Google OAuth Service Configuration on external app

To use the OAuth service of Google in our app, we need to create a project in our gcp console and create a API service in it.

1. Go to GCP Console and login with your google account. Create a project to get started.

2. Select the created project and click on “API and Services”

3. Create a OAuth Consent screen for external access

• Select User Type as “External” and click on Create.

4. Add the webapp details where you will add this Oauth service

• Add your App name
• User support email will be the mail which you use to create the project.
• Adding logo for the app is optional

5. Add the authorized domain that is going to use this service. The subsequent sub-domain can use it afterwards.

• Also add a developer contact email (can be any)

6. Now create a OAuth client ID in Credentials

7. Add all the details about the domain that is going to use service along with callback url

• Select Application Type as “Web App”
• Add the Name of App (This will appear to users when trying to authenticate with google)
• Add the domain or sub-domain in the Authorized Javascript Origin
• The redirect URL formats goes as {{url}}/api/auth/callback/google
• Finally click create to get the client ID and secret to add our app and use the service.

This post can be very helpful while creating OAuth for in-house authentication.