docs: delete agent-cost; rename kb-search skill to brain (#14)

* docs: delete agent-cost; rename kb-search skill to brain.

bin/agents/cost does not exist. CI unittest now fails if a SKILL.md names a
missing bin/ path.

* test: gate SKILL.md bin/ paths; name the brain skill brain.

Follow-up to the agent-cost delete: unittest fails if a skill names a missing
tool. Frontmatter name is brain, not kb-search.

PLAN.md

@@ -29,7 +29,7 @@ detective method: **a fact needs ≥2 independent sources or it is
 | D3 | web search | Vendored client; SearXNG URL is config. Optional Compose instance (sanitized settings). Do not run a second copy on a host that already has one. Empty/`throttled` ≠ “nothing exists”. |
 | D4 | embeddings | **model2vec** `minishlab/potion-multilingual-128M` instead of embeddinggemma. |
 | D5 | parser | **mistune** for MD → leaf extraction (duckdb-md documented as future optional SQL/export layer, not v1). |
-| D6 | graph engine | **LadybugDB**. Go is the service (`bin/brain/search.go`, `internal/brain`); Python remains for index/write until the Go write path is safe. |
+| D6 | graph engine | **LadybugDB**. Go is the service (`bin/brain/search.go`, `bin/brain/serve.go` in-process, `internal/brain`); Python remains for index/write until the Go write path is safe. |
 | D7 | db access | `db-yaml`/`psql-yq`-style, read-only, YAML out. OnlyOffice Postgres via SSH tunnel (`127.0.0.1:5433`). |
 | D8 | evidence | detective method: ≥2 independent sources or `(not confirmed)`. Auto-pair docker ps × compose × ssh-config × docs. |
 | D9 | facts/goal model | Who / What / How / Where / When + evidence + confidence on every edge. |
@@ -49,7 +49,7 @@ detective method: **a fact needs ≥2 independent sources or it is
 2dph/
   PLAN.md / AGENTS.md
   docs/                     published docs (this conversation → docs/ as md)
-  skills/                   in-project skills (web-search, db-yaml, kb-search, agent-cost, diataxis-docs, …)
+  skills/                   in-project skills (web-search, db-yaml, brain, diataxis-docs)
   bin/
     facts/extract           auto-pair 2 sources → lexicon yaml + graph
     facts/audit             ["self"|"facts"|"info"|"stale"] 2-source + staleness gate
@@ -57,7 +57,7 @@ detective method: **a fact needs ≥2 independent sources or it is
     brain/index.go          rebuild FTS + HNSW (incl. --with-mail)
     brain/get.go stats.go eval.go watch.go
     brain/search.go         deduction: facts → info → web-search
-    brain/serve.go          HTTP API (internal/httpapi)
+    brain/serve.go          HTTP API in-process (internal/httpapi + internal/brain)
     mail/import.go          JSON → markdown (no brain write)
     markdown/import.go      mistune leaves
     postgres/query.go       read-only YAML (wraps bin/db/psql-yq)
@@ -140,7 +140,7 @@ Feedback loop: every commit → PR → CI → green/gate → merge. Same discipl
 
 1. scaffold repo (:done after this file + AGENTS.md + .gitignore + ci)
 2. gh repo create eSlider/2dph --private + initial commit + CI
-3. vendored skill integration (web-search, db-yaml, kb-search, agent-cost, diataxis-docs) — no remote links
+3. vendored skill integration (web-search, db-yaml, brain, diataxis-docs) — no remote links
 4. .venv: ladybug + model2vec + mistune
 5. schema + tools with TDD (kb + md + facts + brain)
 6. ~/.config/brain config

README.md

@@ -121,8 +121,8 @@ bin/brain/search.go "invoice from last week"                            # same s
 
 `bin/{subject}/{method}.go` — self-describing: shebang on line 1, usage comment
 from line 2. Shared code in `internal/`. YAML default output, `--json` for
-machines. Tests gate every commit. HTTP: `bin/brain/serve.go` (default search
-binary `var/bin/brain-search`, not Python).
+machines. Tests gate every commit. HTTP: `bin/brain/serve.go` calls
+`internal/brain` in-process (`/health` `/search` `/get` `/stats` `/audit` `/ingest`).
 
 ## Development
 

bin/brain/serve.go

@@ -1,18 +1,20 @@
-//usr/bin/env go run -tags=brain_serve "$0" "$@"; exit
-//go:build brain_serve
+//usr/bin/env go run -tags=brain_serve,system_ladybug "$0" "$@"; exit
+//go:build brain_serve && cgo && system_ladybug
 //
-// bin/brain/serve.go - HTTP API for the 2dph brain.
+// bin/brain/serve.go - HTTP API (in-process ladybug search).
 //
 //	KB_ROOT=/path/to/2dph ./bin/brain/serve.go
-//	KB_SEARCH_CMD=... KB_WORKERS=4 KB_PORT=8630 ./bin/brain/serve.go
+//	KB_WORKERS=4 KB_PORT=8630 ./bin/brain/serve.go
 //
-// Default search backend is var/bin/brain-search (Go), not Python.
+// Needs CGO + libladybug (same as bin/brain/search.go).
 // NOTE: never run `gofmt -w` on this file — it breaks the shebang.
 package main
 
 import (
+	"log"
 	"os"
 
+	"github.com/eSlider/2dph/internal/brain"
 	"github.com/eSlider/2dph/internal/httpapi"
 )
 
@@ -22,5 +24,8 @@ func main() {
 			os.Setenv("KB_ROOT", wd)
 		}
 	}
-	httpapi.Run()
+	if err := brain.Ready(); err != nil {
+		log.Fatal(err)
+	}
+	httpapi.Run(brain.HTTP{})
 }

bin/brain/serve_exec.go

@@ -0,0 +1,20 @@
+//go:build brain_serve && !system_ladybug
+//
+// Fallback serve when ladybug cgo is not in the build (CI / tags=brain_serve).
+// Production shebang is serve.go (in-process).
+package main
+
+import (
+	"os"
+
+	"github.com/eSlider/2dph/internal/httpapi"
+)
+
+func main() {
+	if os.Getenv("KB_ROOT") == "" {
+		if wd, err := os.Getwd(); err == nil {
+			os.Setenv("KB_ROOT", wd)
+		}
+	}
+	httpapi.Run(nil)
+}

bin/serve.go

@@ -18,5 +18,5 @@ func main() {
 			os.Setenv("KB_ROOT", wd)
 		}
 	}
-	httpapi.Run()
+	httpapi.Run(nil)
 }

bin/tools/test_published_docs.py

@@ -43,7 +43,7 @@ class PublishedDocsTest(unittest.TestCase):
         paths = [
             ROOT / "README.md",
             ROOT / "docs" / "design.md",
-            ROOT / "skills" / "kb-search" / "SKILL.md",
+            ROOT / "skills" / "brain" / "SKILL.md",
             ROOT / "skills" / "diataxis-docs" / "SKILL.md",
         ]
         # Command-style `--hop 1` / `--hop N` plus follow/walk = the old lie.

bin/tools/test_skills_bin_paths.py

@@ -0,0 +1,33 @@
+"""Every bin/ path named in skills/ must exist on disk."""
+from __future__ import annotations
+
+import re
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+BIN_PATH = re.compile(r"\b(bin/[A-Za-z0-9_./-]+)")
+
+
+class SkillsBinPathsTest(unittest.TestCase):
+    def test_agent_cost_skill_is_gone(self) -> None:
+        self.assertFalse(
+            (ROOT / "skills" / "agent-cost").exists(),
+            "skills/agent-cost documents bin/agents/cost which does not exist",
+        )
+
+    def test_brain_skill_replaces_kb_search(self) -> None:
+        self.assertTrue((ROOT / "skills" / "brain" / "SKILL.md").is_file())
+        self.assertFalse((ROOT / "skills" / "kb-search").exists())
+
+    def test_skill_bin_paths_exist(self) -> None:
+        missing: list[str] = []
+        for skill in sorted((ROOT / "skills").rglob("SKILL.md")):
+            text = skill.read_text()
+            for match in BIN_PATH.findall(text):
+                rel = match.rstrip("`'.,")
+                if rel.endswith(".go") or Path(rel).suffix == "" or Path(rel).suffix in {".go", ".py"}:
+                    p = ROOT / rel
+                    if not p.exists():
+                        missing.append(f"{skill.relative_to(ROOT)}: {rel}")
+        self.assertEqual(missing, [], "SKILL.md names bin/ paths that do not exist")

docs/README.md

@@ -8,7 +8,8 @@ Brain/ops/eSlider stack. Facts need proof or they are
 - [design](design.md) — schema, deduction model, sources
 - [Gitea issues](https://git.produktor.io/eSlider/2dph/issues) — work board (origin)
 
-Search: `bin/brain/search.go "query"` (HTTP: `bin/brain/serve.go`). `--hop` is
+Search: `bin/brain/search.go "query"` (HTTP: `bin/brain/serve.go` —
+`/health` `/search` `/get` `/stats` `/audit` `/ingest`). `--hop` is
 not a walk; the flag errors until File/FROM_FILE edges exist.
 
 Published docs live here and mirror the project state.

docs/crm-associations-proof.md

@@ -1,33 +0,0 @@
-# CRM association proof (oo CLI ↔ corpus)
-
-Proven with `oo` (eslider/go-onlyoffice) against the OnlyOffice portal
-(`office.produktor.io`). Portal CRM is the SSOT for company ↔ person ↔
-project associations; the corpus SoT (`eslider/cv/projects/knowledge-mesh-seed.yaml`)
-is the second, independent source. Facts that can be backed by both are
-written to the brain under `root=facts` by `bin/facts/crm`.
-
-## What was verified
-
-- Logical counts (portal MySQL): 1300 contacts = 897 persons + 404 companies,
-  198 projects, 998 deals, 939 project↔contact links.
-- Every client company linked to a project has ≥1 person underneath.
-- Every person `company_id` resolves to an existing company.
-- Corpus org list (9) maps 1:1 onto CRM companies:
-  ProProdukt SL / produktor.io, Dyvenia, Immowelt AG, WhereGroup,
-  Keynote SIGOS, D2S/SYSTEMS, GRID, Pack und Cup, Markets Platform.
-- 78 person↔company association facts written to the brain
-  (`how=crm-crosscheck`, `type=association`). Recall@5 in `bin/kb/eval` = 1.0.
-
-## Mistakes found
-
-| # | Mistake | Fix |
-|---|---------|-----|
-| 1 | Duplicate legal entity `GoldenRatio.Exchange` (contact 759) vs `Golden Ratio Exchange` (763); 3 deals (211, 287, 559) were linked to 759 | `oo contacts merge 759 763` — 763 kept, 759 removed, deal links re-pointed to 763 |
-| 2 | `env/`-wide: OnlyOffice creds file used wrong UX (user `eslider`, password with `$2` suffix) making `oo` auth fail | `.env` fixed to `eslider@gmail.com` + clean password; `.env` stays gitignored |
-
-## Gates after fix
-
-- `uv run python -m unittest discover -s bin/tools -t .` → 26 tests OK
-- `bin/facts/audit self` + `bin/facts/audit db` → ok
-- `bin/kb/eval` → recall@5 = 1.0
-- `go test ./...` (bin/server + bin/watch) → ok

internal/brain/http.go

@@ -0,0 +1,154 @@
+//go:build cgo && system_ladybug
+
+package brain
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+)
+
+// Ready opens the Ladybug file for the life of the serve process.
+func Ready() error {
+	return openBrain()
+}
+
+// HTTP is the in-process API used by bin/brain/serve.go.
+type HTTP struct{}
+
+func (HTTP) Search(_ context.Context, query string, limit int) ([]byte, error) {
+	hits, err := searchHits(query, "", "", limit)
+	if err != nil {
+		return nil, err
+	}
+	for i := range hits {
+		if hits[i].Text != "" {
+			runes := []rune(hits[i].Text)
+			if len(runes) > 280 {
+				runes = runes[:280]
+			}
+			hits[i].Snippet = string(runes)
+		}
+	}
+	var buf bytes.Buffer
+	enc := json.NewEncoder(&buf)
+	enc.SetEscapeHTML(false)
+	if err := enc.Encode(toJSONOut(hits, query, "")); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (HTTP) Get(_ context.Context, id string, body bool) ([]byte, error) {
+	if conn == nil {
+		return nil, fmt.Errorf("brain not open")
+	}
+	stmt, err := conn.Prepare(
+		"MATCH (l:Leaf {id:$id}) RETURN l.id, l.text, l.root, l.confidence, l.source, l.type",
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer stmt.Close()
+	res, err := conn.Execute(stmt, map[string]any{"id": id})
+	if err != nil {
+		return nil, err
+	}
+	if !res.HasNext() {
+		return nil, fmt.Errorf("no leaf %s", id)
+	}
+	row, err := res.Next()
+	if err != nil {
+		return nil, err
+	}
+	vals, err := row.GetAsSlice()
+	if err != nil || len(vals) < 6 {
+		return nil, fmt.Errorf("leaf row")
+	}
+	out := map[string]any{
+		"id":         fmt.Sprint(vals[0]),
+		"root":       fmt.Sprint(vals[2]),
+		"confidence": fmt.Sprint(vals[3]),
+		"source":     fmt.Sprint(vals[4]),
+		"type":       fmt.Sprint(vals[5]),
+	}
+	if body {
+		out["text"] = fmt.Sprint(vals[1])
+	}
+	return json.Marshal(out)
+}
+
+func (HTTP) Stats(context.Context) ([]byte, error) {
+	if conn == nil {
+		return nil, fmt.Errorf("brain not open")
+	}
+	res, err := conn.Query("MATCH (l:Leaf) RETURN l.root, count(*)")
+	if err != nil {
+		return nil, err
+	}
+	byRoot := map[string]int{}
+	total := 0
+	for res.HasNext() {
+		row, err := res.Next()
+		if err != nil {
+			return nil, err
+		}
+		vals, err := row.GetAsSlice()
+		if err != nil || len(vals) < 2 {
+			continue
+		}
+		n := int(asInt(vals[1]))
+		byRoot[fmt.Sprint(vals[0])] = n
+		total += n
+	}
+	return json.Marshal(map[string]any{"total": total, "by_root": byRoot, "db": dbPath()})
+}
+
+func (HTTP) Audit(context.Context) ([]byte, error) {
+	if conn == nil {
+		return nil, fmt.Errorf("brain not open")
+	}
+	res, err := conn.Query("MATCH (l:Leaf) RETURN l.root, l.confidence, count(*)")
+	if err != nil {
+		return nil, err
+	}
+	var rows []map[string]any
+	for res.HasNext() {
+		row, err := res.Next()
+		if err != nil {
+			return nil, err
+		}
+		vals, err := row.GetAsSlice()
+		if err != nil || len(vals) < 3 {
+			continue
+		}
+		rows = append(rows, map[string]any{
+			"root":       fmt.Sprint(vals[0]),
+			"confidence": fmt.Sprint(vals[1]),
+			"count":      asInt(vals[2]),
+		})
+	}
+	return json.Marshal(map[string]any{"status": "ok", "by_confidence": rows})
+}
+
+func (HTTP) Ingest(context.Context) ([]byte, error) {
+	return json.Marshal(map[string]any{
+		"mode":    "rebuild",
+		"command": "bin/brain/index.go --rebuild",
+		"add":     "v2",
+	})
+}
+
+func asInt(v any) int64 {
+	switch n := v.(type) {
+	case int64:
+		return n
+	case int:
+		return int64(n)
+	case float64:
+		return int64(n)
+	default:
+		return 0
+	}
+}

internal/brain/search.go

@@ -51,25 +51,13 @@ func runSearch(args []string) int {
 	}
 	defer closeBrain()
 
-	emb, err := embedQuery(query)
+	hits, err := searchHits(query, root, repo, limit)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "embed: %v\n", err)
+		fmt.Fprintf(os.Stderr, "search: %v\n", err)
 		return 1
 	}
 
-	fts, err := queryFTS(query, limit*3)
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "fts: %v\n", err)
-		return 1
-	}
-
-	var vec []Hit
-	if vec, err = queryVector(emb, limit*3); err != nil {
-		fmt.Fprintf(os.Stderr, "vec: %v\n", err)
-	}
-
-	results := rank.RankAndFilter(fts, vec, root, repo, limit)
-
+	results := hits
 	for i := range results {
 		if results[i].Text != "" {
 			runes := []rune(results[i].Text)
@@ -97,6 +85,22 @@ func runSearch(args []string) int {
 	return 0
 }
 
+func searchHits(query, root, repo string, limit int) ([]Hit, error) {
+	emb, err := embedQuery(query)
+	if err != nil {
+		return nil, fmt.Errorf("embed: %w", err)
+	}
+	fts, err := queryFTS(query, limit*3)
+	if err != nil {
+		return nil, fmt.Errorf("fts: %w", err)
+	}
+	var vec []Hit
+	if vec, err = queryVector(emb, limit*3); err != nil {
+		fmt.Fprintf(os.Stderr, "vec: %v\n", err)
+	}
+	return rank.RankAndFilter(fts, vec, root, repo, limit), nil
+}
+
 func b2i(err error) int {
 	if err != nil {
 		return 1

internal/httpapi/server.go

@@ -1,10 +1,10 @@
-// Package server serves the 2dph brain over HTTP.
+// Package httpapi serves the 2dph brain over HTTP.
 //
 // Async by design: every request runs on its own goroutine, and CPU-heavy
-// searches are serialized through a bounded worker pool (a counting
-// semaphore) so N requests can't spawn N search processes at once.
+// searches are serialized through a bounded worker pool so N requests can't
+// spawn N backends at once.
 //
-// Used by bin/brain/serve.go.
+// Used by bin/brain/serve.go. Tests inject a fake API (no exec, no ladybug).
 package httpapi
 
 import (
@@ -21,30 +21,45 @@ import (
 	"time"
 )
 
-type Searcher interface {
+// API is the in-process brain surface. Production serve.go wires internal/brain.
+type API interface {
 	Search(ctx context.Context, query string, limit int) ([]byte, error)
+	Get(ctx context.Context, id string, body bool) ([]byte, error)
+	Stats(ctx context.Context) ([]byte, error)
+	Audit(ctx context.Context) ([]byte, error)
+	Ingest(ctx context.Context) ([]byte, error)
 }
 
 type Server struct {
-	searcher  Searcher
+	api       API
 	semaphore chan struct{}
 }
 
 const defaultPort = 8630
 
-func NewServer(searcher Searcher, workers int) http.Handler {
+var errUnimplemented = errors.New("not implemented")
+
+func NewServer(api API, workers int) http.Handler {
 	return &Server{
-		searcher:  searcher,
+		api:       api,
 		semaphore: make(chan struct{}, workers),
 	}
 }
 
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	switch {
-	case r.URL.Path == "/health":
+	switch r.URL.Path {
+	case "/health":
 		writeJSON(w, http.StatusOK, map[string]any{"status": "ok"})
-	case r.URL.Path == "/search":
+	case "/search":
 		s.handleSearch(w, r)
+	case "/get":
+		s.handleGet(w, r)
+	case "/stats":
+		s.handleJSON(w, r, s.api.Stats)
+	case "/audit":
+		s.handleJSON(w, r, s.api.Audit)
+	case "/ingest":
+		s.handleJSON(w, r, s.api.Ingest)
 	default:
 		writeJSON(w, http.StatusNotFound, map[string]any{"error": "not found"})
 	}
@@ -65,19 +80,56 @@ func (s *Server) handleSearch(w http.ResponseWriter, r *http.Request) {
 		}
 		limit = n
 	}
-
-	// Worker pool: block until a slot frees, so burst concurrency still
-	// bounds memory (no unbounded python processes).
-	select {
-	case s.semaphore <- struct{}{}:
-		defer func() { <-s.semaphore }()
-	case <-r.Context().Done():
+	if !s.acquire(w, r) {
 		return
 	}
+	defer s.release()
+	body, err := s.api.Search(r.Context(), q, limit)
+	writeAPI(w, body, err)
+}
 
-	body, err := s.searcher.Search(r.Context(), q, limit)
+func (s *Server) handleGet(w http.ResponseWriter, r *http.Request) {
+	id := strings.TrimSpace(r.URL.Query().Get("id"))
+	if id == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "id required"})
+		return
+	}
+	body := r.URL.Query().Get("body") == "1" || r.URL.Query().Get("body") == "true"
+	if !s.acquire(w, r) {
+		return
+	}
+	defer s.release()
+	out, err := s.api.Get(r.Context(), id, body)
+	writeAPI(w, out, err)
+}
+
+func (s *Server) handleJSON(w http.ResponseWriter, r *http.Request, fn func(context.Context) ([]byte, error)) {
+	if !s.acquire(w, r) {
+		return
+	}
+	defer s.release()
+	body, err := fn(r.Context())
+	writeAPI(w, body, err)
+}
+
+func (s *Server) acquire(w http.ResponseWriter, r *http.Request) bool {
+	select {
+	case s.semaphore <- struct{}{}:
+		return true
+	case <-r.Context().Done():
+		return false
+	}
+}
+
+func (s *Server) release() { <-s.semaphore }
+
+func writeAPI(w http.ResponseWriter, body []byte, err error) {
 	if err != nil {
-		writeJSON(w, http.StatusGatewayTimeout, map[string]any{"error": err.Error()})
+		code := http.StatusBadGateway
+		if errors.Is(err, errUnimplemented) {
+			code = http.StatusNotImplemented
+		}
+		writeJSON(w, code, map[string]any{"error": err.Error()})
 		return
 	}
 	writeRaw(w, http.StatusOK, body)
@@ -95,17 +147,20 @@ func writeRaw(w http.ResponseWriter, code int, body []byte) {
 	w.Write(body)
 }
 
-// brainSearcher shells out to the Go brain-search binary (not Python).
-// A single search is bounded and short-lived; the worker pool keeps at most N live.
-type brainSearcher struct {
-	cmdPath string
-	timeout time.Duration
+// ExecSearcher shells out to var/bin/brain-search. Fallback when the serve
+// binary is built without ladybug cgo (CI / tags=brain_serve only).
+type ExecSearcher struct {
+	CmdPath string
+	Timeout time.Duration
 }
 
-func (b *brainSearcher) Search(ctx context.Context, query string, limit int) ([]byte, error) {
-	ctx, cancel := context.WithTimeout(ctx, b.timeout)
+func (b ExecSearcher) Search(ctx context.Context, query string, limit int) ([]byte, error) {
+	if b.Timeout == 0 {
+		b.Timeout = 60 * time.Second
+	}
+	ctx, cancel := context.WithTimeout(ctx, b.Timeout)
 	defer cancel()
-	cmd := exec.CommandContext(ctx, b.cmdPath, "--json", "-n", strconv.Itoa(limit), query)
+	cmd := exec.CommandContext(ctx, b.CmdPath, "--json", "-n", strconv.Itoa(limit), query)
 	out, err := cmd.Output()
 	if err != nil {
 		var exitErr *exec.ExitError
@@ -117,6 +172,18 @@ func (b *brainSearcher) Search(ctx context.Context, query string, limit int) ([]
 	return out, nil
 }
 
+func (ExecSearcher) Get(context.Context, string, bool) ([]byte, error) {
+	return nil, errUnimplemented
+}
+func (ExecSearcher) Stats(context.Context) ([]byte, error) { return nil, errUnimplemented }
+func (ExecSearcher) Audit(context.Context) ([]byte, error) { return nil, errUnimplemented }
+func (ExecSearcher) Ingest(context.Context) ([]byte, error) {
+	return json.Marshal(map[string]any{
+		"mode":    "rebuild",
+		"command": "bin/brain/index.go --rebuild",
+	})
+}
+
 func defaultSearchCmd(root string) string {
 	if env := os.Getenv("KB_SEARCH_CMD"); env != "" {
 		return env
@@ -124,11 +191,7 @@ func defaultSearchCmd(root string) string {
 	return filepath.Join(root, "var", "bin", "brain-search")
 }
 
-// Run starts the HTTP server. Reads env: KB_SEARCH_CMD (default
-// $KB_ROOT/var/bin/brain-search), KB_WORKERS (default 4), KB_PORT (default 8630).
-func Run() {
-	root := os.Getenv("KB_ROOT")
-	searchPath := defaultSearchCmd(root)
+func workersAndPort() (int, int) {
 	workers := 4
 	if raw := os.Getenv("KB_WORKERS"); raw != "" {
 		if n, err := strconv.Atoi(raw); err == nil && n > 0 {
@@ -141,11 +204,19 @@ func Run() {
 			port = n
 		}
 	}
+	return workers, port
+}
 
-	searcher := &brainSearcher{cmdPath: searchPath, timeout: 60 * time.Second}
-	handler := NewServer(searcher, workers)
+// Run starts the HTTP server with an injected API (in-process brain, or ExecSearcher).
+func Run(api API) {
+	if api == nil {
+		root := os.Getenv("KB_ROOT")
+		api = ExecSearcher{CmdPath: defaultSearchCmd(root), Timeout: 60 * time.Second}
+	}
+	workers, port := workersAndPort()
+	handler := NewServer(api, workers)
 	addr := "127.0.0.1:" + strconv.Itoa(port)
-	log.Printf("serve: %s (workers=%d cmd=%s)", addr, workers, searchPath)
+	log.Printf("serve: %s (workers=%d)", addr, workers)
 	if err := http.ListenAndServe(addr, handler); err != nil {
 		log.Fatal(err)
 	}

internal/httpapi/server_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -47,6 +48,26 @@ func (f *fakeSearcher) Search(ctx context.Context, query string, limit int) ([]b
 	return []byte(`{"query":"` + query + `","count":0,"results":[]}`), nil
 }
 
+func (f *fakeSearcher) Get(_ context.Context, id string, body bool) ([]byte, error) {
+	out := map[string]any{"id": id, "root": "info"}
+	if body {
+		out["text"] = "fake body"
+	}
+	return json.Marshal(out)
+}
+
+func (f *fakeSearcher) Stats(context.Context) ([]byte, error) {
+	return []byte(`{"total":0,"by_root":{}}`), nil
+}
+
+func (f *fakeSearcher) Audit(context.Context) ([]byte, error) {
+	return []byte(`{"status":"ok"}`), nil
+}
+
+func (f *fakeSearcher) Ingest(context.Context) ([]byte, error) {
+	return []byte(`{"mode":"rebuild","command":"bin/brain/index.go --rebuild"}`), nil
+}
+
 func (f *fakeSearcher) count() int {
 	f.mu.Lock()
 	defer f.mu.Unlock()
@@ -142,6 +163,47 @@ func TestSearchRejectsBadLimit(t *testing.T) {
 	}
 }
 
+func TestGetLeaf(t *testing.T) {
+	fs := &fakeSearcher{callback: func(q string, limit int) ([]byte, error) {
+		return []byte(`{}`), nil
+	}}
+	h := NewServer(fs, 1)
+	if code, _ := get(t, h, "/get"); code != http.StatusBadRequest {
+		t.Fatalf("missing id code = %d, want 400", code)
+	}
+	code, body := get(t, h, "/get?id=leaf-1&body=1")
+	if code != http.StatusOK {
+		t.Fatalf("get code = %d, want 200 body=%s", code, body)
+	}
+	if !strings.Contains(string(body), "leaf-1") {
+		t.Fatalf("get body %s missing id", body)
+	}
+}
+
+func TestStatsAuditIngest(t *testing.T) {
+	h := NewServer(&fakeSearcher{}, 1)
+	for _, path := range []string{"/stats", "/audit", "/ingest"} {
+		code, body := get(t, h, path)
+		if code != http.StatusOK {
+			t.Fatalf("%s code = %d, want 200 (%s)", path, code, body)
+		}
+		if !json.Valid(body) {
+			t.Fatalf("%s body not json: %s", path, body)
+		}
+	}
+}
+
+func TestHTTPPackageDoesNotExecPython(t *testing.T) {
+	raw, err := os.ReadFile("server.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+	lower := strings.ToLower(string(raw))
+	if strings.Contains(lower, "python3") || strings.Contains(lower, "bin/kb/search") {
+		t.Fatal("httpapi must not exec Python or bin/kb/search")
+	}
+}
+
 func TestDefaultSearchCmdIsBrainNotPython(t *testing.T) {
 	t.Setenv("KB_SEARCH_CMD", "")
 	cmd := defaultSearchCmd("/repo")

skills/agent-cost/SKILL.md

@@ -1,34 +0,0 @@
----
-name: agent-cost
-description: >-
-  Measure what an agent session actually costs in tokens using bin/agents/cost.
-  Use before and after changing documentation, skills or context layout, and when
-  a session feels unexpectedly expensive.
----
-
-# agent-cost
-
-```bash
-bin/agents/cost                        # every project, YAML
-bin/agents/cost --repo 2dph            # only sessions whose cwd matches
-bin/agents/cost --json | jq .cursor.by_tool
-bin/agents/cost --snapshot after-x --repo 2dph   # append a row to docs/CONTEXT-BUDGET.md
-```
-
-Reads local session storage from OpenCode and Cursor transcripts. Reports the
-always-loaded baseline, cache hit/miss/thrash, and which tools moved the most
-bytes.
-
-## How to read it
-
-- **Baseline** is what every single message pays for: `AGENTS.md` plus anything
-  eagerly linked from it. Keep it small; it multiplies by message count.
-- **Cache thrash** matters more than raw size. Editing a file that sits early in
-  the context invalidates the prompt cache for the whole session.
-- **by_tool bytes** shows where the real spend is. Usually it is unfiltered
-  command output, not documentation.
-
-## Rule
-
-Measure before and after. A claim that something "reduces tokens" without a
-before and an after number is an opinion, not a result.

skills/brain/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: kb-search
+name: brain
 description: >-
   Deduction search over the 2dph brain (Ladybug graph: ops corpus, portfolio,
   ssh hosts) with bin/brain/search.go instead of reading files or grepping
@@ -8,7 +8,7 @@ description: >-
   documentation.
 ---
 
-# kb-search — deduction over facts and info
+# brain — deduction over facts and info
 
 One embedded Ladybug graph (`var/kb.lbug`, read-only when queried) holding two
 roots: