Firebase Auth returns PROJECT_SOFT_DELETED after project undelete — Firestore restored but Auth still broken

[sonermezgitci]

Operating System

macOS

Environment (if applicable)

Node.js 23, Next.js 14, next-firebase-auth

Firebase SDK Version

firebase@10.x

Firebase SDK Product(s)

Auth

Project Tooling

Next.js 14 (Pages Router), Firebase Admin SDK, next-firebase-auth

Detailed Problem Description

Our Firebase project (sporty-e1e3a) was soft-deleted and restored via UndeleteProject.

What we were trying to achieve:
Allow users to log in again after project restoration.

What actually happened:

• Firestore: FULLY RESTORED (281 users, all collections intact)
• Firebase Storage: WORKING (files serving normally)
• Firebase Authentication: STILL BROKEN

Error:
POST https://identitytoolkit.googleapis.com/v1/projects/sporty-e1e3a/accounts:query
HTTP 400 — PROJECT_SOFT_DELETED

Firestore restored automatically after ~5 days. Auth has not restored after the same
period. All 281 registered users are locked out. Project lifecycleState shows ACTIVE
in the management API, but Auth service remains soft-deleted.

Steps and code to reproduce issue

1. Soft-delete a Firebase project via Google Cloud Console
2. Restore it via UndeleteProject API or Firebase Console
3. Wait several days — Firestore and Storage restore automatically
4. Attempt any Firebase Auth API call:

const admin = require('firebase-admin');
const auth = admin.auth();
await auth.listUsers();
// → Error: PROJECT_SOFT_DELETED

Or via REST:
POST https://identitytoolkit.googleapis.com/v1/projects/sporty-e1e3a/accounts:query
Authorization: Bearer <valid_token>
→ HTTP 400: PROJECT_SOFT_DELETED

5. Project lifecycleState = ACTIVE in management API
6. Auth remains broken indefinitely

[DellaBitta]

Hi @sonermezgitci ,

Thanks for the issue report. Any sort of service issues (like side effects from undeleting a project) are handled by the Firebase service team team, and therefore have a different support system. Could you please open an issue in Firebase Support for this issue? Thank you, and good luck!