Firebase Admin Node.js SDK v5.12.0

Authentication

• A new auth.createSessionCookie() method for creating a session cookie from a Firebase ID token.
• A new auth.verifySessionCookie() method for validating a given session cookie string.

Cloud Messaging

• Added the mutableContent optional field to the messaging.Aps type. This can be used to set the mutable-content property when sending FCM messages to APNS targets.
• Added support for specifying arbitrary key-value fields in the messaging.Aps type.