Neda/Back

NEDA Backend

NEDA is a FastAPI backend for real-time group voice communication. It includes authentication, user/group management, WebSocket signaling, Redis for real-time state, and PostgreSQL for persistent data.

Tech Stack

• FastAPI + Uvicorn
• SQLAlchemy (Async) + asyncpg
• PostgreSQL
• Redis
• Alembic
• LiveKit

Project Structure

core/          config, security, deps
alembic/       database migrations
db/            database/redis setup
domains/       domain modules (auth, users, admin, groups, realtime, notifications)
integrations/  external integrations (LiveKit)
scripts/       utility scripts (create_admin)
main.py        FastAPI app entrypoint

Active Routes

• POST /auth/login
• GET /users/
• POST /admin/users
• POST /admin/users/{user_id}/logout
• POST /admin/users/{user_id}/reset-secret
• GET /admin/users
• GET /admin/groups
• POST /groups/
• GET /groups/my
• GET /groups/admin/all
• GET /groups/{group_id}/members
• POST /groups/{group_id}/invite
• DELETE /groups/{group_id}/members/{user_id}
• WS /ws/groups/{group_id}

Environment Variables

Create a .env file in the project root:

APP_NAME=NEDA
DEBUG=False

SECRET_KEY=change-me
ACCESS_TOKEN_EXPIRE_MINUTES=30
ALGORITHM=HS256
SECRET_PASS_LENGTH=32

POSTGRES_DB=neda
POSTGRES_USER=neda_user
POSTGRES_PASSWORD=neda_pass
DATABASE_URL=postgresql+asyncpg://neda_user:neda_pass@postgres:5432/neda

REDIS_URL=redis://redis:6379/0

LIVEKIT_API_KEY=neda_key
LIVEKIT_API_SECRET=neda_secret
LIVEKIT_HOST=http://livekit:7880
LIVEKIT_PORT=7880
LIVEKIT_TCP_PORT=7881
LIVEKIT_UDP_PORT=7882

LiveKit note:

• livekit.yaml.template is a template, not a direct runtime config.
• The livekit container generates /etc/livekit.yaml from env values at startup.
• Raw YAML does not automatically resolve ${...} placeholders unless templated first.

Run With Docker

docker compose up --build -d

Services:

• API: http://localhost:8000
• Swagger Docs: http://localhost:8000/docs
• LiveKit: http://localhost:7880
• Postgres: localhost:5432
• Redis: localhost:6379

API logs:

docker compose logs -f api

Create Admin (Inside Docker)

After services are up, create the initial admin user inside the API container:

docker compose exec api python -m scripts.create_admin

The script asks for username and optional phone_number, creates the user with is_admin=True, and prints the initial secret.

Admin API Hardening

• POST /admin/users creates only non-admin users.
• Sending is_admin in the payload is not allowed and returns 422.
• Admin creation is only allowed through the server-side script: scripts/create_admin.py.

Invalid payload example:

{
  "username": "new_user",
  "phone_number": "09123456789",
  "is_admin": true
}

Admin login:

• Endpoint: POST /auth/login
• Body:

{
  "username": "admin_username",
  "secret": "printed_secret"
}

Database Migrations (Alembic)

This project uses Alembic, and env.py reads DATABASE_URL from .env.

Apply migrations (inside Docker):

docker compose exec api alembic upgrade head

Create a new migration (autogenerate):

docker compose exec api alembic revision --autogenerate -m "your_message"

Check current DB revision:

docker compose exec api alembic current

Show migration history:

docker compose exec api alembic history

Important: run alembic upgrade head before starting the API in a new environment.

Local Development (Without Docker)

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Run migrations:

alembic upgrade head

Start API:

uvicorn main:app --reload

Realtime Notes

• Presence is stored in Redis.
• Speaker lock is managed atomically in Redis.
• LiveKit tokens for listener/speaker roles are issued during the WebSocket flow.