Chat Backend

FastAPI backend for a Telegram-like chat app with direct messages, groups, and channels.

Features

• Direct messages — 1:1 conversations between users
• Groups — multi-user chats where all members can post
• Channels — broadcast rooms; only owners/admins post, subscribers read
• JWT authentication
• PostgreSQL + async SQLAlchemy

Quick start

# Start PostgreSQL and API
docker compose up --build

# API docs: http://localhost:8000/docs

Local development with uv

docker compose up db db-init -d

uv sync --dev
export DATABASE_URL=postgresql+asyncpg://chat:chat@localhost:5432/chat
export TEST_DATABASE_URL=postgresql+asyncpg://chat:chat@localhost:5432/chat_test

uv run uvicorn app.main:app --reload

Tests

docker compose up db db-init -d
uv run pytest tests/unit -v
uv run pytest tests/e2e -v

API overview

Method	Path	Description
POST	/api/auth/register	Register user
POST	/api/auth/login	Login (OAuth2 form)
GET	/api/auth/me	Current user
POST	/api/conversations/dm/{user_id}	Start or get DM
POST	/api/conversations	Create group or channel
GET	/api/conversations	List user's conversations
POST	/api/conversations/{id}/messages	Send message
GET	/api/conversations/{id}/messages	List messages