Google Quickstart

Set up the application

Visit the Google Developers Console at https://console.developers.google.com and create a new project. In the “APIs & auth” section, click on “Credentials”, and then click the “Create a new Client ID” button. Select “Web Application” for the application type, and click the “Configure consent screen” button. Put in your application information, and click Save. Once you’ve done that, you’ll see two new fields: “Authorized JavaScript origins” and “Authorized redirect URIs”. Put http://localhost:5000/login/google/authorized into “Authorized redirect URIs”, and click “Create Client ID”. Take note of the “Client ID” and “Client Secret” for the application.

Code

from flask import Flask, redirect, url_for
from flask_dance.contrib.google import make_google_blueprint, google

app = Flask(__name__)
app.secret_key = "supersekrit"
blueprint = make_google_blueprint(
    client_id="my-key-here",
    client_secret="my-secret-here",
    scope=["profile", "email"]
)
app.register_blueprint(blueprint, url_prefix="/login")

@app.route("/")
def index():
    if not google.authorized:
        return redirect(url_for("google.login"))
    resp = google.get("/oauth2/v2/userinfo")
    assert resp.ok, resp.text
    return "You are {email} on Google".format(email=resp.json()["email"])

if __name__ == "__main__":
    app.run()

Note

You must replace my-key-here and my-secret-here with the client ID and client secret that you got from your Google application.

Note

If you are running this code on Heroku, you’ll need to use the werkzeug.contrib.fixers.ProxyFix middleware. See Proxies and HTTPS.

If you run this code locally or without HTTPS enabled (see warning below), you must set the OAUTHLIB_INSECURE_TRANSPORT environment variable to to disable the HTTPS requirement imposed by oauthlib, which is part of Flask-Dance. For example, if you put this code in a file named google.py on your machine, you could run:

$ export OAUTHLIB_INSECURE_TRANSPORT=1
$ export OAUTHLIB_RELAX_TOKEN_SCOPE=1
$ python google.py

Visit `http://localhost:5000`_ in your browser, and you should start the OAuth dance immediately.

Warning

OAUTHLIB_INSECURE_TRANSPORT should only be used for local testing or over trusted connections. By default, all OAuth interactions must occur over secure https connections (this is enfored by oauthlib). However, setting OAUTHLIB_INSECURE_TRANSPORT disables this enforcement and allows OAuth to occur over insecure http connections.

However, you can (and probably should) set OAUTHLIB_RELAX_TOKEN_SCOPE when running in production.

Explanation

This code makes a blueprint that implements the views necessary to be a consumer in the OAuth dance. The blueprint has two views: /google, which is the view that the user visits to begin the OAuth dance, and /google/authorized, which is the view that the user is redirected to at the end of the OAuth dance. Because we set the url_prefix to be /login, the end result is that the views are at /login/google and /login/google/authorized. The second view is the “authorized redirect URI” that you must tell Google about when you create the application.

The google variable is a requests.Session instance, which will be be preloaded with the user’s access token once the user has gone through the OAuth dance. You can check the google.authorized boolean to determine if the access token is loaded. Whether the access token is loaded or not, you can use all the normal requests methods, like get() and post(), to make HTTP requests. If you only specify the path component of the URL, the domain will default to https://www.googleapis.com.