Logto is an Auth0 alternative designed for modern apps and SaaS products. It offers both Cloud and Open-source services to help you quickly launch your identity and management (IAM) system. Enjoy authentication, authorization, and multi-tenant management all in one.
We recommend starting with a free development tenant on Logto Cloud. This allows you to explore all the features easily.
In this article, we will go through the steps to quickly build the Facebook sign-in experience (user authentication) with Python and Logto.
Prerequisites
- A running Logto instance. Check out the introduction page to get started.
- Basic knowledge of Python.
- A usable Facebook account.
Create an application in Logtoβ
Logto is based on OpenID Connect (OIDC) authentication and OAuth 2.0 authorization. It supports federated identity management across multiple applications, commonly called Single Sign-On (SSO).
To create your Traditional web application, simply follow these steps:
- Open the Logto Console. In the "Get started" section, click the "View all" link to open the application frameworks list. Alternatively, you can navigate to Logto Console > Applications, and click the "Create application" button.
- In the opening modal, click the "Traditional web" section or filter all the available "Traditional web" frameworks using the quick filter checkboxes on the left. Click the "Flask" framework card to start creating your application.
- Enter the application name, e.g., "Bookstore," and click "Create application".
π Ta-da! You just created your first application in Logto. You'll see a congrats page which includes a detailed integration guide. Follow the guide to see what the experience will be in your application.
Integrate Flask SDKβ
- The example uses Flask, but the concepts are the same for other frameworks.
- The Python sample project is available on our Python SDK repo.
- Logto SDK leverages coroutines, remember to use
await
when calling async functions.
Installationβ
Execute in the project root directory:
pip install logto # or `poetry add logto` or whatever you use
Init LogtoClientβ
First, create a Logto config:
from logto import LogtoClient, LogtoConfig
client = LogtoClient(
LogtoConfig(
endpoint="https://you-logto-endpoint.app", # Replace with your Logto endpoint
appId="replace-with-your-app-id",
appSecret="replace-with-your-app-secret",
),
)
You can find and copy "App Secret" from application details page in Admin Console:
Also replace the default memory storage with a persistent storage, for example:
from logto import LogtoClient, LogtoConfig, Storage
from flask import session
from typing import Union
class SessionStorage(Storage):
def get(self, key: str) -> Union[str, None]:
return session.get(key, None)
def set(self, key: str, value: Union[str, None]) -> None:
session[key] = value
def delete(self, key: str) -> None:
session.pop(key, None)
client = LogtoClient(
LogtoConfig(...),
storage=SessionStorage(),
)
See Storage for more details.
Implement sign-in and sign-outβ
In your web application, add a route to properly handle the sign-in request from users. Let's use /sign-in
as an example:
@app.route("/sign-in")
async def sign_in():
# Get the sign-in URL and redirect the user to it
return redirect(await client.signIn(
redirectUri="http://localhost:3000/callback",
))
Replace http://localhost:3000/callback
with the callback URL you set in your Logto Console for this application.
If you want to show the sign-up page on the first screen, you can set interactionMode
to signUp
:
@app.route("/sign-in")
async def sign_in():
return redirect(await client.signIn(
redirectUri="http://localhost:3000/callback",
interactionMode="signUp", # Show the sign-up page on the first screen
))
Now, whenever your users visit http://localhost:3000/sign-in
, it will start a new sign-in attempt and redirect the user to the Logto sign-in page.
Note Creating a sign-in route isn't the only way to start a sign-in attempt. You can always use the
signIn
method to get the sign-in URL and redirect the user to it.
After the user makes a signing-out request, Logto will clear all user authentication information in the session.
To clean up the Python session and Logto session, a sign-out route can be implemented as follows:
@app.route("/sign-out")
async def sign_out():
return redirect(
# Redirect the user to the home page after a successful sign-out
await client.signOut(postLogoutRedirectUri="http://localhost:3000/")
)
Handle authentication statusβ
In Logto SDK, we can use client.isAuthenticated()
to check the authentication status, if the user is signed in, the value will be true, otherwise, the value will be false.
Here we also implement a simple home page for demonstration:
- If the user is not signed in, show a sign-in button;
- If the user is signed in, show a sign-out button.
@app.route("/")
async def home():
if client.isAuthenticated() is False:
return "Not authenticated <a href='/sign-in'>Sign in</a>"
return "Authenticated <a href='/sign-out'>Sign out</a>"
Checkpoint: Test your applicationβ
Now, you can test your application:
- Run your application, you will see the sign-in button.
- Click the sign-in button, the SDK will init the sign-in process and redirect you to the Logto sign-in page.
- After you signed in, you will be redirected back to your application and see the sign-out button.
- Click the sign-out button to clear token storage and sign out.
Add Facebook connectorβ
To enable quick sign-in and improve user conversion, connect with Flask as an identity provider. The Logto social connector helps you establish this connection in minutes by allowing several parameter inputs.
To add a social connector, simply follow these steps:
- Navigate to Console > Connectors > Social Connectors.
- Click "Add social connector" and select "Facebook".
- Follow the README guide and complete required fields and customize settings.
If you are following the in-place Connector guide, you can skip the next section.
Set up Facebook loginβ
Register a Facebook developer accountβ
Register as a Facebook Developer if you don't already have one
Set up a Facebook appβ
- Visit the Apps page.
- Click your existing app or create a new one if needed.
- The selected app type is up to you, but it should have the product Facebook Login.
- On the app dashboard page, scroll to the "Add a product" section and click the "Set up" button on the "Facebook Login" card.
- Skip the Facebook Login Quickstart page, and click the sidebar -> "Products" -> "Facebook Login" -> "Settings".
- In the Facebook Login Settings page, fill
${your_logto_origin}/callback/${connector_id}
in the "Valid OAuth Redirect URIs" field. Theconnector_id
can be found on the top bar of the Logto Admin Console connector details page. E.g.:https://logto.dev/callback/${connector_id}
for productionhttps://localhost:3001/callback/${connector_id}
for testing in the local environment
- Click the "Save changes" button at the bottom right corner.
Compose the connector JSONβ
- In the Facebook app dashboard page, click the sidebar -> "Settings" -> "Basic".
- You will see the "App ID" and "App secret" on the panel.
- Click the "Show" button following the App secret input box to copy its content.
- Fill out the Logto connector settings:
- Fill out the
clientId
field with the string from App ID. - Fill out the
clientSecret
field with the string from App secret. - Fill out the
scope
field with a comma or space separated list of permissions in string. If you do not specify a scope, the default scope isemail,public_profile
.
- Fill out the
Test sign-in with Facebook's test usersβ
You can use the accounts of the test, developer, and admin users to test sign-in with the related app under both development and live app modes.
You can also take the app live directly so that any Facebook user can sign in with the app.
- In the app dashboard page, click the sidebar -> "Roles" -> "Test Users".
- Click the "Create test users" button to create a testing user.
- Click the "Options" button of the existing test user, and you will see more operations, e.g., "Change name and password".
Publish Facebook sign-in settingsβ
Usually, only the test, admin, and developer users can sign in with the related app under development mode.
To enable normal Facebook users sign-in with the app in the production environment, you maybe need to switch your Facebook app to live mode, depending on the app type. E.g., the pure business type app doesn't have the "live" switch button, but it won't block your use.
- In the Facebook app dashboard page, click the sidebar -> "Settings" -> "Basic".
- Fill out the "Privacy Policy URL" and "User data deletion" fields on the panel if required.
- Click the "Save changes" button at the bottom right corner.
- Click the "Live" switch button on the app top bar.
Config typesβ
Name | Type |
---|---|
clientId | string |
clientSecret | string |
scope | string |
Save your configurationβ
Double check you have filled out necessary values in the Logto connector configuration area. Click "Save and Done" (or "Save changes") and the Facebook connector should be available now.
Enable Facebook connector in Sign-in Experienceβ
Once you create a social connector successfully, you can enable it as a "Continue with Facebook" button in Sign-in Experience.
- Navigate to Console > Sign-in experience > Sign-up and sign-in.
- (Optional) Choose "Not applicable" for sign-up identifier if you need social login only.
- Add configured Facebook connector to the "Social sign-in" section.
Testing and Validationβ
Return to your Python app. You should now be able to sign in with Facebook. Enjoy!
Further readingsβ
End-user flows: Logto provides a out-of-the-box authentication flows including MFA and enterprise SSO, along with powerful APIs for flexible implementation of account settings, security verification, and multi-tenant experience.
Authorization: Authorization defines the actions a user can do or resources they can access after being authenticated. Explore how to protect your API for native and single-page applications and implement Role-based Access Control (RBAC).
Organizations: Particularly effective in multi-tenant SaaS and B2B apps, the organization feature enable tenant creation, member management, organization-level RBAC, and just-in-time-provisioning.
Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.