close

Execute Workflow

Execute a deployed workflow synchronously, asynchronously, or as Server-Sent Events. Public workflows permit anonymous synchronous and streaming execution; asynchronous execution requires an API key. A synchronous run that exceeds its execution timeout returns HTTP 200 with status: "failed" and error.code: "TIMEOUT" rather than an HTTP error, so branch on status. Each option carries the modes it requires and the modes that reject it; a violated combination is a 400.

POST/api/v2/workflows/{id}/execute

Authorization

apiKey
X-API-Key<token>

Your Sim API key, personal or workspace-scoped. Generate one under Settings, then API Keys. Operations that reject workspace keys say so in their own description.

In: header

Path Parameters

id*string

Unique workflow identifier.

Length1 <= length

Header Parameters

x-run-id?string

Caller-supplied run identifier, available only to API-key callers. A one-shot uniqueness claim, NOT an idempotency key: reusing a value fails with 409 and error.details.code: "RUN_ID_CONFLICT" rather than replaying the original result. To retry safely, send a fresh value per attempt, or omit the header and let the server allocate one.

Match^[A-Za-z0-9._:-]+$
Length1 <= length <= 128
x-sim-via?string

Comma-separated workflow identifiers naming the workflow-to-workflow call chain that led to this request. Each hop appends its own workflow id, and Sim sets it automatically; supply it yourself only when relaying an existing chain. A chain at the maximum depth is rejected with 409 and error.details.code: "CALL_CHAIN_DEPTH_EXCEEDED".

Request Body

application/json

Input and execution-mode options for a deployed workflow. Each option carries the modes it requires and the modes that reject it; a violated combination is a 400.

TypeScript Definitions

Use the request body type in TypeScript.

Response Body

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

application/json

curl -X POST "https://www.sim.ai/api/v2/workflows/3b1f7c92-8d4e-4a6b-9c0d-5e2f8a714b36/execute" \  -H "X-API-Key: YOUR_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "input": {      "ticketId": "ticket_123"    }  }'
{
  "data": {
    "runId": "run_8f14e45f-ceea-467f-a",
    "workflowId": "3b1f7c92-8d4e-4a6b-9c0d-5e2f8a714b36",
    "status": "completed",
    "output": {
      "result": "Ticket routed to Support"
    },
    "error": null,
    "startedAt": "2026-08-09T18:04:10.000Z",
    "endedAt": "2026-08-09T18:04:11.000Z",
    "durationMs": 1000
  }
}
{
  "data": {
    "runId": "run_8f14e45f-ceea-467f-a",
    "statusUrl": "https://www.sim.ai/api/v2/workflows/3b1f7c92-8d4e-4a6b-9c0d-5e2f8a714b36/runs/run_8f14e45f-ceea-467f-a"
  }
}
{
  "error": {
    "code": "BAD_REQUEST",
    "message": "Invalid request"
  }
}
{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "API key required"
  }
}
{
  "error": {
    "code": "USAGE_LIMIT_EXCEEDED",
    "message": "Usage limit exceeded. Please upgrade your plan to continue."
  }
}
{
  "error": {
    "code": "FORBIDDEN",
    "message": "Insufficient workspace permissions",
    "details": {
      "code": "INSUFFICIENT_WORKSPACE_ROLE"
    }
  }
}
{
  "error": {
    "code": "NOT_FOUND",
    "message": "Not found"
  }
}
{
  "error": {
    "code": "CONFLICT",
    "message": "Run ID has already been used",
    "details": {
      "code": "RUN_ID_CONFLICT",
      "runId": "0f7c1a2e-9b3d-4c58-8a21-6d4e5f7a9b01"
    }
  }
}
{
  "error": {
    "code": "PAYLOAD_TOO_LARGE",
    "message": "Request body is too large"
  }
}
{
  "error": {
    "code": "RATE_LIMITED",
    "message": "API rate limit exceeded",
    "details": {
      "retryAfter": "2026-01-01T00:00:30.000Z"
    }
  }
}
{
  "error": {
    "code": "CLIENT_CLOSED_REQUEST",
    "message": "Client cancelled request",
    "details": {
      "runId": "0f7c1a2e-9b3d-4c58-8a21-6d4e5f7a9b01"
    }
  }
}
{
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "Internal server error"
  }
}
{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "message": "Service temporarily unavailable"
  }
}
POSTRollback WorkflowGETList Workflow Folders