diff --git a/server/src/__tests__/pipelines-service.test.ts b/server/src/__tests__/pipelines-service.test.ts
new file mode 100644
index 00000000000..2dfb62844bf
--- /dev/null
+++ b/server/src/__tests__/pipelines-service.test.ts
@@ -0,0 +1,527 @@
+import { randomUUID } from "node:crypto";
+import { eq, sql } from "drizzle-orm";
+import { afterAll, afterEach, beforeAll, describe, expect, it } from "vitest";
+import {
+  agents,
+  companies,
+  createDb,
+  pipelineAutomationExecutions,
+  pipelineCaseBlockers,
+  pipelineCaseEvents,
+  pipelineCases,
+  pipelineStages,
+  pipelineTransitions,
+  pipelines,
+  routines,
+} from "@paperclipai/db";
+import {
+  getEmbeddedPostgresTestSupport,
+  startEmbeddedPostgresTestDatabase,
+} from "./helpers/embedded-postgres.js";
+import { pipelineService, type PipelineActor } from "../services/pipelines.ts";
+
+const embeddedPostgresSupport = await getEmbeddedPostgresTestSupport();
+const describeEmbeddedPostgres = embeddedPostgresSupport.supported ? describe : describe.skip;
+
+if (!embeddedPostgresSupport.supported) {
+  console.warn(
+    `Skipping embedded Postgres pipeline service tests on this host: ${embeddedPostgresSupport.reason ?? "unsupported environment"}`,
+  );
+}
+
+describeEmbeddedPostgres("pipelineService", () => {
+  let db!: ReturnType<typeof createDb>;
+  let svc!: ReturnType<typeof pipelineService>;
+  let tempDb: Awaited<ReturnType<typeof startEmbeddedPostgresTestDatabase>> | null = null;
+
+  const userActor: PipelineActor = { type: "user", userId: "board-user" };
+
+  beforeAll(async () => {
+    tempDb = await startEmbeddedPostgresTestDatabase("paperclip-pipelines-service-");
+    db = createDb(tempDb.connectionString);
+    svc = pipelineService(db);
+  }, 20_000);
+
+  afterEach(async () => {
+    await db.delete(pipelineAutomationExecutions);
+    await db.delete(pipelineCaseBlockers);
+    await db.delete(pipelineCaseEvents);
+    await db.delete(pipelineCases);
+    await db.delete(pipelineTransitions);
+    await db.delete(pipelineStages);
+    await db.delete(pipelines);
+    await db.delete(routines);
+    await db.delete(agents);
+    await db.delete(companies);
+  });
+
+  afterAll(async () => {
+    await tempDb?.cleanup();
+  });
+
+  async function seedCompany() {
+    const [company] = await db.insert(companies).values({
+      name: "Pipeline Co",
+      issuePrefix: `P${randomUUID().replace(/-/g, "").slice(0, 6).toUpperCase()}`,
+    }).returning();
+    return company!;
+  }
+
+  async function seedPipeline(options?: { enforceTransitions?: boolean }) {
+    const company = await seedCompany();
+    const pipeline = await svc.createPipeline({
+      companyId: company.id,
+      key: `content-${randomUUID().slice(0, 8)}`,
+      name: "Content",
+      enforceTransitions: options?.enforceTransitions ?? false,
+      actor: userActor,
+    });
+    const stages = await svc.listStages(company.id, pipeline.id);
+    return { company, pipeline, stages, byKey: new Map(stages.map((stage) => [stage.key, stage])) };
+  }
+
+  async function eventCount(caseId: string) {
+    const [{ count }] = await db
+      .select({ count: sql<number>`count(*)::int` })
+      .from(pipelineCaseEvents)
+      .where(eq(pipelineCaseEvents.caseId, caseId));
+    return count ?? 0;
+  }
+
+  it("seeds default stages and protects non-empty stage deletion", async () => {
+    const { company, pipeline, byKey } = await seedPipeline();
+
+    expect([...byKey.keys()]).toEqual(["intake", "in_progress", "review", "done", "cancelled"]);
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "stage-delete",
+      title: "Stage delete guard",
+      actor: userActor,
+    });
+
+    await expect(
+      svc.deleteStage({ companyId: company.id, pipelineId: pipeline.id, stageId: byKey.get("intake")!.id }),
+    ).rejects.toMatchObject({ status: 422, details: { code: "stage_has_cases" } });
+
+    await svc.deleteStage({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      stageId: byKey.get("intake")!.id,
+      moveCasesToStageId: byKey.get("in_progress")!.id,
+    });
+    const [moved] = await db.select().from(pipelineCases).where(eq(pipelineCases.id, created.case.id));
+    expect(moved!.stageId).toBe(byKey.get("in_progress")!.id);
+  });
+
+  it("implements idempotent single and batch ingest", async () => {
+    const { company, pipeline } = await seedPipeline();
+
+    const first = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "release-1",
+      title: "Release 1",
+      actor: userActor,
+    });
+    const second = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "release-1",
+      title: "Duplicate title is ignored",
+      actor: userActor,
+    });
+
+    expect(first.created).toBe(true);
+    expect(second.created).toBe(false);
+    expect(second.case.id).toBe(first.case.id);
+    expect(await eventCount(first.case.id)).toBe(1);
+
+    await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "existing-2",
+      title: "Existing 2",
+      actor: userActor,
+    });
+    const batch = await svc.ingestCases({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      actor: userActor,
+      items: [
+        { caseKey: "new-1", title: "New 1" },
+        { caseKey: "new-2", title: "New 2" },
+        { caseKey: "release-1", title: "Existing 1" },
+        { caseKey: "new-3", title: "New 3" },
+        { caseKey: "existing-2", title: "Existing 2 again" },
+      ],
+    });
+
+    expect(batch).toHaveLength(5);
+    expect(batch.filter((item) => item.ok && item.created)).toHaveLength(3);
+    const [{ count }] = await db.select({ count: sql<number>`count(*)::int` }).from(pipelineCases);
+    expect(count).toBe(5);
+  });
+
+  it("rejects stale content PATCH without writing an event", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "patch",
+      title: "Patch me",
+      actor: userActor,
+    });
+    await svc.patchCaseContent({
+      companyId: company.id,
+      caseId: created.case.id,
+      title: "Patched",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    const before = await eventCount(created.case.id);
+
+    await expect(
+      svc.patchCaseContent({
+        companyId: company.id,
+        caseId: created.case.id,
+        title: "Stale",
+        expectedVersion: 1,
+        actor: userActor,
+      }),
+    ).rejects.toMatchObject({ status: 409, details: { code: "version_conflict", version: 2 } });
+    expect(await eventCount(created.case.id)).toBe(before);
+  });
+
+  it("lets exactly one parallel transition with the same expectedVersion succeed", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "parallel",
+      title: "Parallel transition",
+      actor: userActor,
+    });
+
+    const attempts = await Promise.allSettled([
+      svc.transitionCase({
+        companyId: company.id,
+        caseId: created.case.id,
+        toStageKey: "in_progress",
+        expectedVersion: 1,
+        actor: userActor,
+      }),
+      svc.transitionCase({
+        companyId: company.id,
+        caseId: created.case.id,
+        toStageKey: "review",
+        expectedVersion: 1,
+        actor: userActor,
+      }),
+    ]);
+
+    expect(attempts.filter((attempt) => attempt.status === "fulfilled")).toHaveLength(1);
+    expect(attempts.filter((attempt) => attempt.status === "rejected")).toHaveLength(1);
+    const [row] = await db.select().from(pipelineCases).where(eq(pipelineCases.id, created.case.id));
+    expect(row!.version).toBe(2);
+    expect(await eventCount(created.case.id)).toBe(2);
+  });
+
+  it("enforces active leases and lets the holder transition with the lease token", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "lease",
+      title: "Leased case",
+      actor: userActor,
+    });
+    const owner: PipelineActor = { type: "user", userId: "owner" };
+    const other: PipelineActor = { type: "user", userId: "other" };
+
+    const claimed = await svc.claimCase({ companyId: company.id, caseId: created.case.id, actor: owner });
+    await expect(svc.claimCase({ companyId: company.id, caseId: created.case.id, actor: other })).rejects.toMatchObject({
+      status: 409,
+      details: { code: "lease_held" },
+    });
+    await expect(
+      svc.transitionCase({
+        companyId: company.id,
+        caseId: created.case.id,
+        toStageKey: "in_progress",
+        expectedVersion: 1,
+        actor: other,
+      }),
+    ).rejects.toMatchObject({ status: 409, details: { code: "lease_held" } });
+
+    const transitioned = await svc.transitionCase({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "in_progress",
+      expectedVersion: 1,
+      leaseToken: claimed.leaseToken,
+      actor: owner,
+    });
+    expect(transitioned.case.version).toBe(2);
+    expect(await eventCount(created.case.id)).toBe(3);
+  });
+
+  it("expires leases on read before a new claim", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "expired-lease",
+      title: "Expired lease",
+      actor: userActor,
+    });
+    await db.update(pipelineCases).set({
+      leaseOwnerType: "user",
+      leaseUserId: "old-owner",
+      leaseToken: randomUUID(),
+      leaseExpiresAt: new Date(Date.now() - 5_000),
+    }).where(eq(pipelineCases.id, created.case.id));
+
+    const claimed = await svc.claimCase({ companyId: company.id, caseId: created.case.id, actor: { type: "user", userId: "new-owner" } });
+
+    expect(claimed.leaseUserId).toBe("new-owner");
+    const events = await svc.listCaseEvents(company.id, created.case.id);
+    expect(events.map((event) => event.type)).toEqual(["ingested", "lease_expired", "claimed"]);
+  });
+
+  it("enforces transition edges only when enforceTransitions is enabled", async () => {
+    const { company, pipeline } = await seedPipeline({ enforceTransitions: true });
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "edges",
+      title: "Transition edges",
+      actor: userActor,
+    });
+
+    await expect(
+      svc.transitionCase({
+        companyId: company.id,
+        caseId: created.case.id,
+        toStageKey: "done",
+        expectedVersion: 1,
+        actor: userActor,
+      }),
+    ).rejects.toMatchObject({ status: 409, details: { code: "transition_not_allowed" } });
+
+    await db.update(pipelines).set({ enforceTransitions: false }).where(eq(pipelines.id, pipeline.id));
+    const moved = await svc.transitionCase({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "done",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    expect(moved.case.terminalKind).toBe("done");
+  });
+
+  it("blocks transitions while blockers are not done", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const blocked = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "blocked",
+      title: "Blocked case",
+      actor: userActor,
+    });
+    const blocker = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "blocker",
+      title: "Blocking case",
+      actor: userActor,
+    });
+    await db.insert(pipelineCaseBlockers).values({
+      companyId: company.id,
+      caseId: blocked.case.id,
+      blockedByCaseId: blocker.case.id,
+    });
+
+    await expect(
+      svc.transitionCase({
+        companyId: company.id,
+        caseId: blocked.case.id,
+        toStageKey: "in_progress",
+        expectedVersion: 1,
+        actor: userActor,
+      }),
+    ).rejects.toMatchObject({ status: 409, details: { code: "blocked" } });
+
+    await svc.transitionCase({
+      companyId: company.id,
+      caseId: blocker.case.id,
+      toStageKey: "done",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    const moved = await svc.transitionCase({
+      companyId: company.id,
+      caseId: blocked.case.id,
+      toStageKey: "in_progress",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    expect(moved.case.version).toBe(2);
+  });
+
+  it("records suggestion supersede, accept, and dismiss lifecycles", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "suggest-accept",
+      title: "Suggestion accept",
+      actor: userActor,
+    });
+    const first = await svc.suggestTransition({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "review",
+      rationale: "Needs review",
+      actor: userActor,
+    });
+    const second = await svc.suggestTransition({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "in_progress",
+      rationale: "Actually draft first",
+      actor: userActor,
+    });
+    expect(second.suggestion.id).not.toBe(first.suggestion.id);
+
+    const accepted = await svc.resolveSuggestion({
+      companyId: company.id,
+      caseId: created.case.id,
+      suggestionId: second.suggestion.id,
+      decision: "accept",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    expect(accepted.case.version).toBe(2);
+    const acceptEvents = await svc.listCaseEvents(company.id, created.case.id);
+    expect(acceptEvents.map((event) => event.type)).toEqual([
+      "ingested",
+      "transition_suggested",
+      "transition_suggested",
+      "transitioned",
+      "suggestion_resolved",
+    ]);
+
+    const dismissCase = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "suggest-dismiss",
+      title: "Suggestion dismiss",
+      actor: userActor,
+    });
+    const suggestion = await svc.suggestTransition({
+      companyId: company.id,
+      caseId: dismissCase.case.id,
+      toStageKey: "review",
+      rationale: "Maybe review",
+      actor: userActor,
+    });
+    await svc.resolveSuggestion({
+      companyId: company.id,
+      caseId: dismissCase.case.id,
+      suggestionId: suggestion.suggestion.id,
+      decision: "dismiss",
+      reason: "Not ready",
+      actor: userActor,
+    });
+    const [dismissed] = await db.select().from(pipelineCases).where(eq(pipelineCases.id, dismissCase.case.id));
+    expect(dismissed!.pendingSuggestion).toBeNull();
+    expect(dismissed!.version).toBe(1);
+  });
+
+  it("writes an event for each case mutation and rejects agent mutations without run provenance", async () => {
+    const { company, pipeline } = await seedPipeline();
+    const agentActor = { type: "agent", agentId: randomUUID() } as PipelineActor;
+    await expect(
+      svc.ingestCase({
+        companyId: company.id,
+        pipelineId: pipeline.id,
+        caseKey: "bad-agent",
+        title: "Bad provenance",
+        actor: agentActor,
+      }),
+    ).rejects.toMatchObject({ status: 422, details: { code: "run_id_required" } });
+
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "events",
+      title: "Events",
+      actor: userActor,
+    });
+    expect(await eventCount(created.case.id)).toBe(1);
+    await svc.patchCaseContent({ companyId: company.id, caseId: created.case.id, title: "Updated", actor: userActor });
+    expect(await eventCount(created.case.id)).toBe(2);
+    const claimed = await svc.claimCase({ companyId: company.id, caseId: created.case.id, actor: { type: "user", userId: "claimer" } });
+    expect(await eventCount(created.case.id)).toBe(3);
+    await svc.releaseCase({ companyId: company.id, caseId: created.case.id, leaseToken: claimed.leaseToken, actor: { type: "user", userId: "claimer" } });
+    expect(await eventCount(created.case.id)).toBe(4);
+    await svc.transitionCase({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "in_progress",
+      expectedVersion: 2,
+      actor: userActor,
+    });
+    expect(await eventCount(created.case.id)).toBe(5);
+  });
+
+  it("creates a stage-entry automation ledger idempotently with the transition event", async () => {
+    const company = await seedCompany();
+    const [agent] = await db.insert(agents).values({
+      companyId: company.id,
+      name: "Routine Agent",
+      role: "engineer",
+      adapterType: "codex_local",
+      adapterConfig: {},
+      runtimeConfig: {},
+      permissions: {},
+    }).returning();
+    const [routine] = await db.insert(routines).values({
+      companyId: company.id,
+      title: "Draft on enter",
+      assigneeAgentId: agent!.id,
+    }).returning();
+    const pipeline = await svc.createPipeline({
+      companyId: company.id,
+      key: "automation",
+      name: "Automation",
+      actor: userActor,
+      stages: [
+        { key: "intake", name: "Intake", kind: "open" },
+        { key: "drafting", name: "Drafting", kind: "working", config: { onEnter: { type: "run_routine", routineId: routine!.id } } },
+        { key: "done", name: "Done", kind: "done" },
+        { key: "cancelled", name: "Cancelled", kind: "cancelled" },
+      ],
+    });
+    const created = await svc.ingestCase({
+      companyId: company.id,
+      pipelineId: pipeline.id,
+      caseKey: "automation",
+      title: "Automation case",
+      actor: userActor,
+    });
+
+    const moved = await svc.transitionCase({
+      companyId: company.id,
+      caseId: created.case.id,
+      toStageKey: "drafting",
+      expectedVersion: 1,
+      actor: userActor,
+    });
+    expect(moved.automationLedger?.routineId).toBe(routine!.id);
+    const ledgers = await db.select().from(pipelineAutomationExecutions);
+    expect(ledgers).toHaveLength(1);
+    expect(ledgers[0]!.triggeringEventId).toBe(moved.event.id);
+  });
+});
diff --git a/server/src/services/pipelines.ts b/server/src/services/pipelines.ts
new file mode 100644
index 00000000000..7789e63473c
--- /dev/null
+++ b/server/src/services/pipelines.ts
@@ -0,0 +1,921 @@
+import { randomUUID } from "node:crypto";
+import { and, asc, eq, isNull, ne, or, sql } from "drizzle-orm";
+import type { Db } from "@paperclipai/db";
+import {
+  pipelineAutomationExecutions,
+  pipelineCaseBlockers,
+  pipelineCaseEvents,
+  pipelineCases,
+  pipelineStages,
+  pipelineTransitions,
+  pipelines,
+} from "@paperclipai/db";
+import { conflict, HttpError, notFound, unprocessable } from "../errors.js";
+
+const DEFAULT_LEASE_MS = 15 * 60 * 1000;
+const MAX_LEASE_MS = 24 * 60 * 60 * 1000;
+const MAX_CASE_KEY_LENGTH = 1024;
+const MAX_BATCH_INGEST = 200;
+const MAX_FIELDS_BYTES = 64 * 1024;
+
+const DEFAULT_STAGES = [
+  { key: "intake", name: "Intake", kind: "open", position: 100 },
+  { key: "in_progress", name: "In progress", kind: "working", position: 200 },
+  { key: "review", name: "Review", kind: "review", position: 300 },
+  { key: "done", name: "Done", kind: "done", position: 900 },
+  { key: "cancelled", name: "Cancelled", kind: "cancelled", position: 1000 },
+] as const;
+
+export type PipelineActor =
+  | { type: "user"; userId: string }
+  | { type: "agent"; agentId: string; runId: string }
+  | { type: "system" };
+
+export type PipelineStageKind = "open" | "working" | "review" | "done" | "cancelled";
+
+export type PipelineStageConfig = Record<string, unknown> & {
+  autonomy?: "manual" | "suggest" | "auto";
+  onEnter?: {
+    type?: "run_routine";
+    routineId?: string;
+    id?: string;
+  };
+};
+
+type PipelineDb = Db | Parameters<Parameters<Db["transaction"]>[0]>[0];
+
+function nowDate() {
+  return new Date();
+}
+
+function eventActorPatch(actor: PipelineActor) {
+  if (actor.type === "agent") {
+    assertActorProvenance(actor);
+    return { actorType: "agent", actorAgentId: actor.agentId, runId: actor.runId };
+  }
+  if (actor.type === "user") {
+    return { actorType: "user", actorUserId: actor.userId };
+  }
+  return { actorType: "system" };
+}
+
+function assertActorProvenance(actor: PipelineActor) {
+  if (actor.type === "agent" && !actor.runId) {
+    throw unprocessable("Agent pipeline mutations require a run id", { code: "run_id_required" });
+  }
+}
+
+function assertCaseKey(caseKey: string) {
+  if (caseKey.length > MAX_CASE_KEY_LENGTH) {
+    throw unprocessable("caseKey must be at most 1024 characters", { code: "validation" });
+  }
+}
+
+function assertJsonSize(value: unknown, label: string) {
+  const bytes = Buffer.byteLength(JSON.stringify(value ?? {}), "utf8");
+  if (bytes > MAX_FIELDS_BYTES) {
+    throw unprocessable(`${label} must be at most 64KB`, { code: "validation" });
+  }
+}
+
+function isTerminalKind(kind: string | null | undefined) {
+  return kind === "done" || kind === "cancelled";
+}
+
+function terminalKindForStage(kind: string) {
+  return isTerminalKind(kind) ? kind : null;
+}
+
+function hasValidLease(row: typeof pipelineCases.$inferSelect, now = nowDate()) {
+  return Boolean(row.leaseToken && row.leaseExpiresAt && row.leaseExpiresAt.getTime() > now.getTime());
+}
+
+function leaseOwner(row: typeof pipelineCases.$inferSelect) {
+  if (row.leaseOwnerType === "agent") {
+    return { type: "agent", agentId: row.leaseAgentId, expiresAt: row.leaseExpiresAt };
+  }
+  if (row.leaseOwnerType === "user") {
+    return { type: "user", userId: row.leaseUserId, expiresAt: row.leaseExpiresAt };
+  }
+  return { type: row.leaseOwnerType, expiresAt: row.leaseExpiresAt };
+}
+
+function actorOwnsLease(row: typeof pipelineCases.$inferSelect, actor: PipelineActor, leaseToken?: string | null) {
+  if (!row.leaseToken) return true;
+  if (leaseToken && leaseToken === row.leaseToken) return true;
+  if (actor.type === "agent") return row.leaseOwnerType === "agent" && row.leaseAgentId === actor.agentId;
+  if (actor.type === "user") return row.leaseOwnerType === "user" && row.leaseUserId === actor.userId;
+  return false;
+}
+
+function conflictDetailsForCase(row: typeof pipelineCases.$inferSelect, stage?: typeof pipelineStages.$inferSelect | null) {
+  return {
+    code: "version_conflict",
+    version: row.version,
+    stage: stage ? { id: stage.id, key: stage.key, kind: stage.kind } : { id: row.stageId },
+  };
+}
+
+function stageConfig(stage: typeof pipelineStages.$inferSelect): PipelineStageConfig {
+  return (stage.config ?? {}) as PipelineStageConfig;
+}
+
+async function writeCaseEvent(
+  db: PipelineDb,
+  input: {
+    companyId: string;
+    caseId: string;
+    type: string;
+    actor: PipelineActor;
+    fromStageId?: string | null;
+    toStageId?: string | null;
+    payload?: Record<string, unknown>;
+  },
+) {
+  const [event] = await db
+    .insert(pipelineCaseEvents)
+    .values({
+      companyId: input.companyId,
+      caseId: input.caseId,
+      type: input.type,
+      ...eventActorPatch(input.actor),
+      fromStageId: input.fromStageId ?? null,
+      toStageId: input.toStageId ?? null,
+      payload: input.payload ?? {},
+    })
+    .returning();
+  return event!;
+}
+
+async function getPipelineOrThrow(db: PipelineDb, companyId: string, pipelineId: string) {
+  const row = await db
+    .select()
+    .from(pipelines)
+    .where(and(eq(pipelines.id, pipelineId), eq(pipelines.companyId, companyId)))
+    .limit(1)
+    .then((rows) => rows[0] ?? null);
+  if (!row) throw notFound("Pipeline not found");
+  return row;
+}
+
+async function getStageOrThrow(db: PipelineDb, pipelineId: string, stageId: string) {
+  const row = await db
+    .select()
+    .from(pipelineStages)
+    .where(and(eq(pipelineStages.id, stageId), eq(pipelineStages.pipelineId, pipelineId)))
+    .limit(1)
+    .then((rows) => rows[0] ?? null);
+  if (!row) throw notFound("Pipeline stage not found");
+  return row;
+}
+
+async function getStageByKeyOrThrow(db: PipelineDb, pipelineId: string, key: string) {
+  const row = await db
+    .select()
+    .from(pipelineStages)
+    .where(and(eq(pipelineStages.pipelineId, pipelineId), eq(pipelineStages.key, key)))
+    .limit(1)
+    .then((rows) => rows[0] ?? null);
+  if (!row) throw notFound("Pipeline stage not found");
+  return row;
+}
+
+async function getCaseWithStageOrThrow(db: PipelineDb, companyId: string, caseId: string) {
+  const row = await db
+    .select({ case: pipelineCases, stage: pipelineStages, pipeline: pipelines })
+    .from(pipelineCases)
+    .innerJoin(pipelineStages, eq(pipelineCases.stageId, pipelineStages.id))
+    .innerJoin(pipelines, eq(pipelineCases.pipelineId, pipelines.id))
+    .where(and(eq(pipelineCases.id, caseId), eq(pipelineCases.companyId, companyId), eq(pipelines.companyId, companyId)))
+    .limit(1)
+    .then((rows) => rows[0] ?? null);
+  if (!row) throw notFound("Pipeline case not found");
+  return row;
+}
+
+async function expireLeaseIfNeeded(db: PipelineDb, row: typeof pipelineCases.$inferSelect, actor: PipelineActor) {
+  const now = nowDate();
+  if (!row.leaseToken || !row.leaseExpiresAt || row.leaseExpiresAt.getTime() > now.getTime()) {
+    return row;
+  }
+
+  const [updated] = await db
+    .update(pipelineCases)
+    .set({
+      leaseOwnerType: null,
+      leaseAgentId: null,
+      leaseUserId: null,
+      leaseToken: null,
+      leaseExpiresAt: null,
+      updatedAt: now,
+    })
+    .where(and(eq(pipelineCases.id, row.id), eq(pipelineCases.leaseToken, row.leaseToken)))
+    .returning();
+  if (!updated) return row;
+
+  await writeCaseEvent(db, {
+    companyId: row.companyId,
+    caseId: row.id,
+    type: "lease_expired",
+    actor,
+    payload: { previousOwner: leaseOwner(row), expiredAt: now.toISOString() },
+  });
+  return updated;
+}
+
+async function assertLeaseAvailable(
+  db: PipelineDb,
+  row: typeof pipelineCases.$inferSelect,
+  actor: PipelineActor,
+  leaseToken?: string | null,
+) {
+  const current = await expireLeaseIfNeeded(db, row, { type: "system" });
+  if (hasValidLease(current) && !actorOwnsLease(current, actor, leaseToken)) {
+    throw conflict("Pipeline case lease is held", { code: "lease_held", lease: leaseOwner(current) });
+  }
+  return current;
+}
+
+async function assertNoOpenBlockers(db: PipelineDb, row: typeof pipelineCases.$inferSelect, toStage: typeof pipelineStages.$inferSelect) {
+  if (toStage.kind === "cancelled") return;
+  const blockers = await db
+    .select({
+      id: pipelineCases.id,
+      caseKey: pipelineCases.caseKey,
+      title: pipelineCases.title,
+      terminalKind: pipelineCases.terminalKind,
+    })
+    .from(pipelineCaseBlockers)
+    .innerJoin(pipelineCases, eq(pipelineCaseBlockers.blockedByCaseId, pipelineCases.id))
+    .where(
+      and(
+        eq(pipelineCaseBlockers.companyId, row.companyId),
+        eq(pipelineCaseBlockers.caseId, row.id),
+        or(isNull(pipelineCases.terminalKind), ne(pipelineCases.terminalKind, "done")),
+      ),
+    );
+  if (blockers.length > 0) {
+    throw conflict("Pipeline case is blocked", { code: "blocked", blockers });
+  }
+}
+
+async function enqueueStageAutomationLedger(
+  db: PipelineDb,
+  input: {
+    companyId: string;
+    caseId: string;
+    stage: typeof pipelineStages.$inferSelect;
+    eventId: string;
+  },
+) {
+  const config = stageConfig(input.stage);
+  const onEnter = config.onEnter;
+  if (!onEnter || onEnter.type !== "run_routine" || !onEnter.routineId) return null;
+  const automationId = onEnter.id ?? `${input.stage.id}:on_enter`;
+  const [ledger] = await db
+    .insert(pipelineAutomationExecutions)
+    .values({
+      companyId: input.companyId,
+      caseId: input.caseId,
+      automationId,
+      triggeringEventId: input.eventId,
+      routineId: onEnter.routineId,
+      status: "succeeded",
+    })
+    .onConflictDoNothing({
+      target: [
+        pipelineAutomationExecutions.caseId,
+        pipelineAutomationExecutions.automationId,
+        pipelineAutomationExecutions.triggeringEventId,
+      ],
+    })
+    .returning();
+  return ledger ?? null;
+}
+
+export function pipelineService(db: Db) {
+  async function transitionCaseInTransaction(
+    tx: PipelineDb,
+    input: {
+      companyId: string;
+      caseId: string;
+      toStageId?: string;
+      toStageKey?: string;
+      expectedVersion: number;
+      leaseToken?: string | null;
+      actor: PipelineActor;
+      transitionClass?: "manual" | "suggested" | "auto";
+      suggestionId?: string;
+      reason?: string | null;
+    },
+  ) {
+    if (input.transitionClass === "auto") {
+      throw unprocessable("Pipeline auto autonomy is not enabled", { code: "autonomy_not_enabled" });
+    }
+    const { case: existing, stage: fromStage, pipeline } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+    if (pipeline.archivedAt) throw unprocessable("Pipeline is archived", { code: "pipeline_archived" });
+    const current = await assertLeaseAvailable(tx, existing, input.actor, input.leaseToken);
+    if (current.version !== input.expectedVersion) {
+      throw conflict("Pipeline case version conflict", conflictDetailsForCase(current, fromStage));
+    }
+    if (fromStage.kind === "review" && input.actor.type === "agent") {
+      const config = stageConfig(fromStage);
+      if (config.reviewerKind !== "any") {
+        throw new HttpError(403, "Human review is required", { code: "review_required" });
+      }
+    }
+
+    const toStage = input.toStageId
+      ? await getStageOrThrow(tx, current.pipelineId, input.toStageId)
+      : await getStageByKeyOrThrow(tx, current.pipelineId, input.toStageKey ?? "");
+    const toConfig = stageConfig(toStage);
+    if (toConfig.autonomy === "auto") {
+      throw unprocessable("Pipeline auto autonomy is not enabled", { code: "autonomy_not_enabled" });
+    }
+    if (pipeline.enforceTransitions && fromStage.id !== toStage.id) {
+      const allowed = await tx
+        .select({ id: pipelineTransitions.id })
+        .from(pipelineTransitions)
+        .where(
+          and(
+            eq(pipelineTransitions.pipelineId, current.pipelineId),
+            eq(pipelineTransitions.fromStageId, fromStage.id),
+            eq(pipelineTransitions.toStageId, toStage.id),
+          ),
+        )
+        .limit(1)
+        .then((rows) => rows[0] ?? null);
+      if (!allowed) {
+        throw conflict("Pipeline transition is not allowed", { code: "transition_not_allowed" });
+      }
+    }
+    await assertNoOpenBlockers(tx, current, toStage);
+
+    const enteringTerminal = terminalKindForStage(toStage.kind);
+    const [updated] = await tx
+      .update(pipelineCases)
+      .set({
+        stageId: toStage.id,
+        version: current.version + 1,
+        terminalKind: enteringTerminal,
+        terminalAt: enteringTerminal ? nowDate() : null,
+        pendingSuggestion: input.suggestionId === current.pendingSuggestion?.id ? null : current.pendingSuggestion,
+        leaseOwnerType: enteringTerminal ? null : current.leaseOwnerType,
+        leaseAgentId: enteringTerminal ? null : current.leaseAgentId,
+        leaseUserId: enteringTerminal ? null : current.leaseUserId,
+        leaseToken: enteringTerminal ? null : current.leaseToken,
+        leaseExpiresAt: enteringTerminal ? null : current.leaseExpiresAt,
+        updatedAt: nowDate(),
+      })
+      .where(and(eq(pipelineCases.id, current.id), eq(pipelineCases.version, current.version)))
+      .returning();
+    if (!updated) {
+      const latest = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+      throw conflict("Pipeline case version conflict", conflictDetailsForCase(latest.case, latest.stage));
+    }
+
+    const event = await writeCaseEvent(tx, {
+      companyId: input.companyId,
+      caseId: current.id,
+      type: "transitioned",
+      actor: input.actor,
+      fromStageId: fromStage.id,
+      toStageId: toStage.id,
+      payload: {
+        previousVersion: current.version,
+        version: updated.version,
+        suggestionId: input.suggestionId ?? null,
+        reason: input.reason ?? null,
+        transitionClass: input.transitionClass ?? "manual",
+      },
+    });
+    const ledger = await enqueueStageAutomationLedger(tx, {
+      companyId: input.companyId,
+      caseId: current.id,
+      stage: toStage,
+      eventId: event.id,
+    });
+    return { case: updated, event, automationLedger: ledger };
+  }
+
+  const service = {
+    async createPipeline(input: {
+      companyId: string;
+      key: string;
+      name: string;
+      description?: string | null;
+      projectId?: string | null;
+      enforceTransitions?: boolean;
+      stages?: Array<{ key: string; name: string; kind: PipelineStageKind; position?: number; config?: PipelineStageConfig }>;
+      actor: PipelineActor;
+    }) {
+      return db.transaction(async (tx) => {
+        const [pipeline] = await tx
+          .insert(pipelines)
+          .values({
+            companyId: input.companyId,
+            key: input.key,
+            name: input.name,
+            description: input.description ?? null,
+            projectId: input.projectId ?? null,
+            enforceTransitions: input.enforceTransitions ?? false,
+            createdByUserId: input.actor.type === "user" ? input.actor.userId : null,
+            createdByAgentId: input.actor.type === "agent" ? input.actor.agentId : null,
+          })
+          .returning();
+        const stageInputs = input.stages?.length
+          ? input.stages.map((stage, index) => ({ ...stage, position: stage.position ?? (index + 1) * 100 }))
+          : DEFAULT_STAGES.map((stage) => ({ ...stage, config: {} }));
+        const insertedStages = await tx
+          .insert(pipelineStages)
+          .values(stageInputs.map((stage) => ({
+            pipelineId: pipeline!.id,
+            key: stage.key,
+            name: stage.name,
+            kind: stage.kind,
+            position: stage.position,
+            config: stage.config ?? {},
+          })))
+          .returning();
+
+        if (!insertedStages.some((stage) => stage.kind === "done") || !insertedStages.some((stage) => stage.kind === "cancelled")) {
+          throw unprocessable("Pipeline must include at least one done stage and one cancelled stage", { code: "validation" });
+        }
+
+        if (!input.stages?.length) {
+          const byKey = new Map(insertedStages.map((stage) => [stage.key, stage]));
+          const edges = [
+            ["intake", "in_progress"],
+            ["in_progress", "review"],
+            ["review", "done"],
+          ] as const;
+          await tx.insert(pipelineTransitions).values(edges.map(([from, to]) => ({
+            pipelineId: pipeline!.id,
+            fromStageId: byKey.get(from)!.id,
+            toStageId: byKey.get(to)!.id,
+          })));
+        }
+
+        return { ...pipeline!, stages: insertedStages };
+      });
+    },
+
+    async listStages(companyId: string, pipelineId: string) {
+      await getPipelineOrThrow(db, companyId, pipelineId);
+      return db
+        .select()
+        .from(pipelineStages)
+        .where(eq(pipelineStages.pipelineId, pipelineId))
+        .orderBy(asc(pipelineStages.position), asc(pipelineStages.createdAt));
+    },
+
+    async createStage(input: {
+      companyId: string;
+      pipelineId: string;
+      key: string;
+      name: string;
+      kind: PipelineStageKind;
+      position: number;
+      config?: PipelineStageConfig;
+    }) {
+      await getPipelineOrThrow(db, input.companyId, input.pipelineId);
+      const [stage] = await db
+        .insert(pipelineStages)
+        .values({
+          pipelineId: input.pipelineId,
+          key: input.key,
+          name: input.name,
+          kind: input.kind,
+          position: input.position,
+          config: input.config ?? {},
+        })
+        .returning();
+      return stage!;
+    },
+
+    async deleteStage(input: {
+      companyId: string;
+      pipelineId: string;
+      stageId: string;
+      moveCasesToStageId?: string | null;
+      actor?: PipelineActor;
+    }) {
+      return db.transaction(async (tx) => {
+        await getPipelineOrThrow(tx, input.companyId, input.pipelineId);
+        const stage = await getStageOrThrow(tx, input.pipelineId, input.stageId);
+        const targetStage = input.moveCasesToStageId
+          ? await getStageOrThrow(tx, input.pipelineId, input.moveCasesToStageId)
+          : null;
+        const casesInStage = await tx
+          .select()
+          .from(pipelineCases)
+          .where(and(eq(pipelineCases.pipelineId, input.pipelineId), eq(pipelineCases.stageId, stage.id)));
+        if (casesInStage.length > 0 && !targetStage) {
+          throw unprocessable("Cannot delete a stage that holds cases without moveCasesToStageId", { code: "stage_has_cases" });
+        }
+        if (targetStage) {
+          const movedCases = await tx
+            .update(pipelineCases)
+            .set({
+              stageId: targetStage.id,
+              version: sql`${pipelineCases.version} + 1`,
+              terminalKind: terminalKindForStage(targetStage.kind),
+              terminalAt: isTerminalKind(targetStage.kind) ? nowDate() : null,
+              updatedAt: nowDate(),
+            })
+            .where(and(eq(pipelineCases.pipelineId, input.pipelineId), eq(pipelineCases.stageId, stage.id)))
+            .returning();
+          for (const movedCase of movedCases) {
+            const previous = casesInStage.find((row) => row.id === movedCase.id);
+            await writeCaseEvent(tx, {
+              companyId: input.companyId,
+              caseId: movedCase.id,
+              type: "transitioned",
+              actor: input.actor ?? { type: "system" },
+              fromStageId: stage.id,
+              toStageId: targetStage.id,
+              payload: {
+                reason: "stage_deleted",
+                previousVersion: previous?.version ?? movedCase.version - 1,
+                version: movedCase.version,
+              },
+            });
+          }
+        }
+        await tx.delete(pipelineTransitions).where(or(eq(pipelineTransitions.fromStageId, stage.id), eq(pipelineTransitions.toStageId, stage.id)));
+        await tx.delete(pipelineStages).where(eq(pipelineStages.id, stage.id));
+        return { deleted: true };
+      });
+    },
+
+    async createTransition(input: { companyId: string; pipelineId: string; fromStageId: string; toStageId: string; label?: string | null }) {
+      await getPipelineOrThrow(db, input.companyId, input.pipelineId);
+      await getStageOrThrow(db, input.pipelineId, input.fromStageId);
+      await getStageOrThrow(db, input.pipelineId, input.toStageId);
+      const [transition] = await db
+        .insert(pipelineTransitions)
+        .values({
+          pipelineId: input.pipelineId,
+          fromStageId: input.fromStageId,
+          toStageId: input.toStageId,
+          label: input.label ?? null,
+        })
+        .returning();
+      return transition!;
+    },
+
+    async ingestCase(input: {
+      companyId: string;
+      pipelineId: string;
+      caseKey?: string | null;
+      title: string;
+      summary?: string | null;
+      fields?: Record<string, unknown>;
+      stageKey?: string | null;
+      parentCaseId?: string | null;
+      actor: PipelineActor;
+    }) {
+      assertJsonSize(input.fields ?? {}, "fields");
+      assertActorProvenance(input.actor);
+      const caseKey = input.caseKey ?? randomUUID();
+      assertCaseKey(caseKey);
+
+      return db.transaction(async (tx) => {
+        const pipeline = await getPipelineOrThrow(tx, input.companyId, input.pipelineId);
+        if (pipeline.archivedAt) throw unprocessable("Pipeline is archived", { code: "pipeline_archived" });
+        const stage = input.stageKey
+          ? await getStageByKeyOrThrow(tx, input.pipelineId, input.stageKey)
+          : await tx
+            .select()
+            .from(pipelineStages)
+            .where(eq(pipelineStages.pipelineId, input.pipelineId))
+            .orderBy(asc(pipelineStages.position), asc(pipelineStages.createdAt))
+            .limit(1)
+            .then((rows) => rows[0] ?? null);
+        if (!stage) throw unprocessable("Pipeline has no stages", { code: "validation" });
+
+        const [inserted] = await tx
+          .insert(pipelineCases)
+          .values({
+            companyId: input.companyId,
+            pipelineId: input.pipelineId,
+            stageId: stage.id,
+            caseKey,
+            title: input.title,
+            summary: input.summary ?? null,
+            fields: input.fields ?? {},
+            parentCaseId: input.parentCaseId ?? null,
+            terminalKind: terminalKindForStage(stage.kind),
+            terminalAt: isTerminalKind(stage.kind) ? nowDate() : null,
+            createdByUserId: input.actor.type === "user" ? input.actor.userId : null,
+            createdByAgentId: input.actor.type === "agent" ? input.actor.agentId : null,
+            originRunId: input.actor.type === "agent" ? input.actor.runId : null,
+          })
+          .onConflictDoNothing({ target: [pipelineCases.pipelineId, pipelineCases.caseKey] })
+          .returning();
+
+        if (!inserted) {
+          const existing = await tx
+            .select()
+            .from(pipelineCases)
+            .where(and(eq(pipelineCases.pipelineId, input.pipelineId), eq(pipelineCases.caseKey, caseKey)))
+            .limit(1)
+            .then((rows) => rows[0] ?? null);
+          if (!existing) throw conflict("Pipeline case ingest conflict", { code: "ingest_conflict" });
+          return { case: existing, created: false };
+        }
+
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: inserted.id,
+          type: "ingested",
+          actor: input.actor,
+          toStageId: stage.id,
+          payload: { caseKey },
+        });
+        return { case: inserted, created: true };
+      });
+    },
+
+    async ingestCases(input: {
+      companyId: string;
+      pipelineId: string;
+      items: Array<{
+        caseKey?: string | null;
+        title: string;
+        summary?: string | null;
+        fields?: Record<string, unknown>;
+        stageKey?: string | null;
+        parentCaseId?: string | null;
+      }>;
+      actor: PipelineActor;
+    }) {
+      if (input.items.length > MAX_BATCH_INGEST) {
+        throw unprocessable("Batch ingest supports at most 200 items", { code: "validation" });
+      }
+      const seen = new Set<string>();
+      return Promise.all(input.items.map(async (item) => {
+        const key = item.caseKey ?? null;
+        if (key) {
+          if (seen.has(key)) {
+            return { ok: false as const, caseKey: key, error: { code: "duplicate_batch_key" } };
+          }
+          seen.add(key);
+        }
+        try {
+          const result = await service.ingestCase({
+            ...item,
+            companyId: input.companyId,
+            pipelineId: input.pipelineId,
+            actor: input.actor,
+          });
+          return { ok: true as const, ...result };
+        } catch (error) {
+          const httpError = error as { status?: number; message?: string; details?: unknown };
+          return {
+            ok: false as const,
+            caseKey: key,
+            error: { status: httpError.status ?? 500, message: httpError.message ?? "Unknown error", details: httpError.details },
+          };
+        }
+      }));
+    },
+
+    async patchCaseContent(input: {
+      companyId: string;
+      caseId: string;
+      title?: string;
+      summary?: string | null;
+      fields?: Record<string, unknown>;
+      expectedVersion?: number;
+      leaseToken?: string | null;
+      actor: PipelineActor;
+    }) {
+      if (input.fields !== undefined) assertJsonSize(input.fields, "fields");
+      return db.transaction(async (tx) => {
+        const { case: existing, stage } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+        const current = await assertLeaseAvailable(tx, existing, input.actor, input.leaseToken);
+        if (input.expectedVersion !== undefined && current.version !== input.expectedVersion) {
+          throw conflict("Pipeline case version conflict", conflictDetailsForCase(current, stage));
+        }
+        const patch: Partial<typeof pipelineCases.$inferInsert> = {
+          version: current.version + 1,
+          updatedAt: nowDate(),
+        };
+        if (input.title !== undefined) patch.title = input.title;
+        if (input.summary !== undefined) patch.summary = input.summary;
+        if (input.fields !== undefined) patch.fields = input.fields;
+
+        const [updated] = await tx
+          .update(pipelineCases)
+          .set(patch)
+          .where(and(eq(pipelineCases.id, current.id), eq(pipelineCases.version, current.version)))
+          .returning();
+        if (!updated) {
+          const latest = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+          throw conflict("Pipeline case version conflict", conflictDetailsForCase(latest.case, latest.stage));
+        }
+
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: updated.id,
+          type: "updated",
+          actor: input.actor,
+          payload: { previousVersion: current.version, version: updated.version },
+        });
+        return updated;
+      });
+    },
+
+    async claimCase(input: {
+      companyId: string;
+      caseId: string;
+      actor: Extract<PipelineActor, { type: "user" | "agent" }>;
+      leaseMs?: number;
+    }) {
+      return db.transaction(async (tx) => {
+        const { case: existing } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+        const current = await expireLeaseIfNeeded(tx, existing, { type: "system" });
+        if (hasValidLease(current) && !actorOwnsLease(current, input.actor, null)) {
+          throw conflict("Pipeline case lease is held", { code: "lease_held", lease: leaseOwner(current) });
+        }
+        const leaseMs = Math.min(Math.max(input.leaseMs ?? DEFAULT_LEASE_MS, 1_000), MAX_LEASE_MS);
+        const token = randomUUID();
+        const expiresAt = new Date(Date.now() + leaseMs);
+        const [updated] = await tx
+          .update(pipelineCases)
+          .set({
+            leaseOwnerType: input.actor.type,
+            leaseAgentId: input.actor.type === "agent" ? input.actor.agentId : null,
+            leaseUserId: input.actor.type === "user" ? input.actor.userId : null,
+            leaseToken: token,
+            leaseExpiresAt: expiresAt,
+            updatedAt: nowDate(),
+          })
+          .where(eq(pipelineCases.id, current.id))
+          .returning();
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: current.id,
+          type: "claimed",
+          actor: input.actor,
+          payload: { leaseToken: token, leaseExpiresAt: expiresAt.toISOString() },
+        });
+        return updated!;
+      });
+    },
+
+    async releaseCase(input: {
+      companyId: string;
+      caseId: string;
+      actor: PipelineActor;
+      leaseToken?: string | null;
+      force?: boolean;
+    }) {
+      return db.transaction(async (tx) => {
+        const { case: existing } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+        const current = await expireLeaseIfNeeded(tx, existing, { type: "system" });
+        if (!input.force && hasValidLease(current) && !actorOwnsLease(current, input.actor, input.leaseToken)) {
+          throw conflict("Pipeline case lease is held", { code: "lease_held", lease: leaseOwner(current) });
+        }
+        const [updated] = await tx
+          .update(pipelineCases)
+          .set({
+            leaseOwnerType: null,
+            leaseAgentId: null,
+            leaseUserId: null,
+            leaseToken: null,
+            leaseExpiresAt: null,
+            updatedAt: nowDate(),
+          })
+          .where(eq(pipelineCases.id, current.id))
+          .returning();
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: current.id,
+          type: "lease_released",
+          actor: input.actor,
+          payload: { forced: input.force === true },
+        });
+        return updated!;
+      });
+    },
+
+    async transitionCase(input: {
+      companyId: string;
+      caseId: string;
+      toStageId?: string;
+      toStageKey?: string;
+      expectedVersion: number;
+      leaseToken?: string | null;
+      actor: PipelineActor;
+      transitionClass?: "manual" | "suggested" | "auto";
+      suggestionId?: string;
+      reason?: string | null;
+    }) {
+      return db.transaction((tx) => transitionCaseInTransaction(tx, input));
+    },
+
+    async suggestTransition(input: {
+      companyId: string;
+      caseId: string;
+      toStageKey: string;
+      rationale: string;
+      confidence?: number;
+      actor: PipelineActor;
+    }) {
+      return db.transaction(async (tx) => {
+        const { case: existing } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+        await getStageByKeyOrThrow(tx, existing.pipelineId, input.toStageKey);
+        const suggestion = {
+          id: randomUUID(),
+          toStageKey: input.toStageKey,
+          rationale: input.rationale,
+          confidence: input.confidence,
+          suggestedByAgentId: input.actor.type === "agent" ? input.actor.agentId : undefined,
+          runId: input.actor.type === "agent" ? input.actor.runId : undefined,
+          createdAt: nowDate().toISOString(),
+        };
+        const superseded = existing.pendingSuggestion ?? null;
+        const [updated] = await tx
+          .update(pipelineCases)
+          .set({ pendingSuggestion: suggestion, updatedAt: nowDate() })
+          .where(eq(pipelineCases.id, existing.id))
+          .returning();
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: existing.id,
+          type: "transition_suggested",
+          actor: input.actor,
+          payload: { suggestion, supersededSuggestionId: superseded?.id ?? null },
+        });
+        return { case: updated!, suggestion };
+      });
+    },
+
+    async resolveSuggestion(input: {
+      companyId: string;
+      caseId: string;
+      suggestionId: string;
+      decision: "accept" | "dismiss";
+      expectedVersion?: number;
+      actor: PipelineActor;
+      reason?: string | null;
+      leaseToken?: string | null;
+    }) {
+      return db.transaction(async (tx) => {
+        const { case: existing } = await getCaseWithStageOrThrow(tx, input.companyId, input.caseId);
+        const suggestion = existing.pendingSuggestion;
+        if (!suggestion || suggestion.id !== input.suggestionId) {
+          throw conflict("Pipeline suggestion is not pending", { code: "suggestion_not_pending" });
+        }
+        if (input.decision === "dismiss") {
+          const [updated] = await tx
+            .update(pipelineCases)
+            .set({ pendingSuggestion: null, updatedAt: nowDate() })
+            .where(eq(pipelineCases.id, existing.id))
+            .returning();
+          const event = await writeCaseEvent(tx, {
+            companyId: input.companyId,
+            caseId: existing.id,
+            type: "suggestion_resolved",
+            actor: input.actor,
+            payload: { suggestionId: input.suggestionId, decision: "dismiss", reason: input.reason ?? null },
+          });
+          return { case: updated!, event };
+        }
+
+        const transition = await transitionCaseInTransaction(tx, {
+          companyId: input.companyId,
+          caseId: input.caseId,
+          toStageKey: suggestion.toStageKey,
+          expectedVersion: input.expectedVersion ?? existing.version,
+          actor: input.actor,
+          leaseToken: input.leaseToken,
+          transitionClass: "suggested",
+          suggestionId: input.suggestionId,
+          reason: input.reason,
+        });
+        await writeCaseEvent(tx, {
+          companyId: input.companyId,
+          caseId: existing.id,
+          type: "suggestion_resolved",
+          actor: input.actor,
+          payload: { suggestionId: input.suggestionId, decision: "accept", reason: input.reason ?? null },
+        });
+        return transition;
+      });
+    },
+
+    async listCaseEvents(companyId: string, caseId: string) {
+      await getCaseWithStageOrThrow(db, companyId, caseId);
+      return db
+        .select()
+        .from(pipelineCaseEvents)
+        .where(and(eq(pipelineCaseEvents.companyId, companyId), eq(pipelineCaseEvents.caseId, caseId)))
+        .orderBy(asc(pipelineCaseEvents.createdAt));
+    },
+  };
+
+  return service;
+}