Flask (Python)

When developing a Flask-based API, the built-in Werkzeug development server provides a debugger which shows an interactive traceback in the browser when an unhandled error occurs during a request.

For more information, visit https://flask.palletsprojects.com/en/latest/debugging/.

⚠️ These settings are appropriate for development testing, but should not be used in production.

Include Traceback on Server Error

Either set the FLASK_ENV=development environment variable prior to running your app:

$ export FLASK_ENV=development
$ flask run

Or, include the debug=true flag when running from Python code

from flask import Flask
app = Flask(__name__)

if __name__ == '__main__':    
    app.run(debug=True)

Whenever the fuzzer triggers an error, Flask will include the traceback in the response.