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

# ContainerFile

## Fields

| Field         | Type                                                                              | Required             | Description                                                                                       | Example                    |
| ------------- | --------------------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------- | -------------------------- |
| `Bytes`       | `int64`                                                                           | :heavy\_check\_mark: | File size in bytes.                                                                               | 123                        |
| `ContainerID` | `string`                                                                          | :heavy\_check\_mark: | The container the file belongs to — echoes the `container_id` path parameter (OpenAI field name). | sess\_abc123               |
| `CreatedAt`   | `int64`                                                                           | :heavy\_check\_mark: | Unix timestamp (seconds) when the file was last synced.                                           | 1755640000                 |
| `ID`          | `string`                                                                          | :heavy\_check\_mark: | Container file id: `cfile_` + base64url of the file path.                                         | cfile\_b3V0L3JlcG9ydC5jc3Y |
| `Object`      | [components.ContainerFileObject](../../models/components/containerfileobject.mdx) | :heavy\_check\_mark: | N/A                                                                                               | container.file             |
| `Path`        | `string`                                                                          | :heavy\_check\_mark: | Container-relative file path.                                                                     | out/report.csv             |
| `Source`      | [components.ContainerFileSource](../../models/components/containerfilesource.mdx) | :heavy\_check\_mark: | Container files are always produced by the assistant sandbox.                                     | assistant                  |