FastAPI Expert
Guides an agent to build async FastAPI and Pydantic V2 APIs with auth, database and tests
- Repository
- Jeffallan/claude-skills
- Stars
- 12,176
- Licence
- MIT
- Files
- 7 files
What it does
When installed, the agent follows a structured playbook for building Python web APIs with FastAPI, a popular framework. It writes request and response models that validate data with Pydantic V2, sets up async database access with SQLAlchemy, adds JWT login tokens, and writes pytest tests. It also loads reference notes on WebSockets, routing, and migrating from Django when relevant.
Great for
- Python developers starting or extending a FastAPI backend
- Teams moving an existing Django or DRF project toward async FastAPI
- Developers who want consistent Pydantic V2 and async SQLAlchemy patterns
Skip it if
- Non-programmers who only want a finished app, since the output is code that still needs to be run and reviewed
- Production auth without review: the sample JWT code uses a placeholder secret key and a hardcoded-looking config, so security must be checked by a human before deployment
Try asking
- “Create a FastAPI router with user signup endpoints that hash passwords and return 201 or 409 status codes”
- “Define Pydantic V2 models with field validators for an orders API”
- “Add JWT bearer authentication with a get_current_user dependency to my FastAPI app”
- “Write async pytest tests with httpx for my existing FastAPI endpoints”
Install in 3 steps
- 1
Download the skill
The ZIP contains the 7 original files, the MIT licence and an attribution note.
fastapi-expert.zip - 2
Add it to your agent
Claude Code (all projects)
mkdir -p ~/.claude/skills && unzip fastapi-expert.zip -d ~/.claude/skills/Claude Code / Agent SDK (this project only)
mkdir -p .claude/skills && unzip fastapi-expert.zip -d .claude/skills/Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.
- 3
Ask for the task
No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.
Get better results
- Give the agent your existing project layout and database choice so generated files match your structure.
- Replace the placeholder SECRET_KEY with an environment variable and review the auth code before use.
- Ask the agent to run pytest and check the /docs OpenAPI page after each endpoint group, as the skill recommends.
What's inside
- references/async-sqlalchemy.md
- references/authentication.md
- references/endpoints-routing.md
- references/migration-from-django.md
- references/pydantic-v2.md
- references/testing-async.md
- SKILL.md
Redistributed unmodified from Jeffallan/claude-skills under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.