> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-7021d5f4.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# CustomToolCallOutputItem - Python SDK

> CustomToolCallOutputItem 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 output from a custom (freeform-grammar) tool call execution. Mirrors `function_call_output` but is matched to a `custom_tool_call` rather than a `function_call`.

## Fields

| Field     | Type                                                                                                                                                         | Required             | Description |
| --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------- | ----------- |
| `call_id` | *str*                                                                                                                                                        | :heavy\_check\_mark: | N/A         |
| `id`      | *Optional\[str]*                                                                                                                                             | :heavy\_minus\_sign: | N/A         |
| `output`  | [components.CustomToolCallOutputItemOutputUnion2](/client-sdks/python/api-reference/components/customtoolcalloutputitemoutputunion2)                         | :heavy\_check\_mark: | N/A         |
| `type`    | [components.CustomToolCallOutputItemTypeCustomToolCallOutput](/client-sdks/python/api-reference/components/customtoolcalloutputitemtypecustomtoolcalloutput) | :heavy\_check\_mark: | N/A         |