> ## Documentation Index
> Fetch the complete documentation index at: https://docs.modelslab.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Workflows API

> Build and run multi-step AI workflows. List available workflows, execute them with custom parameters, and monitor execution status.

The Workflows API allows you to execute your custom workflows programmatically. Each workflow you create can be enabled as an API endpoint with its own unique parameters and responses.

## Base URL

```
https://modelslab.com/api/v1/workflows
```

## Authentication

All Workflows API requests require authentication using your ModelsLab API key. Include your API key in the request header:

```
key: YOUR_API_KEY
```

You can find your API key in your [dashboard settings](https://modelslab.com/dashboard/api-keys).

## Rate Limiting

Each workflow has its own configurable rate limit (default: 10 requests per minute per user). When you exceed the rate limit, you'll receive a `429 Too Many Requests` response with a `retry_after` field indicating when you can retry.

## Webhooks

If your workflow has a webhook URL configured, execution results will be automatically sent to that URL when the workflow completes or fails.

**Webhook Payload:**

```json theme={null}
{
  "event": "workflow.completed",
  "execution_id": 12345,
  "workflow_id": "uuid-string",
  "status": "completed",
  "output": {
    "output": ["https://cdn.modelslab.com/generated/image1.png"]
  },
  "completed_at": "2024-01-15T10:30:15Z"
}
```