SandboxAPI

MCP Languages License

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.

Links

• Website
• Playground
• RapidAPI Listing
• MCP Specification

License

MIT