SandboxAPI MCP Server

Give your AI agent the ability to execute code in 8 programming languages, safely.

SandboxAPI MCP Server connects any MCP-compatible AI client (Claude, Cursor, VS Code, Windsurf, etc.) to secure code execution. Every execution runs inside a gVisor-sandboxed Docker container with no network access, strict resource limits, and ephemeral filesystems.

Quick Start

Option 1: Remote Server (No Setup)

Connect directly to the hosted endpoint. No local installation required.

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "sandboxapi": {
      "url": "https://mcp.sandboxapi.dev/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

VS Code (.vscode/mcp.json):

{
  "servers": {
    "sandboxapi": {
      "url": "https://mcp.sandboxapi.dev/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Cursor (~/.cursor/mcp.json):

{
  "mcpServers": {
    "sandboxapi": {
      "url": "https://mcp.sandboxapi.dev/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Option 2: Docker

docker run -d \
  -p 8081:8081 \
  -e SANDBOXAPI_API_KEY=your_sandboxapi_key \
  -e MCP_API_KEY=your_mcp_auth_key \
  sandboxapi/mcp:latest

Then point your client to http://localhost:8081/mcp.

Option 3: Build from Source

git clone https://github.com/sandboxapi/sandboxapi-mcp.git
cd sandboxapi-mcp
go build -o sandboxapi-mcp .

export SANDBOXAPI_API_KEY=your_key
export MCP_API_KEY=optional_auth_key
./sandboxapi-mcp

Available Tools

`execute_code`

Execute code in a sandboxed container.

Parameter	Type	Required	Description
`language`	string	Yes	`python3`, `javascript`, `typescript`, `bash`, `java`, `cpp`, `c`, `go`
`code`	string	Yes	Source code to execute (max 1MB)
`timeout`	number	No	Timeout in seconds (default: 10, max: 300)
`stdin`	string	No	Standard input to pass to the program

`execute_batch`

Execute multiple code snippets. Each runs in its own isolated sandbox.

Parameter	Type	Required	Description
`executions`	array	Yes	Array of `{language, code, timeout?, stdin?}` objects

`list_languages`

List all supported programming languages with versions and example code. No parameters.

Supported Languages

Language	Version	Aliases
Python	3.12	`python3`, `python`, `py`
JavaScript	Node 22	`javascript`, `js`, `node`
TypeScript	5.4	`typescript`, `ts`
Go	1.22	`go`, `golang`
Java	21	`java`, `jdk`
C++	GCC 14	`cpp`, `c++`
C	GCC 14	`c`, `gcc`
Bash	5.2	`bash`, `sh`, `shell`

Environment Variables

Variable	Required	Description
`SANDBOXAPI_API_KEY`	Yes	API key for the SandboxAPI backend
`MCP_API_KEY`	No	Auth key for the MCP endpoint (omit for open access)
`MCP_PORT`	No	Port to listen on (default: `8081`)
`SANDBOXAPI_URL`	No	API base URL (default: `https://api.sandboxapi.dev`)

Security

Every code execution is isolated with defense-in-depth:

gVisor (runsc) — User-space kernel intercepts all syscalls
Network isolation — Executed code cannot make outbound connections
Resource limits — CPU, memory, and disk usage are capped
Ephemeral containers — Destroyed immediately after execution
Read-only filesystem — No persistent writes between executions
Code size limits — Source code capped at 1MB
Timeout enforcement — Hard kill after configured timeout

API Key

Get your API key at sandboxapi.dev or through RapidAPI.

License

MIT

SandboxAPI