A modular FastAPI backend that powers social features such as posts, reels/stories, group messaging, notifications, and moderation workflows. Code is organised under �pp/ into core config, domain modules, services, and routers so each concern stays isolated and testable.

�ash python -m venv venv source venv/bin/activate # or .\\venv\\Scripts\\activate on Windows pip install -r requirements.txt cp .env.example .env # provide secrets like DATABASE_URL, REDIS_URL, etc.

Key environment variables:

• APP_ENV (production/development/test) toggles heavy integrations.
• DATABASE_URL / TEST_DATABASE_URL control SQLAlchemy connections.
• REDIS_URL, CORS_ORIGINS, FRONTEND_BASE_URL tune caching and API boundaries.
• ALLOWED_HOSTS comma-separated allowlist for TrustedHostMiddleware (default *).
• FORCE_HTTPS (bool) enables HTTPSRedirectMiddleware in production.
• STATIC_ROOT / UPLOADS_ROOT determine on-disk static + user-upload dirs mounted at /static and /uploads; corresponding STATIC_CACHE_CONTROL / UPLOADS_CACHE_CONTROL headers control browser caching.
• FACEBOOK_APP_ID / FACEBOOK_APP_SECRET and TWITTER_API_KEY / TWITTER_API_SECRET configure the additional OAuth providers exposed under /auth/facebook and /auth/twitter.

�ash python -m pytest -q # unit/integration tests python scripts/perf_startup.py # startup regression guard

Static checks are enforced locally through pre-commit: �ash pip install pre-commit pre-commit install pre-commit run --all-files # optional before pushing

GitHub Actions workflow (.github/workflows/ci.yml) runs on pushes/pull-requests to main. It installs dependencies, executes Ruff linting, pytest, and the startup smoke test with APP_ENV=test so heavy services (Firebase, schedulers) stay disabled.

• Deploy the API behind a WAF/CDN (e.g., Cloudflare, Azure FrontDoor). Combine the edge allowlist with the ALLOWED_HOSTS and FORCE_HTTPS flags to restrict origins and force TLS end-to-end.
• /livez and /readyz are lightweight health checks that can be used by your load balancer/WAF to decide when to route traffic.

• docs/DEVELOPER_GUIDE.md contains architecture notes, configuration tips, and testing requirements.
• REARCHITECTURE_ROADMAP.md tracks the phased refactor/feature plan.

Contributions should follow the module/service/router structure and include tests whenever behaviour changes.