Recoding — Exercise Platform

v1.0.0 · Live · Code Runner

A controlled environment for running timed coding and writing exercises with live anti-cheat monitoring.

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What is this?

Recoding is a web platform where instructors assign exercises to participants, set time limits, and monitor activity in real time. Participants complete written or coding exercises in a browser-based editor. Every keystroke, paste, and focus loss is recorded. When time runs out, everything is saved automatically.

Instructors can create exercises, upload questions from Markdown files, assign participants, set timing, and review submissions with full typing replay.

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Who uses it?

Role	What they do
Instructor	Creates exercises, uploads questions, assigns participants, sets timing, monitors live activity, reviews submissions, manages users
Participant	Logs in, sees assigned exercises, answers questions in the editor, submits answers, changes password

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Features

Instructor

• Create and manage exercises (title, slug, timing, assignments)
• Upload questions from .md files or add manually through the UI
• Enable/disable exercises per session
• Live monitor — see paste events, focus losses, and keystrokes in real time with participant names
• Review submissions with full typing replay, paste events, focus-loss timeline
• Export submissions as CSV
• User management — create accounts, reset passwords, delete participants
• Audit log on all instructor actions
• Search across exercises, submissions, users, and live events

Participant

• Written questions — text editor with autosave every 25 seconds
• Coding drills — Monaco editor (VS Code engine) with live Go execution
• Navigate between questions, continue from where you left off
• Change password from settings page

Platform

• Anti-cheat: paste detection, focus-loss tracking, edit event recording
• Timed sessions — start time, end time, or duration limit
• Neon PostgreSQL (serverless, HTTPS)
• Custom Go code runner deployed on Render
• CI/CD: GitHub Actions build check + Vercel preview deployments
• Branch protection: preview → main requires passing CI

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Tech stack

Layer	Technology
Framework	Next.js 14 (App Router)
Database	PostgreSQL via Neon (serverless, HTTPS)
Auth	NextAuth.js (credentials + JWT)
Editor	Monaco Editor
Code runner	Custom Go service (jvcByte/code-runner)
Deployment	Vercel (app) + Render (runner) + Neon (database)
CI	GitHub Actions

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Getting started

1. Clone with submodules

git clone --recurse-submodules https://github.com/jvcByte/recoding.git
cd recoding
npm install

2. Configure environment

cp .env.example .env.local

Fill in .env.local:

DATABASE_URL=postgresql://user:password@host-pooler.region.neon.tech/dbname?sslmode=require
NEXTAUTH_SECRET=<openssl rand -base64 32>
NEXTAUTH_URL=http://localhost:3000
RUNNER_URL=https://your-runner.onrender.com
RUNNER_API_KEY=<openssl rand -base64 32>

3. Set up the database

npm run migrate          # create all tables
npm run seed             # seed exercises and default users
npm run import-questions # import questions from docs/ into DB

Default accounts:

• instructor / instructor123
• participant / participant123

4. Start the dev server

npm run dev

Open http://localhost:3000.

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Code runner

Coding drills require the code-runner service — a lightweight Go HTTP server that compiles and runs participant code.

Deploy to Render (free tier):

1. Go to render.com → New → Web Service
2. Connect github.com/jvcByte/code-runner
3. Runtime: Docker
4. Add env var: RUNNER_API_KEY=<same secret as in main app>
5. Deploy, then set RUNNER_URL=https://your-service.onrender.com in the main app

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Available scripts

Command	Description
npm run dev	Start development server
npm run build	Build for production
npm run migrate	Apply pending database migrations
npm run migrate:fresh	Drop all tables, re-run migrations, seed, import questions
npm run seed	Seed exercises and default users
npm run import-questions	Import questions from docs/ into the database
npm run create-users	Bulk-create users from docs/users/users.md
npm run cleanup	Delete autosave history older than 30 days
npm run reset-password <username> <password>	Reset a user's password

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Project structure

app/
  api/           — API route handlers
  instructor/    — Instructor dashboard pages
  participant/   — Participant session pages
  components/    — Shared UI components (Navbar, SearchInput, LogoutButton)
docs/
  ascii-art/     — ASCII art coding drills (11 questions)
  ascii-art-web/ — ASCII art web coding drills (12 questions)
  go-reloaded/   — Go-reloaded written questions (15 questions)
  prompt-piscine/— Prompt engineering written questions
  banner_files/  — standard.txt, shadow.txt, thinkertoy.txt (injected as stdin)
  users/         — users.md with participant credentials
lib/
  auth.ts        — NextAuth configuration
  db.ts          — Neon serverless database client
  flagging.ts    — Anti-cheat flag evaluation
  questions.ts   — Exercise content loader
  audit.ts       — Audit log helper
  rateLimit.ts   — Login rate limiter
  utils.ts       — Shared utility functions
migrations/      — SQL migration files (versioned)
runner/          — Go code runner (git submodule → jvcByte/code-runner)
scripts/         — CLI utilities
.github/
  workflows/
    ci.yml       — Build check on PRs to main/preview

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Exercises

Slug	Type	Questions	Description
ascii-art	Code (Go)	11	Build an ASCII art renderer from scratch
ascii-art-web	Code (Go)	12	Serve ASCII art over HTTP
go-reloaded	Written	15	Reflect on building a text transformation tool
prompt-basics	Written	12	Prompt engineering fundamentals
prompt-patterns	Written	12	Advanced prompting patterns
ai-ethics	Written	12	AI ethics scenarios
debug-control	Written	12	Debugging mindset
ethical-ai	Written	12	Ethical AI in practice
reasoning-flow	Written	15	Reasoning and flow
role-prompt	Written	15	Role-based prompting
tool-prompts	Written	15	Tool-use prompting

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License

MIT