## Add Session Resource

`beta.sessions.resources.add(session_id, **kwargs) -> BetaManagedAgentsFileResource`

**post** `/v1/sessions/{session_id}/resources`

Add Session Resource

### Parameters

- `session_id: String`

- `file_id: String`

  ID of a previously uploaded file.

- `type: :file`

  - `:file`

- `mount_path: String`

  Mount path in the container. Defaults to `/mnt/session/uploads/<file_id>`.

- `betas: Array[AnthropicBeta]`

  Optional header to specify the beta version(s) you want to use.

  - `String = String`

  - `AnthropicBeta = :"message-batches-2024-09-24" | :"prompt-caching-2024-07-31" | :"computer-use-2024-10-22" | 23 more`

    - `:"message-batches-2024-09-24"`

    - `:"prompt-caching-2024-07-31"`

    - `:"computer-use-2024-10-22"`

    - `:"computer-use-2025-01-24"`

    - `:"pdfs-2024-09-25"`

    - `:"token-counting-2024-11-01"`

    - `:"token-efficient-tools-2025-02-19"`

    - `:"output-128k-2025-02-19"`

    - `:"files-api-2025-04-14"`

    - `:"mcp-client-2025-04-04"`

    - `:"mcp-client-2025-11-20"`

    - `:"dev-full-thinking-2025-05-14"`

    - `:"interleaved-thinking-2025-05-14"`

    - `:"code-execution-2025-05-22"`

    - `:"extended-cache-ttl-2025-04-11"`

    - `:"context-1m-2025-08-07"`

    - `:"context-management-2025-06-27"`

    - `:"model-context-window-exceeded-2025-08-26"`

    - `:"skills-2025-10-02"`

    - `:"fast-mode-2026-02-01"`

    - `:"output-300k-2026-03-24"`

    - `:"user-profiles-2026-03-24"`

    - `:"advisor-tool-2026-03-01"`

    - `:"managed-agents-2026-04-01"`

    - `:"cache-diagnosis-2026-04-07"`

    - `:"thinking-token-count-2026-05-13"`

### Returns

- `class BetaManagedAgentsFileResource`

  - `id: String`

  - `created_at: Time`

    A timestamp in RFC 3339 format

  - `file_id: String`

  - `mount_path: String`

  - `type: :file`

    - `:file`

  - `updated_at: Time`

    A timestamp in RFC 3339 format

### Example

```ruby
require "anthropic"

anthropic = Anthropic::Client.new(api_key: "my-anthropic-api-key")

beta_managed_agents_file_resource = anthropic.beta.sessions.resources.add(
  "sesn_011CZkZAtmR3yMPDzynEDxu7",
  file_id: "file_011CNha8iCJcU1wXNR6q4V8w",
  type: :file
)

puts(beta_managed_agents_file_resource)
```

#### Response

```json
{
  "id": "sesrsc_011CZkZBJq5dWxk9fVLNcPht",
  "created_at": "2026-03-15T10:00:00Z",
  "file_id": "file_011CNha8iCJcU1wXNR6q4V8w",
  "mount_path": "/uploads/receipt.pdf",
  "type": "file",
  "updated_at": "2026-03-15T10:00:00Z"
}
```