---
title: "Start a sandbox"
method: POST
path: "/v2/sandboxes/boxes/{name}/start"
tags: ["sandboxes"]
---

# Start a sandbox

`POST /v2/sandboxes/boxes/{name}/start`

Start a stopped or failed sandbox. This endpoint is not idempotent.

## Path parameters

- `name` string, required

## Response `202`

Accepted

- SandboxesSandboxResponse
  - `created_at` string
  - `created_by` string
  - `dataplane_url` string
  - `delete_after_stop_seconds` integer
  - `fs_capacity_bytes` integer
  - `id` string
  - `idle_ttl_seconds` integer
  - `mem_bytes` integer
  - `name` string
  - `proxy_config` SandboxesProxyConfig
    - `access_control` SandboxesAccessControl
      - `allow_list` string[]
      - `deny_list` string[]
    - `callbacks` SandboxesCallback[]
      - `full_request` boolean
      - `match_hosts` string[], required
      - `request_headers` SandboxesProxyHeader[]
        - `is_set` boolean
        - `name` string, required
        - `type` 'plaintext' | 'opaque' | 'workspace_secret', required
        - `value` string
      - `ttl_seconds` integer, required
      - `url` string, required
    - `no_proxy` string[]
    - `rules` SandboxesProxyRule[]
      - `enabled` boolean
      - `headers` SandboxesProxyHeader[]
        - `is_set` boolean
        - `name` string, required
        - `type` 'plaintext' | 'opaque' | 'workspace_secret', required
        - `value` string
      - `match_hosts` string[], required
      - `match_paths` string[]
      - `name` string, required
  - `size_class` string
  - `snapshot_id` string
  - `status` string
  - `status_message` string
  - `stopped_at` string
  - `updated_at` string
  - `updated_by` string
  - `vcpus` integer

## Other responses

- `400` — Bad Request
- `403` — Forbidden
- `404` — Not Found
- `500` — Internal Server Error

## Changes

- **2026-05-27** `a0acb3a6a101` — 2 warning, 9 info
  - removed the optional property `expires_at` from the response with the `202` status
  - removed the optional property `ttl_seconds` from the response with the `202` status
  - added the optional property `created_by` to the response with the `202` status
  - added the optional property `delete_after_stop_seconds` to the response with the `202` status
  - …7 more
- **2026-04-30** `99490d1e837e` — 1 warning, 2 info
  - removed the optional property `template_name` from the response with the `202` status
  - added the optional property `proxy_config/callbacks` to the response with the `202` status
  - added the optional property `size_class` to the response with the `202` status
- **2026-04-13** `e86be67718ee` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/langchain-ai/apis/langsmith/changes/v2/sandboxes/boxes/:name/start/post.md)

---

[API](https://skmtc.dev/langchain-ai/apis/langsmith.md) · [All operations](https://skmtc.dev/langchain-ai/apis/langsmith/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/langchain-ai/langsmith/revisions/a0acb3a6a101/schema)