LibreChat/api/server/services/Endpoints/agents/initialize.spec.js

const mongoose = require('mongoose');
const {
  ResourceType,
  PermissionBits,
  PrincipalType,
  PrincipalModel,
  MAX_SUBAGENT_DEPTH,
  MAX_SUBAGENT_GRAPH_NODES,
  MAX_SUBAGENT_RUN_CONFIGS,
  Constants,
  ErrorTypes,
} = require('librechat-data-provider');
const { MongoMemoryServer } = require('mongodb-memory-server');

const mockInitializeAgent = jest.fn();
const mockValidateAgentModel = jest.fn();

function deferred() {
  let resolve;
  const promise = new Promise((resolvePromise) => {
    resolve = resolvePromise;
  });
  return { promise, resolve };
}

jest.mock('@librechat/agents', () => ({
  ...jest.requireActual('@librechat/agents'),
  createContentAggregator: jest.fn(() => ({
    contentParts: [],
    aggregateContent: jest.fn(),
  })),
}));

jest.mock('@librechat/api', () => ({
  ...jest.requireActual('@librechat/api'),
  initializeAgent: (...args) => mockInitializeAgent(...args),
  validateAgentModel: (...args) => mockValidateAgentModel(...args),
  GenerationJobManager: { setCollectedUsage: jest.fn() },
  getCustomEndpointConfig: jest.fn(),
  createSequentialChainEdges: jest.fn(),
}));

/** Captured by the `getDefaultHandlers` mock so tests can drive the
 *  `ON_TOOL_EXECUTE` pipeline with a real subagent id and observe whether
 *  the tool context (agent, tool_resources, skill ACLs) was preserved. */
let capturedToolExecuteOptions;
let capturedDefaultHandlerOptions;
const mockArtifactToolEndCallback = jest.fn();
jest.mock('~/server/controllers/agents/callbacks', () => ({
  createToolEndCallback: jest.fn(() => mockArtifactToolEndCallback),
  createAttachmentEmitter: jest.fn(() => jest.fn()),
  createBackgroundCodeResultHandler: jest.fn(() => jest.fn()),
  getDefaultHandlers: jest.fn((opts) => {
    capturedDefaultHandlerOptions = opts;
    capturedToolExecuteOptions = opts?.toolExecuteOptions;
    return {};
  }),
}));

const mockLoadToolsForExecution = jest.fn();
jest.mock('~/server/services/ToolService', () => ({
  loadAgentTools: jest.fn(),
  loadToolsForExecution: (...args) => mockLoadToolsForExecution(...args),
  isFatalAgentInitializationError: (error) =>
    [
      'AGENT_EXPECTED_MCP_TOOLS_UNAVAILABLE',
      'resource_recovery_required',
      'stateful_code_environment_not_allowed',
    ].includes(error?.code),
}));

jest.mock('~/server/controllers/ModelController', () => ({
  getModelsConfig: jest.fn().mockResolvedValue({}),
}));

let agentClientArgs;
jest.mock('~/server/controllers/agents/client', () => {
  return jest.fn().mockImplementation((args) => {
    agentClientArgs = args;
    return {};
  });
});

jest.mock('./addedConvo', () => ({
  processAddedConvo: jest.fn().mockResolvedValue({ userMCPAuthMap: undefined }),
}));

jest.mock('~/cache', () => ({
  logViolation: jest.fn(),
}));

const { initializeClient } = require('./initialize');
const { getSkillDbMethods, getSkillToolDeps } = require('./skillDeps');
const { loadAgentTools } = require('~/server/services/ToolService');
const { getModelsConfig } = require('~/server/controllers/ModelController');
const { logger } = require('@librechat/data-schemas');
const { User, AclEntry } = require('~/db/models');
const { createAgent, createSkill, updateAgent } = require('~/models');
const db = require('~/models');

jest.spyOn(logger, 'warn').mockImplementation(() => {});

const PRIMARY_ID = 'agent_primary';
const TARGET_ID = 'agent_target';
const AUTHORIZED_ID = 'agent_authorized';

describe('initializeClient — processAgent ACL gate', () => {
  let mongoServer;
  let testUser;

  beforeAll(async () => {
    mongoServer = await MongoMemoryServer.create();
    await mongoose.connect(mongoServer.getUri());
  });

  afterAll(async () => {
    await mongoose.disconnect();
    await mongoServer.stop();
  });

  beforeEach(async () => {
    await mongoose.connection.dropDatabase();
    jest.clearAllMocks();
    agentClientArgs = undefined;
    capturedDefaultHandlerOptions = undefined;

    testUser = await User.create({
      email: 'test@example.com',
      name: 'Test User',
      username: 'testuser',
      role: 'USER',
    });

    mockValidateAgentModel.mockResolvedValue({ isValid: true });
  });

  const makeReq = () => ({
    user: { id: testUser._id.toString(), role: 'USER' },
    body: { conversationId: 'conv_1', files: [] },
    config: { endpoints: {} },
    _resumableStreamId: null,
  });

  const makeEndpointOption = () => ({
    agent: Promise.resolve({
      id: PRIMARY_ID,
      name: 'Primary',
      provider: 'openai',
      model: 'gpt-4',
      tools: [],
    }),
    model_parameters: { model: 'gpt-4' },
    endpoint: 'agents',
  });

  const makePrimaryConfig = (edges) => ({
    id: PRIMARY_ID,
    endpoint: 'agents',
    edges,
    toolDefinitions: [],
    toolRegistry: new Map(),
    userMCPAuthMap: null,
    tool_resources: {},
    resendFiles: true,
    maxContextTokens: 4096,
    codeExecutionContext: {
      baseUrl: 'https://code-default.example.com',
      codeSessionKey: 'execute_code',
      executionProfile: 'default',
      statefulSessions: false,
    },
  });

  it('replaces untrusted artifact route metadata with the executing agent context', async () => {
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));

    await initializeClient({
      req: makeReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    const data = { output: { name: 'execute_code', artifact: { files: [] } } };
    await capturedDefaultHandlerOptions.toolEndCallback(data, {
      langgraph_node: `tools=${PRIMARY_ID}`,
      codeExecutionContext: {
        baseUrl: 'https://attacker.invalid',
        executionProfile: 'stateful',
      },
    });

    expect(mockArtifactToolEndCallback).toHaveBeenLastCalledWith(
      data,
      expect.objectContaining({
        codeExecutionContext: expect.objectContaining({
          baseUrl: 'https://code-default.example.com',
          executionProfile: 'default',
        }),
      }),
    );
  });

  it('threads the owning job epoch into resumable event handlers', async () => {
    const {
      createAttachmentEmitter,
      createToolEndCallback,
    } = require('~/server/controllers/agents/callbacks');
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));
    const req = makeReq();
    req._resumableStreamId = 'conv_1';

    await initializeClient({
      req,
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
      jobCreatedAt: 1234,
    });

    expect(capturedDefaultHandlerOptions).toEqual(
      expect.objectContaining({
        streamId: 'conv_1',
        jobCreatedAt: 1234,
      }),
    );
    expect(createToolEndCallback).toHaveBeenCalledWith(
      expect.objectContaining({
        streamId: 'conv_1',
        jobCreatedAt: 1234,
      }),
    );
    expect(createAttachmentEmitter).toHaveBeenCalledWith({
      res: {},
      streamId: 'conv_1',
      jobCreatedAt: 1234,
    });

    mockLoadToolsForExecution.mockResolvedValue({ loadedTools: [], configurable: {} });
    await capturedToolExecuteOptions.loadTools([], PRIMARY_ID);
    expect(mockLoadToolsForExecution).toHaveBeenCalledWith(
      expect.objectContaining({
        streamId: 'conv_1',
        jobCreatedAt: 1234,
      }),
    );
  });

  it('propagates an expected-MCP-tools failure from the runtime tool loader', async () => {
    const toolError = Object.assign(new Error('Expected MCP tools are unavailable'), {
      code: 'AGENT_EXPECTED_MCP_TOOLS_UNAVAILABLE',
      statusCode: 503,
    });
    loadAgentTools.mockRejectedValueOnce(toolError);
    mockInitializeAgent.mockImplementationOnce(async ({ req, res, loadTools, agent }) => {
      await loadTools({
        req,
        res,
        tools: ['run_query_mcp_warehouse'],
        model: agent.model,
        agentId: agent.id,
        provider: agent.provider,
      });
      return makePrimaryConfig([]);
    });

    await expect(
      initializeClient({
        req: makeReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toBe(toolError);
  });

  it('aborts the run when a handoff target resolves none of its expected MCP tools', async () => {
    const target = await createAgent({
      id: AUTHORIZED_ID,
      name: 'Target Agent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['run_query_mcp_warehouse'],
    });
    await AclEntry.create({
      principalType: PrincipalType.USER,
      principalId: testUser._id,
      principalModel: PrincipalModel.USER,
      resourceType: ResourceType.AGENT,
      resourceId: target._id,
      permBits: PermissionBits.VIEW,
      grantedBy: testUser._id,
    });

    const toolError = Object.assign(new Error('Target Agent expected MCP tools are unavailable'), {
      code: 'AGENT_EXPECTED_MCP_TOOLS_UNAVAILABLE',
      statusCode: 503,
    });
    loadAgentTools.mockRejectedValueOnce(toolError);
    mockInitializeAgent
      .mockResolvedValueOnce(
        makePrimaryConfig([{ from: PRIMARY_ID, to: AUTHORIZED_ID, edgeType: 'handoff' }]),
      )
      .mockImplementationOnce(async ({ req, res, loadTools, agent }) => {
        await loadTools({
          req,
          res,
          tools: agent.tools,
          model: agent.model,
          agentId: agent.id,
          provider: agent.provider,
        });
      });

    await expect(
      initializeClient({
        req: makeReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toBe(toolError);
  });

  it('should skip handoff agent and filter its edge when user lacks VIEW access', async () => {
    await createAgent({
      id: TARGET_ID,
      name: 'Target Agent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });

    const edges = [{ from: PRIMARY_ID, to: TARGET_ID, edgeType: 'handoff' }];
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig(edges));

    await initializeClient({
      req: makeReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    expect(agentClientArgs.agent.edges).toEqual([]);
  });

  it('should initialize handoff agent and keep its edge when user has VIEW access', async () => {
    const authorizedAgent = await createAgent({
      id: AUTHORIZED_ID,
      name: 'Authorized Agent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });

    await AclEntry.create({
      principalType: PrincipalType.USER,
      principalId: testUser._id,
      principalModel: PrincipalModel.USER,
      resourceType: ResourceType.AGENT,
      resourceId: authorizedAgent._id,
      permBits: PermissionBits.VIEW,
      grantedBy: testUser._id,
    });

    const edges = [{ from: PRIMARY_ID, to: AUTHORIZED_ID, edgeType: 'handoff' }];
    const requestAttachment = { file_id: 'request_file', filename: 'request.txt' };
    const primaryContextAttachment = { file_id: 'primary_context', filename: 'primary.txt' };
    const handoffContextAttachment = { file_id: 'handoff_context', filename: 'handoff.txt' };
    const primaryConfig = {
      ...makePrimaryConfig(edges),
      attachments: [primaryContextAttachment, requestAttachment],
      requestAttachments: [requestAttachment],
      agentContextAttachments: [primaryContextAttachment],
    };
    const handoffConfig = {
      id: AUTHORIZED_ID,
      edges: [],
      toolDefinitions: [],
      toolRegistry: new Map(),
      userMCPAuthMap: null,
      tool_resources: {},
      agentContextAttachments: [handoffContextAttachment],
    };

    let callCount = 0;
    mockInitializeAgent.mockImplementation(() => {
      callCount++;
      return callCount === 1 ? Promise.resolve(primaryConfig) : Promise.resolve(handoffConfig);
    });

    await initializeClient({
      req: makeReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(mockInitializeAgent).toHaveBeenCalledTimes(2);
    expect(agentClientArgs.agent.edges).toHaveLength(1);
    expect(agentClientArgs.agent.edges[0].to).toBe(AUTHORIZED_ID);
    expect(agentClientArgs.attachments).toEqual([requestAttachment]);
    expect(agentClientArgs.agentContextAttachmentsByAgentId.get(PRIMARY_ID)).toEqual([
      primaryContextAttachment,
    ]);
    expect(agentClientArgs.agentContextAttachmentsByAgentId.get(AUTHORIZED_ID)).toEqual([
      handoffContextAttachment,
    ]);
  });

  it('does not enable skill authoring for VIEW-only shared skills', async () => {
    const { skill } = await createSkill({
      name: 'shared-view-only',
      description: 'Use for read-only sharing.',
      body: '# Shared view-only skill\n',
      author: new mongoose.Types.ObjectId(),
      authorName: 'Skill Owner',
    });
    await AclEntry.create({
      principalType: PrincipalType.USER,
      principalId: testUser._id,
      principalModel: PrincipalModel.USER,
      resourceType: ResourceType.SKILL,
      resourceId: skill._id,
      permBits: PermissionBits.VIEW,
      grantedBy: testUser._id,
    });

    const endpointOption = makeEndpointOption();
    endpointOption.agent = Promise.resolve({
      id: PRIMARY_ID,
      name: 'Primary',
      provider: 'openai',
      model: 'gpt-4',
      tools: [],
      skills_enabled: true,
    });
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));
    const req = makeReq();
    req.config.endpoints.agents = { capabilities: ['skills'] };
    const canCreateSkillSpy = jest
      .spyOn(getSkillToolDeps(), 'canCreateSkill')
      .mockResolvedValue(false);

    try {
      await initializeClient({
        req,
        res: {},
        signal: new AbortController().signal,
        endpointOption,
      });
    } finally {
      canCreateSkillSpy.mockRestore();
    }

    const initializeParams = mockInitializeAgent.mock.calls[0][0];
    expect(initializeParams.accessibleSkillIds.map(String)).toContain(skill._id.toString());
    expect(initializeParams.skillAuthoringAvailable).toBe(false);
  });

  it('enables skill authoring when model specs enable skills for an ephemeral agent', async () => {
    const endpointOption = makeEndpointOption();
    endpointOption.spec = 'spec-skills';
    endpointOption.agent = Promise.resolve({
      id: Constants.EPHEMERAL_AGENT_ID,
      name: 'Ephemeral Primary',
      provider: 'openai',
      model: 'gpt-4',
      tools: [],
    });
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));
    const req = makeReq();
    req.config.endpoints.agents = { capabilities: ['skills'] };
    req.config.modelSpecs = {
      list: [{ name: 'spec-skills', skills: true }],
    };
    const canCreateSkillSpy = jest
      .spyOn(getSkillToolDeps(), 'canCreateSkill')
      .mockResolvedValue(true);

    try {
      await initializeClient({
        req,
        res: {},
        signal: new AbortController().signal,
        endpointOption,
      });
    } finally {
      canCreateSkillSpy.mockRestore();
    }

    const initializeParams = mockInitializeAgent.mock.calls[0][0];
    expect(initializeParams.agent.skills_enabled).toBe(true);
    expect(initializeParams.skillAuthoringAvailable).toBe(true);
  });

  it('loads model validation and skill permissions without serial waits', async () => {
    const models = deferred();
    const createPermission = deferred();
    const req = makeReq();
    req.config.endpoints.agents = { capabilities: ['skills'] };
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));
    getModelsConfig.mockReturnValueOnce(models.promise);
    const canCreateSkillSpy = jest
      .spyOn(getSkillToolDeps(), 'canCreateSkill')
      .mockReturnValue(createPermission.promise);

    try {
      const initialization = initializeClient({
        req,
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      });

      expect(getModelsConfig).toHaveBeenCalledWith(req);
      expect(canCreateSkillSpy).toHaveBeenCalledWith({ req });

      models.resolve({});
      await new Promise((resolve) => setImmediate(resolve));
      expect(mockValidateAgentModel).toHaveBeenCalledTimes(1);
      expect(mockInitializeAgent).not.toHaveBeenCalled();

      createPermission.resolve(false);
      await initialization;
      expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    } finally {
      canCreateSkillSpy.mockRestore();
    }
  });

  it('resolves model-spec skill names through deployment-aware skill methods', async () => {
    const deploymentSkillId = new mongoose.Types.ObjectId();
    await AclEntry.create({
      principalType: PrincipalType.USER,
      principalId: testUser._id,
      principalModel: PrincipalModel.USER,
      resourceType: ResourceType.SKILL,
      resourceId: new mongoose.Types.ObjectId(),
      permBits: PermissionBits.VIEW,
      grantedBy: testUser._id,
    });
    const endpointOption = makeEndpointOption();
    endpointOption.spec = 'spec-deployment-skill';
    endpointOption.agent = Promise.resolve({
      id: Constants.EPHEMERAL_AGENT_ID,
      name: 'Ephemeral Primary',
      provider: 'openai',
      model: 'gpt-4',
      tools: [],
    });
    mockInitializeAgent.mockResolvedValue(makePrimaryConfig([]));
    const req = makeReq();
    req.config.endpoints.agents = { capabilities: ['skills'] };
    req.config.modelSpecs = {
      list: [{ name: 'spec-deployment-skill', skills: ['deployment-skill'] }],
    };
    const getSkillByNameSpy = jest.spyOn(getSkillDbMethods(), 'getSkillByName').mockResolvedValue({
      _id: deploymentSkillId,
      name: 'deployment-skill',
      source: 'deployment',
    });
    const canCreateSkillSpy = jest
      .spyOn(getSkillToolDeps(), 'canCreateSkill')
      .mockResolvedValue(false);

    try {
      await initializeClient({
        req,
        res: {},
        signal: new AbortController().signal,
        endpointOption,
      });

      expect(getSkillByNameSpy).toHaveBeenCalledWith(
        'deployment-skill',
        expect.any(Array),
        expect.any(Object),
      );
      const initializeParams = mockInitializeAgent.mock.calls[0][0];
      expect(initializeParams.agent.skills_enabled).toBe(true);
      expect(initializeParams.agent.skills).toEqual([deploymentSkillId.toString()]);
    } finally {
      getSkillByNameSpy.mockRestore();
      canCreateSkillSpy.mockRestore();
    }
  });
});

describe('initializeClient — subagent loading', () => {
  const SUBAGENT_ID = 'agent_subagent_1';
  const DUPLICATE_SUBAGENT_ID = 'agent_subagent_dup';
  const HANDOFF_AND_SUB_ID = 'agent_handoff_and_sub';

  let mongoServer;
  let testUser;

  beforeAll(async () => {
    mongoServer = await MongoMemoryServer.create();
    await mongoose.connect(mongoServer.getUri());
  });

  afterAll(async () => {
    await mongoose.disconnect();
    await mongoServer.stop();
  });

  beforeEach(async () => {
    await mongoose.connection.dropDatabase();
    jest.clearAllMocks();
    agentClientArgs = undefined;
    capturedToolExecuteOptions = undefined;
    mockLoadToolsForExecution.mockReset();
    mockLoadToolsForExecution.mockResolvedValue({ loadedTools: [] });

    testUser = await User.create({
      email: 'subagent@example.com',
      name: 'Subagent User',
      username: 'subuser',
      role: 'USER',
    });

    mockValidateAgentModel.mockResolvedValue({ isValid: true });
  });

  /** Grant the test user VIEW on an agent so processAgent loads it. */
  const grantView = async (agentDoc) => {
    await AclEntry.create({
      principalType: PrincipalType.USER,
      principalId: testUser._id,
      principalModel: PrincipalModel.USER,
      resourceType: ResourceType.AGENT,
      resourceId: agentDoc._id,
      permBits: PermissionBits.VIEW,
      grantedBy: testUser._id,
    });
  };

  /** Build a request with the `subagents` capability enabled. */
  const makeSubagentReq = () => ({
    user: { id: testUser._id.toString(), role: 'USER' },
    body: { conversationId: 'conv_sub', files: [] },
    config: {
      endpoints: {
        agents: {
          capabilities: ['subagents'],
        },
      },
    },
    _resumableStreamId: null,
  });

  const makeEndpointOption = () => ({
    agent: Promise.resolve({
      id: PRIMARY_ID,
      name: 'Primary',
      provider: 'openai',
      model: 'gpt-4',
      tools: [],
    }),
    model_parameters: { model: 'gpt-4' },
    endpoint: 'agents',
  });

  const makePrimaryConfig = ({ edges = [], subagents, agent_ids }) => ({
    id: PRIMARY_ID,
    endpoint: 'agents',
    edges,
    toolDefinitions: [],
    toolRegistry: new Map(),
    userMCPAuthMap: null,
    tool_resources: {},
    resendFiles: true,
    maxContextTokens: 4096,
    subagents,
    agent_ids,
  });

  const makeSubagentConfig = (id) => ({
    id,
    endpoint: 'agents',
    edges: [],
    toolDefinitions: [{ name: 'web', description: 'web', parameters: {} }],
    toolRegistry: new Map([['web', { name: 'web' }]]),
    userMCPAuthMap: null,
    tool_resources: { file_search: { file_ids: ['file_1'] } },
    accessibleSkillIds: ['skill_1'],
    actionsEnabled: true,
    resendFiles: false,
    maxContextTokens: 4096,
  });

  const makeNestedSubagentConfig = (id, childIds = []) => ({
    ...makeSubagentConfig(id),
    subagents: { enabled: true, allowSelf: false, agent_ids: childIds },
  });

  const createViewableAgent = async (id, subagents) => {
    const agent = await createAgent({
      id,
      name: id,
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
      subagents,
    });
    await grantView(agent);
    return agent;
  };

  it('defers pure-subagent MCP initialization until the descriptor is selected', async () => {
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Data Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['run_query_mcp_warehouse'],
    });
    await grantView(subAgent);

    const toolError = Object.assign(new Error('Subagent expected MCP tools are unavailable'), {
      code: 'AGENT_EXPECTED_MCP_TOOLS_UNAVAILABLE',
      statusCode: 503,
    });
    loadAgentTools.mockRejectedValueOnce(toolError);
    mockInitializeAgent
      .mockResolvedValueOnce(
        makePrimaryConfig({
          subagents: { enabled: true, allowSelf: true, agent_ids: [SUBAGENT_ID] },
        }),
      )
      .mockImplementationOnce(async ({ req, res, loadTools, agent }) => {
        await loadTools({
          req,
          res,
          tools: agent.tools,
          model: agent.model,
          agentId: agent.id,
          provider: agent.provider,
        });
      });

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    await expect(
      agentClientArgs.agent.lazySubagentConfigs[0].resolve({
        signal: new AbortController().signal,
      }),
    ).rejects.toBe(toolError);
  });

  it('defers pure-subagent resource recovery until the descriptor is selected', async () => {
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Code Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['execute_code'],
    });
    await grantView(subAgent);

    const resourceRecoveryError = Object.assign(new Error('resource recovery required'), {
      code: ErrorTypes.RESOURCE_RECOVERY_REQUIRED,
      status: 409,
      statusCode: 409,
    });
    mockInitializeAgent
      .mockResolvedValueOnce(
        makePrimaryConfig({
          subagents: { enabled: true, allowSelf: true, agent_ids: [SUBAGENT_ID] },
        }),
      )
      .mockRejectedValueOnce(resourceRecoveryError);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    await expect(
      agentClientArgs.agent.lazySubagentConfigs[0].resolve({
        signal: new AbortController().signal,
      }),
    ).rejects.toBe(resourceRecoveryError);
  });

  it('advertises a configured subagent without initializing it, then initializes it on selection', async () => {
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Explicit Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['web'],
      stateful_code_environment: 'agent-user',
    });
    await grantView(subAgent);

    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: true, agent_ids: [SUBAGENT_ID] },
    });
    const subagentConfig = makeSubagentConfig(SUBAGENT_ID);

    let call = 0;
    let subagentConvoFileIds;
    mockInitializeAgent.mockImplementation(async (params, dbDeps) => {
      call += 1;
      if (call === 1) {
        return primaryConfig;
      }
      subagentConvoFileIds = await dbDeps.getConvoFiles(params.conversationId);
      return subagentConfig;
    });

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    expect(agentClientArgs.agent.lazySubagentConfigs).toHaveLength(1);
    expect(agentClientArgs.agent.lazySubagentConfigs[0]).toEqual(
      expect.objectContaining({
        id: SUBAGENT_ID,
        configId: expect.any(String),
        statefulCodeEnvironment: 'agent-user',
      }),
    );
    expect(agentClientArgs.agent.lazySubagentConfigs[0]).not.toHaveProperty('tools');
    expect(agentClientArgs.agent.lazySubagentConfigs[0]).not.toHaveProperty('tool_resources');
    expect(agentClientArgs.agent.lazySubagentConfigs[0]).not.toHaveProperty('_id');

    await agentClientArgs.agent.lazySubagentConfigs[0].resolve({
      signal: new AbortController().signal,
    });

    expect(mockInitializeAgent).toHaveBeenCalledTimes(2);
    const subagentDbDeps = mockInitializeAgent.mock.calls[1][1];
    expect(subagentDbDeps.getConvoFiles).toBeInstanceOf(Function);
    expect(subagentDbDeps.db).toBeUndefined();
    expect(subagentConvoFileIds).toEqual([]);

    /** Subagent-only agents must NOT appear in `agentConfigs` — otherwise the
     *  graph would treat them as a parallel/handoff node. */
    expect(agentClientArgs.agentConfigs).toBeDefined();
    expect(agentClientArgs.agentConfigs.has(SUBAGENT_ID)).toBe(false);
  });

  it('rejects a disallowed lazy subagent scope before exposing it for prewarm', async () => {
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Disallowed Stateful Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['execute_code'],
      stateful_code_sessions: true,
      stateful_code_environment: 'conversation',
    });
    await grantView(subAgent);
    mockInitializeAgent.mockResolvedValue(
      makePrimaryConfig({
        subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
      }),
    );
    const req = makeSubagentReq();
    req.config.endpoints.agents.capabilities.push('execute_code', 'stateful_code_sessions');
    req.config.endpoints.agents.statefulCodeSessions = { allowedEnvironments: ['user'] };

    await expect(
      initializeClient({
        req,
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toMatchObject({
      code: ErrorTypes.STATEFUL_CODE_ENVIRONMENT_NOT_ALLOWED,
    });

    expect(agentClientArgs).toBeUndefined();
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
  });

  it('omits a descriptor when its metadata lookup fails without aborting the primary run', async () => {
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);
    jest.spyOn(db, 'getAgentWithVersionCount').mockRejectedValueOnce(new Error('transient read'));

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(agentClientArgs.agent.lazySubagentConfigs).toEqual([]);
    expect(logger.error).toHaveBeenCalledWith(
      expect.stringContaining(`Error loading subagent metadata ${SUBAGENT_ID}`),
      expect.any(Error),
    );
  });

  it('uses exact custom-endpoint identity for descriptor reasoning history', async () => {
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Custom Subagent',
      provider: 'caseprovider',
      model: 'custom-model',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });
    await grantView(subAgent);
    mockInitializeAgent.mockResolvedValue(
      makePrimaryConfig({
        subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
      }),
    );
    const req = makeSubagentReq();
    req.config.endpoints.custom = [
      { name: 'CaseProvider', customParams: { includeReasoningHistory: true } },
      { name: 'caseprovider', customParams: { includeReasoningHistory: false } },
    ];

    await initializeClient({
      req,
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(agentClientArgs.agent.lazySubagentConfigs[0].includeReasoningHistory).toBe(false);
  });

  it('fails closed when a selected subagent configuration changes after advertisement', async () => {
    await createViewableAgent(SUBAGENT_ID);
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });
    await updateAgent({ id: SUBAGENT_ID }, { instructions: 'Changed after descriptor creation.' });

    await expect(
      agentClientArgs.agent.lazySubagentConfigs[0].resolve({
        signal: new AbortController().signal,
      }),
    ).rejects.toThrow(`Subagent ${SUBAGENT_ID} changed`);
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
  });

  it('rechecks VIEW permission when a descriptor is selected', async () => {
    const subAgent = await createViewableAgent(SUBAGENT_ID);
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });
    await AclEntry.deleteMany({ resourceId: subAgent._id });

    await expect(
      agentClientArgs.agent.lazySubagentConfigs[0].resolve({
        signal: new AbortController().signal,
      }),
    ).rejects.toThrow(`no longer have access to subagent ${SUBAGENT_ID}`);
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
  });

  it('preserves subagent tool context for ON_TOOL_EXECUTE (Codex P1 regression guard)', async () => {
    /** Verifies the Codex P1 fix: `agentToolContexts.delete(subagentId)` is
     *  NOT called for subagent-only agents, so when the child dispatches
     *  `ON_TOOL_EXECUTE` the parent can still resolve its tool context
     *  (agent, tool_resources, skill ACLs, actionsEnabled) to run tools
     *  with the right scope. We drive the real `loadTools` closure that
     *  `initializeClient` wires into `toolExecuteOptions`. */
    const subAgent = await createAgent({
      id: SUBAGENT_ID,
      name: 'Explicit Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: ['web'],
    });
    await grantView(subAgent);

    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    const subagentConfig = makeSubagentConfig(SUBAGENT_ID);

    let call = 0;
    mockInitializeAgent.mockImplementation(() =>
      Promise.resolve(++call === 1 ? primaryConfig : subagentConfig),
    );

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    await agentClientArgs.agent.lazySubagentConfigs[0].resolve({
      signal: new AbortController().signal,
    });
    expect(capturedToolExecuteOptions?.loadTools).toBeInstanceOf(Function);

    /** Invoke the real closure with the subagent's id. If `agentToolContexts`
     *  had been deleted (as in the pre-fix code), this would call
     *  `loadToolsForExecution` with `agent: undefined` — actions/resource-
     *  scoped tools would silently drop. */
    await capturedToolExecuteOptions.loadTools(['web'], SUBAGENT_ID);

    expect(mockLoadToolsForExecution).toHaveBeenCalledTimes(1);
    const arg = mockLoadToolsForExecution.mock.calls[0][0];
    expect(arg.agent).toBeDefined();
    expect(arg.agent.id).toBe(SUBAGENT_ID);
    expect(arg.toolRegistry).toBeInstanceOf(Map);
    expect(arg.tool_resources).toEqual({ file_search: { file_ids: ['file_1'] } });
    expect(arg.actionsEnabled).toBe(true);
  });

  it('threads run-scoped MCP tool definitions into ON_TOOL_EXECUTE loading', async () => {
    /** Regression guard for the request-scoped MCP/PTC handoff: the
     *  `mcpAvailableTools` discovered at run start must survive
     *  `buildAgentToolContext` and reach `loadToolsForExecution`, otherwise
     *  request-scoped servers reinitialize on every programmatic tool call
     *  and can trip the MCP circuit breaker under parallel calls. */
    const mcpTool = 'list_tables_mcp_ClickHouse';
    const mcpAvailableTools = {
      ClickHouse: {
        [mcpTool]: {
          type: 'function',
          function: {
            name: mcpTool,
            description: 'List tables',
            parameters: { type: 'object', properties: {} },
          },
        },
      },
    };
    const primaryConfig = {
      ...makePrimaryConfig({}),
      toolRegistry: new Map([[mcpTool, { name: mcpTool }]]),
      mcpAvailableTools,
    };
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(capturedToolExecuteOptions?.loadTools).toBeInstanceOf(Function);
    await capturedToolExecuteOptions.loadTools([mcpTool], PRIMARY_ID);

    expect(mockLoadToolsForExecution).toHaveBeenCalledTimes(1);
    expect(mockLoadToolsForExecution).toHaveBeenCalledWith(
      expect.objectContaining({ mcpAvailableTools }),
    );
  });

  it('deduplicates repeated ids in subagents.agent_ids', async () => {
    const subAgent = await createAgent({
      id: DUPLICATE_SUBAGENT_ID,
      name: 'Dup Subagent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });
    await grantView(subAgent);

    const primaryConfig = makePrimaryConfig({
      subagents: {
        enabled: true,
        allowSelf: false,
        /** Same id three times — the backend must not load the agent
         *  repeatedly and must not emit three SubagentConfig entries. */
        agent_ids: [DUPLICATE_SUBAGENT_ID, DUPLICATE_SUBAGENT_ID, DUPLICATE_SUBAGENT_ID],
      },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    /** Repeated ids produce one lightweight descriptor and no eager child initialization. */
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    expect(agentClientArgs.agent.lazySubagentConfigs).toHaveLength(1);
  });

  it('does not initialize a descriptor after its SDK cancellation signal aborts', async () => {
    await createViewableAgent(SUBAGENT_ID);
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });
    const controller = new AbortController();
    controller.abort(new Error('cancelled'));

    await expect(
      agentClientArgs.agent.lazySubagentConfigs[0].resolve({ signal: controller.signal }),
    ).rejects.toThrow('cancelled');
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
  });

  it('rejects promptly when cancellation occurs during lazy initialization', async () => {
    await createViewableAgent(SUBAGENT_ID);
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [SUBAGENT_ID] },
    });
    const initialization = deferred();
    const initializationStarted = deferred();
    mockInitializeAgent.mockResolvedValueOnce(primaryConfig).mockImplementationOnce((params) => {
      initializationStarted.resolve(params);
      return initialization.promise;
    });

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });
    const controller = new AbortController();
    const resolution = agentClientArgs.agent.lazySubagentConfigs[0].resolve({
      signal: controller.signal,
    });
    const selectedInitParams = await initializationStarted.promise;
    controller.abort(new Error('cancelled in flight'));

    await expect(resolution).rejects.toThrow('cancelled in flight');
    expect(selectedInitParams.loadTools).not.toBe(mockInitializeAgent.mock.calls[0][0].loadTools);
    initialization.resolve(makeSubagentConfig(SUBAGENT_ID));
  });

  it('rejects nested subagent chains deeper than MAX_SUBAGENT_DEPTH', async () => {
    const ids = Array.from(
      { length: MAX_SUBAGENT_DEPTH + 1 },
      (_, index) => `agent_depth_${index}`,
    );
    for (const [index, id] of ids.entries()) {
      await createViewableAgent(id, {
        enabled: true,
        allowSelf: false,
        agent_ids: index < ids.length - 1 ? [ids[index + 1]] : [],
      });
    }

    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: [ids[0]] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await expect(
      initializeClient({
        req: makeSubagentReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toThrow(`maximum depth of ${MAX_SUBAGENT_DEPTH}`);
    expect(logger.warn).toHaveBeenCalledWith(
      '[initializeClient] Subagent graph depth limit exceeded',
      expect.objectContaining({
        agentId: ids[MAX_SUBAGENT_DEPTH - 1],
        primaryAgentId: PRIMARY_ID,
        depth: MAX_SUBAGENT_DEPTH,
        maxSubagentDepth: MAX_SUBAGENT_DEPTH,
      }),
    );
    expect(agentClientArgs).toBeUndefined();
  });

  it('preserves deeper path depth when a handoff root is also a nested subagent', async () => {
    const chainIds = Array.from(
      { length: MAX_SUBAGENT_DEPTH },
      (_, index) => `agent_overlap_depth_${index}`,
    );
    await createViewableAgent(HANDOFF_AND_SUB_ID, {
      enabled: true,
      allowSelf: false,
      agent_ids: [chainIds[0]],
    });
    for (const [index, id] of chainIds.entries()) {
      await createViewableAgent(id, {
        enabled: true,
        allowSelf: false,
        agent_ids: index < chainIds.length - 1 ? [chainIds[index + 1]] : [],
      });
    }

    const edges = [{ from: PRIMARY_ID, to: HANDOFF_AND_SUB_ID, edgeType: 'handoff' }];
    const primaryConfig = makePrimaryConfig({
      edges,
      subagents: { enabled: true, allowSelf: false, agent_ids: [HANDOFF_AND_SUB_ID] },
    });
    const sharedConfig = makeNestedSubagentConfig(HANDOFF_AND_SUB_ID, [chainIds[0]]);
    mockInitializeAgent.mockImplementation(({ agent }) =>
      Promise.resolve(agent.id === PRIMARY_ID ? primaryConfig : sharedConfig),
    );

    await expect(
      initializeClient({
        req: makeSubagentReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toThrow(`maximum depth of ${MAX_SUBAGENT_DEPTH}`);
    expect(agentClientArgs).toBeUndefined();
  });

  it('rejects subagent graphs that exceed MAX_SUBAGENT_GRAPH_NODES unique agents', async () => {
    const firstLevelIds = Array.from({ length: 10 }, (_, index) => `agent_graph_${index}`);
    const secondLevelIdsByParent = new Map(
      firstLevelIds.map((id) => [
        id,
        Array.from({ length: 5 }, (_, index) => `${id}_child_${index}`),
      ]),
    );
    for (const id of firstLevelIds) {
      await createViewableAgent(id, {
        enabled: true,
        allowSelf: false,
        agent_ids: secondLevelIdsByParent.get(id),
      });
    }
    for (const id of Array.from(secondLevelIdsByParent.values()).flat()) {
      await createViewableAgent(id, { enabled: true, allowSelf: false, agent_ids: [] });
    }

    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: firstLevelIds },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await expect(
      initializeClient({
        req: makeSubagentReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toThrow(`maximum of ${MAX_SUBAGENT_GRAPH_NODES} unique agents`);
    expect(logger.warn).toHaveBeenCalledWith(
      '[initializeClient] Subagent graph node limit exceeded',
      expect.objectContaining({
        primaryAgentId: PRIMARY_ID,
        loadedSubagentCount: MAX_SUBAGENT_GRAPH_NODES,
        maxSubagentGraphNodes: MAX_SUBAGENT_GRAPH_NODES,
      }),
    );
    expect(agentClientArgs).toBeUndefined();
  });

  it('rejects a branching DAG that exceeds expanded descriptor capacity', async () => {
    const width = 3;
    const layers = Array.from({ length: MAX_SUBAGENT_DEPTH }, (_, level) =>
      Array.from({ length: width }, (_, index) => `agent_descriptor_${level}_${index}`),
    );
    for (let level = 0; level < layers.length; level++) {
      const childIds = level < layers.length - 1 ? layers[level + 1] : [];
      for (const id of layers[level]) {
        await createViewableAgent(id, { enabled: true, allowSelf: false, agent_ids: childIds });
      }
    }

    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: false, agent_ids: layers[0] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await expect(
      initializeClient({
        req: makeSubagentReq(),
        res: {},
        signal: new AbortController().signal,
        endpointOption: makeEndpointOption(),
      }),
    ).rejects.toThrow(`maximum of ${MAX_SUBAGENT_RUN_CONFIGS} expanded entries`);
    expect(logger.warn).toHaveBeenCalledWith(
      '[initializeClient] Subagent run configuration limit exceeded',
      expect.objectContaining({
        expandedConfigCount: MAX_SUBAGENT_RUN_CONFIGS + 1,
        maxSubagentRunConfigs: MAX_SUBAGENT_RUN_CONFIGS,
        rootAgentIds: [PRIMARY_ID],
      }),
    );
    expect(agentClientArgs).toBeUndefined();
  });

  it('keeps an agent in `agentConfigs` when it is BOTH a handoff target and a subagent', async () => {
    /** Overlap case: the same child is used both via handoff edges (needs to
     *  be in agentConfigs) and as a subagent (needs to be in
     *  subagentAgentConfigs, and its tool context preserved). The pipeline
     *  shouldn't silently drop it from the handoff map. */
    const shared = await createAgent({
      id: HANDOFF_AND_SUB_ID,
      name: 'Shared Agent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });
    await grantView(shared);

    const edges = [{ from: PRIMARY_ID, to: HANDOFF_AND_SUB_ID, edgeType: 'handoff' }];
    const primaryConfig = makePrimaryConfig({
      edges,
      subagents: {
        enabled: true,
        allowSelf: false,
        agent_ids: [HANDOFF_AND_SUB_ID],
      },
    });
    const sharedConfig = makeSubagentConfig(HANDOFF_AND_SUB_ID);

    let call = 0;
    mockInitializeAgent.mockImplementation(() =>
      Promise.resolve(++call === 1 ? primaryConfig : sharedConfig),
    );

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(agentClientArgs.agent.subagentAgentConfigs).toHaveLength(1);
    /** Shared agent must stay in agentConfigs — it's still the handoff target. */
    expect(agentClientArgs.agentConfigs.has(HANDOFF_AND_SUB_ID)).toBe(true);
  });

  it('clears subagents config on primary when the capability is disabled', async () => {
    /** Admin can turn subagents off at the endpoint level even if an agent was
     *  configured for them. The primary's `subagents` field should be
     *  suppressed so run.ts never builds a SubagentConfig. */
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: true, allowSelf: true, agent_ids: [] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    const req = makeSubagentReq();
    /** Remove the capability from the admin config. */
    req.config.endpoints.agents.capabilities = [];

    await initializeClient({
      req,
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    expect(agentClientArgs.agent.subagents).toBeUndefined();
    expect(agentClientArgs.agent.subagentAgentConfigs).toEqual([]);
  });

  it('clears subagents on handoff agents too when capability is disabled (Codex P2 regression)', async () => {
    /** Codex P2: the capability gate must suppress `subagents` on EVERY
     *  loaded config, not just the primary. `run.ts` iterates all agents
     *  and calls `buildSubagentConfigs` per agent, so a handoff target
     *  with `subagents.enabled: true` persisted on its document would
     *  otherwise still expose self-spawn even when the admin has disabled
     *  the capability globally. */
    const authorized = await createAgent({
      id: AUTHORIZED_ID,
      name: 'Handoff Agent',
      provider: 'openai',
      model: 'gpt-4',
      author: new mongoose.Types.ObjectId(),
      tools: [],
    });
    await grantView(authorized);

    const edges = [{ from: PRIMARY_ID, to: AUTHORIZED_ID, edgeType: 'handoff' }];
    const primaryConfig = makePrimaryConfig({
      edges,
      subagents: { enabled: true, allowSelf: true, agent_ids: [] },
    });
    const handoffConfig = {
      id: AUTHORIZED_ID,
      endpoint: 'agents',
      edges: [],
      toolDefinitions: [],
      toolRegistry: new Map(),
      userMCPAuthMap: null,
      tool_resources: {},
      /** Handoff agent document has subagents enabled of its own accord. */
      subagents: { enabled: true, allowSelf: true, agent_ids: [] },
    };

    let callCount = 0;
    mockInitializeAgent.mockImplementation(() =>
      Promise.resolve(++callCount === 1 ? primaryConfig : handoffConfig),
    );

    const req = makeSubagentReq();
    /** Capability OFF at endpoint level. */
    req.config.endpoints.agents.capabilities = [];

    await initializeClient({
      req,
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    /** Primary cleared. */
    expect(agentClientArgs.agent.subagents).toBeUndefined();
    /** Handoff target must ALSO be cleared — otherwise its self-spawn
     *  would still fire when run.ts iterates agentConfigs. */
    const handoffLoaded = agentClientArgs.agentConfigs.get(AUTHORIZED_ID);
    expect(handoffLoaded).toBeDefined();
    expect(handoffLoaded.subagents).toBeUndefined();
    expect(handoffLoaded.subagentAgentConfigs).toBeUndefined();
  });

  it('skips subagent loading entirely when the feature is disabled on the agent', async () => {
    const primaryConfig = makePrimaryConfig({
      subagents: { enabled: false, allowSelf: true, agent_ids: [SUBAGENT_ID] },
    });
    mockInitializeAgent.mockResolvedValue(primaryConfig);

    await initializeClient({
      req: makeSubagentReq(),
      res: {},
      signal: new AbortController().signal,
      endpointOption: makeEndpointOption(),
    });

    /** Only one initializeAgent call — for the primary. No subagent loaded. */
    expect(mockInitializeAgent).toHaveBeenCalledTimes(1);
    expect(agentClientArgs.agent.subagentAgentConfigs).toEqual([]);
  });
});