Flask Python

Our Flask integration lets you instrument individual HTTP requests. Please note that Blackfire supports Flask 0.12 and higher.

Install Blackfire for Python.

Automatic Instrumentation

The recommended way to use Blackfire with Flask is to use the blackfire-python command, as it configures the needed bits for you.

Run your webserver with blackfire-python command:

export FLASK_APP=hello.py
blackfire-python flask run

Or with gunicorn:

blackfire-python gunicorn myproject:app

Manual Installation

If you prefer configuring Flask manually, you can add the following call manually within your code:

import blackfire

This call should be made as early as possible in the lifecycle of an application, ideally before any other import statements.

Then, restart your server.


We used to provide a Flask middleware along with the Blackfire Python SDK, blackfire.middleware.FlaskMiddleware.

This middleware is now deprecated in favor of the blackfire-python or the blackfire.patch_all() call. Using the middleware will trigger a deprecation warning.

Profiling HTTP Requests

You can use the blackfire curl command to profile specific requests:

blackfire curl http://localhost:5000/

You can also use one of our browser extensions for Firefox or Chrome.

Read more about profiling web applications with a browser, or profiling with the CLI.