> ## 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

## Example Usage

```typescript theme={null}
import { ContainerFile } from "@openrouter/sdk/models";

let value: ContainerFile = {
  bytes: 123,
  containerId: "sess_abc123",
  createdAt: 1755640000,
  id: "cfile_b3V0L3JlcG9ydC5jc3Y",
  object: "container.file",
  path: "out/report.csv",
  source: "assistant",
};
```

## Fields

| Field         | Type                                                            | Required             | Description                                                                                       | Example                    |
| ------------- | --------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------- | -------------------------- |
| `bytes`       | *number*                                                        | :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`   | *number*                                                        | :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`      | [models.ContainerFileObject](../models/containerfileobject.mdx) | :heavy\_check\_mark: | N/A                                                                                               | container.file             |
| `path`        | *string*                                                        | :heavy\_check\_mark: | Container-relative file path.                                                                     | out/report.csv             |
| `source`      | [models.ContainerFileSource](../models/containerfilesource.mdx) | :heavy\_check\_mark: | Container files are always produced by the assistant sandbox.                                     | assistant                  |