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

# Errors

> How the API reports failures

Failures return the same `{message, error, data}` envelope as successes, with `error: true` and an HTTP status code that signals the failure class.

```json theme={null}
{
  "message": "Validation failed",
  "error": true,
  "data": {
    "detail": "..."
  }
}
```

## Status codes

| Status | Meaning                                                                                                     |
| ------ | ----------------------------------------------------------------------------------------------------------- |
| `400`  | Validation failed — `data` describes the invalid fields                                                     |
| `401`  | Missing, invalid, expired, or disabled API key                                                              |
| `403`  | The key's member lacks permission for this entity or record                                                 |
| `404`  | Record not found in the key's workspace                                                                     |
| `409`  | Conflict — for example, deleting a record that still has active related records; `data.blocking` lists them |
| `429`  | Rate limit exceeded — retry after the window resets                                                         |

## Deletion conflicts

`DELETE` performs a logical delete. If active related records depend on the record, the API refuses with `409` and lists the blocking records so you can resolve them first:

```json theme={null}
{
  "message": "Cannot delete: active related records exist.",
  "error": true,
  "data": {
    "blocking": []
  }
}
```

## Rate limiting

`429` responses mean the key exhausted its hourly window. Check the `X-RateLimit-Remaining` and `X-RateLimit-Reset` headers on previous responses to pace your requests — see [Authentication](/docs/api-reference/authentication).