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

# Add a Session resource

> Attach a file resource to an existing Session.

`POST /api/v1/cloud/sessions/{session_id}/resources`

Attaches one file resource to an existing Session. GitHub repository and Memory Store resources are attached when creating the Session; this add endpoint accepts only `type: "file"`.

## Path parameters

| Parameter    | Type   | Description                        |
| ------------ | ------ | ---------------------------------- |
| `session_id` | string | Session ID with the `sess_` prefix |

## Headers

| Header          | Required | Description         |
| --------------- | -------- | ------------------- |
| `Authorization` | Yes      | `Bearer $QODER_PAT` |
| `Content-Type`  | Yes      | `application/json`  |

## Request body

| Field        | Type           | Required | Description                                                 |
| ------------ | -------------- | -------- | ----------------------------------------------------------- |
| `type`       | string         | Yes      | Must be `"file"`                                            |
| `file_id`    | string         | Yes      | File ID obtained from the Files API. The file must be ready |
| `mount_path` | string \| null | No       | Mount path. Defaults to `/mnt/session/uploads/<file_id>`    |

## Example request

```bash theme={null}
curl -X POST https://api.qoder.com/api/v1/cloud/sessions/sess_019e392c0d1e74e095d21ea4c6b41def/resources \
  -H "Authorization: Bearer $QODER_PAT" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "file",
    "file_id": "file_abc123def456",
    "mount_path": "/data/inputs/spec.md"
  }'
```

## Example response

**HTTP 200 OK**

```json theme={null}
{
  "id": "sesr_0e4323e8f47ba34853f5409e",
  "type": "file",
  "file_id": "file_019ef2a07a06704fb899908c29eed779",
  "mount_path": "/mnt/session/uploads/file_019ef2a07a06704fb899908c29eed779",
  "created_at": "2026-06-23T05:53:19.77484Z",
  "updated_at": "2026-06-23T05:53:38.185714Z"
}
```

## Errors

| HTTP | Type                    | Trigger                                                                                               |
| ---- | ----------------------- | ----------------------------------------------------------------------------------------------------- |
| 400  | `invalid_request_error` | Malformed request, unsupported type, missing `file_id`, or invalid mount path                         |
| 401  | `authentication_error`  | PAT invalid or expired                                                                                |
| 404  | `not_found_error`       | Session or file does not exist                                                                        |
| 409  | `invalid_request_error` | Session is archived or terminated, file is not ready, or the file is already attached to this session |

**HTTP 400 Bad Request**

```json theme={null}
{
  "type": "error",
  "request_id": "cb80235f-76a2-4ff3-9e28-5aa2da12dc14",
  "error": {
    "type": "invalid_request_error",
    "message": "Field 'type' must be 'file'."
  }
}
```

**HTTP 400 Bad Request**

```json theme={null}
{
  "type": "error",
  "request_id": "cb80235f-76a2-4ff3-9e28-5aa2da12dc14",
  "error": {
    "type": "invalid_request_error",
    "message": "Field 'file_id' is required."
  }
}
```

**HTTP 404 Not Found**

```json theme={null}
{
  "type": "error",
  "request_id": "cb80235f-76a2-4ff3-9e28-5aa2da12dc14",
  "error": {
    "type": "not_found_error",
    "message": "File 'file_fake_test_id' was not found."
  }
}
```

See [Errors](/cloud-agents/api/conventions/errors) for the full error envelope.

## Related

<CardGroup cols={2}>
  <Card title="Start a session" icon="play" href="/cloud-agents/sessions">
    Run an agent against an environment as a stateful conversation.
  </Card>
</CardGroup>