The Principal Dev – Masterclass for Tech Leads

The Principal Dev – Masterclass for Tech LeadsJuly 17-18

Join

Pydantic Logfire — Know more. Build faster.

CI codecov pypi license versions Join Slack

From the team behind Pydantic Validation, Pydantic Logfire is an observability platform built on the same belief as our open source library — that the most powerful tools can be easy to use.

What sets Logfire apart:

See the documentation for more information.

Feel free to report issues and ask any questions about Logfire in this repository!

This repo contains the Python SDK for logfire and documentation; the server application for recording and displaying data is closed source.

Using Logfire

This is a very brief overview of how to use Logfire, the documentation has much more detail.

Install

pip install logfire

(learn more)

Authenticate

logfire auth

(learn more)

Manual tracing

Here's a simple manual tracing (aka logging) example:

import logfire
from datetime import date

logfire.configure()
logfire.info('Hello, {name}!', name='world')

with logfire.span('Asking the user their {question}', question='age'):
    user_input = input('How old are you [YYYY-mm-dd]? ')
    dob = date.fromisoformat(user_input)
    logfire.debug('{dob=} {age=!r}', dob=dob, age=date.today() - dob)

(learn more)

Integration

Or you can also avoid manual instrumentation and instead integrate with lots of popular packages, here's an example of integrating with FastAPI:

import logfire
from pydantic import BaseModel
from fastapi import FastAPI

app = FastAPI()

logfire.configure()
logfire.instrument_fastapi(app)
# next, instrument your database connector, http library etc. and add the logging handler

class User(BaseModel):
    name: str
    country_code: str

@app.post('/')
async def add_user(user: User):
    # we would store the user here
    return {'message': f'{user.name} added'}

(learn more)

Logfire gives you a view into how your code is running like this:

Logfire screenshot

Contributing

We'd love anyone interested to contribute to the Logfire SDK and documentation, see the contributing guide.

Reporting a Security Vulnerability

See our security policy.

Logfire Open-Source and Closed-Source Boundaries

The Logfire SDKs (we also have them for TypeScript and Rust) are open source, and you can use them to export data to any OTel-compatible backend.

The Logfire platform (the UI and backend) is closed source. You can self-host it by purchasing an enterprise license.

Join libs.tech

...and unlock some superpowers

GitHub

We won't share your data with anyone else.