What is R's PlacePrep?

R's PlacePrep is a free, open-source placement preparation platform for engineering students. It provides company-wise previous year questions with detailed solutions, timed mock exams, university PYQs, and aptitude & coding practice for TCS NQT, Infosys IRT, Accenture, and more.

Is R's PlacePrep free to use?

Yes! R's PlacePrep is 100% free and open-source. All placement papers, mock exams, university PYQs, and solutions are accessible without any payment or subscription.

Which companies are covered on PlacePrep?

PlacePrep covers placement papers from TCS (NQT), Infosys (IRT), Accenture, Wipro, Cognizant (GenC), Capgemini, and more. Papers are organized by year and exam type with detailed solutions.

Does PlacePrep have mock exams?

Yes! PlacePrep offers timed mock exams that simulate real placement test conditions with fullscreen mode, anti-cheat measures, auto-submission, and instant evaluation with detailed performance reports.

Technical Reference

Quick reference for every command you'll need when running PlacePrep in self-hosted / exam mode.

For the full step-by-step guide, see Self-Hosting.

Application Commands

Start / Stop

powershell
# Start Docker (local Appwrite) + Next.js dev server (students can connect over LAN)
bun run exam:start

# Stop everything — kills Next.js process and stops Docker containers
bun run exam:stop

# Build the Next.js app (required after changing .env or after updating code)
bun run build

# Start the Next.js dev server manually (without Docker)
bun run dev

# Start the Next.js production server manually (after build)
bun run start

Database Setup

powershell
# Create all Appwrite collections in the CLOUD database
bun run setup:appwrite

# Create all Appwrite collections in the LOCAL (Docker) database
bun run setup:appwrite:local

# Bootstrap the local admin user (only needed once, before first pre-exam sync)
bun run scripts/bootstrap-local-admin.ts

Docker Commands

Start / Stop Containers

powershell
# Start local Appwrite stack in background (detached)
docker compose -f docker/exam-mode/docker-compose.yml up -d

# Stop containers (data is preserved in volumes)
docker compose -f docker/exam-mode/docker-compose.yml down

# Stop containers AND wipe ALL local data (volumes deleted — run ONLY after post-exam sync)
docker compose -f docker/exam-mode/docker-compose.yml down -v

# Restart containers
docker compose -f docker/exam-mode/docker-compose.yml restart

Status & Verification

powershell
# List all running containers
docker ps

# List all containers (including stopped ones)
docker ps -a

# Show status of exam-mode compose services
docker compose -f docker/exam-mode/docker-compose.yml ps

# Check resource usage (CPU, memory) of running containers
docker stats

# List Docker images on your machine
docker images

# Show disk usage by images, containers, and volumes
docker system df

Logs

powershell
# Stream Appwrite server logs (live — press Ctrl+C to stop)
docker logs appwrite -f

# Stream Appwrite database logs
docker logs appwrite-db -f

# Stream MariaDB logs
docker logs appwrite-mariadb -f

# View last 100 lines of Appwrite logs (no streaming)
docker logs appwrite --tail 100

# View logs for all compose services at once
docker compose -f docker/exam-mode/docker-compose.yml logs -f

Volumes & Data

powershell
# List Docker volumes
docker volume ls

# Inspect a volume (find its mount path)
docker volume inspect appwrite-uploads

# Remove a specific volume manually
docker volume rm <volume-name>

# Remove ALL unused volumes (careful — affects all Docker projects)
docker volume prune

Cleanup

powershell
# Remove stopped containers, unused networks, dangling images, and build cache
docker system prune

# Also remove unused volumes (frees the most space — use carefully)
docker system prune --volumes

# Remove all unused images (not just dangling ones)
docker image prune -a

Network & Port Commands (Windows)

Find Your Machine's IP

powershell
# Show all network adapters and their IPs
ipconfig

# Show only the IPv4 address of your active adapter
ipconfig | findstr "IPv4"

Look for the IPv4 Address under your active Wi-Fi or Ethernet adapter (e.g. 192.168.1.42). Students connect to http://192.168.1.42:3000.

Port Troubleshooting

powershell
# Find which process is using port 3000
netstat -ano | findstr :3000

# Find which process is using port 80 (used by local Appwrite)
netstat -ano | findstr :80

# Kill a process by PID (replace <PID> with the number from netstat output)
taskkill /F /PID <PID>

# Kill the entire process tree by PID (use if the above doesn't work)
taskkill /T /F /PID <PID>

Firewall

powershell
# Allow port 3000 through Windows Firewall (so students can connect)
netsh advfirewall firewall add rule name="PlacePrep Exam" dir=in action=allow protocol=TCP localport=3000

# Remove the rule when done
netsh advfirewall firewall delete rule name="PlacePrep Exam"

# Allow port 80 (if students need direct Appwrite console access — usually not needed)
netsh advfirewall firewall add rule name="PlacePrep Appwrite" dir=in action=allow protocol=TCP localport=80

Sync API Reference

These endpoints are called by the exam dashboard UI. You can also call them directly for scripting or debugging.

Pre-Exam Sync: Cloud → Local


POST http://localhost:3000/api/exam-mode/sync-to-local
Headers:
  x-user-id: <admin-user-id>          (normal auth)
  x-admin-key: <APPWRITE_LOCAL_API_KEY>  (bootstrap auth — use when DB is empty)

Body (optional — restrict to specific exams):
{
  "examIds": ["exam_id_1", "exam_id_2"]
}

Post-Exam Sync: Local → Cloud


POST http://localhost:3000/api/exam-mode/sync-to-cloud
Headers:
  x-user-id: <admin-user-id>

Body (optional — restrict to specific exams):
{
  "examIds": ["exam_id_1"]
}

Auto-Submit Expired Exams


POST http://localhost:3000/api/exam-mode/auto-submit-expired

Force-submits all in-progress attempts whose exam end time has passed. Called automatically by the dashboard every 15 seconds.

Register Walk-in Student


POST http://localhost:3000/api/exam-mode/register-local
Body:
{
  "name": "Student Name",
  "email": "student@college.edu",
  "registration_number": "22105109024",
  "branch": "CSE",
  "college_name": "Example College"
}
Response:
{
  "userId": "...",
  "examPassword": "exam2026"
}

Common Bug Fixes

Port 3000 still in use after Ctrl+C

powershell
# Find the PID using port 3000
netstat -ano | findstr :3000

# Kill it
taskkill /T /F /PID <PID>

Or use the dedicated stop command:

powershell
bun run exam:stop

Port 80 already in use (Appwrite won't start)

Port 80 is typically occupied by IIS (Windows), Nginx, or XAMPP.

powershell
# Stop IIS
iisreset /stop

# Or find and kill the process using port 80
netstat -ano | findstr :80
taskkill /F /PID <PID>

Then retry:

powershell
docker compose -f docker/exam-mode/docker-compose.yml up -d

"exam-db" database missing after container restart

The database persists in a Docker volume and should survive restarts. If it's gone, it means you ran down -v previously. Recreate the schema:

powershell
bun run setup:appwrite:local

Then run the pre-exam sync again to pull data from cloud.

Docker containers keep restarting / crashing

powershell
# Check logs for the specific container that's failing
docker logs appwrite -f

# Common cause: not enough disk space
docker system df

# Free up space if needed
docker system prune

Pre-exam sync authentication error (first run)

The local DB is empty — use bootstrap auth:

On the exam dashboard, click the 🔑 key icon
Enter the value of APPWRITE_LOCAL_API_KEY from your .env
Click Sync

Post-exam sync: users not appearing in cloud

Make sure you're running Post-Exam Sync (Local → Cloud), not pre-exam. Check the sync report — the users (local → cloud) row should show +N for newly created users. Existing cloud users show as skipped (normal).

Build fails after changing `.env`

Environment variables with NEXT_PUBLIC_ prefix are baked into the build at compile time. After changing them:

powershell
# Clear Next.js build cache
Remove-Item -Recurse -Force .next

# Rebuild
bun run build

Appwrite console unreachable at localhost/console

powershell
# Check if the container is running
docker ps

# If not running, start it
docker compose -f docker/exam-mode/docker-compose.yml up -d

# If running but console is unreachable, check logs
docker logs appwrite --tail 50

Wait 30–60 seconds after starting for Appwrite to fully initialize.

Important File Locations

File	Purpose
`.env`	All environment variables — never commit this file
`docker/exam-mode/docker-compose.yml`	Docker Compose config for local Appwrite stack
`docker/exam-mode/appwrite.env`	Appwrite internal secrets — change before production use
`.next-server.pid`	PID file written by `exam:start` — used by `exam:stop` to kill the process
`scripts/exam-start.ts`	Script that starts Docker + Next.js
`scripts/exam-stop.ts`	Script that kills Next.js + stops Docker
`scripts/setup-appwrite.ts`	Creates all Appwrite collections (cloud or local)
`src/lib/exam-mode/syncService.ts`	Core sync logic (cloud↔local)
`src/app/api/exam-mode/`	All exam-mode API routes

Environment Variable Quick Reference

env
# ── Cloud Appwrite ────────────────────────────────────────────────────
NEXT_PUBLIC_APPWRITE_ENDPOINT=https://cloud.appwrite.io/v1
NEXT_PUBLIC_APPWRITE_PROJECT_ID=your_cloud_project_id
NEXT_PUBLIC_APPWRITE_DATABASE_ID=your_cloud_database_id
APPWRITE_API_KEY=your_cloud_api_key

# ── Exam Mode ─────────────────────────────────────────────────────────
EXAM_MODE=true
APPWRITE_LOCAL_ENDPOINT=http://localhost/v1
APPWRITE_LOCAL_PROJECT_ID=your_local_project_id
APPWRITE_LOCAL_DATABASE_ID=exam-db
APPWRITE_LOCAL_API_KEY=your_local_api_key

# ── Exam Password (shared by all students) ────────────────────────────
EXAM_PASSWORD_PREFIX=exam2026

# ── Optional: IP restriction for exam APIs ────────────────────────────
EXAM_ALLOWED_IPS=192.168.1.0/24