Firebase iOS SDK 12.18.0 (Aug 19, 2026): FCM token API deprecations and steadier analytics session_start

Firebase shipped Firebase Apple SDK 12.18.0 and, buried in a long changelog, there are a couple of items worth flagging if you rely on Firebase for push, analytics, or release-cadence stability.

• Source: Firebase, “Firebase Apple SDK Release Notes” (Version 12.18.0, published Aug 19, 2026)
• Read: https://firebase.google.com/support/release-notes/ios

The two changes most likely to affect growth operations

1. FCM token APIs are being deprecated Firebase is deprecating a set of token-related APIs (including tokenWithCompletion:, deleteTokenWithCompletion:, and related notifications/callbacks) in favor of newer, Installation ID based registration APIs.

   Why you should care: token handling is one of those things that fails “quietly” and shows up later as softer push delivery, missing registration refreshes, or strange device level churn.

2. Analytics session_start reliability got a fix The release notes mention race condition fixes that caused session_start events to not report consistently on app launch.

   Why you should care: if your dashboards or cohort logic treat session_start as a baseline, launch race conditions can become phantom changes in retention, DAU, and campaign comparisons.

Tiny win (30 minutes)

• Add a quick push + analytics smoke test to your release checklist: install fresh, opt in to push, verify token refresh, open app from a push, then confirm analytics events land.
• If you have custom wrappers around token APIs, put a ticket on the board to align with the new FID based APIs before it becomes an emergency.

Read the source: https://firebase.google.com/support/release-notes/ios