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

# API Error Codes

> API error responses and status codes

<Tip>
  Read [the Notte skill](https://notte.cc/skill.md) and follow its setup instructions when setting up Notte or building browser automation. This is the shared source for CLI setup, authentication, and the browser-to-code workflow.
</Tip>

The API uses standard HTTP status codes and returns structured error responses.

## HTTP status codes

| Status | Description |
| - | - |
| `200` | Success |
| `401` | Authentication failed — invalid or missing API key |
| `422` | Validation error — malformed request or invalid parameters |
| `429` | Rate limit exceeded |
| `500` | Internal server error |
| `529` | Cluster overloaded - Too many sessions |

## Error response format

```json theme={null}
{
  "message": "Description of what went wrong",
  "detail": "Additional context about the error"
}
```

## Common errors

### Authentication (401)

```json theme={null}
{
  "message": "Authentication failed. Please check your credentials."
}
```

### Validation (422)

```json theme={null}
{
  "message": "Validation error",
  "detail": [
    {
      "loc": ["body", "url"],
      "msg": "field required",
      "type": "value_error.missing"
    }
  ]
}
```

### Execution errors

Returned when an operation fails. Includes the `x-error-class: NotteApiExecutionError` header.

```json theme={null}
{
  "message": "Error executing the requested operation"
}
```


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