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

# Error codes

> Handle Darwin HTTP errors and structured Action states.

## HTTP errors

| Status | Meaning                                                        | What to do                                                |
| ------ | -------------------------------------------------------------- | --------------------------------------------------------- |
| `400`  | The request is malformed or fails validation.                  | Correct the fields listed in the response.                |
| `401`  | Authentication is missing or expired.                          | Authenticate again or replace the credential.             |
| `403`  | The credential lacks the required scope or authority.          | Request the correct scope or user authorization.          |
| `404`  | The resource does not exist or is not visible.                 | Verify the identifier and owner context.                  |
| `409`  | The mutation conflicts with current state or replay history.   | Read the current Action before retrying.                  |
| `429`  | The caller is sending requests too quickly.                    | Respect `Retry-After` and back off.                       |
| `5xx`  | Darwin or an upstream provider could not complete the request. | Retry transient failures without changing the request ID. |

## Structured Action states

A successful HTTP response can still require user input, connection, payment, approval, or more authority. Render the supplied `status`, `actionRequired`, and `availableActions`; do not convert them into a generic error or success message.

## Support context

Record the operation, status code, latency, `actionId`, `requestId`, and Darwin response correlation ID. Never log API keys, OAuth tokens, provider credentials, payment data, or unredacted sensitive inputs.