./<server title>
 oo dav fileops                        # active move/copy operations (status polling)
 ```
 
+### Search (`oo search`)
+
+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`).
+
 ### Bulk tools (`cmd/`)
 
 Small single-purpose binaries for bulk Documents work. All of them pace
@@ -714,6 +733,7 @@ kontolink IN.xlsx oo-index.tsv OUT.xlsx [FILE_ID] [AMOUNTS_TSV]
 | `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`, `--json`) |
 
 The CLI reads only `.env` from the current working directory (godotenv is a
 CLI-only concern — the library itself never loads dotfiles).
diff --git a/cmd/oo/dav.go b/cmd/oo/dav.go
index 4683444..56272f4 100644
--- a/cmd/oo/dav.go
+++ b/cmd/oo/dav.go
@@ -25,6 +25,7 @@ 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())
@@ -184,6 +185,32 @@ 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
+			}
+			if err := c.DeleteDavItems(cmd.Context(), folderIDs, args); 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",
diff --git a/cmd/oo/main.go b/cmd/oo/main.go
index c91baaa..82ab8e8 100644
--- a/cmd/oo/main.go
+++ b/cmd/oo/main.go
@@ -18,6 +18,7 @@
 //	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] [--json]
 //
 // CRM association rules: docs/crm-associations.md
 //
diff --git a/cmd/oo/search.go b/cmd/oo/search.go
new file mode 100644
index 0000000..2ceab0e
--- /dev/null
+++ b/cmd/oo/search.go
@@ -0,0 +1,72 @@
+package main
+
+import (
+	onlyoffice "github.com/eslider/go-onlyoffice"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(searchCmd())
+}
+
+// searchCmd queries the OnlyOffice Elasticsearch index directly. The REST
+// /api/2.0/files/@search endpoint only searches file names in the database;
+// content search needs ES (see docs/elasticsearch.md).
+func searchCmd() *cobra.Command {
+	var (
+		content bool
+		folder  string
+		limit   int
+		asJSON  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" +
+			"Requires ONLYOFFICE_ES_URL (and optionally ONLYOFFICE_ES_INDEX,\n" +
+			"ONLYOFFICE_TENANT). See docs/elasticsearch.md for the tunnel setup.",
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if asJSON {
+				outputFormat = "json"
+			}
+			es, err := onlyoffice.NewESSearcher(onlyoffice.ESConfigFromEnv())
+			if err != nil {
+				return err
+			}
+			hits, err := es.Search(cmd.Context(), onlyoffice.SearchQuery{
+				Text:      args[0],
+				InContent: content,
+				FolderID:  folder,
+				Limit:     limit,
+			})
+			if err != nil {
+				return err
+			}
+			rows := make([]map[string]any, 0, len(hits))
+			for _, h := range hits {
+				rows = append(rows, map[string]any{
+					"id":        h.ID,
+					"title":     h.Title,
+					"folder":    h.ParentID,
+					"score":     h.Score,
+					"highlight": h.Highlight,
+				})
+			}
+			if outputFormat == "json" {
+				printJSON(rows)
+				return nil
+			}
+			printTable([]string{"id", "title", "folder", "score", "highlight"}, rows)
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&content, "content", false, "also match extracted document content")
+	cmd.Flags().StringVar(&folder, "folder", "", "limit to a Documents folder id")
+	cmd.Flags().IntVar(&limit, "limit", 20, "maximum number of results")
+	cmd.Flags().BoolVar(&asJSON, "json", false, "shorthand for --output json")
+	return cmd
+}
diff --git a/cmd/oo/search_test.go b/cmd/oo/search_test.go
new file mode 100644
index 0000000..ea1716c
--- /dev/null
+++ b/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())
+	}
+}
diff --git a/cmd/pdfamount/main.go b/cmd/pdfamount/main.go
index d6b991e..6690caa 100644
--- a/cmd/pdfamount/main.go
+++ b/cmd/pdfamount/main.go
@@ -18,7 +18,52 @@ import (
 	onlyoffice "github.com/eslider/go-onlyoffice"
 )
 
-var amountRe = regexp.MustCompile(`(?i)(zu zahlender betrag|rechnungsbetrag)\s*[:\s]*([0-9][0-9.]*,[0-9]{2})`)
+// 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 {
@@ -105,20 +150,159 @@ func pdfAmount(ctx context.Context, c *onlyoffice.Client, id string) (string, er
 	if err := cmd.Run(); err != nil {
 		return "", err
 	}
-	m := amountRe.FindStringSubmatch(buf.String())
-	if m == nil {
-		return "", nil
-	}
-	return parseDe(m[2]), nil
+	return extractAmount(buf.String()), nil
 }
 
-// parseDe turns "1.234,56" into 1234.56.
-func parseDe(s string) string {
-	s = strings.ReplaceAll(s, ".", "")
-	s = strings.ReplaceAll(s, ",", ".")
-	v, err := strconv.ParseFloat(s, 64)
-	if err != nil {
-		return s
+// 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
 	}
-	return strconv.FormatFloat(v, 'f', 2, 64)
+	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
 }
diff --git a/cmd/pdfamount/main_test.go b/cmd/pdfamount/main_test.go
new file mode 100644
index 0000000..4e70b38
--- /dev/null
+++ b/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)
+		}
+	}
+}
diff --git a/docs/elasticsearch.md b/docs/elasticsearch.md
new file mode 100644
index 0000000..05df5d6
--- /dev/null
+++ b/docs/elasticsearch.md
@@ -0,0 +1,125 @@
+---
+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, залитых через API, не работает (нет
+  `attachment.content`) — только Office-форматы.
diff --git a/file_core.go b/file_core.go
new file mode 100644
index 0000000..b9766ca
--- /dev/null
+++ b/file_core.go
@@ -0,0 +1,199 @@
+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
+	Version  int
+	Provider string
+}
+
+// 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.
+type SearchQuery struct {
+	Text       string
+	InContent  bool
+	FolderID   string
+	Extensions []string
+	Limit      int
+}
+
+// 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) or
+// ProviderDAV. Unknown or empty names select the REST backend. The full facade
+// (backend composition) is deliberately left to a later change.
+func (c *Client) FileStore(backend string) FileStore {
+	switch strings.ToLower(strings.TrimSpace(backend)) {
+	case ProviderDAV, "webdav":
+		return &davStore{c: c}
+	default:
+		return &restStore{c: c}
+	}
+}
+
+// Files returns the default (REST) file store.
+func (c *Client) Files() FileStore { return c.FileStore(ProviderREST) }
+
+// 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
+	}
+	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(),
+		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(),
+		Provider: provider,
+	}
+}
+
+// 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))
+}
diff --git a/file_core_test.go b/file_core_test.go
new file mode 100644
index 0000000..91aa6c2
--- /dev/null
+++ b/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)
+	}
+}
diff --git a/file_dav.go b/file_dav.go
new file mode 100644
index 0000000..9183831
--- /dev/null
+++ b/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
+}
diff --git a/file_es.go b/file_es.go
new file mode 100644
index 0000000..9c2db76
--- /dev/null
+++ b/file_es.go
@@ -0,0 +1,285 @@
+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        = 200
+	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")
+	}
+	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 != "" {
+		filter = append(filter, esClause{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"`
+	Wildcard   map[string]any `json:"wildcard,omitempty"`
+}
+
+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
+		}
+		var parent string
+		path := make([]string, 0, len(h.Source.Folders))
+		for i, f := range h.Source.Folders {
+			path = append(path, f.FolderID)
+			if i == 0 {
+				parent = f.FolderID
+			}
+		}
+		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.
+func esHighlightText(hl map[string][]string) string {
+	for _, key := range []string{"document.attachment.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 ""
+}
diff --git a/file_es_integration_test.go b/file_es_integration_test.go
new file mode 100644
index 0000000..ce4e891
--- /dev/null
+++ b/file_es_integration_test.go
@@ -0,0 +1,135 @@
+//go:build integration
+
+package onlyoffice
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/xuri/excelize/v2"
+)
+
+// 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
+}
diff --git a/file_es_test.go b/file_es_test.go
new file mode 100644
index 0000000..ee60ef1
--- /dev/null
+++ b/file_es_test.go
@@ -0,0 +1,188 @@
+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:      999,
+	}, "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.Term != nil && f.Term["folders.folderId"] != nil:
+			folder++
+			if f.Term["folders.folderId"] != "649" {
+				t.Errorf("folder filter = %+v", f.Term)
+			}
+		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 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)
+	}
+	if h0.ParentID != "438" || !reflect.DeepEqual(h0.Path, []string{"438", "11"}) {
+		t.Errorf("hit0 path = %v parent = %q", 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)
+	}
+}
diff --git a/file_rest.go b/file_rest.go
new file mode 100644
index 0000000..ed236a2
--- /dev/null
+++ b/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
+}
diff --git a/file_store_integration_test.go b/file_store_integration_test.go
new file mode 100644
index 0000000..4533cf8
--- /dev/null
+++ b/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
+}
diff --git a/files.go b/files.go
index 767d5d6..b3f38bc 100644
--- a/files.go
+++ b/files.go
@@ -324,19 +324,22 @@ 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)
-	}
-	if err != nil {
-		return nil, err
-	}
-	if raw, merr := json.Marshal(out); merr == nil {
-		if ferr := fileopsError(raw); ferr != nil {
-			return nil, ferr
+		raw, err = c.putJSON(ctx, "/api/2.0/files/fileops/move.json", body)
+		if err != nil {
+			return nil, err
 		}
 	}
-	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.