I want to pass the locale and timezone info to apps via a JWT

dan

If we want to use FusionAuth to authenticate an user to a third party application, we want that the third party application uses the language and the timezone from the FusionAuth user settings. If I connect an external identity provider with FusionAuth, the claim "locale" (defined in openid connect: https://openid.net/specs/openid-connect-core-1_0.html#StandardClaims) will be stored in FusionAuth, but FusionAuth doesn't send the claim while authentication about SSO.

Moved over from https://github.com/FusionAuth/fusionauth-issues/issues/401

dan

I solved it by myself with a lambda function:

Create a lambda with type JWT populate
Add the following code:

function populate(jwt, user, registration) {
  preferredLanguages = user.preferredLanguages;
  
  if(preferredLanguages === null || preferredLanguages === undefined || preferredLanguages.length === 0) {
    return;  
  }
  
  // set first preferred language to jwt
  jwt.locale = user.preferredLanguages[0];
  
  // set zoneinfo to jwt
  jwt.zoneinfo = user.timezone;
}

Finally, in your application settings click on JWT and set your lambda function to Access token populate lambda.

dan

There's additional localization and internationalization doc that was written recently here: https://fusionauth.io/docs/v1/tech/core-concepts/localization-and-internationalization/