Online Judge Server
FreeNot checkedProvides tools for AI agents to interact with the Orange Juice Online Judge API by managing problems and code submissions. Users can list problems, retrieve det
About
Provides tools for AI agents to interact with the Orange Juice Online Judge API by managing problems and code submissions. Users can list problems, retrieve detailed descriptions, submit source code, and track submission status through natural language.
README
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(oroj-mcp-serverif installed via pip) - Environment: Set
OJ_URL,OJ_USERNAME, andOJ_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"].
Install Online Judge Server in Claude Desktop, Claude Code & Cursor
unyly install online-judge-mcp-serverInstalls into Claude Desktop, Claude Code, Cursor & VS Code — handles npx, uvx and build-from-source repos for you.
First time? Get the CLI: curl -fsSL https://unyly.org/install | sh
Or configure manually
Run in your terminal:
claude mcp add online-judge-mcp-server -- uvx oj-mcp-serverStep-by-step: how to install Online Judge Server
FAQ
Is Online Judge Server MCP free?
Yes, Online Judge Server MCP is free — one-click install via Unyly at no cost.
Does Online Judge Server need an API key?
No, Online Judge Server runs without API keys or environment variables.
Is Online Judge Server hosted or self-hosted?
A hosted option is available: Unyly runs the server in the cloud, no local setup required.
How do I install Online Judge Server in Claude Desktop, Claude Code or Cursor?
Open Online Judge Server on unyly.org, pick your client tab (Claude Desktop, Claude Code, Cursor) and press Install — the config is generated automatically, no JSON editing.
Related MCPs
GitHub
PRs, issues, code search, CI status
by GitHubFilesystem
Secure file operations with configurable access controls.
Memory
Knowledge graph-based persistent memory system.
Template MCP Server
A CLI tool to create a new Model Context Protocol server project with TypeScript support, dual transport options, and an extensible structure
by mcpdotdirectAmap Maps Mcp Server
MCP server for using the AMap Maps API
by duxiaohuiSupabase
Database, auth and storage
by SupabaseEverything
Reference / test server with prompts, resources, and tools.
Git
Tools to read, search, and manipulate Git repositories.
Sequential Thinking
Dynamic and reflective problem-solving through thought sequences.
Time
Time and timezone conversion capabilities.
Compare Online Judge Server with
Not sure what to pick?
Find your stack in 60 seconds
Author?
Embed badge for your README
Browse similar
All development MCPs
