FastAPI

Python

Server & API

Build fast, modern Python APIs with automatic documentation.

What it does

FastAPI is a Python web framework for building APIs. It's fast, generates automatic documentation, validates inputs using Pydantic, and supports async. It's quickly become the go-to choice for Python APIs, especially for AI/ML backends.

When to use it

Use this when you need to build a Python backend API — especially if you're connecting an AI model to a frontend.

Real example

You've built a Python image classification model and want your React frontend to be able to call it. Prompt: 'Create a FastAPI app with a POST /classify endpoint that accepts a base64 image string, runs it through the model, and returns a JSON with the predicted label and confidence score.'

Good to know

Great for exposing ML models or data processing scripts as an API that a frontend can call.

Alternatives

Flask Django

Install

$ pip install fastapi uvicorn

Use cases

APIPython backendREST APIAI backend

Language

Python

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