## Acknowledge Work

**post** `/v1/environments/{environment_id}/work/{work_id}/ack`

Note: these endpoints are called automatically by the pre-built environment worker provided in the SDKs and CLI, for orchestrating sessions with self-hosted sandbox environments. They are included here as a reference; you do not need to invoke them directly.

Acknowledge receipt of a work item, transitioning it from 'queued' to 'starting' and removing it from the queue.

### Path Parameters

- `environment_id: string`

- `work_id: string`

### Header Parameters

- `"anthropic-beta": optional array of AnthropicBeta`

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

  - `string`

  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 25 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"`

    - `"server-side-fallback-2026-06-01"`

    - `"fallback-credit-2026-06-01"`

### Returns

- `BetaSelfHostedWork object { id, acknowledged_at, created_at, 9 more }`

  Work resource representing a unit of work in a self-hosted environment.

  Work items are queued when sessions are created or when long-dormant sessions
  receive new messages. The environment worker polls for work to execute in a
  self-hosted sandbox.

  - `id: string`

    Work identifier (e.g., 'work_...')

  - `acknowledged_at: string`

    RFC 3339 timestamp when the work item was acknowledged and assigned to a self-hosted sandbox

  - `created_at: string`

    RFC 3339 timestamp when work was created

  - `data: BetaSessionWorkData`

    The actual work to be performed

    - `id: string`

      Session identifier (e.g., 'session_...')

    - `type: "session"`

      Type of work data

      - `"session"`

  - `environment_id: string`

    Environment identifier this work belongs to (e.g., `env_...`)

  - `latest_heartbeat_at: string`

    RFC 3339 timestamp of the most recent heartbeat

  - `metadata: map[string]`

    User-provided metadata key-value pairs associated with this work item

  - `started_at: string`

    RFC 3339 timestamp when work execution started

  - `state: "queued" or "starting" or "active" or 2 more`

    Current state of the work item

    - `"queued"`

    - `"starting"`

    - `"active"`

    - `"stopping"`

    - `"stopped"`

  - `stop_requested_at: string`

    RFC 3339 timestamp when stop was requested

  - `stopped_at: string`

    RFC 3339 timestamp when work execution stopped

  - `type: "work"`

    The type of object (always 'work')

    - `"work"`

### Example

```http
curl https://api.anthropic.com/v1/environments/$ENVIRONMENT_ID/work/$WORK_ID/ack \
    -X POST \
    -H 'anthropic-version: 2023-06-01' \
    -H 'anthropic-beta: managed-agents-2026-04-01' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY"
```

#### Response

```json
{
  "id": "id",
  "acknowledged_at": "acknowledged_at",
  "created_at": "created_at",
  "data": {
    "id": "id",
    "type": "session"
  },
  "environment_id": "environment_id",
  "latest_heartbeat_at": "latest_heartbeat_at",
  "metadata": {
    "foo": "string"
  },
  "started_at": "started_at",
  "state": "queued",
  "stop_requested_at": "stop_requested_at",
  "stopped_at": "stopped_at",
  "type": "work"
}
```
