diff --git a/Makefile b/Makefile
index f52b6bc..4daf58d 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,7 @@ GO ?= go
 
 build:
 	$(GO) build ./...
+	cd services/atomizer && $(GO) build ./...
 
 run:
 	$(GO) run ./cmd/app
@@ -16,6 +17,13 @@ test:
 test-integration:
 	$(GO) test -tags=integration ./...
 
+# Requires the mock services running:
+#   docker compose --profile mocks up -d --build atomizer-mock work-performer
+test-contract:
+	ATOMIZER_TOKEN=$$(grep '^ATOMIZER_TOKEN=' .env | cut -d= -f2-) \
+	WORK_PERFORMER_TOKEN=$$(grep '^WORK_PERFORMER_TOKEN=' .env | cut -d= -f2-) \
+	$(GO) test -tags=contract -count=1 -timeout=8m ./internal/contract/
+
 lint:
 	@unformatted=$$(gofmt -l .); if [ -n "$$unformatted" ]; then \
 		echo "gofmt needed on:"; echo "$$unformatted"; exit 1; fi
diff --git a/PROGRESS.md b/PROGRESS.md
index f35a237..71ef961 100644
--- a/PROGRESS.md
+++ b/PROGRESS.md
@@ -11,3 +11,4 @@
 - Phase 8 (bounty board + lifecycle): developer board (pool-scoped, filters/search/sort, stale age badges, hide-competing-claims setting, saved filters), claim/withdraw/decline/approve, assign-to-AI via §5.2 client + HMAC-verified idempotent callback w/ artifact ingestion into GridFS, start/submit/abandon/unassign, comments (sanitized, @mentions→notifications), time log, review queue + per-AC checklist on timeline, immutable bountyAwards on approve (humans only), notifications center + bell + WS toasts, my-tasks kanban, task detail page, pool management UI, server-side HTML sanitizer w/ XSS vector tests — full lifecycle integration tests green.
 - Phase 9 (messaging): conversations (dm dedupe/group/project), sanitized rich-text messages, file/image attachments (generic POST /api/v1/files w/ rate limit), per-conversation unread counts + mark-read, chat-file access limited to participants, mentions→notifications, typing indicator over WS inbound relay, two-pane messages UI (contenteditable composer, formatting toolbar, drag&drop upload, inline previews + lightbox, live delivery, polling fallback), user directory search — integration tests green.
 - Phase 10 (metrics): aggregation pipelines over bountyAwards + timelines (totals, weekly $dateTrunc buckets, per-developer/per-customer, approval rate, time logged, assign→approve lead time, atomization lead time, open board depth), CSV export, leaderboard w/ opt-out (profile setting), dependency-free SVG line+bar charts, developer/consultant/admin dashboards — integration tests green.
+- Phase 11 (mock services): services/atomizer (own Go module, ports 8090, bearer auth, OpenAI-compatible chat completions + native /v1/messages via LLM_API_STYLE, strict-JSON prompt, fence-stripping defensive parse, one retry, deterministic equal-split fallback, exact sum normalization); services/work-performer (Node 20, zero deps, single-concurrency queue, TASK.md + attachment download + optional git clone, claude -p --output-format json --dangerously-skip-permissions, simulated result when CLI unavailable, artifact serving, HMAC-signed callbacks with retry); compose profile mocks w/ healthchecks + ${HOME}/.claude mounts; contract tests pass live (WP ran real Claude Code via mounted host creds). UFW rule added for container→host callbacks.
diff --git a/docker-compose.yml b/docker-compose.yml
index 5d9e882..c5825e7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -39,5 +39,52 @@ services:
       retries: 3
       start_period: 10s
 
+  # --- placeholder external services (docker compose --profile mocks up) ---
+  # Two fully independent services: separate builds, ports, tokens (§5).
+  atomizer-mock:
+    build: ./services/atomizer
+    profiles: ["mocks"]
+    restart: unless-stopped
+    environment:
+      PORT: "8090"
+      ATOMIZER_TOKEN: ${ATOMIZER_TOKEN}
+      ANTHROPIC_API_KEY: ${ANTHROPIC_API_KEY:-}
+      ANTHROPIC_OPENAI_BASE_URL: ${ANTHROPIC_OPENAI_BASE_URL:-https://api.anthropic.com/v1}
+      ANTHROPIC_MODEL: ${ANTHROPIC_MODEL:-claude-sonnet-4-6}
+      LLM_API_STYLE: ${LLM_API_STYLE:-openai}
+    ports:
+      - "127.0.0.1:8090:8090"
+    healthcheck:
+      test: ["CMD", "wget", "-qO-", "http://127.0.0.1:8090/healthz"]
+      interval: 10s
+      timeout: 5s
+      retries: 3
+      start_period: 5s
+
+  work-performer:
+    build: ./services/work-performer
+    profiles: ["mocks"]
+    restart: unless-stopped
+    environment:
+      PORT: "8091"
+      WORK_PERFORMER_TOKEN: ${WORK_PERFORMER_TOKEN}
+      PUBLIC_BASE_URL: http://work-performer:8091
+    # host Claude Code config/secrets, read-only (§9.2)
+    volumes:
+      - ${HOME}/.claude:/root/.claude
+      - ${HOME}/.claude.json:/root/.claude.json
+      - work-data:/work
+    ports:
+      - "127.0.0.1:8091:8091"
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
+    healthcheck:
+      test: ["CMD-SHELL", "node -e \"fetch('http://127.0.0.1:8091/healthz').then(r=>process.exit(r.ok?0:1)).catch(()=>process.exit(1))\""]
+      interval: 10s
+      timeout: 5s
+      retries: 3
+      start_period: 5s
+
 volumes:
   mongo-data:
+  work-data:
diff --git a/internal/contract/contract_test.go b/internal/contract/contract_test.go
new file mode 100644
index 0000000..02c436e
--- /dev/null
+++ b/internal/contract/contract_test.go
@@ -0,0 +1,258 @@
+//go:build contract
+
+// Contract tests for the two mock services (§13). They run against live
+// containers:
+//
+//	docker compose --profile mocks -f docker-compose.yml -f docker-compose.test.yml up -d --build
+//	ATOMIZER_TOKEN=… WORK_PERFORMER_TOKEN=… go test -tags=contract ./internal/contract/
+//
+// URLs default to the loopback ports published by the mocks profile.
+package contract
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"math"
+	"net"
+	"net/http"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"bountyboard/internal/workperform"
+)
+
+func env(k, def string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return def
+}
+
+var (
+	atomizerURL    = env("CONTRACT_ATOMIZER_URL", "http://127.0.0.1:8090")
+	performerURL   = env("CONTRACT_PERFORMER_URL", "http://127.0.0.1:8091")
+	atomizerToken  = os.Getenv("ATOMIZER_TOKEN")
+	performerToken = os.Getenv("WORK_PERFORMER_TOKEN")
+)
+
+func postJSON(t *testing.T, url, token string, body any) (*http.Response, []byte) {
+	t.Helper()
+	b, _ := json.Marshal(body)
+	req, _ := http.NewRequest(http.MethodPost, url, bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	if token != "" {
+		req.Header.Set("Authorization", "Bearer "+token)
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("POST %s: %v", url, err)
+	}
+	data, _ := io.ReadAll(resp.Body)
+	resp.Body.Close()
+	return resp, data
+}
+
+func TestAtomizerContract(t *testing.T) {
+	// healthz
+	resp, err := http.Get(atomizerURL + "/healthz")
+	if err != nil {
+		t.Skipf("atomizer not reachable at %s (start the mocks profile): %v", atomizerURL, err)
+	}
+	resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Fatalf("healthz: %d", resp.StatusCode)
+	}
+
+	// wrong bearer token rejected (when a token is configured)
+	if atomizerToken != "" {
+		r, _ := postJSON(t, atomizerURL+"/v1/atomize", "wrong-token", map[string]any{"taskId": "x", "title": "x"})
+		if r.StatusCode != http.StatusUnauthorized {
+			t.Fatalf("wrong token: %d, want 401", r.StatusCode)
+		}
+	}
+
+	// atomize honors the §5.1 response contract
+	r, data := postJSON(t, atomizerURL+"/v1/atomize", atomizerToken, map[string]any{
+		"taskId":             "01JCONTRACT",
+		"title":              "Implement user import",
+		"description":        "Import users from CSV with mapping and validation.",
+		"acceptanceCriteria": []string{"valid rows imported", "errors reported per row"},
+		"constraints":        map[string]int{"minTasks": 2, "maxTasks": 5},
+	})
+	if r.StatusCode != http.StatusOK {
+		t.Fatalf("atomize: %d %s", r.StatusCode, data)
+	}
+	var out struct {
+		Tasks []struct {
+			Title             string  `json:"title"`
+			Description       string  `json:"description"`
+			EffortCoefficient float64 `json:"effortCoefficient"`
+		} `json:"tasks"`
+		Model string `json:"model"`
+	}
+	if err := json.Unmarshal(data, &out); err != nil {
+		t.Fatalf("decode: %v: %s", err, data)
+	}
+	if len(out.Tasks) < 2 || len(out.Tasks) > 5 {
+		t.Fatalf("task count %d outside constraints", len(out.Tasks))
+	}
+	sum := 0.0
+	for _, task := range out.Tasks {
+		if task.Title == "" || task.EffortCoefficient <= 0 || task.EffortCoefficient > 1 {
+			t.Fatalf("bad task: %+v", task)
+		}
+		sum += task.EffortCoefficient
+	}
+	if math.Abs(sum-1) > 0.001 {
+		t.Fatalf("coefficient sum %v, want 1±0.001", sum)
+	}
+
+	// extend returns exactly one task with coefficient in (0, 2]
+	r, data = postJSON(t, atomizerURL+"/v1/extend", atomizerToken, map[string]any{
+		"taskId": "01JCONTRACT", "title": "Implement user import",
+		"description":   "Import users from CSV.",
+		"extensionNote": "add reusable column-mapping presets",
+	})
+	if r.StatusCode != http.StatusOK {
+		t.Fatalf("extend: %d %s", r.StatusCode, data)
+	}
+	var ext struct {
+		Task struct {
+			Title             string  `json:"title"`
+			EffortCoefficient float64 `json:"effortCoefficient"`
+		} `json:"task"`
+	}
+	if err := json.Unmarshal(data, &ext); err != nil {
+		t.Fatalf("decode extend: %v", err)
+	}
+	if ext.Task.Title == "" || ext.Task.EffortCoefficient <= 0 || ext.Task.EffortCoefficient > 2 {
+		t.Fatalf("bad extension: %+v", ext.Task)
+	}
+
+	// extend without a note is rejected
+	r, _ = postJSON(t, atomizerURL+"/v1/extend", atomizerToken, map[string]any{
+		"taskId": "x", "title": "x",
+	})
+	if r.StatusCode != http.StatusBadRequest {
+		t.Fatalf("extend without note: %d, want 400", r.StatusCode)
+	}
+}
+
+func TestWorkPerformerContract(t *testing.T) {
+	resp, err := http.Get(performerURL + "/healthz")
+	if err != nil {
+		t.Skipf("work performer not reachable at %s (start the mocks profile): %v", performerURL, err)
+	}
+	resp.Body.Close()
+	if resp.StatusCode != 200 {
+		t.Fatalf("healthz: %d", resp.StatusCode)
+	}
+
+	// callback receiver on the host, reachable from the container via
+	// host.docker.internal (extra_hosts: host-gateway)
+	callbackCh := make(chan struct {
+		body []byte
+		sig  string
+	}, 1)
+	ln, err := net.Listen("tcp", "0.0.0.0:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer ln.Close()
+	go http.Serve(ln, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, _ := io.ReadAll(r.Body)
+		select {
+		case callbackCh <- struct {
+			body []byte
+			sig  string
+		}{body, r.Header.Get("X-Signature")}:
+		default:
+		}
+		w.WriteHeader(200)
+	}))
+	port := ln.Addr().(*net.TCPAddr).Port
+	callbackURL := fmt.Sprintf("http://host.docker.internal:%d/cb", port)
+
+	r, data := postJSON(t, performerURL+"/v1/jobs", performerToken, map[string]any{
+		"taskId": "01JCONTRACTWP", "title": "Write hello world",
+		"description":        "Create hello.txt containing hello world.",
+		"acceptanceCriteria": []string{"hello.txt exists"},
+		"callbackUrl":        callbackURL,
+	})
+	if r.StatusCode != http.StatusAccepted {
+		t.Fatalf("submit: %d %s", r.StatusCode, data)
+	}
+	var accepted struct {
+		JobID  string `json:"jobId"`
+		Status string `json:"status"`
+	}
+	if err := json.Unmarshal(data, &accepted); err != nil || accepted.JobID == "" {
+		t.Fatalf("bad 202 body: %s", data)
+	}
+
+	// status endpoint
+	req, _ := http.NewRequest(http.MethodGet, performerURL+"/v1/jobs/"+accepted.JobID, nil)
+	req.Header.Set("Authorization", "Bearer "+performerToken)
+	sResp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	sBody, _ := io.ReadAll(sResp.Body)
+	sResp.Body.Close()
+	var status struct {
+		Status string `json:"status"`
+	}
+	if err := json.Unmarshal(sBody, &status); err != nil {
+		t.Fatalf("status decode: %s", sBody)
+	}
+	if !strings.Contains("queued running succeeded failed", status.Status) {
+		t.Fatalf("status %q", status.Status)
+	}
+
+	// HMAC-signed callback arrives (the simulated path is fast; the real
+	// claude path may take minutes — allow a generous window)
+	select {
+	case cb := <-callbackCh:
+		if !workperform.VerifySignature(performerToken, cb.body, cb.sig) {
+			t.Fatalf("callback signature invalid")
+		}
+		var payload workperform.Callback
+		if err := json.Unmarshal(cb.body, &payload); err != nil {
+			t.Fatalf("callback decode: %v", err)
+		}
+		if payload.JobID != accepted.JobID || payload.TaskID != "01JCONTRACTWP" {
+			t.Fatalf("callback ids: %+v", payload)
+		}
+		if payload.Status != "succeeded" && payload.Status != "failed" {
+			t.Fatalf("callback status %q", payload.Status)
+		}
+		// artifacts must be fetchable (rewrite in-network host for the host-side test)
+		for _, a := range payload.Artifacts {
+			url := strings.Replace(a.URL, "http://work-performer:8091", performerURL, 1)
+			aResp, err := http.Get(url)
+			if err != nil || aResp.StatusCode != 200 {
+				t.Fatalf("artifact %s not fetchable: %v %v", a.URL, err, aResp)
+			}
+			aResp.Body.Close()
+		}
+	case <-time.After(5 * time.Minute):
+		t.Fatal("no callback within 5 minutes")
+	}
+
+	// cancel is accepted for unknown-but-wellformed ids → 404, and DELETE on
+	// a finished job still answers
+	req, _ = http.NewRequest(http.MethodDelete, performerURL+"/v1/jobs/"+accepted.JobID, nil)
+	req.Header.Set("Authorization", "Bearer "+performerToken)
+	dResp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dResp.Body.Close()
+	if dResp.StatusCode != 200 {
+		t.Fatalf("cancel: %d", dResp.StatusCode)
+	}
+}
diff --git a/services/atomizer/Dockerfile b/services/atomizer/Dockerfile
new file mode 100644
index 0000000..a1922dd
--- /dev/null
+++ b/services/atomizer/Dockerfile
@@ -0,0 +1,14 @@
+# --- build ---
+FROM golang:1.26-alpine AS build
+WORKDIR /src
+COPY go.mod ./
+COPY *.go ./
+RUN CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" -o /out/atomizer .
+
+# --- runtime ---
+FROM alpine:3.21
+RUN apk add --no-cache ca-certificates && adduser -S -G nogroup app
+USER app
+COPY --from=build /out/atomizer /usr/local/bin/atomizer
+EXPOSE 8090
+ENTRYPOINT ["/usr/local/bin/atomizer"]
diff --git a/services/atomizer/atomizer-mock b/services/atomizer/atomizer-mock
new file mode 100755
index 0000000..bcff00e
Binary files /dev/null and b/services/atomizer/atomizer-mock differ
diff --git a/services/atomizer/go.mod b/services/atomizer/go.mod
new file mode 100644
index 0000000..62f0021
--- /dev/null
+++ b/services/atomizer/go.mod
@@ -0,0 +1,3 @@
+module atomizer-mock
+
+go 1.26
diff --git a/services/atomizer/llm.go b/services/atomizer/llm.go
new file mode 100644
index 0000000..552cceb
--- /dev/null
+++ b/services/atomizer/llm.go
@@ -0,0 +1,252 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"strings"
+	"time"
+)
+
+// llmClient calls Anthropic via the OpenAI-compatible chat-completions
+// endpoint (default) or the native Messages API (LLM_API_STYLE=anthropic).
+// Plain net/http, no SDK (§9.1).
+type llmClient struct {
+	cfg  config
+	log  *slog.Logger
+	http *http.Client
+}
+
+func newLLMClient(cfg config, log *slog.Logger) *llmClient {
+	return &llmClient{cfg: cfg, log: log, http: &http.Client{Timeout: 110 * time.Second}}
+}
+
+const atomizeSystem = `You are an expert software project planner. You split one ticket into small, well-scoped, independently deliverable developer tasks.
+Respond with ONLY a JSON object, no prose and no markdown fences, exactly matching:
+{"tasks":[{"title":"...","description":"...","acceptanceCriteria":["..."],"effortCoefficient":0.25}],"notes":"short advice for the consultant"}
+Rules: between MIN and MAX tasks; every effortCoefficient is a number in (0,1]; all effortCoefficients MUST sum to exactly 1.0; titles are concise; descriptions are self-contained instructions; each task has 1-4 testable acceptance criteria.`
+
+const extendSystem = `You are an expert software project planner. You design exactly ONE additional sibling task that extends the given task's functionality per the extension note.
+Respond with ONLY a JSON object, no prose and no markdown fences, exactly matching:
+{"task":{"title":"...","description":"...","acceptanceCriteria":["..."],"effortCoefficient":0.4},"notes":"short advice"}
+Rules: effortCoefficient is the effort RELATIVE to the source task, a number in (0,2].`
+
+func ticketPrompt(req atomizeRequest) string {
+	var sb strings.Builder
+	fmt.Fprintf(&sb, "TICKET: %s\n\nDESCRIPTION:\n%s\n", req.Title, req.Description)
+	if len(req.AcceptanceCriteria) > 0 {
+		sb.WriteString("\nACCEPTANCE CRITERIA:\n")
+		for _, c := range req.AcceptanceCriteria {
+			fmt.Fprintf(&sb, "- %s\n", c)
+		}
+	}
+	if len(req.Links) > 0 {
+		fmt.Fprintf(&sb, "\nLINKS: %s\n", strings.Join(req.Links, ", "))
+	}
+	for _, a := range req.Attachments {
+		fmt.Fprintf(&sb, "ATTACHMENT: %s (%s) %s\n", a.Name, a.MimeType, a.URL)
+	}
+	return sb.String()
+}
+
+func (l *llmClient) atomize(ctx context.Context, req atomizeRequest, minT, maxT int) ([]subTask, string, string, error) {
+	if l.cfg.apiKey == "" {
+		return fallbackAtomize(req, minT, maxT), "offline-fallback", "Deterministic split (no ANTHROPIC_API_KEY configured).", nil
+	}
+	system := strings.NewReplacer("MIN", fmt.Sprint(minT), "MAX", fmt.Sprint(maxT)).Replace(atomizeSystem)
+	user := ticketPrompt(req)
+	if req.SubdivisionNote != "" {
+		user += "\nCONSULTANT NOTE: " + req.SubdivisionNote
+	}
+
+	var parsed struct {
+		Tasks []subTask `json:"tasks"`
+		Notes string    `json:"notes"`
+	}
+	raw, err := l.completeWithRetry(ctx, system, user, func(text string) error {
+		if err := json.Unmarshal([]byte(stripFences(text)), &parsed); err != nil {
+			return err
+		}
+		if len(parsed.Tasks) == 0 {
+			return fmt.Errorf("no tasks in response")
+		}
+		for _, t := range parsed.Tasks {
+			if t.Title == "" || t.EffortCoefficient <= 0 {
+				return fmt.Errorf("invalid task entry")
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		l.log.Warn("llm atomize failed, using fallback", "err", err)
+		return fallbackAtomize(req, minT, maxT), "offline-fallback",
+			"LLM unavailable (" + err.Error() + "); deterministic split.", nil
+	}
+	_ = raw
+	return parsed.Tasks, l.cfg.model, parsed.Notes, nil
+}
+
+func (l *llmClient) extend(ctx context.Context, req atomizeRequest) (subTask, string, string, error) {
+	if l.cfg.apiKey == "" {
+		return fallbackExtend(req), "offline-fallback", "Deterministic extension (no ANTHROPIC_API_KEY configured).", nil
+	}
+	user := ticketPrompt(req) + "\nEXTENSION NOTE (required scope): " + req.ExtensionNote
+
+	var parsed struct {
+		Task  subTask `json:"task"`
+		Notes string  `json:"notes"`
+	}
+	_, err := l.completeWithRetry(ctx, extendSystem, user, func(text string) error {
+		if err := json.Unmarshal([]byte(stripFences(text)), &parsed); err != nil {
+			return err
+		}
+		if parsed.Task.Title == "" {
+			return fmt.Errorf("no task in response")
+		}
+		return nil
+	})
+	if err != nil {
+		l.log.Warn("llm extend failed, using fallback", "err", err)
+		return fallbackExtend(req), "offline-fallback",
+			"LLM unavailable (" + err.Error() + "); deterministic extension.", nil
+	}
+	return parsed.Task, l.cfg.model, parsed.Notes, nil
+}
+
+// completeWithRetry runs the chat completion and retries ONCE on parse
+// failure with a corrective hint (§9.1).
+func (l *llmClient) completeWithRetry(ctx context.Context, system, user string,
+	validate func(string) error) (string, error) {
+	text, err := l.complete(ctx, system, user)
+	if err != nil {
+		return "", err
+	}
+	if vErr := validate(text); vErr == nil {
+		return text, nil
+	} else {
+		l.log.Warn("llm response failed validation, retrying once", "err", vErr)
+	}
+	text, err = l.complete(ctx, system,
+		user+"\n\nIMPORTANT: your previous reply was not valid JSON matching the schema. Reply with ONLY the JSON object.")
+	if err != nil {
+		return "", err
+	}
+	if vErr := validate(text); vErr != nil {
+		return "", fmt.Errorf("invalid JSON after retry: %w", vErr)
+	}
+	return text, nil
+}
+
+func (l *llmClient) complete(ctx context.Context, system, user string) (string, error) {
+	if l.cfg.apiStyle == "anthropic" {
+		return l.completeNative(ctx, system, user)
+	}
+	return l.completeOpenAI(ctx, system, user)
+}
+
+// completeOpenAI uses Anthropic's OpenAI-compatible endpoint.
+func (l *llmClient) completeOpenAI(ctx context.Context, system, user string) (string, error) {
+	body, _ := json.Marshal(map[string]any{
+		"model":      l.cfg.model,
+		"max_tokens": 4096,
+		"messages": []map[string]string{
+			{"role": "system", "content": system},
+			{"role": "user", "content": user},
+		},
+	})
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		l.cfg.baseURL+"/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+l.cfg.apiKey)
+	data, err := l.do(req)
+	if err != nil {
+		return "", err
+	}
+	var out struct {
+		Choices []struct {
+			Message struct {
+				Content string `json:"content"`
+			} `json:"message"`
+		} `json:"choices"`
+	}
+	if err := json.Unmarshal(data, &out); err != nil {
+		return "", fmt.Errorf("decode chat completion: %w", err)
+	}
+	if len(out.Choices) == 0 {
+		return "", fmt.Errorf("no choices in response")
+	}
+	return out.Choices[0].Message.Content, nil
+}
+
+// completeNative uses the native Anthropic Messages API (flip via
+// LLM_API_STYLE=anthropic if the compatibility endpoint misbehaves, §9.1).
+func (l *llmClient) completeNative(ctx context.Context, system, user string) (string, error) {
+	body, _ := json.Marshal(map[string]any{
+		"model":      l.cfg.model,
+		"max_tokens": 4096,
+		"system":     system,
+		"messages":   []map[string]string{{"role": "user", "content": user}},
+	})
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		l.cfg.baseURL+"/messages", bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("x-api-key", l.cfg.apiKey)
+	req.Header.Set("anthropic-version", "2023-06-01")
+	data, err := l.do(req)
+	if err != nil {
+		return "", err
+	}
+	var out struct {
+		Content []struct {
+			Type string `json:"type"`
+			Text string `json:"text"`
+		} `json:"content"`
+	}
+	if err := json.Unmarshal(data, &out); err != nil {
+		return "", fmt.Errorf("decode messages response: %w", err)
+	}
+	for _, c := range out.Content {
+		if c.Type == "text" {
+			return c.Text, nil
+		}
+	}
+	return "", fmt.Errorf("no text content in response")
+}
+
+func (l *llmClient) do(req *http.Request) ([]byte, error) {
+	resp, err := l.http.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	data, err := io.ReadAll(io.LimitReader(resp.Body, 10<<20))
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("llm api status %d: %.300s", resp.StatusCode, data)
+	}
+	return data, nil
+}
+
+// stripFences defensively removes markdown code fences and surrounding prose
+// (§9.1) by slicing from the first '{' to the last '}'.
+func stripFences(s string) string {
+	s = strings.TrimSpace(s)
+	if i := strings.IndexByte(s, '{'); i >= 0 {
+		if j := strings.LastIndexByte(s, '}'); j > i {
+			return s[i : j+1]
+		}
+	}
+	return s
+}
diff --git a/services/atomizer/main.go b/services/atomizer/main.go
new file mode 100644
index 0000000..65a531f
--- /dev/null
+++ b/services/atomizer/main.go
@@ -0,0 +1,243 @@
+// atomizer-mock is the standalone placeholder Atomization Service (§5.1,
+// §9.1). It calls Anthropic through the OpenAI-compatible chat-completions
+// endpoint by default, or the native Messages API when
+// LLM_API_STYLE=anthropic, and falls back to a deterministic equal split
+// when no ANTHROPIC_API_KEY is configured so the whole system works offline.
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+)
+
+type config struct {
+	port     string
+	token    string
+	apiKey   string
+	baseURL  string
+	model    string
+	apiStyle string // openai | anthropic
+}
+
+func loadConfig() config {
+	get := func(k, def string) string {
+		if v := os.Getenv(k); v != "" {
+			return v
+		}
+		return def
+	}
+	return config{
+		port:     get("PORT", "8090"),
+		token:    os.Getenv("ATOMIZER_TOKEN"),
+		apiKey:   os.Getenv("ANTHROPIC_API_KEY"),
+		baseURL:  strings.TrimRight(get("ANTHROPIC_OPENAI_BASE_URL", "https://api.anthropic.com/v1"), "/"),
+		model:    get("ANTHROPIC_MODEL", "claude-sonnet-4-6"),
+		apiStyle: get("LLM_API_STYLE", "openai"),
+	}
+}
+
+type subTask struct {
+	Title              string   `json:"title"`
+	Description        string   `json:"description"`
+	AcceptanceCriteria []string `json:"acceptanceCriteria"`
+	EffortCoefficient  float64  `json:"effortCoefficient"`
+}
+
+type atomizeRequest struct {
+	TaskID             string   `json:"taskId"`
+	Title              string   `json:"title"`
+	Description        string   `json:"description"`
+	AcceptanceCriteria []string `json:"acceptanceCriteria"`
+	Attachments        []struct {
+		Name     string `json:"name"`
+		URL      string `json:"url"`
+		MimeType string `json:"mimeType"`
+	} `json:"attachments"`
+	Links           []string `json:"links"`
+	SubdivisionNote string   `json:"subdivisionNote"`
+	ExtensionNote   string   `json:"extensionNote"`
+	Constraints     *struct {
+		MinTasks int `json:"minTasks"`
+		MaxTasks int `json:"maxTasks"`
+	} `json:"constraints"`
+}
+
+type server struct {
+	cfg config
+	log *slog.Logger
+	llm *llmClient
+}
+
+func main() {
+	cfg := loadConfig()
+	log := slog.New(slog.NewJSONHandler(os.Stdout, nil))
+	s := &server{cfg: cfg, log: log, llm: newLLMClient(cfg, log)}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) {
+		writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
+	})
+	mux.HandleFunc("POST /v1/atomize", s.auth(s.handleAtomize))
+	mux.HandleFunc("POST /v1/extend", s.auth(s.handleExtend))
+
+	srv := &http.Server{Addr: ":" + cfg.port, Handler: mux, ReadHeaderTimeout: 10 * time.Second}
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+	go func() {
+		log.Info("atomizer-mock listening", "port", cfg.port,
+			"llm", map[bool]string{true: "anthropic:" + cfg.apiStyle, false: "fallback (no api key)"}[cfg.apiKey != ""])
+		if err := srv.ListenAndServe(); err != http.ErrServerClosed {
+			log.Error("serve", "err", err)
+			os.Exit(1)
+		}
+	}()
+	<-ctx.Done()
+	shutCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	srv.Shutdown(shutCtx)
+}
+
+func writeJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(v)
+}
+
+func writeErr(w http.ResponseWriter, status int, code, msg string) {
+	writeJSON(w, status, map[string]any{"error": map[string]string{"code": code, "message": msg}})
+}
+
+func (s *server) auth(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if s.cfg.token != "" && r.Header.Get("Authorization") != "Bearer "+s.cfg.token {
+			writeErr(w, http.StatusUnauthorized, "unauthorized", "missing or invalid bearer token")
+			return
+		}
+		next(w, r)
+	}
+}
+
+func (s *server) handleAtomize(w http.ResponseWriter, r *http.Request) {
+	var req atomizeRequest
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4<<20)).Decode(&req); err != nil {
+		writeErr(w, http.StatusBadRequest, "bad_request", err.Error())
+		return
+	}
+	minT, maxT := 2, 8
+	if req.Constraints != nil {
+		if req.Constraints.MinTasks > 0 {
+			minT = req.Constraints.MinTasks
+		}
+		if req.Constraints.MaxTasks > 0 {
+			maxT = req.Constraints.MaxTasks
+		}
+	}
+	if minT > maxT {
+		minT = maxT
+	}
+
+	tasks, model, notes, err := s.llm.atomize(r.Context(), req, minT, maxT)
+	if err != nil {
+		s.log.Error("atomize failed", "taskId", req.TaskID, "err", err)
+		writeErr(w, http.StatusBadGateway, "llm_failed", err.Error())
+		return
+	}
+	normalizeSum(tasks)
+	writeJSON(w, http.StatusOK, map[string]any{"tasks": tasks, "model": model, "notes": notes})
+}
+
+func (s *server) handleExtend(w http.ResponseWriter, r *http.Request) {
+	var req atomizeRequest
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4<<20)).Decode(&req); err != nil {
+		writeErr(w, http.StatusBadRequest, "bad_request", err.Error())
+		return
+	}
+	if strings.TrimSpace(req.ExtensionNote) == "" {
+		writeErr(w, http.StatusBadRequest, "note_required", "extensionNote is required")
+		return
+	}
+	task, model, notes, err := s.llm.extend(r.Context(), req)
+	if err != nil {
+		s.log.Error("extend failed", "taskId", req.TaskID, "err", err)
+		writeErr(w, http.StatusBadGateway, "llm_failed", err.Error())
+		return
+	}
+	if task.EffortCoefficient <= 0 || task.EffortCoefficient > 2 {
+		task.EffortCoefficient = 0.3
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"task": task, "model": model, "notes": notes})
+}
+
+// normalizeSum forces coefficients to sum to exactly 1.0.
+func normalizeSum(tasks []subTask) {
+	sum := 0.0
+	for _, t := range tasks {
+		sum += t.EffortCoefficient
+	}
+	if sum <= 0 {
+		eq := 1.0 / float64(len(tasks))
+		for i := range tasks {
+			tasks[i].EffortCoefficient = eq
+		}
+		sum = 1.0
+	}
+	total := 0.0
+	largest := 0
+	for i := range tasks {
+		tasks[i].EffortCoefficient = round4(tasks[i].EffortCoefficient / sum)
+		total += tasks[i].EffortCoefficient
+		if tasks[i].EffortCoefficient > tasks[largest].EffortCoefficient {
+			largest = i
+		}
+	}
+	tasks[largest].EffortCoefficient = round4(tasks[largest].EffortCoefficient + 1 - total)
+}
+
+func round4(v float64) float64 {
+	return float64(int64(v*10000+0.5)) / 10000
+}
+
+func fallbackAtomize(req atomizeRequest, minT, maxT int) []subTask {
+	n := (minT + maxT) / 2
+	if n < 1 {
+		n = 3
+	}
+	out := make([]subTask, n)
+	eq := round4(1.0 / float64(n))
+	for i := range out {
+		out[i] = subTask{
+			Title:              fmt.Sprintf("%s — part %d of %d", req.Title, i+1, n),
+			Description:        fmt.Sprintf("Deterministic offline split %d/%d of:\n\n%s", i+1, n, req.Description),
+			AcceptanceCriteria: append([]string{}, req.AcceptanceCriteria...),
+			EffortCoefficient:  eq,
+		}
+	}
+	return out
+}
+
+func fallbackExtend(req atomizeRequest) subTask {
+	return subTask{
+		Title:              req.Title + " — extension: " + firstLine(req.ExtensionNote, 60),
+		Description:        "Deterministic offline extension of the source task.\n\nRequested scope: " + req.ExtensionNote,
+		AcceptanceCriteria: []string{"extension scope implemented: " + firstLine(req.ExtensionNote, 120)},
+		EffortCoefficient:  0.3,
+	}
+}
+
+func firstLine(s string, max int) string {
+	if i := strings.IndexByte(s, '\n'); i >= 0 {
+		s = s[:i]
+	}
+	if len(s) > max {
+		s = s[:max]
+	}
+	return s
+}
diff --git a/services/work-performer/Dockerfile b/services/work-performer/Dockerfile
new file mode 100644
index 0000000..6ac7967
--- /dev/null
+++ b/services/work-performer/Dockerfile
@@ -0,0 +1,9 @@
+FROM node:20-bookworm
+RUN apt-get update && apt-get install -y --no-install-recommends git ca-certificates \
+    && rm -rf /var/lib/apt/lists/* \
+    && npm install -g @anthropic-ai/claude-code
+WORKDIR /srv
+COPY server.js .
+RUN mkdir -p /work
+EXPOSE 8091
+CMD ["node", "server.js"]
diff --git a/services/work-performer/server.js b/services/work-performer/server.js
new file mode 100644
index 0000000..92ffd04
--- /dev/null
+++ b/services/work-performer/server.js
@@ -0,0 +1,294 @@
+#!/usr/bin/env node
+// work-performer: standalone placeholder Work Performer Service (§5.2, §9.2).
+// Plain Node http server, no framework. For each job it prepares
+// /work/{jobId}/TASK.md and runs the Claude Code CLI; if the CLI is missing
+// or fails to start (e.g. no credentials mounted), it produces a simulated
+// result so the whole flow stays demonstrable offline. The HTTP contract —
+// not this implementation — is the deliverable.
+'use strict';
+
+const http = require('http');
+const https = require('https');
+const crypto = require('crypto');
+const fs = require('fs');
+const path = require('path');
+const { execFile, execFileSync } = require('child_process');
+
+const PORT = parseInt(process.env.PORT || '8091', 10);
+const TOKEN = process.env.WORK_PERFORMER_TOKEN || '';
+const WORK_DIR = process.env.WORK_DIR || '/work';
+const PUBLIC_BASE = process.env.PUBLIC_BASE_URL || `http://work-performer:${PORT}`;
+
+const jobs = new Map(); // jobId -> {status, taskId, request, startedAt, finishedAt, cancel}
+const queue = [];
+let running = false; // single-job concurrency (§9.2)
+
+const log = (msg, extra) =>
+  console.log(JSON.stringify({ ts: new Date().toISOString(), msg, ...extra }));
+
+function json(res, status, body) {
+  const data = JSON.stringify(body);
+  res.writeHead(status, { 'Content-Type': 'application/json' });
+  res.end(data);
+}
+const errJson = (res, status, code, message) =>
+  json(res, status, { error: { code, message } });
+
+function readBody(req) {
+  return new Promise((resolve, reject) => {
+    const chunks = [];
+    let size = 0;
+    req.on('data', (c) => {
+      size += c.length;
+      if (size > 4 << 20) { reject(new Error('body too large')); req.destroy(); return; }
+      chunks.push(c);
+    });
+    req.on('end', () => resolve(Buffer.concat(chunks)));
+    req.on('error', reject);
+  });
+}
+
+function download(url, dest) {
+  return new Promise((resolve, reject) => {
+    const mod = url.startsWith('https:') ? https : http;
+    const file = fs.createWriteStream(dest);
+    mod.get(url, (res) => {
+      if (res.statusCode !== 200) {
+        file.close(); fs.rmSync(dest, { force: true });
+        reject(new Error(`download ${url}: status ${res.statusCode}`));
+        return;
+      }
+      res.pipe(file);
+      file.on('finish', () => file.close(resolve));
+    }).on('error', (e) => { file.close(); fs.rmSync(dest, { force: true }); reject(e); });
+  });
+}
+
+function postCallback(urlStr, payload) {
+  return new Promise((resolve, reject) => {
+    const body = Buffer.from(JSON.stringify(payload));
+    const sig = crypto.createHmac('sha256', TOKEN).update(body).digest('hex');
+    const url = new URL(urlStr);
+    const mod = url.protocol === 'https:' ? https : http;
+    const req = mod.request(url, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        'Content-Length': body.length,
+        'X-Signature': sig,
+      },
+    }, (res) => { res.resume(); resolve(res.statusCode); });
+    req.on('error', reject);
+    req.end(body);
+  });
+}
+
+function claudeAvailable() {
+  try {
+    execFileSync('claude', ['--version'], { timeout: 15000, stdio: 'pipe' });
+    return true;
+  } catch (e) {
+    return false;
+  }
+}
+
+function buildTaskMD(r) {
+  const lines = [`# ${r.title}`, '', r.description || '', ''];
+  if ((r.acceptanceCriteria || []).length) {
+    lines.push('## Acceptance criteria', '');
+    r.acceptanceCriteria.forEach((c) => lines.push(`- ${c}`));
+    lines.push('');
+  }
+  if ((r.links || []).length) {
+    lines.push('## Links', '');
+    r.links.forEach((l) => lines.push(`- ${l}`));
+    lines.push('');
+  }
+  if ((r.attachments || []).length) {
+    lines.push('## Attachments (downloaded into ./attachments)', '');
+    r.attachments.forEach((a) => lines.push(`- ${a.name}`));
+    lines.push('');
+  }
+  if (r.context && r.context.instructions) {
+    lines.push('## Extra instructions', '', r.context.instructions, '');
+  }
+  lines.push('Produce your changes in this directory. Write a SUMMARY.md describing what you did.');
+  return lines.join('\n');
+}
+
+function listProducedFiles(dir, before) {
+  const out = [];
+  const walk = (d) => {
+    for (const entry of fs.readdirSync(d, { withFileTypes: true })) {
+      if (entry.name === '.git' || entry.name === 'attachments') continue;
+      const full = path.join(d, entry.name);
+      if (entry.isDirectory()) { walk(full); continue; }
+      const rel = path.relative(dir, full);
+      if (!before.has(rel) && fs.statSync(full).size <= 20 << 20) out.push(rel);
+    }
+  };
+  walk(dir);
+  return out.slice(0, 20);
+}
+
+async function runJob(jobId) {
+  const job = jobs.get(jobId);
+  if (!job || job.status !== 'queued') return;
+  job.status = 'running';
+  job.startedAt = new Date().toISOString();
+  const r = job.request;
+  const dir = path.join(WORK_DIR, jobId);
+  let result;
+  try {
+    fs.mkdirSync(path.join(dir, 'attachments'), { recursive: true });
+
+    // optional repo clone (§9.2)
+    if (r.context && r.context.repositoryUrl) {
+      const args = ['clone', '--depth', '1'];
+      if (r.context.branch) args.push('-b', r.context.branch);
+      args.push(r.context.repositoryUrl, path.join(dir, 'repo'));
+      await new Promise((resolve) => {
+        execFile('git', args, { timeout: 120000 }, (err, _o, stderr) => {
+          if (err) log('git clone failed', { jobId, err: String(stderr || err) });
+          resolve();
+        });
+      });
+    }
+    for (const a of r.attachments || []) {
+      try {
+        await download(a.url, path.join(dir, 'attachments', path.basename(a.name)));
+      } catch (e) { log('attachment download failed', { jobId, name: a.name, err: e.message }); }
+    }
+    fs.writeFileSync(path.join(dir, 'TASK.md'), buildTaskMD(r));
+    const before = new Set(['TASK.md']);
+
+    if (claudeAvailable()) {
+      result = await new Promise((resolve) => {
+        const child = execFile('claude',
+          ['-p', fs.readFileSync(path.join(dir, 'TASK.md'), 'utf8'),
+            '--output-format', 'json', '--dangerously-skip-permissions'],
+          { cwd: dir, timeout: 30 * 60 * 1000, maxBuffer: 32 << 20 },
+          (err, stdout, stderr) => {
+            if (job.cancel) { resolve({ status: 'failed', summary: 'job canceled', log: '' }); return; }
+            if (err) {
+              resolve({ status: 'failed', summary: `claude execution failed: ${err.message}`,
+                log: String(stderr || '').slice(-4000) });
+              return;
+            }
+            let summary = 'Claude Code completed the task.';
+            try {
+              const parsed = JSON.parse(stdout);
+              summary = parsed.result || parsed.summary || summary;
+            } catch (e) { summary = String(stdout).slice(0, 1000) || summary; }
+            resolve({ status: 'succeeded', summary: String(summary).slice(0, 4000),
+              log: String(stdout).slice(-4000) });
+          });
+        job.kill = () => child.kill('SIGTERM');
+      });
+    } else {
+      // offline placeholder result keeps the end-to-end flow demonstrable
+      const summary = `Simulated work performer result (Claude Code CLI not available in this container).\n` +
+        `Reviewed task "${r.title}" with ${(r.acceptanceCriteria || []).length} acceptance criteria.`;
+      fs.writeFileSync(path.join(dir, 'SUMMARY.md'),
+        `# Simulated result\n\n${summary}\n\nThis placeholder proves the §5.2 contract end to end.`);
+      result = { status: 'succeeded', summary, log: 'claude CLI unavailable; produced simulated SUMMARY.md' };
+    }
+
+    const artifacts = listProducedFiles(dir, before).map((rel) => ({
+      name: rel.replace(/\//g, '_'),
+      url: `${PUBLIC_BASE}/artifacts/${jobId}/${encodeURIComponent(rel)}`,
+    }));
+    result.artifacts = artifacts;
+  } catch (e) {
+    result = { status: 'failed', summary: `job crashed: ${e.message}`, log: '', artifacts: [] };
+  }
+
+  job.status = result.status;
+  job.finishedAt = new Date().toISOString();
+  const payload = {
+    jobId, taskId: r.taskId, status: result.status,
+    summary: result.summary, artifacts: result.artifacts || [], log: result.log || '',
+  };
+  for (let attempt = 1; attempt <= 3; attempt++) {
+    try {
+      const code = await postCallback(r.callbackUrl, payload);
+      log('callback delivered', { jobId, code });
+      break;
+    } catch (e) {
+      log('callback failed', { jobId, attempt, err: e.message });
+      await new Promise((s) => setTimeout(s, attempt * 2000));
+    }
+  }
+}
+
+async function pump() {
+  if (running) return;
+  const next = queue.shift();
+  if (!next) return;
+  running = true;
+  try { await runJob(next); } finally {
+    running = false;
+    setImmediate(pump);
+  }
+}
+
+const server = http.createServer(async (req, res) => {
+  const url = new URL(req.url, `http://${req.headers.host}`);
+
+  if (req.method === 'GET' && url.pathname === '/healthz') {
+    return json(res, 200, { status: 'ok' });
+  }
+
+  // artifact downloads are unauthenticated within the compose network
+  const artMatch = url.pathname.match(/^\/artifacts\/([\w]+)\/(.+)$/);
+  if (req.method === 'GET' && artMatch) {
+    const file = path.join(WORK_DIR, artMatch[1], decodeURIComponent(artMatch[2]));
+    if (!file.startsWith(path.join(WORK_DIR, artMatch[1]) + path.sep) || !fs.existsSync(file)) {
+      return errJson(res, 404, 'not_found', 'artifact not found');
+    }
+    res.writeHead(200, { 'Content-Type': 'application/octet-stream' });
+    return fs.createReadStream(file).pipe(res);
+  }
+
+  if (TOKEN && req.headers.authorization !== `Bearer ${TOKEN}`) {
+    return errJson(res, 401, 'unauthorized', 'missing or invalid bearer token');
+  }
+
+  if (req.method === 'POST' && url.pathname === '/v1/jobs') {
+    let body;
+    try { body = JSON.parse(await readBody(req)); }
+    catch (e) { return errJson(res, 400, 'bad_request', e.message); }
+    if (!body.taskId || !body.title || !body.callbackUrl) {
+      return errJson(res, 400, 'bad_request', 'taskId, title and callbackUrl are required');
+    }
+    const jobId = 'wp_' + crypto.randomBytes(8).toString('hex');
+    jobs.set(jobId, { status: 'queued', taskId: body.taskId, request: body,
+      startedAt: null, finishedAt: null, cancel: false });
+    queue.push(jobId);
+    setImmediate(pump);
+    log('job queued', { jobId, taskId: body.taskId });
+    return json(res, 202, { jobId, status: 'queued' });
+  }
+
+  const jobMatch = url.pathname.match(/^\/v1\/jobs\/(wp_[\w]+)$/);
+  if (jobMatch) {
+    const job = jobs.get(jobMatch[1]);
+    if (!job) return errJson(res, 404, 'not_found', 'job not found');
+    if (req.method === 'GET') {
+      return json(res, 200, { jobId: jobMatch[1], status: job.status,
+        startedAt: job.startedAt, finishedAt: job.finishedAt });
+    }
+    if (req.method === 'DELETE') { // best-effort cancel (§5.2)
+      job.cancel = true;
+      const idx = queue.indexOf(jobMatch[1]);
+      if (idx >= 0) { queue.splice(idx, 1); job.status = 'failed'; job.finishedAt = new Date().toISOString(); }
+      if (job.kill) try { job.kill(); } catch (e) { /* already gone */ }
+      return json(res, 200, { jobId: jobMatch[1], status: 'cancel_requested' });
+    }
+  }
+
+  errJson(res, 404, 'not_found', 'unknown endpoint');
+});
+
+server.listen(PORT, () => log('work-performer listening', { port: PORT, claude: claudeAvailable() }));
+process.on('SIGTERM', () => server.close(() => process.exit(0)));