Online Judge MCP Server

This is a Model Context Protocol (MCP) server that provides AI agents with tools to interact with an Online Judge API.

Features

Provides the following tools:

• list_problems(offset, limit): List available problems on the OJ.
• list_my_submissions(offset, limit): List recent submissions made by the authenticated user.
• get_problem_details(problem_id): Fetch detailed descriptions, samples, limits, and rules of a problem.
• submit_code(problem_id, code, language): Submit source code to a specific problem.
• get_submission_status(submission_id): Check the polling status of a code submission.

Quickstart

Using uvx (Recommended)

The easiest way to run this server is using uvx, which automatically downloads the correct Python version, creates an ephemeral environment, and runs the tool seamlessly:

set OJ_URL="http://localhost:8000" # Replace with actual OJ URL
set OJ_USERNAME="your-username"
set OJ_PASSWORD="your-password"

uvx oj-mcp-server

Using pip or pipx

Alternatively, you can install the package directly into your Python environment:

pip install oj-mcp-server
oj-mcp-server

Usage with MCP Clients

To use this server, add it to your MCP client's configuration (e.g., Claude Desktop, Cursor, Cline).

Claude Desktop

Add the following to your claude_desktop_config.json:

{
  "mcpServers": {
    "oj-mcp-server": {
      "command": "uvx",
      "args": ["oj-mcp-server"],
      "env": {
        "OJ_URL": "http://localhost:8000",
        "OJ_USERNAME": "your-username",
        "OJ_PASSWORD": "your-password"
      }
    }
  }
}

Note: If you installed globally via pip, simply change "command" to "oj-mcp-server" and "args" to [].

Cursor & Cline

In the MCP settings panel, add a new server:

• Type: command
• Name: oj-mcp-server
• Command: uvx oj-mcp-server (or oj-mcp-server if installed via pip)
• Environment: Set OJ_URL, OJ_USERNAME, and OJ_PASSWORD

OpenCode

Add this configured server inside your opencode.json (under the mcp key):

{
  "mcp": {
    "oj-mcp-server": {
      "type": "local",
      "command": ["uvx", "oj-mcp-server"],
      "environment": {
        "OJ_URL": "http://localhost:8000",
        "OJ_USERNAME": "your-username",
        "OJ_PASSWORD": "your-password"
      }
    }
  }
}

Note: If using pip, change the command array to ["oj-mcp-server"].