This repository is a production-grade FastAPI boilerplate (named 'Fastro') designed to accelerate building SaaS backends. It provides a complete, modular architecture with three layers: infrastructure (config, caching, rate limiting, auth, logging, database), interfaces (REST API, admin panel), and vertical-slice modules (user, tier, API keys, rate limits). The codebase is fully async, uses SQLAlchemy 2.0 with `MappedAsDataclass`, Pydantic v2, and FastCRUD for generic CRUD operations. Authentication is session-based via the external `crudauth` library, with server-side sessions, CSRF, OAuth (Google wired), and API key support. Caching and rate limiting follow a provider pattern with swappable Redis/Memcached backends. The repo also includes a CLI tool (`bp`) with plugin discovery for commands and features, a multi-stage Dockerfile, Alembic migrations, and extensive documentation (though some docs describe aspirational features not yet implemented). A paid fork (FastroAI) adds payments, email, and frontend, but the free boilerplate is self-contained and functional.