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

# Errors

> OAuth error codes for token, revoke, and consent redirects.

OAuth token and revoke endpoints return JSON errors with an `error` code and optional `error_description`.

## Token errors

| `error`                  | Typical cause                                                                  |
| ------------------------ | ------------------------------------------------------------------------------ |
| `invalid_client`         | Unknown client id or wrong client secret                                       |
| `invalid_grant`          | Invalid, expired, or reused code; redirect URI mismatch; invalid refresh token |
| `invalid_request`        | Missing required parameters                                                    |
| `unsupported_grant_type` | Grant type other than `authorization_code` or `refresh_token`                  |
| `invalid_token`          | Invalid or missing access token on protected endpoints                         |

## Consent redirect errors

These appear as query parameters on your `redirect_uri`:

| `error`            | Meaning                                                                  |
| ------------------ | ------------------------------------------------------------------------ |
| `access_denied`    | User denied access                                                       |
| `consent_required` | `consent=skip` was set but new scopes need an interactive consent screen |

## Example error body

```json theme={null}
{
  "error": "invalid_grant",
  "error_description": "Authorization code is invalid or expired"
}
```