> ## 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 |