Code Sandbox API MCP Server

by br0ski777 Your server? Claim it

not responding

Code Sandbox API is listed as active in the registry but did not answer our last check. It exposes 1 tools. Last commit 2 Sep 2026.

Execute Python, JavaScript, SQL code in a sandbox. x402 micropayment.

Uptime history 51 days of history · worst day 0%

51 days agonow

0.0%

Uptime 24h

0 of 92 checks

Tools

read from the server

18 ms

Response time

average over 24h

Stars

last commit 2 Sep 2026

What the code does

We read the source, 15 h ago · tools taken from the live server · rules 3dff92dd89df

Capabilities

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

Runs an external command src/logic.ts:51

    const proc = Bun.spawn([python, "-c", code], {

Executes code built at runtime src/logic.ts:32

    const fn = new Function("return (async () => { const __results = []; const console = { log: (...a) => __results.push(a.map(String).join(' ')), error: (...a) => __results.push('[error] ' + a.map(String).join(' ')), warn: (...a) => __results.push('[warn] ' + a.map(String).join(…

Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.

This code can reach further than it looks

We found places where it runs commands, builds paths or queries from values it is given. None of that is a flaw by itself — it becomes one when the code changes, and code changes quietly between releases. We re-read it on every one.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 2 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add code-sandbox --transport http https://code-sandbox.api.klymax402.com/mcp

~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "code-sandbox": {
      "url": "https://code-sandbox.api.klymax402.com/mcp"
    }
  }
}

~/.codex/config.toml

[mcp_servers.code-sandbox]
url = "https://code-sandbox.api.klymax402.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "code-sandbox": {
      "url": "https://code-sandbox.api.klymax402.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "mcpServers": {
    "code-sandbox": {
      "url": "https://code-sandbox.api.klymax402.com/mcp"
    }
  }
}

Available tools 1

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

code

code_execute_sandbox

Use this when you need to execute Python, JavaScript, or SQL code in a sandboxed environment and get the output. Supports Python (subprocess), JavaScript (eval), and SQL (in-memory SQLite). 1. output: stdout captured from code execution (max 10KB) 2. language: the language that was executed 3. executionTimeMs: execution duration in milliseconds 4. exitCode: process exit code (0 = success) 5. error: error message if execution failed (null on success) Example output: {"output":"Hello World\n42\n","language":"python","executionTimeMs":234,"exitCode":0,"error":null} Use this FOR running calculations, data transformations, validating code snippets, or querying in-memory databases. Essential when you need computed results rather than static data. Do NOT use for persistent file storage -- sandbox is ephemeral. Do NOT use for generating hashes -- use crypto_generate_hash. Do NOT use for PDF generation -- use document_generate_pdf. Do NOT use for web scraping -- use web_scrape_to_markdown.

Endpoints

URL	Transport	State	Latency	Checked
https://code-sandbox.api.klymax402.com/mcp	sse	answering	18 ms	2 min ago

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Code Sandbox API — questions

Answers built from our own checks of this server.

What can Code Sandbox API do?

It exposes 1 tools, read directly from the server on our last check. Among them: code_execute_sandbox. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is Code Sandbox API working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 0 of 92 checks got a reply (0.0%), average response time 18 ms. The bar chart above shows every period we have measured.

The registry lists Code Sandbox API as active — why does it not respond?

The official MCP registry stores what the author submitted; it does not verify that the server still runs. We check the endpoint ourselves, and this one does not answer. Catalogues that copy the registry without checking will show it as working.

How do I connect Code Sandbox API?

Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Code Sandbox API need an API key?

No. Code Sandbox API completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 1 of them are readable on this page. This is what we observed, not what the docs claim.

Is Code Sandbox API open source?

Yes — it is published under the MIT licence, written in TypeScript, 0 stars on GitHub and 1 open issue. The source link is on this page, so you can read exactly what it does with your data before you connect it.