Flask

On this page, we get you up and running with Sentry's SDK, so that it will automatically report errors and exceptions in your application.

Don't already have an account and Sentry project established? Head over to sentry.io, then return to this page.

Install

Sentry captures data by using an SDK within your application’s runtime.

Install sentry-sdk from PyPI with the flask extra:

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pip install --upgrade 'sentry-sdk[flask]'

Configure

Configuration should happen as early as possible in your application's lifecycle.

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import sentry_sdk
from flask import Flask
from sentry_sdk.integrations.flask import FlaskIntegration

sentry_sdk.init(
    dsn="https://examplePublicKey@o0.ingest.sentry.io/0",
    integrations=[FlaskIntegration()],

    # Set traces_sample_rate to 1.0 to capture 100%
    # of transactions for performance monitoring.
    # We recommend adjusting this value in production.
    traces_sample_rate=1.0,

    # By default the SDK will try to use the SENTRY_RELEASE
    # environment variable, or infer a git commit
    # SHA as release, however you may want to set
    # something more human-readable.
    # release="myapp@1.0.0",
)

app = Flask(__name__)

Verify

This snippet includes an intentional error, so you can test that everything is working as soon as you set it up:

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@app.route('/debug-sentry')
def trigger_error():
    division_by_zero = 1 / 0

After initialization:

  • If you use flask-login and have set send_default_pii=True in your call to init, user data (current user id, email address, username) is attached to the event.
  • Request data is attached to all events: HTTP method, URL, headers, form data, JSON payloads. Sentry excludes raw bodies and multipart file uploads.
  • Logging with app.logger or any logger creates breadcrumbs when the Logging integration, which is enabled by default.

To view and resolve the recorded error, log into sentry.io and open your project. Clicking on the error's title will open a page where you can see detailed information and mark it as resolved.