HackerEarth MCP

hackerearth-mcp

mcp-name: io.github.pratham-jain33/hackerearth-mcp

Also listed on Glama with one-click deploy.

Give any AI assistant a code run button.

Unofficial community project. Not made by, endorsed by, or affiliated with HackerEarth. You bring your own free HackerEarth API key.

Why

AI assistants are great at writing code and terrible at knowing whether it works. They guess. This server plugs into any MCP-compatible assistant (Claude Desktop, Claude Code, Cursor, and more) and lets it actually run code in 24 programming languages on HackerEarth's sandboxed servers, then read the real output. No local toolchains to install. Nothing untrusted ever touches your machine.

Tools

Tool	Description
run_code	Sends code plus a language to HackerEarth, waits for it to run, and returns the printed output and any error messages.
list_languages	Lists every language HackerEarth can run, with the exact identifiers to pass to run_code. Takes no inputs.

Installation

# Quick install via uvx (recommended)
uvx hackerearth-mcp

# Or install with pip
pip install hackerearth-mcp

# Install from source
git clone https://github.com/pratham-jain33/hackerearth-mcp
cd hackerearth-mcp
python -m venv .venv
.venv/bin/pip install -e .

Features

• Exposes two MCP tools: run_code and list_languages.
• Executes code in 24 programming languages via HackerEarth's sandboxed cloud servers.
• Provides friendly language aliases (e.g., python → PYTHON3).
• Returns real program output and error messages.
• Gracefully handles missing HACKEREARTH_KEY and unknown languages without making network calls.
• Lists all supported language identifiers.
• Simple installation via uvx or pip.
• Compatible with any MCP‑compatible AI assistant (Claude Desktop, Cursor, etc.).

Tech/framework used

• Language: Python (>=3.10)
• Core libraries: FastMCP (provides MCP server framework), requests (HTTP client)

Quickstart

1. Get a free HackerEarth API key

Register a client in the HackerEarth developer dashboard to receive a client-secret. The free tier includes a generous request quota.

2. Install

No cloning needed:

uvx hackerearth-mcp

or with pip:

pip install hackerearth-mcp

From source instead:

git clone https://github.com/pratham-jain33/hackerearth-mcp
cd hackerearth-mcp
python -m venv .venv
.venv/bin/pip install -e .

3. Connect your assistant

Claude Desktop config file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "hackerearth": {
      "command": "uvx",
      "args": ["hackerearth-mcp"],
      "env": {
        "HACKEREARTH_KEY": "paste-your-client-secret-here"
      }
    }
  }
}

From source, point at your checkout instead:

{
  "mcpServers": {
    "hackerearth": {
      "command": "/absolute/path/to/hackerearth-mcp/.venv/bin/python",
      "args": ["/absolute/path/to/hackerearth-mcp/server.py"],
      "env": {
        "HACKEREARTH_KEY": "paste-your-client-secret-here"
      }
    }
  }
}

Restart Claude Desktop, then try: "run this Python program and tell me what it prints: print(6 * 7)"

Configuration

Variable	Required	Description
HACKEREARTH_KEY	Yes	Your HackerEarth client-secret. Read from the environment, never hardcoded, never sent to the assistant in chat.

How it works

(This section is written by the project's author.)

1. You ask the assistant to run some code.
2. The assistant calls run_code with the code and the language.
3. The server sends it to HackerEarth with your key and gets back a tracking token.
4. The server polls HackerEarth until the run finishes.
5. HackerEarth runs the code in a sealed sandbox on their machines.
6. The server hands the output back to the assistant, which explains it to you.

Screenshots

Code style

No explicit linting or formatting tools are configured. The code follows standard PEP 8 conventions as observed in the source files.

Build status

Example session

You:    Is this Fibonacci function correct? Run it and show me the first 10 numbers.
        def fib(n):
            a, b = 0, 1
            for _ in range(n):
                print(a, end=" ")
                a, b = b, a + b
        fib(10)

Claude: [calls run_code with your function]
        It works. The output is: 0 1 1 2 3 5 8 13 21 34

Roadmap

• v0.1 — code submission, status polling, output download, compile/runtime error reporting, 24-language list
• v0.2 — PyPI packaging, install and run with a single uvx hackerearth-mcp command, server.json for the official MCP registry
• Published to the official MCP registry and Glama; submitted to awesome-mcp

Contributing

Issues and pull requests are welcome. If you add a tool, write its description the way you'd explain it to a smart friend who has never seen it — the assistant reads that text to decide when to use it.

License

MIT © Pratham Jain. See LICENSE.

Acknowledgments

Built on HackerEarth's code execution API and the Model Context Protocol. Thanks to HackerEarth for a genuinely developer-friendly free tier.

Tests

The repository includes a local test script test_local.py. To run the tests:

pip install fastmcp requests
python test_local.py

The GitHub Actions workflow test.yml executes the same commands on each push/pull request.

API reference

• run_code(code: str, language: str) -> str Executes the supplied code in the specified language on HackerEarth and returns the program's printed output or error messages.
• list_languages() -> str Returns a newline‑separated list of all supported language identifiers (e.g., PYTHON3, JAVASCRIPT_NODE).
• _normalize_language(lang: str) -> str (internal) Normalizes user‑provided language names or aliases to the exact HackerEarth identifiers.
• MCP registration is performed via FastMCP("hackerearth-mcp") which automatically registers the two tools above.

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