Overview

FastAPI 0.118, released on February 1, 2025, brings performance improvements and better automatic documentation.

Main Features

Performance improvements

Response serialization is optimized with better Pydantic v2 model support and streaming.

python 
from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()

class Item(BaseModel):
    name: str
    price: float

@app.post('/items/')
async def create_item(item: Item):
    return {'name': item.name, 'price_ttc': item.price * 1.2}

OpenAPI documentation

OpenAPI documentation generation is improved with better support for complex types and examples.

python 
from fastapi import FastAPI, Query

app = FastAPI(title='My API', version='1.0')

@app.get('/search/')
async def search(
    q: str = Query(min_length=3, examples=['python', 'fastapi']),
    limit: int = Query(default=10, le=100),
):
    return {'query': q, 'limit': limit}

Sources