> ## Documentation Index > Fetch the complete documentation index at: https://docs.capy.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create and start thread > Create a new captain thread and immediately start execution, optionally assigning existing project tags. ## OpenAPI ````yaml POST /v1/threads openapi: 3.1.0 info: title: Capy API version: 1.0.0 servers: - url: https://capy.ai/api security: - bearerAuth: [] tags: - name: threads - name: sessions - name: tasks - name: projects - name: tags - name: models - name: usage - name: setup - name: snapshots - name: browser-snapshots - name: environment-variables - name: automations paths: /v1/threads: post: tags: - threads summary: Create and start thread description: >- Create a new captain thread and immediately start execution, optionally assigning existing project tags. operationId: createAndStartThread parameters: [] requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateThreadBody' responses: '200': description: Success content: application/json: schema: $ref: '#/components/schemas/CreateThreadResponse' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '422': $ref: '#/components/responses/ValidationError' '500': $ref: '#/components/responses/InternalError' security: - bearerAuth: [] components: schemas: CreateThreadBody: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: projectId: type: string impersonateUserEmail: type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ prompt: type: string minLength: 1 model: type: string enum: - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-opus-4-5 - claude-sonnet-4-6 - claude-haiku-4-5 - gpt-5.5 - gpt-5.5-pro - gpt-5.4 - gpt-5.4-mini - gpt-5.3-codex - gpt-5.3-codex-spark - gemini-3.1-pro-preview - gemini-3-flash-preview - grok-4-1-fast - glm-5.2 - glm-5.1 - glm-5v-turbo - glm-5 - deepseek-v4-pro - glm-5-turbo - glm-4.7 - kimi-k2.7-code - kimi-k2.6 - qwen3-coder - claude-fable-5 speed: type: string enum: - fast - standard reasoning: type: object properties: mode: type: string enum: - 'off' - 'on' - none - minimal - low - medium - high - xhigh - max required: - mode additionalProperties: false buildModel: type: string enum: - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-opus-4-5 - claude-sonnet-4-6 - claude-haiku-4-5 - gpt-5.5 - gpt-5.5-pro - gpt-5.4 - gpt-5.4-mini - gpt-5.3-codex - gpt-5.3-codex-spark - gemini-3.1-pro-preview - gemini-3-flash-preview - grok-4-1-fast - glm-5.2 - glm-5.1 - glm-5v-turbo - glm-5 - deepseek-v4-pro - glm-5-turbo - glm-4.7 - kimi-k2.7-code - kimi-k2.6 - qwen3-coder - claude-fable-5 buildSpeed: type: string enum: - fast - standard buildReasoning: type: object properties: mode: type: string enum: - 'off' - 'on' - none - minimal - low - medium - high - xhigh - max required: - mode additionalProperties: false repos: type: array items: type: object properties: repoFullName: type: string branch: type: string required: - repoFullName - branch additionalProperties: false browserSnapshotIds: type: array items: type: string attachmentUrls: type: array items: type: string format: uri tags: maxItems: 20 type: array items: type: string minLength: 1 maxLength: 64 pattern: ^[a-z0-9][a-z0-9_-]{0,63}$ slack: type: object properties: channel: type: string minLength: 1 required: - channel additionalProperties: false reliabilityInvestigationId: type: string pattern: ^rel_[a-f0-9]{40}$ required: - projectId - prompt additionalProperties: false CreateThreadResponse: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: id: type: string projectId: type: string title: anyOf: - type: string - type: 'null' status: type: string enum: - active - idle - archived description: >- Coarse Captain run-loop status retained for compatibility. Prefer runState/waitingOn/blockedOn for completion and waiting UX. runState: type: string enum: - running - queued - waiting - blocked - ready - archived description: Full computed execution state for the agent thread. waitingOn: type: array items: type: string enum: - task - review - ci - timer - worker description: Async system dependencies expected to continue without user action. blockedOn: type: array items: type: string enum: - auth - permission description: User/integration gates required before progress can continue. pendingWakeups: type: integer minimum: 0 maximum: 9007199254740991 description: Pending append-and-resume notifications waiting to be processed. participants: type: array items: type: object properties: userId: type: string userType: type: string enum: - human - service_user firstParticipatedAt: type: string lastParticipatedAt: type: string required: - userId - userType - firstParticipatedAt - lastParticipatedAt additionalProperties: false tags: type: array items: type: object properties: name: type: string minLength: 1 maxLength: 64 pattern: ^[a-z0-9][a-z0-9_-]{0,63}$ color: type: string enum: - default - primary - success - warning - destructive - blue - purple - pink - orange - lime required: - name - color additionalProperties: false slack: type: object properties: teamId: type: string channelId: type: string threadTs: type: string url: type: string required: - teamId - channelId - threadTs - url additionalProperties: false createdAt: type: string required: - id - projectId - title - status - runState - waitingOn - blockedOn - pendingWakeups - participants - tags - createdAt additionalProperties: false ErrorResponse: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: error: type: object properties: code: type: string message: type: string details: {} required: - code - message additionalProperties: false required: - error additionalProperties: false responses: Unauthorized: description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' Forbidden: description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' NotFound: description: Not found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' ValidationError: description: Validation error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' InternalError: description: Internal error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' securitySchemes: bearerAuth: type: http scheme: bearer description: API token (capy_xxxx). Generate at capy.ai/settings/tokens ````