> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-5b6e02fd.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# OutputMessageItemPhaseUnion - Python SDK

> OutputMessageItemPhaseUnion method reference

<Warning>
  The Python SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/python-sdk/issues).
</Warning>

The phase of an assistant message. Use `commentary` for an intermediate assistant message and `final_answer` for the final assistant message. For follow-up requests with models like `gpt-5.3-codex` and later, preserve and resend phase on all assistant messages. Omitting it can degrade performance. Not used for user messages.

## Supported Types

### `components.OutputMessageItemPhaseCommentary`

```python lines theme={null}
value: components.OutputMessageItemPhaseCommentary = /* values here */
```

### `components.OutputMessageItemPhaseFinalAnswer`

```python lines theme={null}
value: components.OutputMessageItemPhaseFinalAnswer = /* values here */
```

### `Any`

```python lines theme={null}
value: Any = /* values here */
```