> ## Documentation Index
> Fetch the complete documentation index at: https://modal-devin.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Exception reference

> Public modal-devin errors and the action to take for each one.

All library-defined exceptions are importable from `modal_devin`.

## `ModalDevinError`

Base class for errors raised specifically by `modal-devin`. Catch it only when one
fallback is appropriate for every library failure.

## `ConfigurationError`

The application contains an invalid worker name, URL, setting, environment value,
credential, or managed Sandbox override. Correct the reported configuration and
redeploy.

## `ModalCompatibilityError`

This release requires a Modal SDK capability missing from the installed version. Run
`modal-devin doctor`, then install a supported Modal version.

## `OutpostsAPIError`

A Devin API request failed because of authentication, HTTP, connection, or timeout
behavior. Check the credential, outpost, configured API URL, and preceding network error.

## `OutpostsProtocolError`

Devin returned a response outside this release's safe handling range. Check release
compatibility and the original response error; mark the affected invocation as failed.

## `SessionStatusUnknownError`

The worker exited, but `modal-devin` was unable to confirm a safe final session state. It
attempts to preserve the filesystem before raising. Resolve the preceding API or
compatibility problem, then retry or resume the session.

## `WorkerExitedError`

The Devin worker returned a nonzero status after recovery handling. Inspect the
preceding worker output.

```python theme={null}
try:
    worker.run_session(session_id, app=app, image=image)
except WorkerExitedError as error:
    print(error.session_id)
    print(error.returncode)
    raise
```

<ResponseField name="session_id" type="str">
  Session whose worker failed.
</ResponseField>

<ResponseField name="returncode" type="int">
  Nonzero worker process exit status.
</ResponseField>

<Warning>
  Let lifecycle exceptions propagate from the generated function so Modal records
  failed attempts and applies its configured retry policy.
</Warning>