OpenSandbox MCP Sandbox Server

February 3, 2026 ยท View on GitHub

1. Overview

OpenSandbox MCP Server exposes the OpenSandbox Python SDK as MCP tools for Claude Code, Cursor, and other MCP-capable clients. It provides focused sandbox lifecycle management, command execution, and text file operations.

2. Installation & Startup

Source

uv sync
uv run opensandbox-mcp

Package

pip install opensandbox-mcp
opensandbox-mcp

Configuration

Environment variables:

  • OPEN_SANDBOX_API_KEY
  • OPEN_SANDBOX_DOMAIN

CLI overrides:

opensandbox-mcp --api-key ... --domain ... --protocol https

Config fields:

  • api_key: OpenSandbox API key for authentication.
  • domain: OpenSandbox API domain, for example api.opensandbox.io.
  • protocol: http or https for API requests.
  • request_timeout_seconds: HTTP request timeout in seconds.
  • transport: stdio by default, or streamable-http.

Streamable HTTP

opensandbox-mcp \
  --transport streamable-http

3. Integrations

Claude Code stdio

claude mcp add opensandbox-sandbox --transport stdio -- \
  opensandbox-mcp --api-key "$OPEN_SANDBOX_API_KEY" --domain "$OPEN_SANDBOX_DOMAIN"

Claude Code http

claude mcp add opensandbox-sandbox --transport http http://localhost:8000/mcp

Cursor stdio

{
  "mcpServers": {
    "opensandbox-sandbox": {
      "command": "opensandbox-mcp",
      "args": [
        "--api-key",
        "${OPEN_SANDBOX_API_KEY}",
        "--domain",
        "${OPEN_SANDBOX_DOMAIN}"
      ]
    }
  }
}

Cursor http

{
  "mcpServers": {
    "opensandbox-sandbox": {
      "url": "http://localhost:8000/mcp"
    }
  }
}

4. Tools

Notes:

  • All tools operate on a sandbox_id returned by sandbox_create or sandbox_connect.
  • file_read/file_write are text-only; use encoding and range_header for large files.

Sandbox

  • sandbox_create: create a new sandbox and register it locally
  • sandbox_connect: attach to an existing sandbox and register it locally
  • sandbox_kill: terminate a sandbox by ID
  • sandbox_get_info: fetch sandbox info by ID
  • sandbox_list: list sandboxes with optional filter object
  • sandbox_renew: extend sandbox expiration
  • sandbox_healthcheck: check if sandbox is healthy
  • sandbox_get_metrics: get resource metrics
  • sandbox_get_endpoint: get network endpoint for a port

Command Execution

  • command_run: run a command inside a sandbox
  • command_interrupt: interrupt a running command

Filesystem

  • file_read: read a text file
  • file_write: write a text file
  • file_delete: delete files
  • file_search: search for files by glob
  • file_create_directories: create directories
  • file_delete_directories: delete directories
  • file_move: move/rename files or directories
  • file_replace_contents: replace file content

5. Minimal Workflow

  1. sandbox_create -> keep the sandbox_id.
  2. file_write code or assets into the sandbox.
  3. command_run to execute, install dependencies, or start a service.
  4. sandbox_get_endpoint if you expose a port.
  5. sandbox_kill when finished.

6. Usage Examples

Here are some examples of what you can ask an LLM to do:

  • "Create a Python sandbox and run a quick health command."
  • "Write a Python script into the sandbox and run it."
  • "Download a GitHub repo, install dependencies, and run its tests."
  • "Generate a CSV file with fake sales data and run a simple summary script."
  • "Start a tiny web server on port 8000 and return the public URL."
  • "Build a minimal REST API (hello + health) and expose it on port 8000."
  • "Create a tar.gz of /app and report the file size."
  • "Build a simple Snake game and return the web endpoint where it can be accessed."