Stack Picker
a developer-grade decision engine
Back to the picker
Backend

Python (FastAPI)

Modern Python framework with automatic OpenAPI schemas.

Official site
Monthly cost
Free
Popularity
4/5
LLM knowledge
4/5
Difficulty
Medium
#ai-native#open-source

What Python (FastAPI) is good at

Strengths
  • +Excellent for ML/AI workloads
  • +Auto-generated docs
  • +Type hints
Tradeoffs
  • GIL limits concurrency
  • Slower than Go/Node for I/O

Coding-agent prompt

You're writing a FastAPI service. Follow these rules:

- Pydantic v2 models for every request and response body.
- Dependencies via `Depends()` for DB sessions, auth, feature flags — never global state.
- Async endpoints unless you're doing CPU-bound work.
- `response_model` on every route so OpenAPI docs are accurate.
- Use `APIRouter` to split endpoints into modules.
- Run with `uvicorn app.main:app --reload` in dev, `gunicorn -k uvicorn.workers.UvicornWorker` in prod.

Beginner's guide to Python (FastAPI)

In one line: A modern, fast Python framework for building APIs.

FastAPI is a Python library for writing backend APIs. It's popular for machine-learning projects because most ML tools are Python. It auto-generates API docs based on your code.

Try it in your terminal
  • python3 -m venv .venv && source .venv/bin/activate

    Create and activate a virtual environment — an isolated Python sandbox.

  • pip install 'fastapi[standard]'

    Install FastAPI and its recommended extras.

  • fastapi dev main.py

    Start the dev server.

Heads up: Python 'virtual environments' are a must — they stop packages for one project from breaking another.

Browse all categories