December 5, 2018

FastAPI first released

Sebastián Ramírez released FastAPI on December 5, 2018 — an async PythonA high-level language known for readability — dominant in data science, scripting, and web backends. APIApplication programming interface — a defined way for programs to talk to each other or to a service. framework with automatic OpenAPI docs.

What it was for

FastAPIFastAPI uses PythonA high-level language known for readability — dominant in data science, scripting, and web backends. type hints and Pydantic for validation, Starlette for async I/O, and auto-generates Swagger UIUser interface — the parts of software people see and interact with. docs. Used for ML inferenceRunning a trained model to produce predictions — as opposed to the training phase that learns weights. APIs, microservicesAn architecture splitting applications into small independent services — each deployed and scaled separately., and high-throughput backends. Example: `async def read_item(item_id: int)` with request/response schemas enforced at runtime and documented for free.

People

  • Sebastián Ramírezcreator

Why it's here

FastAPI became the default for new PythonA high-level language known for readability — dominant in data science, scripting, and web backends. APIs when async and OpenAPI docs mattered.

Why it mattered

It showed type hints could drive validation, serialization, and documentation in one cohesive framework.

What it solved

Flask lacked native async and automatic APIApplication programming interface — a defined way for programs to talk to each other or to a service. schemas; teams bolted on Marshmallow and manual Swagger.

Media

  • FastAPI
    ImageFastAPI

    Sebastián Ramírez, Public domain, via Wikimedia Commons

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