feat(mcpd): AgentService virtual methods + GC cascade (v3 Stage 2)

State machine for kind=virtual Agent rows. Mirrors what
VirtualLlmService did for Llms in v1, then wires both lifecycles
together so disconnect/heartbeat/GC cascade through both at once.

AgentRepository:
- create/update accept the new lifecycle fields (kind, providerSessionId,
  status, lastHeartbeatAt, inactiveSince).
- Adds findBySessionId, findByLlmId, findStaleVirtuals, findExpiredInactives.

AgentService — new virtual-agent methods:
- registerVirtualAgents(sessionId, inputs, ownerId) — sticky upsert.
  New names insert as kind=virtual/status=active. Existing virtuals
  owned by the same session reactivate; existing inactive virtuals
  from a foreign session can be adopted (sticky reconnect). Refuses
  to overwrite a public agent or a foreign session's still-active
  virtual (HTTP 409). Pinned LLM is resolved via LlmService — caller
  posts Llms first.
- heartbeatVirtualAgents(sessionId) — bumps owned agents on a session
  heartbeat; revives inactive rows.
- markVirtualAgentsInactiveBySession(sessionId) — disconnect cascade.
- deleteVirtualAgentsForLlm(llmId) — defensive cascade for the GC's
  Llm-delete step (Agent.llmId is Restrict).
- gcSweepVirtualAgents() — same shape as VirtualLlmService.gcSweep
  (90s heartbeat-stale → inactive, 4h inactive → delete).

VirtualLlmService:
- Optional AgentService dependency. heartbeat() now also bumps owned
  agents; unbindSession() flips them inactive. gcSweep() runs the
  agent sweep FIRST (so any agent that would block an Llm delete via
  Restrict is already gone), and adds a defensive
  deleteVirtualAgentsForLlm step right before each Llm delete in case
  an agent's heartbeat lagged its Llm's just enough to escape this
  round's 4h cutoff.

main.ts:
- VirtualLlmService construction moves below AgentService so it can
  receive the cascade dependency.

Tests: 13 new in virtual-agent-service.test.ts cover all the register
variants (insert, sticky reconnect, adopt-inactive-foreign, refuse
public-overwrite, refuse foreign-session-active), heartbeat-revive,
disconnect-cascade, deleteVirtualAgentsForLlm scope, GC sweep flip
+ delete + idempotence, and three VirtualLlmService cascade scenarios
(unbindSession, gcSweep deleting agent before Llm, defensive cascade
when agent's heartbeat lagged).

mcpd suite: 854/854 (was 841 + 13 new). Workspace unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/db/prisma/migrations/20260427154803_add_virtual_agent_lifecycle/migration.sql

@@ -0,0 +1,14 @@
+-- Mirror Llm's virtual-provider lifecycle on Agent. Reuses the
+-- existing LlmKind / LlmStatus enums so we don't double-define them.
+-- Existing rows backfill with kind='public' / status='active' so
+-- nothing changes for manually-created agents.
+
+ALTER TABLE "Agent"
+  ADD COLUMN "kind"               "LlmKind"   NOT NULL DEFAULT 'public',
+  ADD COLUMN "providerSessionId"  TEXT,
+  ADD COLUMN "lastHeartbeatAt"    TIMESTAMP(3),
+  ADD COLUMN "status"             "LlmStatus" NOT NULL DEFAULT 'active',
+  ADD COLUMN "inactiveSince"      TIMESTAMP(3);
+
+CREATE INDEX "Agent_kind_status_idx"          ON "Agent"("kind", "status");
+CREATE INDEX "Agent_providerSessionId_idx"    ON "Agent"("providerSessionId");

src/db/prisma/schema.prisma

@@ -479,6 +479,12 @@ model Agent {
   proxyModelName       String? // optional informational override
   defaultParams        Json      @default("{}") // LiteLLM-style: temperature, top_p, top_k, max_tokens, stop, ...
   extras               Json      @default("{}") // future LoRA / tool-allowlist
+  // ── Virtual-agent lifecycle (NULL/default for kind=public, mirrors Llm) ──
+  kind                 LlmKind   @default(public)
+  providerSessionId    String? // mcplocal session that owns this row when virtual
+  lastHeartbeatAt      DateTime?
+  status               LlmStatus @default(active)
+  inactiveSince        DateTime?
   ownerId              String
   version              Int       @default(1)
   createdAt            DateTime  @default(now())
@@ -497,6 +503,8 @@ model Agent {
   @@index([projectId])
   @@index([ownerId])
   @@index([defaultPersonalityId])
+  @@index([kind, status])
+  @@index([providerSessionId])
 }
 
 // ── Personalities (named overlay bundles of prompts on top of an Agent) ──

src/db/tests/agent-schema.test.ts

@@ -317,6 +317,78 @@ describe('agent / chat-thread / chat-message schema', () => {
     expect(reloaded?.defaultPersonalityId).toBeNull();
   });
 
+  // ── v3: Agent.kind virtual + lifecycle fields ──
+
+  it('defaults a freshly inserted Agent to kind=public, status=active', async () => {
+    const user = await makeUser();
+    const llm = await makeLlm('llm-default-kind');
+    const agent = await makeAgent({ name: 'fresh', llmId: llm.id, ownerId: user.id });
+    expect(agent.kind).toBe('public');
+    expect(agent.status).toBe('active');
+    expect(agent.providerSessionId).toBeNull();
+    expect(agent.lastHeartbeatAt).toBeNull();
+    expect(agent.inactiveSince).toBeNull();
+  });
+
+  it('persists kind=virtual + lifecycle fields together', async () => {
+    const user = await makeUser();
+    const llm = await makeLlm('llm-pub-virtual');
+    const now = new Date();
+    const agent = await prisma.agent.create({
+      data: {
+        name: 'local-coder',
+        llmId: llm.id,
+        ownerId: user.id,
+        kind: 'virtual',
+        providerSessionId: 'sess-abc',
+        lastHeartbeatAt: now,
+        status: 'active',
+      },
+    });
+    expect(agent.kind).toBe('virtual');
+    expect(agent.providerSessionId).toBe('sess-abc');
+    expect(agent.lastHeartbeatAt?.getTime()).toBe(now.getTime());
+  });
+
+  it('finds virtual agents by (kind, status) cheaply (GC sweep query)', async () => {
+    const user = await makeUser();
+    const llm = await makeLlm('llm-gc-agent');
+    await prisma.agent.create({ data: { name: 'pub-1', llmId: llm.id, ownerId: user.id } });
+    await prisma.agent.create({
+      data: { name: 'v-active', llmId: llm.id, ownerId: user.id, kind: 'virtual', providerSessionId: 's1' },
+    });
+    await prisma.agent.create({
+      data: { name: 'v-inactive', llmId: llm.id, ownerId: user.id, kind: 'virtual', providerSessionId: 's2', status: 'inactive', inactiveSince: new Date() },
+    });
+
+    const stale = await prisma.agent.findMany({
+      where: { kind: 'virtual', status: 'inactive' },
+      select: { name: true },
+    });
+    expect(stale.map((a) => a.name)).toEqual(['v-inactive']);
+  });
+
+  it('finds agents by providerSessionId (used on mcplocal disconnect cascade)', async () => {
+    const user = await makeUser();
+    const llm = await makeLlm('llm-sess-cascade');
+    await prisma.agent.create({
+      data: { name: 'a', llmId: llm.id, ownerId: user.id, kind: 'virtual', providerSessionId: 'shared' },
+    });
+    await prisma.agent.create({
+      data: { name: 'b', llmId: llm.id, ownerId: user.id, kind: 'virtual', providerSessionId: 'shared' },
+    });
+    await prisma.agent.create({
+      data: { name: 'c', llmId: llm.id, ownerId: user.id, kind: 'virtual', providerSessionId: 'other' },
+    });
+
+    const owned = await prisma.agent.findMany({
+      where: { providerSessionId: 'shared' },
+      select: { name: true },
+      orderBy: { name: 'asc' },
+    });
+    expect(owned.map((a) => a.name)).toEqual(['a', 'b']);
+  });
+
   it('binds the same prompt to multiple personalities of an agent', async () => {
     const user = await makeUser();
     const llm = await makeLlm('llm-shared-prompt');

src/mcpd/src/main.ts

@@ -435,10 +435,8 @@ async function main(): Promise<void> {
     adapters: llmAdapters,
     log: { warn: (msg) => app.log.warn(msg) },
   });
-  // Virtual-provider state machine (kind=virtual rows). The 60-s GC ticker
+  // VirtualLlmService is constructed lower down (after AgentService) so
-  // is started below after `app.listen` so it doesn't fire before the
+  // it can wire the agent-cascade callbacks introduced in v3 Stage 2.
-  // server is accepting traffic.
-  const virtualLlmService = new VirtualLlmService(llmRepo);
   // AgentService + ChatService get fully wired below once projectService and
   // mcpProxyService are constructed (ChatService needs them via the
   // ChatToolDispatcher bridge).
@@ -465,6 +463,10 @@ async function main(): Promise<void> {
   const personalityRepo = new PersonalityRepository(prisma);
   const personalityService = new PersonalityService(personalityRepo, agentRepo, promptRepo);
   const agentService = new AgentService(agentRepo, llmService, projectService, personalityRepo);
+  // Virtual-provider state machine (kind=virtual rows for both Llms and
+  // Agents). v3 wires AgentService for heartbeat/disconnect/GC cascade.
+  // The 60-s GC ticker is started below after `app.listen`.
+  const virtualLlmService = new VirtualLlmService(llmRepo, agentService);
   // ChatService needs the proxy + project repo via the ChatToolDispatcher
   // bridge. The dispatcher's logger references `app.log`, which is not
   // constructed until further down — `chatService` itself is built right
@@ -607,6 +609,7 @@ async function main(): Promise<void> {
     promptRepo,
     chatToolDispatcher,
     personalityRepo,
+    virtualLlmService,
   );
   registerAgentChatRoutes(app, chatService);
   registerLlmInferRoutes(app, {

src/mcpd/src/repositories/agent.repository.ts

@@ -1,4 +1,4 @@
-import type { PrismaClient, Agent, Prisma } from '@prisma/client';
+import type { PrismaClient, Agent, Prisma, LlmKind, LlmStatus } from '@prisma/client';
 
 export interface CreateAgentRepoInput {
   name: string;
@@ -11,6 +11,12 @@ export interface CreateAgentRepoInput {
   defaultParams?: Record<string, unknown>;
   extras?: Record<string, unknown>;
   ownerId: string;
+  // Virtual-agent lifecycle (omit for kind=public).
+  kind?: LlmKind;
+  providerSessionId?: string | null;
+  status?: LlmStatus;
+  lastHeartbeatAt?: Date | null;
+  inactiveSince?: Date | null;
 }
 
 export interface UpdateAgentRepoInput {
@@ -22,6 +28,13 @@ export interface UpdateAgentRepoInput {
   proxyModelName?: string | null;
   defaultParams?: Record<string, unknown>;
   extras?: Record<string, unknown>;
+  // Virtual-agent lifecycle. AgentService is the only public writer; the
+  // VirtualAgentService methods (Stage 2) bypass the public CRUD path.
+  kind?: LlmKind;
+  providerSessionId?: string | null;
+  status?: LlmStatus;
+  lastHeartbeatAt?: Date | null;
+  inactiveSince?: Date | null;
 }
 
 export interface IAgentRepository {
@@ -32,6 +45,11 @@ export interface IAgentRepository {
   create(data: CreateAgentRepoInput): Promise<Agent>;
   update(id: string, data: UpdateAgentRepoInput): Promise<Agent>;
   delete(id: string): Promise<void>;
+  // Virtual-agent lifecycle helpers.
+  findBySessionId(sessionId: string): Promise<Agent[]>;
+  findByLlmId(llmId: string): Promise<Agent[]>;
+  findStaleVirtuals(heartbeatCutoff: Date): Promise<Agent[]>;
+  findExpiredInactives(deletionCutoff: Date): Promise<Agent[]>;
 }
 
 export class AgentRepository implements IAgentRepository {
@@ -69,6 +87,11 @@ export class AgentRepository implements IAgentRepository {
         defaultParams: (data.defaultParams ?? {}) as Prisma.InputJsonValue,
         extras: (data.extras ?? {}) as Prisma.InputJsonValue,
         ownerId: data.ownerId,
+        ...(data.kind !== undefined ? { kind: data.kind } : {}),
+        ...(data.providerSessionId !== undefined ? { providerSessionId: data.providerSessionId } : {}),
+        ...(data.status !== undefined ? { status: data.status } : {}),
+        ...(data.lastHeartbeatAt !== undefined ? { lastHeartbeatAt: data.lastHeartbeatAt } : {}),
+        ...(data.inactiveSince !== undefined ? { inactiveSince: data.inactiveSince } : {}),
       },
     });
   }
@@ -99,6 +122,11 @@ export class AgentRepository implements IAgentRepository {
     if (data.extras !== undefined) {
       updateData.extras = data.extras as Prisma.InputJsonValue;
     }
+    if (data.kind !== undefined) updateData.kind = data.kind;
+    if (data.providerSessionId !== undefined) updateData.providerSessionId = data.providerSessionId;
+    if (data.status !== undefined) updateData.status = data.status;
+    if (data.lastHeartbeatAt !== undefined) updateData.lastHeartbeatAt = data.lastHeartbeatAt;
+    if (data.inactiveSince !== undefined) updateData.inactiveSince = data.inactiveSince;
     // Bump optimistic version on every update.
     updateData.version = { increment: 1 };
     return this.prisma.agent.update({ where: { id }, data: updateData });
@@ -107,4 +135,40 @@ export class AgentRepository implements IAgentRepository {
   async delete(id: string): Promise<void> {
     await this.prisma.agent.delete({ where: { id } });
   }
+
+  // ── Virtual-agent lifecycle queries ──
+
+  async findBySessionId(sessionId: string): Promise<Agent[]> {
+    return this.prisma.agent.findMany({
+      where: { providerSessionId: sessionId },
+      orderBy: { name: 'asc' },
+    });
+  }
+
+  async findByLlmId(llmId: string): Promise<Agent[]> {
+    return this.prisma.agent.findMany({
+      where: { llmId },
+      orderBy: { name: 'asc' },
+    });
+  }
+
+  async findStaleVirtuals(heartbeatCutoff: Date): Promise<Agent[]> {
+    return this.prisma.agent.findMany({
+      where: {
+        kind: 'virtual',
+        status: 'active',
+        lastHeartbeatAt: { lt: heartbeatCutoff },
+      },
+    });
+  }
+
+  async findExpiredInactives(deletionCutoff: Date): Promise<Agent[]> {
+    return this.prisma.agent.findMany({
+      where: {
+        kind: 'virtual',
+        status: 'inactive',
+        inactiveSince: { lt: deletionCutoff },
+      },
+    });
+  }
 }

src/mcpd/src/services/agent.service.ts

@@ -33,12 +33,28 @@ export interface AgentView {
   proxyModelName: string | null;
   defaultParams: AgentChatParams;
   extras: Record<string, unknown>;
+  // Virtual-agent lifecycle (defaults make public agents look like "active").
+  kind: 'public' | 'virtual';
+  status: 'active' | 'inactive' | 'hibernating';
+  lastHeartbeatAt: Date | null;
+  inactiveSince: Date | null;
   ownerId: string;
   version: number;
   createdAt: Date;
   updatedAt: Date;
 }
 
+/** Input shape mcplocal sends per virtual agent on register. */
+export interface VirtualAgentInput {
+  name: string;
+  llmName: string;
+  description?: string;
+  systemPrompt?: string;
+  project?: string;
+  defaultParams?: Record<string, unknown>;
+  extras?: Record<string, unknown>;
+}
+
 export class AgentService {
   constructor(
     private readonly repo: IAgentRepository,
@@ -179,10 +195,162 @@ export class AgentService {
       proxyModelName: row.proxyModelName,
       defaultParams: row.defaultParams as AgentChatParams,
       extras: row.extras as Record<string, unknown>,
+      kind: row.kind,
+      status: row.status,
+      lastHeartbeatAt: row.lastHeartbeatAt,
+      inactiveSince: row.inactiveSince,
       ownerId: row.ownerId,
       version: row.version,
       createdAt: row.createdAt,
       updatedAt: row.updatedAt,
     };
   }
+
+  // ── Virtual-agent lifecycle (v3) ──
+
+  /**
+   * Sticky upsert of virtual agents owned by a publishing mcplocal session.
+   * Mirrors VirtualLlmService.register's semantics:
+   *   - New agents → insert with kind=virtual / status=active.
+   *   - Existing virtual agents owned by the same session → update + reactivate.
+   *   - Existing virtual agents owned by a different session, but currently
+   *     inactive → adopt (sticky reconnect after a session lapse).
+   *   - Existing public agents OR foreign-active virtuals → 409 Conflict.
+   *   - Pinned LLM must already exist (publisher posts Llms first in the same
+   *     register payload).
+   */
+  async registerVirtualAgents(
+    sessionId: string,
+    inputs: VirtualAgentInput[],
+    ownerId: string,
+  ): Promise<AgentView[]> {
+    const now = new Date();
+    const out: AgentView[] = [];
+    for (const a of inputs) {
+      const llm = await this.llms.getByName(a.llmName);
+      const projectId = a.project !== undefined
+        ? (await this.projects.resolveAndGet(a.project)).id
+        : null;
+      const existing = await this.repo.findByName(a.name);
+      if (existing !== null) {
+        if (existing.kind === 'public') {
+          throw Object.assign(
+            new Error(`Cannot publish over public Agent: ${a.name}`),
+            { statusCode: 409 },
+          );
+        }
+        if (existing.providerSessionId !== sessionId && existing.status === 'active') {
+          throw Object.assign(
+            new Error(`Virtual Agent '${a.name}' is already active under a different session`),
+            { statusCode: 409 },
+          );
+        }
+        const updated = await this.repo.update(existing.id, {
+          ...(a.description !== undefined ? { description: a.description } : {}),
+          ...(a.systemPrompt !== undefined ? { systemPrompt: a.systemPrompt } : {}),
+          llmId: llm.id,
+          projectId,
+          ...(a.defaultParams !== undefined ? { defaultParams: a.defaultParams } : {}),
+          ...(a.extras !== undefined ? { extras: a.extras } : {}),
+          kind: 'virtual',
+          providerSessionId: sessionId,
+          status: 'active',
+          lastHeartbeatAt: now,
+          inactiveSince: null,
+        });
+        out.push(await this.toView(updated));
+        continue;
+      }
+      const created = await this.repo.create({
+        name: a.name,
+        ...(a.description !== undefined ? { description: a.description } : {}),
+        ...(a.systemPrompt !== undefined ? { systemPrompt: a.systemPrompt } : {}),
+        llmId: llm.id,
+        projectId,
+        ...(a.defaultParams !== undefined ? { defaultParams: a.defaultParams } : {}),
+        ...(a.extras !== undefined ? { extras: a.extras } : {}),
+        kind: 'virtual',
+        providerSessionId: sessionId,
+        status: 'active',
+        lastHeartbeatAt: now,
+        ownerId,
+      });
+      out.push(await this.toView(created));
+    }
+    return out;
+  }
+
+  /**
+   * Bumps lastHeartbeatAt on every virtual agent owned by the session.
+   * Revives inactive rows. Called from VirtualLlmService.heartbeat so
+   * one publisher heartbeat covers both Llms and Agents.
+   */
+  async heartbeatVirtualAgents(sessionId: string): Promise<void> {
+    const owned = await this.repo.findBySessionId(sessionId);
+    if (owned.length === 0) return;
+    const now = new Date();
+    for (const row of owned) {
+      await this.repo.update(row.id, {
+        lastHeartbeatAt: now,
+        ...(row.status === 'inactive' ? { status: 'active', inactiveSince: null } : {}),
+      });
+    }
+  }
+
+  /** Flip every virtual agent owned by the session to inactive immediately. */
+  async markVirtualAgentsInactiveBySession(sessionId: string): Promise<void> {
+    const owned = await this.repo.findBySessionId(sessionId);
+    const now = new Date();
+    for (const row of owned) {
+      if (row.status === 'active') {
+        await this.repo.update(row.id, { status: 'inactive', inactiveSince: now });
+      }
+    }
+  }
+
+  /**
+   * Cascade-delete virtual agents pinned to a virtual Llm. Called from
+   * VirtualLlmService.gcSweep BEFORE deleting the inactive Llm row, since
+   * Agent.llmId is `onDelete: Restrict` and would otherwise block the
+   * Llm delete.
+   */
+  async deleteVirtualAgentsForLlm(llmId: string): Promise<number> {
+    const pinned = await this.repo.findByLlmId(llmId);
+    let deleted = 0;
+    for (const row of pinned) {
+      if (row.kind !== 'virtual') continue;
+      await this.repo.delete(row.id);
+      deleted += 1;
+    }
+    return deleted;
+  }
+
+  /**
+   * GC sweep for virtual agents — same shape as VirtualLlmService.gcSweep:
+   *   1. Heartbeat-stale active virtuals → inactive (90-s cutoff).
+   *   2. 4-h-old inactive virtuals → delete.
+   * Run BEFORE the LlmService GC sweep so any agent that would have
+   * blocked an Llm delete via Restrict has already been cleared.
+   */
+  async gcSweepVirtualAgents(now: Date = new Date()): Promise<{ markedInactive: number; deleted: number }> {
+    const HEARTBEAT_TIMEOUT_MS = 90_000;
+    const INACTIVE_RETENTION_MS = 4 * 60 * 60 * 1000;
+    let markedInactive = 0;
+    let deleted = 0;
+
+    const heartbeatCutoff = new Date(now.getTime() - HEARTBEAT_TIMEOUT_MS);
+    const stale = await this.repo.findStaleVirtuals(heartbeatCutoff);
+    for (const row of stale) {
+      await this.repo.update(row.id, { status: 'inactive', inactiveSince: now });
+      markedInactive += 1;
+    }
+
+    const deletionCutoff = new Date(now.getTime() - INACTIVE_RETENTION_MS);
+    const expired = await this.repo.findExpiredInactives(deletionCutoff);
+    for (const row of expired) {
+      await this.repo.delete(row.id);
+      deleted += 1;
+    }
+    return { markedInactive, deleted };
+  }
 }

src/mcpd/src/services/chat.service.ts

@@ -31,6 +31,7 @@ import type {
 } from '../repositories/chat.repository.js';
 import type { IPromptRepository } from '../repositories/prompt.repository.js';
 import type { IPersonalityRepository } from '../repositories/personality.repository.js';
+import type { IVirtualLlmService } from './virtual-llm.service.js';
 import type { OpenAiChatRequest, OpenAiMessage } from './llm/types.js';
 import type { AgentChatParams } from '../validation/agent.schema.js';
 import { NotFoundError } from './mcp-server.service.js';
@@ -132,6 +133,14 @@ export class ChatService {
     private readonly promptRepo: IPromptRepository,
     private readonly tools: ChatToolDispatcher,
     private readonly personalities?: IPersonalityRepository,
+    /**
+     * v3: when an Agent is pinned to a `kind=virtual` Llm, inference is
+     * relayed via this service rather than an HTTP adapter (the virtual
+     * row has no upstream URL). Optional so older test wirings still
+     * compile; in those tests the chat path will refuse virtual Llms
+     * with a clear error.
+     */
+    private readonly virtualLlms?: IVirtualLlmService,
   ) {}
 
   async createThread(agentName: string, ownerId: string, title?: string): Promise<{ id: string }> {
@@ -170,14 +179,7 @@ export class ChatService {
     let lastTurnIndex = ctx.startingTurnIndex;
     try {
       for (let i = 0; i < ctx.maxIterations; i += 1) {
-        const adapter = this.adapters.get(ctx.llmType);
+        const result = await this.runOneInference(ctx);
-        const result = await adapter.infer({
-          body: this.buildBody(ctx),
-          modelOverride: ctx.modelOverride,
-          apiKey: ctx.apiKey,
-          url: ctx.url,
-          extraConfig: ctx.extraConfig,
-        });
         const choice = extractChoice(result.body);
         if (choice === null) {
           throw new Error(`Adapter returned no choice (status ${String(result.status)})`);
@@ -240,19 +242,12 @@ export class ChatService {
     const ctx = await this.prepareContext(args);
     try {
       for (let i = 0; i < ctx.maxIterations; i += 1) {
-        const adapter = this.adapters.get(ctx.llmType);
         const accumulated: { content: string; toolCalls: Array<{ id: string; name: string; argumentsJson: string }> } = {
           content: '',
           toolCalls: [],
         };
         let finishReason: string | null = null;
-        for await (const chunk of adapter.stream({
+        for await (const chunk of this.streamInference(ctx)) {
-          body: { ...this.buildBody(ctx), stream: true },
-          modelOverride: ctx.modelOverride,
-          apiKey: ctx.apiKey,
-          url: ctx.url,
-          extraConfig: ctx.extraConfig,
-        })) {
           if (chunk.done === true) break;
           if (chunk.data === '[DONE]') break;
           const evt = parseStreamingChunk(chunk.data);
@@ -347,12 +342,130 @@ export class ChatService {
     }
   }
 
+  /**
+   * Streaming counterpart of runOneInference. Yields raw OpenAI-style
+   * SSE chunks ({data: string; done?: boolean}) regardless of whether
+   * we're hitting a public adapter or relaying through VirtualLlmService.
+   * The caller's `parseStreamingChunk` already speaks OpenAI shape, so
+   * downstream code doesn't need to know which path produced the chunks.
+   */
+  private async *streamInference(ctx: {
+    llmName: string;
+    llmType: string;
+    llmKind: 'public' | 'virtual';
+    modelOverride: string;
+    url: string;
+    apiKey: string;
+    extraConfig: Record<string, unknown>;
+    history: OpenAiMessage[];
+    systemBlock: string;
+    toolList: ChatTool[];
+    mergedParams: AgentChatParams;
+  }): AsyncGenerator<{ data: string; done?: boolean }> {
+    if (ctx.llmKind !== 'virtual') {
+      const adapter = this.adapters.get(ctx.llmType);
+      yield* adapter.stream({
+        body: { ...this.buildBody(ctx), stream: true },
+        modelOverride: ctx.modelOverride,
+        apiKey: ctx.apiKey,
+        url: ctx.url,
+        extraConfig: ctx.extraConfig,
+      });
+      return;
+    }
+    if (this.virtualLlms === undefined) {
+      throw new Error(
+        'virtualLlms dispatcher not wired into ChatService — cannot stream chat with kind=virtual Llm',
+      );
+    }
+    // Bridge VirtualLlmService's onChunk callback API to an async
+    // iterator. Chunks land on the queue from the SSE relay; the
+    // generator drains them in order. ref.done resolves when the
+    // publisher emits its `[DONE]` marker.
+    const ref = await this.virtualLlms.enqueueInferTask(
+      ctx.llmName,
+      { ...this.buildBody(ctx), stream: true },
+      true,
+    );
+    const queue: Array<{ data: string; done?: boolean }> = [];
+    let resolveTick: (() => void) | null = null;
+    const wake = (): void => {
+      const r = resolveTick;
+      resolveTick = null;
+      if (r !== null) r();
+    };
+    const unsubscribe = ref.onChunk((c) => { queue.push(c); wake(); });
+    let finished = false;
+    let failure: Error | null = null;
+    ref.done.then(() => { finished = true; wake(); }).catch((err: Error) => { failure = err; finished = true; wake(); });
+
+    try {
+      while (true) {
+        while (queue.length > 0) {
+          const c = queue.shift()!;
+          yield c;
+          if (c.done === true) return;
+        }
+        if (finished) {
+          if (failure !== null) throw failure;
+          return;
+        }
+        await new Promise<void>((r) => { resolveTick = r; });
+      }
+    } finally {
+      unsubscribe();
+    }
+  }
+
+  /**
+   * Run a single non-streaming inference iteration. Branches on
+   * ctx.llmKind: public goes through the existing adapter registry,
+   * virtual relays through VirtualLlmService.enqueueInferTask (mirrors
+   * the same branch in `routes/llm-infer.ts` from v1 Stage 3).
+   *
+   * Throws when virtualLlms isn't wired but the row is virtual — older
+   * test wirings hit this path.
+   */
+  private async runOneInference(ctx: {
+    llmName: string;
+    llmType: string;
+    llmKind: 'public' | 'virtual';
+    modelOverride: string;
+    url: string;
+    apiKey: string;
+    extraConfig: Record<string, unknown>;
+    history: OpenAiMessage[];
+    systemBlock: string;
+    toolList: ChatTool[];
+    mergedParams: AgentChatParams;
+  }): Promise<{ status: number; body: unknown }> {
+    if (ctx.llmKind === 'virtual') {
+      if (this.virtualLlms === undefined) {
+        throw new Error(
+          'virtualLlms dispatcher not wired into ChatService — cannot chat with kind=virtual Llm',
+        );
+      }
+      const ref = await this.virtualLlms.enqueueInferTask(ctx.llmName, this.buildBody(ctx), false);
+      return ref.done;
+    }
+    const adapter = this.adapters.get(ctx.llmType);
+    return adapter.infer({
+      body: this.buildBody(ctx),
+      modelOverride: ctx.modelOverride,
+      apiKey: ctx.apiKey,
+      url: ctx.url,
+      extraConfig: ctx.extraConfig,
+    });
+  }
+
   private async prepareContext(args: ChatRequestArgs): Promise<{
     threadId: string;
     history: OpenAiMessage[];
     systemBlock: string;
     llmName: string;
     llmType: string;
+    /** v3: 'virtual' means infer is relayed via VirtualLlmService instead of an HTTP adapter. */
+    llmKind: 'public' | 'virtual';
     modelOverride: string;
     url: string;
     apiKey: string;
@@ -435,6 +548,7 @@ export class ChatService {
       systemBlock,
       llmName: llm.name,
       llmType: llm.type,
+      llmKind: llm.kind,
       modelOverride: llm.model,
       url: llm.url,
       apiKey,

src/mcpd/src/services/virtual-llm.service.ts

@@ -28,6 +28,7 @@ import { randomUUID } from 'node:crypto';
 import type { ILlmRepository } from '../repositories/llm.repository.js';
 import type { OpenAiChatRequest } from './llm/types.js';
 import { NotFoundError } from './mcp-server.service.js';
+import type { AgentService } from './agent.service.js';
 
 /** A virtual provider's announcement at registration time. */
 export interface RegisterProviderInput {
@@ -119,7 +120,16 @@ export class VirtualLlmService implements IVirtualLlmService {
    */
   private readonly wakeInFlight = new Map<string, Promise<void>>();
 
-  constructor(private readonly repo: ILlmRepository) {}
+  constructor(
+    private readonly repo: ILlmRepository,
+    /**
+     * Optional. v3 wires AgentService here so the lifecycle cascades:
+     * heartbeat → bump owned agents; disconnect → mark agents inactive;
+     * gcSweep → sweep agents first, then delete pinned-to-Llm cascade
+     * before deleting the Llm itself (Agent.llmId is Restrict).
+     */
+    private readonly agents?: AgentService,
+  ) {}
 
   async register(input: { providerSessionId?: string | null; providers: RegisterProviderInput[] }): Promise<RegisterResult> {
     const sessionId = input.providerSessionId ?? randomUUID();
@@ -184,7 +194,6 @@ export class VirtualLlmService implements IVirtualLlmService {
 
   async heartbeat(providerSessionId: string): Promise<void> {
     const owned = await this.repo.findBySessionId(providerSessionId);
-    if (owned.length === 0) return;
     const now = new Date();
     for (const row of owned) {
       // Bump lastHeartbeatAt; if the row was already inactive (e.g. due to a
@@ -196,6 +205,11 @@ export class VirtualLlmService implements IVirtualLlmService {
           : {}),
       });
     }
+    // Cascade to virtual agents owned by the same session — same heartbeat
+    // covers them. No-op if AgentService isn't wired (older test configs).
+    if (this.agents !== undefined) {
+      await this.agents.heartbeatVirtualAgents(providerSessionId);
+    }
   }
 
   bindSession(providerSessionId: string, handle: VirtualSessionHandle): void {
@@ -214,6 +228,10 @@ export class VirtualLlmService implements IVirtualLlmService {
         await this.repo.update(row.id, { status: 'inactive', inactiveSince: now });
       }
     }
+    // Cascade to virtual agents owned by the same session.
+    if (this.agents !== undefined) {
+      await this.agents.markVirtualAgentsInactiveBySession(providerSessionId);
+    }
     // Reject any in-flight tasks for this session — the relay can't deliver
     // a result POST anymore.
     for (const t of this.tasksById.values()) {
@@ -405,6 +423,16 @@ export class VirtualLlmService implements IVirtualLlmService {
     let markedInactive = 0;
     let deleted = 0;
 
+    // v3: sweep virtual agents FIRST so any Llm-pinned agent that's
+    // about to be cascaded (because its Llm is also expiring) is gone
+    // before we attempt to delete the Llm. Agent.llmId is Restrict and
+    // would otherwise block.
+    if (this.agents !== undefined) {
+      const agentSweep = await this.agents.gcSweepVirtualAgents(now);
+      markedInactive += agentSweep.markedInactive;
+      deleted += agentSweep.deleted;
+    }
+
     const heartbeatCutoff = new Date(now.getTime() - HEARTBEAT_TIMEOUT_MS);
     const stale = await this.repo.findStaleVirtuals(heartbeatCutoff);
     for (const row of stale) {
@@ -415,6 +443,13 @@ export class VirtualLlmService implements IVirtualLlmService {
     const deletionCutoff = new Date(now.getTime() - INACTIVE_RETENTION_MS);
     const expired = await this.repo.findExpiredInactives(deletionCutoff);
     for (const row of expired) {
+      // Final defensive cascade: drop any virtual agents still pinned
+      // to this Llm (e.g. their lastHeartbeatAt happens to lag the
+      // Llm's by a few seconds and they didn't make this round's
+      // 4-h cutoff). Without this we'd hit a Restrict FK error.
+      if (this.agents !== undefined) {
+        await this.agents.deleteVirtualAgentsForLlm(row.id);
+      }
       await this.repo.delete(row.id);
       deleted += 1;
     }

src/mcpd/tests/chat-service-virtual-llm.test.ts

@@ -0,0 +1,251 @@
+import { describe, it, expect, vi } from 'vitest';
+import { ChatService, type ChatToolDispatcher } from '../src/services/chat.service.js';
+import type { AgentService } from '../src/services/agent.service.js';
+import type { LlmService } from '../src/services/llm.service.js';
+import type { LlmAdapterRegistry } from '../src/services/llm/dispatcher.js';
+import type { IChatRepository } from '../src/repositories/chat.repository.js';
+import type { IPromptRepository } from '../src/repositories/prompt.repository.js';
+import type { IVirtualLlmService } from '../src/services/virtual-llm.service.js';
+import type { ChatMessage, ChatThread, Prompt } from '@prisma/client';
+
+const NOW = new Date();
+
+/**
+ * Tests targeting v3 Stage 1's chat.service kind=virtual branch.
+ * Mirror the existing chat-service.test.ts patterns but isolate the
+ * adapter-vs-relay dispatch decision.
+ */
+
+function mockChatRepo(): IChatRepository {
+  const msgs: ChatMessage[] = [];
+  const threads: ChatThread[] = [];
+  let idCounter = 1;
+  return {
+    createThread: vi.fn(async ({ agentId, ownerId, title }) => {
+      const t: ChatThread = {
+        id: `thread-${String(idCounter++)}`, agentId, ownerId,
+        title: title ?? '', lastTurnAt: NOW, createdAt: NOW, updatedAt: NOW,
+      };
+      threads.push(t);
+      return t;
+    }),
+    findThread: vi.fn(async (id: string) => threads.find((t) => t.id === id) ?? null),
+    listThreadsByAgent: vi.fn(async () => []),
+    listMessages: vi.fn(async () => []),
+    appendMessage: vi.fn(async (input) => {
+      const m: ChatMessage = {
+        id: `msg-${String(idCounter++)}`,
+        threadId: input.threadId,
+        turnIndex: input.turnIndex ?? msgs.filter((x) => x.threadId === input.threadId).length,
+        role: input.role,
+        content: input.content,
+        toolCalls: (input.toolCalls ?? null) as ChatMessage['toolCalls'],
+        toolCallId: input.toolCallId ?? null,
+        status: input.status ?? 'complete',
+        createdAt: NOW,
+      };
+      msgs.push(m);
+      return m;
+    }),
+    updateStatus: vi.fn(async (_id, _s) => ({ } as ChatMessage)),
+    markPendingAsError: vi.fn(async () => 0),
+    touchThread: vi.fn(async () => undefined),
+    nextTurnIndex: vi.fn(async () => msgs.length),
+  };
+}
+
+function mockAgents(): AgentService {
+  return {
+    getByName: vi.fn(async (name: string) => ({
+      id: `agent-${name}`, name, description: '',
+      systemPrompt: 'You are a helpful agent.',
+      llm: { id: 'llm-1', name: 'vllm-local' },
+      project: null,
+      defaultPersonality: null,
+      proxyModelName: null,
+      defaultParams: {},
+      extras: {},
+      ownerId: 'owner-1', version: 1, createdAt: NOW, updatedAt: NOW,
+    })),
+  } as unknown as AgentService;
+}
+
+function mockLlmsVirtual(): LlmService {
+  return {
+    getByName: vi.fn(async (name: string) => ({
+      id: 'llm-1', name, type: 'openai', model: 'fake',
+      url: '', tier: 'fast', description: '',
+      apiKeyRef: null, extraConfig: {},
+      kind: 'virtual',
+      status: 'active',
+      lastHeartbeatAt: NOW,
+      inactiveSince: null,
+      version: 1, createdAt: NOW, updatedAt: NOW,
+    })),
+    resolveApiKey: vi.fn(async () => ''),
+  } as unknown as LlmService;
+}
+
+function mockPromptRepo(): IPromptRepository {
+  return {
+    findAll: vi.fn(async () => []),
+    findGlobal: vi.fn(async () => []),
+    findByAgent: vi.fn(async () => []),
+    findById: vi.fn(async () => null),
+    findByNameAndProject: vi.fn(async () => null),
+    findByNameAndAgent: vi.fn(async () => null),
+    create: vi.fn(),
+    update: vi.fn(),
+    delete: vi.fn(),
+  };
+}
+
+function mockTools(): ChatToolDispatcher {
+  return { listTools: vi.fn(async () => []), callTool: vi.fn(async () => ({ ok: true })) };
+}
+
+function emptyAdapterRegistry(): LlmAdapterRegistry {
+  return {
+    get: () => { throw new Error('adapter should not be used for kind=virtual'); },
+  } as unknown as LlmAdapterRegistry;
+}
+
+function mockVirtualLlms(opts: {
+  reply?: string;
+  rejectWith?: Error;
+  streamingChunks?: string[];
+}): IVirtualLlmService {
+  const enqueueInferTask = vi.fn(async (_name: string, _body: unknown, streaming: boolean) => {
+    if (opts.rejectWith !== undefined) {
+      return {
+        taskId: 't-1',
+        done: Promise.reject(opts.rejectWith),
+        onChunk: () => () => undefined,
+      };
+    }
+    if (!streaming) {
+      const body = {
+        choices: [{ message: { content: opts.reply ?? 'hi from relay' }, finish_reason: 'stop' }],
+      };
+      return {
+        taskId: 't-1',
+        done: Promise.resolve({ status: 200, body }),
+        onChunk: () => () => undefined,
+      };
+    }
+    // Streaming path: collect subscribers, push the configured chunks
+    // synchronously, then resolve done.
+    const subs = new Set<(c: { data: string; done?: boolean }) => void>();
+    const chunks = opts.streamingChunks ?? ['{"choices":[{"delta":{"content":"hi from relay"}}]}'];
+    return {
+      taskId: 't-1',
+      done: (async (): Promise<{ status: number; body: unknown }> => {
+        // Wait long enough for the caller to register subscribers
+        // before fanning chunks. Promise.resolve() isn't enough — the
+        // microtask running this IIFE is queued ahead of the caller's
+        // await on enqueueInferTask, so subs would still be empty.
+        await new Promise((r) => setTimeout(r, 0));
+        for (const c of chunks) for (const s of subs) s({ data: c });
+        for (const s of subs) s({ data: '[DONE]', done: true });
+        return { status: 200, body: null };
+      })(),
+      onChunk: (cb): (() => void) => { subs.add(cb); return () => subs.delete(cb); },
+    };
+  });
+  return {
+    register: vi.fn(),
+    heartbeat: vi.fn(),
+    bindSession: vi.fn(),
+    unbindSession: vi.fn(),
+    enqueueInferTask: enqueueInferTask as unknown as IVirtualLlmService['enqueueInferTask'],
+    completeTask: vi.fn(),
+    pushTaskChunk: vi.fn(),
+    failTask: vi.fn(),
+    gcSweep: vi.fn(),
+  };
+}
+
+describe('ChatService — kind=virtual branch (v3 Stage 1)', () => {
+  it('non-streaming relays through VirtualLlmService.enqueueInferTask', async () => {
+    const chatRepo = mockChatRepo();
+    const virtual = mockVirtualLlms({ reply: 'hello back from local' });
+    const svc = new ChatService(
+      mockAgents(),
+      mockLlmsVirtual(),
+      emptyAdapterRegistry(),
+      chatRepo,
+      mockPromptRepo(),
+      mockTools(),
+      undefined,
+      virtual,
+    );
+    const result = await svc.chat({ agentName: 'reviewer', userMessage: 'hi', ownerId: 'owner-1' });
+    expect(result.assistant).toBe('hello back from local');
+    expect(virtual.enqueueInferTask).toHaveBeenCalledWith(
+      'vllm-local',
+      expect.objectContaining({ messages: expect.any(Array) }),
+      false,
+    );
+  });
+
+  it('streaming relays through VirtualLlmService and emits the same text deltas', async () => {
+    const chatRepo = mockChatRepo();
+    const virtual = mockVirtualLlms({
+      streamingChunks: [
+        '{"choices":[{"delta":{"content":"hello "}}]}',
+        '{"choices":[{"delta":{"content":"world"}}]}',
+      ],
+    });
+    const svc = new ChatService(
+      mockAgents(),
+      mockLlmsVirtual(),
+      emptyAdapterRegistry(),
+      chatRepo,
+      mockPromptRepo(),
+      mockTools(),
+      undefined,
+      virtual,
+    );
+    const deltas: string[] = [];
+    for await (const evt of svc.chatStream({ agentName: 'reviewer', userMessage: 'hi', ownerId: 'owner-1' })) {
+      if (evt.type === 'text') deltas.push(evt.delta);
+      if (evt.type === 'final') break;
+    }
+    expect(deltas.join('')).toBe('hello world');
+    expect(virtual.enqueueInferTask).toHaveBeenCalledWith(
+      'vllm-local',
+      expect.objectContaining({ messages: expect.any(Array), stream: true }),
+      true,
+    );
+  });
+
+  it('non-streaming throws a clear error when virtualLlms isn\'t wired but the row is virtual', async () => {
+    const svc = new ChatService(
+      mockAgents(),
+      mockLlmsVirtual(),
+      emptyAdapterRegistry(),
+      mockChatRepo(),
+      mockPromptRepo(),
+      mockTools(),
+      // no personalities, no virtualLlms
+    );
+    await expect(svc.chat({ agentName: 'reviewer', userMessage: 'hi', ownerId: 'owner-1' }))
+      .rejects.toThrow(/virtualLlms dispatcher not wired/);
+  });
+
+  it('non-streaming surfaces the relay\'s rejection (e.g. publisher offline) up to the caller', async () => {
+    const virtual = mockVirtualLlms({ rejectWith: Object.assign(new Error('publisher offline'), { statusCode: 503 }) });
+    const svc = new ChatService(
+      mockAgents(),
+      mockLlmsVirtual(),
+      emptyAdapterRegistry(),
+      mockChatRepo(),
+      mockPromptRepo(),
+      mockTools(),
+      undefined,
+      virtual,
+    );
+    await expect(svc.chat({ agentName: 'reviewer', userMessage: 'hi', ownerId: 'owner-1' }))
+      .rejects.toThrow(/publisher offline/);
+  });
+});

src/mcpd/tests/chat-service.test.ts

@@ -118,12 +118,16 @@ function mockAgents(opts: { defaultPersonality?: { id: string; name: string } |
   } as unknown as AgentService;
 }
 
-function mockLlms(): LlmService {
+function mockLlms(opts: { kind?: 'public' | 'virtual' } = {}): LlmService {
   return {
     getByName: vi.fn(async (name: string) => ({
       id: 'llm-1', name, type: 'openai', model: 'qwen3-thinking',
       url: '', tier: 'fast', description: '',
       apiKeyRef: null, extraConfig: {},
+      kind: opts.kind ?? 'public',
+      status: 'active',
+      lastHeartbeatAt: null,
+      inactiveSince: null,
       version: 1, createdAt: NOW, updatedAt: NOW,
     })),
     resolveApiKey: vi.fn(async () => 'fake-key'),

src/mcpd/tests/virtual-agent-service.test.ts

@@ -0,0 +1,376 @@
+import { describe, it, expect, vi } from 'vitest';
+import { AgentService, type VirtualAgentInput } from '../src/services/agent.service.js';
+import { VirtualLlmService } from '../src/services/virtual-llm.service.js';
+import type { IAgentRepository } from '../src/repositories/agent.repository.js';
+import type { ILlmRepository } from '../src/repositories/llm.repository.js';
+import type { LlmService } from '../src/services/llm.service.js';
+import type { ProjectService } from '../src/services/project.service.js';
+import type { Agent, Llm } from '@prisma/client';
+
+/**
+ * v3 Stage 2 — virtual-agent lifecycle methods on AgentService and the
+ * cascade callbacks wired into VirtualLlmService.gcSweep / heartbeat /
+ * unbindSession. Mirrors the shape of virtual-llm-service.test.ts but
+ * focused on the agent-side state machine + the Llm→Agent cascade.
+ */
+
+const NOW = new Date();
+
+function makeAgent(overrides: Partial<Agent> = {}): Agent {
+  return {
+    id: `agent-${Math.random().toString(36).slice(2, 8)}`,
+    name: 'fake-agent',
+    description: '',
+    systemPrompt: '',
+    llmId: 'llm-1',
+    projectId: null,
+    defaultPersonalityId: null,
+    proxyModelName: null,
+    defaultParams: {} as Agent['defaultParams'],
+    extras: {} as Agent['extras'],
+    kind: 'virtual',
+    providerSessionId: 'sess-1',
+    lastHeartbeatAt: NOW,
+    status: 'active',
+    inactiveSince: null,
+    ownerId: 'owner-1',
+    version: 1,
+    createdAt: NOW,
+    updatedAt: NOW,
+    ...overrides,
+  };
+}
+
+function makeLlm(overrides: Partial<Llm> = {}): Llm {
+  return {
+    id: `llm-${Math.random().toString(36).slice(2, 8)}`,
+    name: 'vllm-local',
+    type: 'openai',
+    model: 'm',
+    url: '',
+    tier: 'fast',
+    description: '',
+    apiKeySecretId: null,
+    apiKeySecretKey: null,
+    extraConfig: {} as Llm['extraConfig'],
+    kind: 'virtual',
+    providerSessionId: 'sess-1',
+    lastHeartbeatAt: NOW,
+    status: 'active',
+    inactiveSince: null,
+    version: 1,
+    createdAt: NOW,
+    updatedAt: NOW,
+    ...overrides,
+  };
+}
+
+function mockAgentRepo(initial: Agent[] = []): IAgentRepository {
+  const rows = new Map<string, Agent>(initial.map((r) => [r.id, r]));
+  let counter = rows.size;
+  return {
+    findAll: vi.fn(async () => [...rows.values()]),
+    findById: vi.fn(async (id: string) => rows.get(id) ?? null),
+    findByName: vi.fn(async (name: string) => {
+      for (const r of rows.values()) if (r.name === name) return r;
+      return null;
+    }),
+    findByProjectId: vi.fn(async () => []),
+    findBySessionId: vi.fn(async (sid: string) =>
+      [...rows.values()].filter((r) => r.providerSessionId === sid)),
+    findByLlmId: vi.fn(async (llmId: string) =>
+      [...rows.values()].filter((r) => r.llmId === llmId)),
+    findStaleVirtuals: vi.fn(async (cutoff: Date) =>
+      [...rows.values()].filter((r) =>
+        r.kind === 'virtual'
+        && r.status === 'active'
+        && r.lastHeartbeatAt !== null
+        && r.lastHeartbeatAt < cutoff)),
+    findExpiredInactives: vi.fn(async (cutoff: Date) =>
+      [...rows.values()].filter((r) =>
+        r.kind === 'virtual'
+        && r.status === 'inactive'
+        && r.inactiveSince !== null
+        && r.inactiveSince < cutoff)),
+    create: vi.fn(async (data) => {
+      counter += 1;
+      const row = makeAgent({
+        id: `agent-${String(counter)}`,
+        name: data.name,
+        description: data.description ?? '',
+        systemPrompt: data.systemPrompt ?? '',
+        llmId: data.llmId,
+        projectId: data.projectId ?? null,
+        kind: data.kind ?? 'public',
+        providerSessionId: data.providerSessionId ?? null,
+        status: data.status ?? 'active',
+        lastHeartbeatAt: data.lastHeartbeatAt ?? null,
+        inactiveSince: data.inactiveSince ?? null,
+        ownerId: data.ownerId,
+      });
+      rows.set(row.id, row);
+      return row;
+    }),
+    update: vi.fn(async (id, data) => {
+      const existing = rows.get(id);
+      if (!existing) throw new Error('not found');
+      const next: Agent = {
+        ...existing,
+        ...(data.description !== undefined ? { description: data.description } : {}),
+        ...(data.systemPrompt !== undefined ? { systemPrompt: data.systemPrompt } : {}),
+        ...(data.llmId !== undefined ? { llmId: data.llmId } : {}),
+        ...(data.projectId !== undefined ? { projectId: data.projectId } : {}),
+        ...(data.kind !== undefined ? { kind: data.kind } : {}),
+        ...(data.providerSessionId !== undefined ? { providerSessionId: data.providerSessionId } : {}),
+        ...(data.status !== undefined ? { status: data.status } : {}),
+        ...(data.lastHeartbeatAt !== undefined ? { lastHeartbeatAt: data.lastHeartbeatAt } : {}),
+        ...(data.inactiveSince !== undefined ? { inactiveSince: data.inactiveSince } : {}),
+      };
+      rows.set(id, next);
+      return next;
+    }),
+    delete: vi.fn(async (id: string) => { rows.delete(id); }),
+  };
+}
+
+function mockLlms(): LlmService {
+  return {
+    getById: vi.fn(async (id: string) => ({ id, name: 'vllm-local', type: 'openai', model: 'm', kind: 'virtual', status: 'active' })),
+    getByName: vi.fn(async (name: string) => ({ id: 'llm-1', name, type: 'openai', model: 'm', kind: 'virtual', status: 'active' })),
+  } as unknown as LlmService;
+}
+
+function mockProjects(): ProjectService {
+  return {
+    getById: vi.fn(async (id: string) => ({ id, name: 'mcpctl-dev' })),
+    resolveAndGet: vi.fn(async (idOrName: string) => ({
+      id: idOrName === 'mcpctl-dev' ? 'proj-1' : 'proj-other',
+      name: idOrName,
+    })),
+  } as unknown as ProjectService;
+}
+
+describe('AgentService — virtual-agent lifecycle (v3 Stage 2)', () => {
+  it('registerVirtualAgents inserts new rows with kind=virtual / status=active', async () => {
+    const repo = mockAgentRepo();
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    const inputs: VirtualAgentInput[] = [
+      { name: 'local-coder', llmName: 'vllm-local', description: 'd', systemPrompt: 's' },
+    ];
+    const out = await svc.registerVirtualAgents('sess-1', inputs, 'owner-1');
+    expect(out).toHaveLength(1);
+    expect(out[0]!.kind).toBe('virtual');
+    expect(out[0]!.status).toBe('active');
+  });
+
+  it('registerVirtualAgents reuses an existing row from the same session (sticky reconnect)', async () => {
+    const existing = makeAgent({ name: 'local-coder', providerSessionId: 'sess-1', status: 'inactive', inactiveSince: NOW });
+    const repo = mockAgentRepo([existing]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    const out = await svc.registerVirtualAgents(
+      'sess-1',
+      [{ name: 'local-coder', llmName: 'vllm-local' }],
+      'owner-1',
+    );
+    expect(out[0]!.id).toBe(existing.id);
+    expect(out[0]!.status).toBe('active');
+  });
+
+  it('registerVirtualAgents adopts an inactive virtual from a different session', async () => {
+    const existing = makeAgent({
+      name: 'local-coder', providerSessionId: 'old-session',
+      status: 'inactive', inactiveSince: NOW,
+    });
+    const repo = mockAgentRepo([existing]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    const out = await svc.registerVirtualAgents(
+      'new-session',
+      [{ name: 'local-coder', llmName: 'vllm-local' }],
+      'owner-1',
+    );
+    expect(out[0]!.id).toBe(existing.id);
+    expect(out[0]!.status).toBe('active');
+  });
+
+  it('registerVirtualAgents refuses to overwrite a public agent (409)', async () => {
+    const repo = mockAgentRepo([makeAgent({ name: 'reviewer', kind: 'public', providerSessionId: null })]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    await expect(svc.registerVirtualAgents(
+      'sess-x',
+      [{ name: 'reviewer', llmName: 'vllm-local' }],
+      'owner-1',
+    )).rejects.toThrow(/Cannot publish over public Agent/);
+  });
+
+  it('registerVirtualAgents refuses if another active session owns the name', async () => {
+    const repo = mockAgentRepo([makeAgent({ name: 'local-coder', providerSessionId: 'other', status: 'active' })]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    await expect(svc.registerVirtualAgents(
+      'mine',
+      [{ name: 'local-coder', llmName: 'vllm-local' }],
+      'owner-1',
+    )).rejects.toThrow(/already active under a different session/);
+  });
+
+  it('heartbeatVirtualAgents bumps + revives inactive', async () => {
+    const past = new Date(Date.now() - 5_000);
+    const a = makeAgent({ name: 'a', providerSessionId: 'sess', status: 'inactive', lastHeartbeatAt: past, inactiveSince: past });
+    const repo = mockAgentRepo([a]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    await svc.heartbeatVirtualAgents('sess');
+    const row = await repo.findByName('a');
+    expect(row?.status).toBe('active');
+    expect(row?.inactiveSince).toBeNull();
+    expect(row!.lastHeartbeatAt!.getTime()).toBeGreaterThan(past.getTime());
+  });
+
+  it('markVirtualAgentsInactiveBySession flips owned actives to inactive', async () => {
+    const repo = mockAgentRepo([
+      makeAgent({ name: 'a', providerSessionId: 'sess' }),
+      makeAgent({ name: 'b', providerSessionId: 'sess' }),
+      makeAgent({ name: 'c', providerSessionId: 'other' }),
+    ]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    await svc.markVirtualAgentsInactiveBySession('sess');
+    expect((await repo.findByName('a'))?.status).toBe('inactive');
+    expect((await repo.findByName('b'))?.status).toBe('inactive');
+    expect((await repo.findByName('c'))?.status).toBe('active');
+  });
+
+  it('deleteVirtualAgentsForLlm deletes only virtuals pinned to that Llm', async () => {
+    const repo = mockAgentRepo([
+      makeAgent({ name: 'v-1', llmId: 'doomed', kind: 'virtual' }),
+      makeAgent({ name: 'v-2', llmId: 'doomed', kind: 'virtual' }),
+      makeAgent({ name: 'pub-1', llmId: 'doomed', kind: 'public', providerSessionId: null }),
+      makeAgent({ name: 'v-other', llmId: 'safe', kind: 'virtual' }),
+    ]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    const deleted = await svc.deleteVirtualAgentsForLlm('doomed');
+    expect(deleted).toBe(2);
+    expect(await repo.findByName('v-1')).toBeNull();
+    expect(await repo.findByName('v-2')).toBeNull();
+    expect(await repo.findByName('pub-1')).not.toBeNull();
+    expect(await repo.findByName('v-other')).not.toBeNull();
+  });
+
+  it('gcSweepVirtualAgents flips heartbeat-stale + deletes 4h-old inactive', async () => {
+    const long = new Date(Date.now() - 5 * 60 * 1000);    // 5 min ago, past 90s cutoff
+    const ancient = new Date(Date.now() - 5 * 60 * 60 * 1000); // 5 h ago, past 4h cutoff
+    const repo = mockAgentRepo([
+      makeAgent({ name: 'stale', providerSessionId: 'a', status: 'active', lastHeartbeatAt: long }),
+      makeAgent({ name: 'old', providerSessionId: 'b', status: 'inactive', inactiveSince: ancient }),
+      makeAgent({ name: 'pub', providerSessionId: null, kind: 'public' }),
+    ]);
+    const svc = new AgentService(repo, mockLlms(), mockProjects());
+    const r = await svc.gcSweepVirtualAgents();
+    expect(r.markedInactive).toBe(1);
+    expect(r.deleted).toBe(1);
+    expect((await repo.findByName('stale'))?.status).toBe('inactive');
+    expect(await repo.findByName('old')).toBeNull();
+    expect(await repo.findByName('pub')).not.toBeNull();
+  });
+});
+
+describe('VirtualLlmService cascade through AgentService (v3 Stage 2)', () => {
+  function mockLlmRepo(initial: Llm[] = []): ILlmRepository {
+    const rows = new Map<string, Llm>(initial.map((r) => [r.id, r]));
+    let counter = rows.size;
+    return {
+      findAll: vi.fn(async () => [...rows.values()]),
+      findById: vi.fn(async (id: string) => rows.get(id) ?? null),
+      findByName: vi.fn(async (name: string) => {
+        for (const r of rows.values()) if (r.name === name) return r;
+        return null;
+      }),
+      findByTier: vi.fn(async () => []),
+      findBySessionId: vi.fn(async (sid: string) =>
+        [...rows.values()].filter((r) => r.providerSessionId === sid)),
+      findStaleVirtuals: vi.fn(async (cutoff: Date) =>
+        [...rows.values()].filter((r) =>
+          r.kind === 'virtual'
+          && r.status === 'active'
+          && r.lastHeartbeatAt !== null
+          && r.lastHeartbeatAt < cutoff)),
+      findExpiredInactives: vi.fn(async (cutoff: Date) =>
+        [...rows.values()].filter((r) =>
+          r.kind === 'virtual'
+          && r.status === 'inactive'
+          && r.inactiveSince !== null
+          && r.inactiveSince < cutoff)),
+      create: vi.fn(async (data) => {
+        counter += 1;
+        const row = makeLlm({ id: `llm-${String(counter)}`, name: data.name, type: data.type });
+        rows.set(row.id, row);
+        return row;
+      }),
+      update: vi.fn(async (id, data) => {
+        const existing = rows.get(id);
+        if (!existing) throw new Error('not found');
+        const next: Llm = { ...existing, ...data } as Llm;
+        rows.set(id, next);
+        return next;
+      }),
+      delete: vi.fn(async (id: string) => { rows.delete(id); }),
+    };
+  }
+
+  it('unbindSession cascades to mark virtual agents inactive', async () => {
+    const llmRepo = mockLlmRepo([makeLlm({ name: 'vllm-local', providerSessionId: 'sess' })]);
+    const agentRepo = mockAgentRepo([
+      makeAgent({ name: 'local-coder', providerSessionId: 'sess' }),
+    ]);
+    const agents = new AgentService(agentRepo, mockLlms(), mockProjects());
+    const svc = new VirtualLlmService(llmRepo, agents);
+    await svc.unbindSession('sess');
+    expect((await agentRepo.findByName('local-coder'))?.status).toBe('inactive');
+  });
+
+  it('gcSweep deletes virtual agents BEFORE their pinned virtual Llm', async () => {
+    const ancient = new Date(Date.now() - 5 * 60 * 60 * 1000);
+    const llmRepo = mockLlmRepo([makeLlm({
+      id: 'doomed-llm', name: 'vllm-local', providerSessionId: 'sess',
+      status: 'inactive', inactiveSince: ancient,
+    })]);
+    const agentRepo = mockAgentRepo([
+      makeAgent({ name: 'pinned', providerSessionId: 'sess', llmId: 'doomed-llm', status: 'inactive', inactiveSince: ancient }),
+    ]);
+    const agents = new AgentService(agentRepo, mockLlms(), mockProjects());
+    const svc = new VirtualLlmService(llmRepo, agents);
+    const r = await svc.gcSweep();
+    expect(r.deleted).toBeGreaterThanOrEqual(2); // 1 agent + 1 llm
+    expect(await llmRepo.findByName('vllm-local')).toBeNull();
+    expect(await agentRepo.findByName('pinned')).toBeNull();
+  });
+
+  it('gcSweep defensive cascade: still drops the agent when its heartbeat lagged the Llm', async () => {
+    // The Llm is past the 4h cutoff. The agent is inactive but only
+    // 1h old — wouldn't be GC'd by gcSweepVirtualAgents on its own.
+    // The defensive cascade in gcSweep deletes it anyway because the
+    // Restrict FK would otherwise block the Llm delete.
+    const ancient = new Date(Date.now() - 5 * 60 * 60 * 1000);
+    const recent = new Date(Date.now() - 1 * 60 * 60 * 1000);
+    const llmRepo = mockLlmRepo([makeLlm({
+      id: 'doomed-llm', name: 'vllm-local', providerSessionId: 'sess',
+      status: 'inactive', inactiveSince: ancient,
+    })]);
+    const agentRepo = mockAgentRepo([
+      makeAgent({ name: 'pinned', providerSessionId: 'sess', llmId: 'doomed-llm', status: 'inactive', inactiveSince: recent }),
+    ]);
+    const agents = new AgentService(agentRepo, mockLlms(), mockProjects());
+    const svc = new VirtualLlmService(llmRepo, agents);
+    await svc.gcSweep();
+    expect(await llmRepo.findByName('vllm-local')).toBeNull();
+    expect(await agentRepo.findByName('pinned')).toBeNull();
+  });
+
+  it('heartbeat cascades to bump owned virtual agents', async () => {
+    const past = new Date(Date.now() - 10_000);
+    const llmRepo = mockLlmRepo([makeLlm({ name: 'vllm-local', providerSessionId: 'sess', lastHeartbeatAt: past })]);
+    const agentRepo = mockAgentRepo([makeAgent({ name: 'local-coder', providerSessionId: 'sess', lastHeartbeatAt: past })]);
+    const agents = new AgentService(agentRepo, mockLlms(), mockProjects());
+    const svc = new VirtualLlmService(llmRepo, agents);
+    await svc.heartbeat('sess');
+    const a = await agentRepo.findByName('local-coder');
+    expect(a!.lastHeartbeatAt!.getTime()).toBeGreaterThan(past.getTime());
+  });
+});