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}.
/api/v2/workflows/{workflowId}/variablesAuthorization
apiKey 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
Unique workflow identifier.
1 <= lengthRequest 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"
}
}