FastAPI Modular Monolith Architecture — Project Scaffolder

Generate production-ready Modular Monolith projects with FastAPI, featuring proper module boundaries, async-first design, dependency injection, shared kernel, and infrastructure following industry best practices.

Overview

A Modular Monolith is a single deployable application organized into loosely coupled, highly cohesive modules — each representing a bounded context. FastAPI's speed, async capabilities, dependency injection system, and automatic API documentation make it an ideal framework for this architecture.

This skill scaffolds complete FastAPI projects with:

• Module isolation: Each module owns its models, repositories, services, routes, schemas, and dependencies
• Async-first design: All I/O operations use async/await (SQLAlchemy async, aiosmtplib, aiocache)
• FastAPI dependency injection: Loose coupling via Depends() and Annotated types
• Generic repository pattern: Base CRUD with pagination, filtering, sorting, and soft deletes
• Inter-module communication: Via gateway contracts and domain events (fastapi-events)
• Shared kernel (core): Cross-cutting concerns — base models, config, services, exception handling
• Database-per-module schema: Logical isolation within a single PostgreSQL database via Alembic
• Production-ready: Docker, Redis caching, task queues (Taskiq), structured logging, rate limiting
• Migration-ready boundaries: Modules can be extracted to microservices later