FastAPI

LoglyMiddleware adds request_id, method, path, client, and user_agent to the Logly context for each request. It logs timing and exceptions automatically.

Installation

This integration requires the fastapi and starlette packages.

uv

uv add logly[fastapi]

pip

pip install "logly[fastapi]"

uv (without extras)

uv add fastapi starlette

pip (without extras)

pip install fastapi starlette

Missing Dependency

If fastapi or starlette is not installed, you'll see:

ModuleNotFoundError: No module named 'fastapi'

Usage

from fastapi import FastAPI
from logly.integrations.fastapi import LoglyMiddleware

app = FastAPI()
app.add_middleware(LoglyMiddleware)

Captured Fields

Field	Source
request_id	UUID generated per request
method	HTTP method (GET, POST, etc.)
path	Request path
client	Client IP address
user_agent	User-Agent header

Full Example

from fastapi import FastAPI
from logly import logger
from logly.integrations.fastapi import LoglyMiddleware

app = FastAPI()
app.add_middleware(LoglyMiddleware)

@app.get("/")
async def root():
    logger.info("Handling request")
    return {"message": "Hello World"}

@app.get("/items/{item_id}")
async def read_item(item_id: int):
    logger.debug("Fetching item {}", item_id)
    return {"item_id": item_id}