Fastapi Patterns

A solid reference for structuring production FastAPI services around dependency injection and explicit layers. You get patterns for app factories with lifespan hooks, separate Pydantic schemas for create/update/response, async database sessions, OAuth2 token dependencies, and test fixtures that override dependencies instead of hitting real resources. The security checklist covers the basics (Argon2, JWT validation, CORS credentials). Useful when you're reviewing a FastAPI PR and want concrete examples of where routers, schemas, and CRUD logic should live, or when you're tired of seeing password hashes leak into response models because someone skipped the response_model declaration.

skills.sh installs: 1.8K
GitHub stars: 229.1K
last updated: Jul 14, 2026

View on GitHub

Install

$ npx -y skills add affaan-m/everything-claude-code --skill fastapi-patterns --agent claude-code

Installs into .claude/skills of the current project.

Files

FastAPI Patterns

Modern, production-grade FastAPI development: project layout, Pydantic v2 schemas, dependency injection, async patterns, auth, transactional service methods, and testing.

Project Structure

my_app/
|-- app/
|   |-- main.py               # App factory, lifespan, middleware
|   |-- config.py             # Settings via pydantic-settings
|   |-- dependencies.py       # Shared FastAPI dependencies
|   |-- database.py           # SQLAlchemy engine + session
|   |-- routers/
|   |   `-- users.py
|   |-- models/               # SQLAlchemy ORM models
|   |   `-- user.py
|   |-- schemas/              # Pydantic request/response schemas
|   |   `-- user.py
|   `-- services/             # Business logic layer
|       `-- user_service.py
|-- tests/
|   |-- conftest.py
|   `-- test_users.py
|-- pyproject.toml
`-- .env

App Factory and Lifespan

# app/main.py
from contextlib import asynccontextmanager
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from app.config import settings
from app.database import engine, Base
from app.routers import users

SKILL.md on GitHub