FastAPI Development
FastAPI is a modern Python framework for building APIs quickly and with excellent performance. Built on Python type hints, it delivers automatic request validation, interactive API docs, and async support, making it one of the fastest Python frameworks available.
At a glance
- Created by
- Sebastián Ramírez
- First released
- 2018
- Language
- Python
- Type
- Web framework
- License
- MIT
What is FastAPI?
FastAPI has become the go-to choice for machine-learning and AI backends, where it wraps models in clean, well-documented, high-throughput APIs. Its developer experience — auto-generated docs and editor autocompletion — is a major reason for its rapid rise.
Why teams choose FastAPI
Among the fastest Python frameworks, with full async support
Automatic request validation from Python type hints
Interactive API documentation generated for free
Excellent fit for ML/AI model serving
Great developer experience with editor autocompletion
When to use FastAPI
- High-performance REST APIs and microservices in Python
- Serving machine-learning and LLM models behind an API
- Async workloads with many concurrent requests
- Backends where auto-generated docs speed up integration
Things to consider
- API-focused — it's not a full web framework with an admin like Django
- Younger ecosystem than Django or Flask
- You assemble ORM, auth, and admin from libraries
What we build with FastAPI
AI / ML APIs
Wrapping models and LLM pipelines in fast, documented endpoints.
Microservices
Lightweight, async services that scale under high concurrency.
Data APIs
Validated, typed APIs serving data to web and mobile clients.
Backend for AI products
The API layer behind RAG, chat, and automation features.
Products & companies built with FastAPI
FastAPI is trusted in production by well-known companies, including:
FastAPI works well with
FastAPI — frequently asked questions
What is FastAPI used for?
FastAPI is used to build high-performance APIs in Python — especially microservices and machine-learning/AI backends — with automatic validation and interactive documentation.
Why is FastAPI popular for AI and machine learning?
Because it pairs Python (the language of ML) with high performance, async support, and automatic docs. It's an ideal, low-friction way to serve models and LLM pipelines behind clean, well-documented APIs.
FastAPI vs Django — what's the difference?
FastAPI is a lightweight, async-first API framework, while Django is a full web framework with an ORM and admin. Choose FastAPI for fast standalone APIs and AI backends; choose Django for complete database-driven web applications.
Who uses FastAPI?
FastAPI is used by teams at Microsoft, Uber, and Netflix, and it's extremely popular across AI and machine-learning projects for serving models.
Related backend technologies
Building with FastAPI?
CodersArts Build ships production FastAPI projects on a fixed scope, price, and timeline — with full source-code ownership on handover.