> ## Documentation Index > Fetch the complete documentation index at: https://docs.eachlabs.ai/llms.txt > Use this file to discover all available pages before exploring further. # Trigger workflow execution > Start an asynchronous workflow execution through api-service. This route forwards to workflows-engine and requires callers to pin the workflow version in the path. The immediate response only confirms the workflow was queued. Downstream workflow lifecycle statuses are `running`, `completed`, `failed`, and `cancelled`. api-service does not expose workflows-engine's bulk trigger route. ## OpenAPI ````yaml /openapi_specs/models.json post /v1/workflows/trigger/{workflowID}/{versionID} openapi: 3.0.3 info: title: each::labs Official API v1 description: > Official each::labs API V1. This API provides access to our comprehensive AI model catalog and other resources. ## Public contract notes - Public API routes handled by request logging include `X-Request-Id` for support and log correlation. Clients may send `X-Request-Id`; otherwise api-service generates one. Root, health, and metrics endpoints are excluded. - REST error bodies keep the backward-compatible JSON shape used by existing clients. Most errors include at least `error`; some shared error paths also include `status` and `details`. Use the HTTP status code as the primary programmatic signal unless an endpoint documents a richer envelope. - Rate-limit and retry headers are endpoint-dependent. If a response includes `Retry-After`, honor it before retrying; otherwise use bounded exponential backoff for retryable 429/5xx responses. - api-service exposes single workflow trigger through `/v1/workflows/trigger/{workflowID}/{versionID}`. Bulk workflow trigger is not routed through api-service; use the workflows-engine public API directly where bulk trigger is required. version: 1.0.0 contact: name: API Support email: support@eachlabs.ai x-logo: url: ./logo-white.svg altText: each::labs servers: - url: https://api.eachlabs.ai description: Production server security: [] tags: - name: AI Models description: Endpoints for listing and retrieving AI models and other resources. - name: AI Models Prediction description: Endpoints for managing model predictions - name: Uploads description: Endpoints for uploading files that can be used as model inputs. - name: Executions description: Endpoints for listing execution history. - name: Workflows description: Endpoints for triggering workflow executions through api-service. - name: OpenAI Compatibility description: OpenAI-compatible endpoints for LLM Router requests. - name: Webhooks description: > Endpoints for retrieving webhook information and delivery history. **Note:** Currently, webhooks are only supported for Workflows V2. We are actively expanding webhook support to other services and will update this documentation as new integrations become available. paths: /v1/workflows/trigger/{workflowID}/{versionID}: post: tags: - Workflows summary: Trigger workflow execution description: > Start an asynchronous workflow execution through api-service. This route forwards to workflows-engine and requires callers to pin the workflow version in the path. The immediate response only confirms the workflow was queued. Downstream workflow lifecycle statuses are `running`, `completed`, `failed`, and `cancelled`. api-service does not expose workflows-engine's bulk trigger route. operationId: triggerWorkflowExecution parameters: - name: workflowID in: path required: true schema: type: string description: Workflow ID or slug to execute. example: wf_abc123 - name: versionID in: path required: true schema: type: string description: Workflow version ID to execute. example: v1 - name: webhook_url in: query required: false schema: type: string format: uri description: >- Optional compatibility query parameter for execution completion webhooks. The request body field takes precedence when both are present. example: https://your-app.com/webhook requestBody: required: false content: application/json: schema: $ref: '#/components/schemas/WorkflowTriggerRequest' example: inputs: prompt: A cinematic establishing shot of a mountain lake webhook_url: https://your-app.com/webhook webhook_secret: your-secret-key responses: '202': description: Workflow execution queued content: application/json: schema: $ref: '#/components/schemas/WorkflowTriggerResponse' example: execution_id: exec_xyz789 status: queued '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '402': $ref: '#/components/responses/PaymentRequired' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '408': $ref: '#/components/responses/RequestTimeout' '409': $ref: '#/components/responses/Conflict' '500': $ref: '#/components/responses/InternalServerError' '502': $ref: '#/components/responses/BadGateway' security: - ApiKeyAuth: [] components: schemas: WorkflowTriggerRequest: type: object properties: inputs: type: object additionalProperties: true description: >- Input values defined by the workflow version. May be omitted for workflows with no inputs. example: prompt: A cinematic establishing shot of a mountain lake webhook_url: type: string format: uri description: Optional webhook URL for workflow execution completion. example: https://your-app.com/webhook webhook_secret: type: string description: Optional secret used to sign workflow webhook requests. example: your-secret-key WorkflowTriggerResponse: type: object properties: execution_id: type: string description: Queued workflow execution identifier. example: exec_xyz789 status: type: string enum: - queued description: Execution queue status returned immediately after triggering. example: queued Error: type: object description: > Backward-compatible REST error body. Endpoint-specific handlers may return only `error`; shared error paths may also include `status` and `details`. properties: status: type: integer description: HTTP status code, when returned by the shared error handler. example: 400 error: type: string description: Safe user-facing error message. example: error message details: nullable: true description: Optional validation or request details for client errors. required: - error responses: BadRequest: description: Bad request headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: slug parameter is required Unauthorized: description: Authentication required or invalid credentials headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: Invalid or missing API key PaymentRequired: description: Insufficient balance headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: insufficient balance Forbidden: description: Forbidden headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: forbidden NotFound: description: Resource not found headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: 'Failed to fetch model: model not found' RequestTimeout: description: Upstream request timed out headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: Request timeout Conflict: description: Conflict with current resource state headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: conflict InternalServerError: description: Internal server error headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: 'Failed to fetch models: internal error' BadGateway: description: Upstream service unavailable headers: X-Request-Id: $ref: '#/components/headers/RequestId' content: application/json: schema: $ref: '#/components/schemas/Error' example: error: workflows-engine unavailable headers: RequestId: description: >- Request correlation ID. Echoes the incoming `X-Request-Id` header or a generated ID. schema: type: string example: 123e4567-e89b-12d3-a456-426614174000 securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: API key for authentication ````