> ## Documentation Index > Fetch the complete documentation index at: https://docs.langchain.com/llms.txt > Use this file to discover all available pages before exploring further. # Create a thread and start a run > Create a thread bound to `agent_id` and start a run on it in one call. Run kwargs are passed through; thread-creation flags go in the optional `thread` envelope. ## OpenAPI ````yaml /langsmith/managed-deep-agents-openapi.json post /threads/runs openapi: 3.1.0 info: title: Managed Deep Agents API version: 0.1.0 description: Create, configure, and run Managed Deep Agents. servers: - url: https://api.smith.langchain.com/v1/deepagents security: - apiKeyAuth: [] tags: - name: Agents description: Create and manage Managed Deep Agent resources. - name: Threads description: Create and inspect durable thread state. - name: Runs description: Start runs on Managed Deep Agent threads. - name: MCP servers description: Register MCP servers and store credentials referenced by agent tools. - name: MCP tools description: Discover tools exposed by registered MCP servers. - name: Auth sessions description: Start and poll OAuth authorization sessions for OAuth MCP servers. paths: /threads/runs: post: tags: - Runs summary: Create a thread and start a run description: >- Create a thread bound to `agent_id` and start a run on it in one call. Run kwargs are passed through; thread-creation flags go in the optional `thread` envelope. operationId: createManagedDeepAgentThreadAndRun requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateThreadAndRunRequest' responses: '200': description: Run returned. content: application/json: schema: type: object additionalProperties: true '201': description: Run created. content: application/json: schema: type: object additionalProperties: true '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '409': $ref: '#/components/responses/Conflict' '422': $ref: '#/components/responses/UnprocessableEntity' '502': $ref: '#/components/responses/BadGateway' components: schemas: CreateThreadAndRunRequest: type: object required: - agent_id properties: agent_id: type: string description: Managed Deep Agent ID. example: 11111111-1111-1111-1111-111111111111 thread: $ref: '#/components/schemas/CreateThreadAndRunThread' additionalProperties: true CreateThreadAndRunThread: type: object properties: thread_id: type: string format: uuid if_exists: type: string enum: - do_nothing - raise metadata: type: object additionalProperties: true options: $ref: '#/components/schemas/CreateThreadOptions' ErrorResponse: type: object properties: type: type: string code: type: string detail: type: string status: type: integer CreateThreadOptions: type: object properties: test_run: type: boolean description: Marks the thread as a test run, filtered out of usage and analytics. skip_memory_write_protection: type: boolean default: false description: >- Controls whether the runtime pauses for human approval before the agent writes to long-term memory on this thread. By default (`false`), the runtime raises a human-in-the-loop interrupt when the agent tries to write or edit files in its memory directory, so the user can approve or reject the write before it persists. Set to `true` to bypass that interrupt and let memory writes proceed immediately — useful for headless or unattended runs. responses: BadRequest: description: Bad request. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: missingRequiredField: summary: Required field missing value: type: https://docs.langchain.com/errors/missing_required_field code: missing_required_field detail: 'Set ''name'' to a non-empty string: ''name'' is required' status: 400 invalidRequestBody: summary: Malformed JSON body value: type: https://docs.langchain.com/errors/invalid_request_body code: invalid_request_body detail: >- Provide a valid JSON request body matching the documented schema status: 400 Unauthorized: description: >- Authentication required. The auth layer returns a simple `{"error": "Unauthorized"}` body that does not match the structured `ErrorResponse` shape used by other 4xx responses. content: application/json: schema: type: object properties: error: type: string examples: missingApiKey: summary: No `X-Api-Key` header supplied value: error: Unauthorized Forbidden: description: >- The authenticated identity does not have access to the resource or feature. The auth layer returns a simple `{"error": "Forbidden"}` body that does not match the structured `ErrorResponse` shape used by other 4xx responses. content: application/json: schema: type: object properties: error: type: string examples: invalidApiKey: summary: API key is invalid or lacks workspace access value: error: Forbidden NotFound: description: Resource not found. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: agentNotFound: summary: Unknown agent ID value: type: https://docs.langchain.com/errors/agent_not_found code: agent_not_found detail: >- Verify the agent ID and that the calling identity has access: agent not found status: 404 Conflict: description: Request conflicts with current resource state. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' UnprocessableEntity: description: Request is syntactically valid but failed validation. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' BadGateway: description: Upstream agent runtime error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: upstreamAuthFailed: summary: >- Upstream runtime rejected the request (e.g. orphaned thread after agent deletion) value: type: https://docs.langchain.com/errors/upstream_auth_failed code: upstream_auth_failed detail: >- Verify that the calling identity is authorized for this organization: upstream agent runtime rejected the request status: 502 securitySchemes: apiKeyAuth: type: apiKey in: header name: X-Api-Key x-default: LANGSMITH_API_KEY ````