Update Workflow Variables

Add, edit, and delete a workflow’s variables. Operations are matched by variable name and applied in order; a batch that changes nothing answers 200 with changed: false. Values are coerced to the declared type, and a value that cannot be coerced is stored as supplied. Read the current set from variables on GET /workflows/{workflowId}.

PATCH/api/v2/workflows/{workflowId}/variables

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

workflowId*string

Unique workflow identifier.

Length1 <= length

Request Body

application/json

Additions, edits, and deletions against a workflow’s variables.

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 PATCH "https://www.sim.ai/api/v2/workflows/3b1f7c92-8d4e-4a6b-9c0d-5e2f8a714b36/variables" \  -H "X-API-Key: YOUR_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "operations": [      {        "operation": "add",        "name": "string",        "type": "string",        "value": null      }    ]  }'
{
  "data": {
    "id": "3b1f7c92-8d4e-4a6b-9c0d-5e2f8a714b36",
    "variableCount": 3,
    "changed": true
  }
}
{
  "error": {
    "code": "BAD_REQUEST",
    "message": "Invalid request"
  }
}
{
  "error": {
    "code": "UNAUTHORIZED",
    "message": "API key required"
  }
}
{
  "error": {
    "code": "FORBIDDEN",
    "message": "Insufficient workspace permissions",
    "details": {
      "code": "INSUFFICIENT_WORKSPACE_ROLE"
    }
  }
}
{
  "error": {
    "code": "NOT_FOUND",
    "message": "Not found"
  }
}
{
  "error": {
    "code": "CONFLICT",
    "message": "Webhook path already in use"
  }
}
{
  "error": {
    "code": "PAYLOAD_TOO_LARGE",
    "message": "Request body is too large"
  }
}
{
  "error": {
    "code": "UNSUPPORTED_MEDIA_TYPE",
    "message": "Request body must be sent as application/json"
  }
}
{
  "error": {
    "code": "LOCKED",
    "message": "Workflow is locked"
  }
}
{
  "error": {
    "code": "RATE_LIMITED",
    "message": "API rate limit exceeded",
    "details": {
      "retryAfter": "2026-01-01T00:00:30.000Z"
    }
  }
}
{
  "error": {
    "code": "INTERNAL_ERROR",
    "message": "Internal server error"
  }
}
{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "message": "Service temporarily unavailable"
  }
}