# API Fastapi Modern

> Building high-performance, type-safe APIs with Python 3.10+ and Pydantic.

- Skill: `jcorpac/api-fastapi-modern` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jcorpac/api-fastapi-modern`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jcorpac/api-fastapi-modern/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: jcorpac (https://skillmd.com/u/jcorpac)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jcorpac/api-fastapi-modern

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# FastAPI Modern Development

FastAPI is the standard for modern Python APIs, offering high performance (comparable to Go/Node.js) and automatic documentation.

## Type Safety (Pydantic)
- **Schemas**: Use Pydantic models for request/response validation and serialization.
- **Automatic Docs**: OpenAPI (Swagger) and Redoc are generated automatically based on type hints.

## Asynchronous Support
- **`async def`**: High concurrency with Python's `asyncio` loop.
- **Dependency Injection**: A powerful system for managing database sessions, auth, and logic.

## Best Practices
- **Strict Typing**: Use Python 3.10+ union types (`int | None`) and `Annotated` for cleaner dependencies.
- **Error Handling**: Use `HTTPException` with consistent JSON structures.