Getting started

Installation

Install fastapi-lazyrouter from PyPI:

pip install fastapi-lazyrouter

Prerequisites

  • Python 3.10 or higher

  • FastAPI 0.119.0 or higher (first version that supports Pydantic v2)

Quick start

The fastest way to get started is to use the auto configuration.

  1. Configure your Pydantic base model to defer schema building:

from pydantic import BaseModel, ConfigDict

class CustomBaseModel(BaseModel):
    model_config = ConfigDict(defer_build=True)
  1. Enable lazy routing on your FastAPI application:

import fastapi
import fastapi_lazyrouter

app = fastapi.FastAPI()
fastapi_lazyrouter.autoconfigure(app)

That’s it! Your routes will now be mounted lazily on the first matching request.

Development version

If you want to work with the latest development version, clone the repository:

git clone https://github.com/FabienArcellier/fastapi-lazyrouter.git
cd fastapi-lazyrouter
poetry install