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

# Errors and best practices

> Common failures and production-safe integration guidance.

## Common errors

| Code                    | Meaning                                                                       |
| ----------------------- | ----------------------------------------------------------------------------- |
| `missing_authorization` | No Bearer token was supplied.                                                 |
| `invalid_token`         | The token is expired, revoked, inactive, unknown, or not valid for the route. |
| `not_found`             | The route or resource is unavailable.                                         |
| `validation_failed`     | A path, query, or body field failed validation.                               |
| `permission_denied`     | The credential is not allowed to perform the requested action.                |

## Production guidance

* Store `pat_...` Project API Tokens server-side only.
* Send `X-Operation-Key` for multi-step jobs so API journeys are easier to inspect.
* Use `include_count=true` only when you need total counts.
* Prefer exact filters and indexes for high-traffic list views.
* Treat export URLs as generated artifacts, not permanent canonical storage.