CD Judge

A free, open-source code execution engine and online judge platform. Run code securely across 10 programming languages in isolated Linux sandboxes with 10x Judge0 limits.

Tech Stack

• Frontend: Next.js 15, React 19, Tailwind CSS v4, shadcn/ui
• API: Hono REST API with OpenAPI spec + tRPC for dashboard
• Database: PostgreSQL with Drizzle ORM
• Queue: BullMQ (Redis)
• Auth: Better Auth (GitHub/Google OAuth)
• Sandbox: Linux isolate (cgroup v2)
• Monorepo: Turborepo + pnpm workspaces

Supported Languages

Python 3, Node.js, TypeScript, Java 17, C++ 17, C, Rust, Go, Ruby, PHP

Quick Start

Prerequisites

• Node.js ^23, pnpm ^10.19
• Docker (for PostgreSQL, Redis, and the worker container)
• Linux with cgroup v2 (for the worker/sandbox)

Setup

pnpm install
cp .env.example .env

Local Development

Start services (db + redis) and the worker container, then run the web app on the host:

make services          # Start PostgreSQL + Redis
make worker            # Start worker container (isolate sandbox)
pnpm db:push           # Push schema to database (first time only)
pnpm dev               # Start Next.js dev server

The app runs at http://localhost:3000 with the API at /api.

Production

make services          # Start PostgreSQL + Redis
make worker            # Start worker container
make web               # Build & start Next.js in production container

Or start everything at once:

make prod              # Start all containers (services + worker + web)

Make Commands

Command	Description
make services	Start db + redis containers
make worker	Start worker container
make web	Build & start web app container (production)
make prod	Start everything (services + worker + web)
make dev	Start all in Docker (turbo dev + worker)
make down	Stop all containers
make logs	Follow all container logs
make logs-worker	Follow worker logs
make logs-web	Follow web app logs
make rebuild-worker	Rebuild worker image from scratch
make rebuild-web	Rebuild web image from scratch
make clean	Stop containers (preserves data)
make dangerously-clean	Stop containers AND delete all data

pnpm Scripts

Script	Description
pnpm dev	Start all dev servers (turbo watch)
pnpm dev:next	Start only the web app
pnpm build	Build all packages
pnpm lint	ESLint all packages
pnpm format	Check formatting (Prettier)
pnpm typecheck	TypeScript check all packages
pnpm db:push	Push Drizzle schema to database
pnpm db:studio	Open Drizzle Studio

API

Interactive API docs are available at /api/docs (Scalar UI). OpenAPI spec at /api/openapi.json.

Submit Code

curl -X POST https://your-host/api/v1/submissions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"lang": "py", "code": "print(42)"}'

Returns {"id": "123"}. Poll for results:

curl https://your-host/api/v1/submissions/123 \
  -H "Authorization: Bearer YOUR_API_KEY"

Response

{
  "id": "123",
  "status": "completed",
  "result": {
    "verdict": "OK",
    "stdout": "42\n",
    "stderr": "",
    "time": 45,
    "memory": 8192,
    "exitCode": 0
  }
}

Verdicts

Verdict	Meaning
OK	Successful execution
CE	Compilation error
RE	Runtime error
TO	Time limit exceeded
SG	Signal (segfault, etc.)
XX	Internal error

Project Structure

├── apps/web              # Next.js frontend + API mount
├── packages/
│   ├── hono-api          # Hono REST API (OpenAPI + Scalar docs)
│   ├── jobs              # BullMQ worker + IsolateRunner sandbox
│   ├── db                # Drizzle ORM schema + PostgreSQL client
│   ├── auth              # Better Auth (GitHub/Google OAuth)
│   └── validators        # Shared Zod schemas
└── tooling/              # Shared ESLint, Prettier, Tailwind, TS configs

Environment Variables

See .env.example for all required variables. Key ones:

• POSTGRES_URL — PostgreSQL connection string
• REDIS_URL — Redis connection string
• BASE_URL — App URL (e.g. http://localhost:3000)
• BETTER_AUTH_SECRET — Auth secret key
• BETTER_AUTH_GITHUB_ID/SECRET — GitHub OAuth credentials
• BETTER_AUTH_GOOGLE_ID/SECRET — Google OAuth credentials

License

MIT