Accept firebase 13 in @angular/fire 22 #3830

firebase 13.1.0 is now npm latest, and @angular/fire 22.0.0-rc.0 declares firebase ^12.18.0 as a peer dependency (#3805). So on a new Angular 22 app, running npm install firebase before ng add @angular/fire@next fails:

npm error ERESOLVE unable to resolve dependency tree
npm error peer firebase@"^12.18.0" from @angular/fire@22.0.0-rc.0

Proposal

I'd like @angular/fire 22.0.0 to accept firebase ^12.18.0 || ^13.0.0:

• Apps on firebase 12 keep working with no change.
• rxfire moves to ^6.3.0, the first release whose peer range includes firebase 13.
• When ng add or the v22 ng update migration writes a firebase entry, it writes the range of the major already installed:
  • ^13.0.0 when firebase 13 is installed.
  • ^12.18.0 otherwise.
• The package keeps building against firebase 12, because the generated wrappers import each function by name from the installed firebase. A new CI job runs the specs against firebase 13.

Why the written range follows the installed major

On npm, ng add installs a missing firebase peer before its schematic runs, at the newest version the range allows. If the schematic then wrote ^12.18.0, the reinstall would downgrade firebase and leave two @firebase/app copies, and the app would fail at startup with "No Firebase App '[DEFAULT]' has been created".

What changes for an app that moves to firebase 13

• @angular/fire/ai re-exports firebase/ai, so VertexAIBackend and the ChatSession class are no longer available.
  • AgentPlatformBackend replaces VertexAIBackend, and the v21 ng update migration already handles it.
• firebase 13's packages declare Node 24.12 or newer.

If you're already on firebase 13 and run into something this doesn't cover, please comment here.