diff --git a/app/src/main/java/app/closer/data/remote/FirestoreCoupleDataSource.kt b/app/src/main/java/app/closer/data/remote/FirestoreCoupleDataSource.kt
index 88805377..621a92e8 100644
--- a/app/src/main/java/app/closer/data/remote/FirestoreCoupleDataSource.kt
+++ b/app/src/main/java/app/closer/data/remote/FirestoreCoupleDataSource.kt
@@ -5,14 +5,19 @@ import app.closer.domain.model.Couple
 import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FirebaseFirestore
 import com.google.firebase.firestore.SetOptions
+import com.google.firebase.functions.FirebaseFunctions
 import kotlinx.coroutines.suspendCancellableCoroutine
+import kotlinx.coroutines.tasks.await
 import javax.inject.Inject
 import javax.inject.Singleton
 import kotlin.coroutines.resume
 import kotlin.coroutines.resumeWithException
 
 @Singleton
-class FirestoreCoupleDataSource @Inject constructor(private val db: FirebaseFirestore) {
+class FirestoreCoupleDataSource @Inject constructor(
+    private val db: FirebaseFirestore,
+    private val functions: FirebaseFunctions
+) {
     private fun coupleRef(coupleId: String) = db.collection(FirestoreCollections.COUPLES).document(coupleId)
     private fun userRef(uid: String) = db.collection(FirestoreCollections.USERS).document(uid)
 
@@ -111,32 +116,10 @@ class FirestoreCoupleDataSource @Inject constructor(private val db: FirebaseFire
         }
     }
 
-    suspend fun leaveCouple(userId: String) {
-        val userSnap = suspendCancellableCoroutine<DocumentSnapshot> { cont ->
-            userRef(userId).get()
-                .addOnSuccessListener { cont.resume(it) }
-                .addOnFailureListener { cont.resumeWithException(it) }
-        }
-        val coupleId = userSnap.getString("coupleId") ?: return
-        val coupleSnap = suspendCancellableCoroutine<DocumentSnapshot> { cont ->
-            coupleRef(coupleId).get()
-                .addOnSuccessListener { cont.resume(it) }
-                .addOnFailureListener { cont.resumeWithException(it) }
-        }
-        @Suppress("UNCHECKED_CAST")
-        val allUserIds = (coupleSnap.get("userIds") as? List<String>) ?: listOf(userId)
-        val partnerId = allUserIds.firstOrNull { it != userId }
-
-        suspendCancellableCoroutine<Unit> { cont ->
-            val batch = db.batch()
-            allUserIds.forEach { uid ->
-                batch.update(userRef(uid), "coupleId", null)
-            }
-            batch.commit()
-                .addOnSuccessListener { cont.resume(Unit) }
-                .addOnFailureListener { cont.resumeWithException(it) }
-        }
-
+    suspend fun leaveCouple() {
+        // The client cannot batch-update the partner's user doc (rules deny cross-user writes).
+        // Delegate to the leaveCoupleCallable Cloud Function which uses the Admin SDK.
+        functions.getHttpsCallable("leaveCoupleCallable").call().await()
     }
 
     @Suppress("UNCHECKED_CAST")
diff --git a/app/src/main/java/app/closer/data/repository/CoupleRepositoryImpl.kt b/app/src/main/java/app/closer/data/repository/CoupleRepositoryImpl.kt
index cac18e77..d03eab7a 100644
--- a/app/src/main/java/app/closer/data/repository/CoupleRepositoryImpl.kt
+++ b/app/src/main/java/app/closer/data/repository/CoupleRepositoryImpl.kt
@@ -62,7 +62,7 @@ class CoupleRepositoryImpl @Inject constructor(
 
     override suspend fun leaveCouple(userId: String): Result<Unit> = runCatching {
         val coupleId = userDataSource.getUser(userId)?.coupleId
-        coupleDataSource.leaveCouple(userId)
+        coupleDataSource.leaveCouple()
         if (coupleId != null) encryptionManager.deleteKeyset(coupleId)
     }
 
diff --git a/app/src/main/java/app/closer/ui/settings/DeleteAccountScreen.kt b/app/src/main/java/app/closer/ui/settings/DeleteAccountScreen.kt
index 37c660a2..21eab2fc 100644
--- a/app/src/main/java/app/closer/ui/settings/DeleteAccountScreen.kt
+++ b/app/src/main/java/app/closer/ui/settings/DeleteAccountScreen.kt
@@ -5,8 +5,6 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import app.closer.core.navigation.AppRoute
 import app.closer.domain.repository.AuthRepository
-import app.closer.domain.repository.CoupleRepository
-import app.closer.domain.repository.UserRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
 import javax.inject.Inject
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -77,9 +75,7 @@ data class DeleteAccountUiState(
 
 @HiltViewModel
 class DeleteAccountViewModel @Inject constructor(
-    private val authRepository: AuthRepository,
-    private val coupleRepository: CoupleRepository,
-    private val userRepository: UserRepository
+    private val authRepository: AuthRepository
 ) : ViewModel() {
 
     private val _uiState = MutableStateFlow(DeleteAccountUiState())
@@ -95,16 +91,15 @@ class DeleteAccountViewModel @Inject constructor(
 
     fun confirmDelete() {
         if (!uiState.value.canDelete) return
-        val uid = authRepository.currentUserId ?: return
         viewModelScope.launch {
             _uiState.update { it.copy(showConfirm = false, isDeleting = true, error = null) }
-            // Delete auth account FIRST so a later cleanup failure never leaves the user
-            // with data gone but an active account. If this throws RecentLoginRequired
-            // we stop before touching any data.
+            // Delete the auth account first. The onUserDelete Cloud Function fires
+            // asynchronously and handles all cascading cleanup: couple unpair,
+            // partner notification, Firestore subcollections, and Storage.
+            // Doing auth deletion first means a RecentLoginRequired failure stops
+            // us before any data is touched (prevents the half-deleted state).
             authRepository.deleteAccount()
                 .onSuccess {
-                    runCatching { coupleRepository.leaveCouple(uid) }
-                    runCatching { userRepository.deleteUserData(uid) }
                     _uiState.update { it.copy(isDeleting = false, navigateTo = AppRoute.ONBOARDING) }
                 }
                 .onFailure { e ->
diff --git a/functions/dist/couples/leaveCoupleCallable.js b/functions/dist/couples/leaveCoupleCallable.js
new file mode 100644
index 00000000..f2f3af00
--- /dev/null
+++ b/functions/dist/couples/leaveCoupleCallable.js
@@ -0,0 +1,88 @@
+"use strict";
+var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
+}) : (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    o[k2] = m[k];
+}));
+var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
+    Object.defineProperty(o, "default", { enumerable: true, value: v });
+}) : function(o, v) {
+    o["default"] = v;
+});
+var __importStar = (this && this.__importStar) || (function () {
+    var ownKeys = function(o) {
+        ownKeys = Object.getOwnPropertyNames || function (o) {
+            var ar = [];
+            for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
+            return ar;
+        };
+        return ownKeys(o);
+    };
+    return function (mod) {
+        if (mod && mod.__esModule) return mod;
+        var result = {};
+        if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
+        __setModuleDefault(result, mod);
+        return result;
+    };
+})();
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.leaveCoupleCallable = void 0;
+const functions = __importStar(require("firebase-functions"));
+const admin = __importStar(require("firebase-admin"));
+/**
+ * HTTPS callable that atomically unlinks a couple.
+ *
+ * The client cannot do this directly because Firestore rules prevent a user
+ * from writing the partner's user document. The Admin SDK bypasses those rules.
+ *
+ * Steps:
+ *  1. Verify the caller is a member of their current couple.
+ *  2. Clear coupleId on both user docs (batch — atomic).
+ *  3. Recursively delete the couple doc and all its subcollections.
+ *
+ * The existing onCoupleLeave Firestore trigger fires after step 2 and handles
+ * partner notification, so we don't duplicate that here.
+ */
+exports.leaveCoupleCallable = functions.https.onCall(async (_data, context) => {
+    var _a, _b, _c, _d;
+    const callerId = (_a = context.auth) === null || _a === void 0 ? void 0 : _a.uid;
+    if (!callerId) {
+        throw new functions.https.HttpsError('unauthenticated', 'Must be signed in.');
+    }
+    const db = admin.firestore();
+    const userDoc = await db.collection('users').doc(callerId).get();
+    const coupleId = (_b = userDoc.data()) === null || _b === void 0 ? void 0 : _b.coupleId;
+    if (!coupleId) {
+        // Already unpaired — idempotent success.
+        return { success: true };
+    }
+    const coupleRef = db.collection('couples').doc(coupleId);
+    const coupleDoc = await coupleRef.get();
+    if (!coupleDoc.exists) {
+        // Couple doc gone — just clear caller's field.
+        await db.collection('users').doc(callerId).update({ coupleId: null });
+        return { success: true };
+    }
+    const userIds = ((_d = (_c = coupleDoc.data()) === null || _c === void 0 ? void 0 : _c.userIds) !== null && _d !== void 0 ? _d : []);
+    if (!userIds.includes(callerId)) {
+        throw new functions.https.HttpsError('permission-denied', 'Not a member of this couple.');
+    }
+    // Clear coupleId for all members atomically.
+    const batch = db.batch();
+    for (const uid of userIds) {
+        batch.update(db.collection('users').doc(uid), { coupleId: null });
+    }
+    await batch.commit();
+    // Recursively delete the couple document and every subcollection beneath it.
+    await db.recursiveDelete(coupleRef);
+    console.log(`[leaveCoupleCallable] user ${callerId} left couple ${coupleId}`);
+    return { success: true };
+});
+//# sourceMappingURL=leaveCoupleCallable.js.map
\ No newline at end of file
diff --git a/functions/dist/couples/leaveCoupleCallable.js.map b/functions/dist/couples/leaveCoupleCallable.js.map
new file mode 100644
index 00000000..a0a799e8
--- /dev/null
+++ b/functions/dist/couples/leaveCoupleCallable.js.map
@@ -0,0 +1 @@
+{"version":3,"file":"leaveCoupleCallable.js","sourceRoot":"","sources":["../../src/couples/leaveCoupleCallable.ts"],"names":[],"mappings":";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAA,8DAA+C;AAC/C,sDAAuC;AAEvC;;;;;;;;;;;;;GAaG;AACU,QAAA,mBAAmB,GAAG,SAAS,CAAC,KAAK,CAAC,MAAM,CAAC,KAAK,EAAE,KAAK,EAAE,OAAO,EAAE,EAAE;;IACjF,MAAM,QAAQ,GAAG,MAAA,OAAO,CAAC,IAAI,0CAAE,GAAG,CAAA;IAClC,IAAI,CAAC,QAAQ,EAAE,CAAC;QACd,MAAM,IAAI,SAAS,CAAC,KAAK,CAAC,UAAU,CAAC,iBAAiB,EAAE,oBAAoB,CAAC,CAAA;IAC/E,CAAC;IAED,MAAM,EAAE,GAAG,KAAK,CAAC,SAAS,EAAE,CAAA;IAE5B,MAAM,OAAO,GAAG,MAAM,EAAE,CAAC,UAAU,CAAC,OAAO,CAAC,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC,GAAG,EAAE,CAAA;IAChE,MAAM,QAAQ,GAAG,MAAA,OAAO,CAAC,IAAI,EAAE,0CAAE,QAA8B,CAAA;IAC/D,IAAI,CAAC,QAAQ,EAAE,CAAC;QACd,yCAAyC;QACzC,OAAO,EAAE,OAAO,EAAE,IAAI,EAAE,CAAA;IAC1B,CAAC;IAED,MAAM,SAAS,GAAG,EAAE,CAAC,UAAU,CAAC,SAAS,CAAC,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAA;IACxD,MAAM,SAAS,GAAG,MAAM,SAAS,CAAC,GAAG,EAAE,CAAA;IAEvC,IAAI,CAAC,SAAS,CAAC,MAAM,EAAE,CAAC;QACtB,+CAA+C;QAC/C,MAAM,EAAE,CAAC,UAAU,CAAC,OAAO,CAAC,CAAC,GAAG,CAAC,QAAQ,CAAC,CAAC,MAAM,CAAC,EAAE,QAAQ,EAAE,IAAI,EAAE,CAAC,CAAA;QACrE,OAAO,EAAE,OAAO,EAAE,IAAI,EAAE,CAAA;IAC1B,CAAC;IAED,MAAM,OAAO,GAAG,CAAC,MAAA,MAAA,SAAS,CAAC,IAAI,EAAE,0CAAE,OAAO,mCAAI,EAAE,CAAa,CAAA;IAC7D,IAAI,CAAC,OAAO,CAAC,QAAQ,CAAC,QAAQ,CAAC,EAAE,CAAC;QAChC,MAAM,IAAI,SAAS,CAAC,KAAK,CAAC,UAAU,CAAC,mBAAmB,EAAE,8BAA8B,CAAC,CAAA;IAC3F,CAAC;IAED,6CAA6C;IAC7C,MAAM,KAAK,GAAG,EAAE,CAAC,KAAK,EAAE,CAAA;IACxB,KAAK,MAAM,GAAG,IAAI,OAAO,EAAE,CAAC;QAC1B,KAAK,CAAC,MAAM,CAAC,EAAE,CAAC,UAAU,CAAC,OAAO,CAAC,CAAC,GAAG,CAAC,GAAG,CAAC,EAAE,EAAE,QAAQ,EAAE,IAAI,EAAE,CAAC,CAAA;IACnE,CAAC;IACD,MAAM,KAAK,CAAC,MAAM,EAAE,CAAA;IAEpB,6EAA6E;IAC7E,MAAM,EAAE,CAAC,eAAe,CAAC,SAAS,CAAC,CAAA;IAEnC,OAAO,CAAC,GAAG,CAAC,8BAA8B,QAAQ,gBAAgB,QAAQ,EAAE,CAAC,CAAA;IAC7E,OAAO,EAAE,OAAO,EAAE,IAAI,EAAE,CAAA;AAC1B,CAAC,CAAC,CAAA"}
\ No newline at end of file
diff --git a/functions/dist/index.js b/functions/dist/index.js
index f79aaac7..c975810a 100644
--- a/functions/dist/index.js
+++ b/functions/dist/index.js
@@ -33,7 +33,7 @@ var __importStar = (this && this.__importStar) || (function () {
     };
 })();
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.health = exports.onGameSessionUpdate = exports.onCoupleLeave = exports.onAnswerWritten = exports.assignDailyQuestionCallable = exports.assignDailyQuestion = exports.createDateMatchOnMutualLove = exports.checkDeviceIntegrity = exports.unlockDueMemoryCapsules = exports.sendChallengeDayReminders = exports.sendPartnerAnsweredNotification = exports.sendDailyQuestionReminder = exports.syncEntitlement = exports.revenueCatWebhook = void 0;
+exports.health = exports.onGameSessionUpdate = exports.onUserDelete = exports.leaveCoupleCallable = exports.onCoupleLeave = exports.onAnswerWritten = exports.assignDailyQuestionCallable = exports.assignDailyQuestion = exports.createDateMatchOnMutualLove = exports.checkDeviceIntegrity = exports.unlockDueMemoryCapsules = exports.sendChallengeDayReminders = exports.sendPartnerAnsweredNotification = exports.sendDailyQuestionReminder = exports.syncEntitlement = exports.revenueCatWebhook = void 0;
 const functions = __importStar(require("firebase-functions"));
 const admin = __importStar(require("firebase-admin"));
 // Initialize the Admin SDK once for every function in this codebase.
@@ -63,6 +63,10 @@ var onAnswerWritten_1 = require("./questions/onAnswerWritten");
 Object.defineProperty(exports, "onAnswerWritten", { enumerable: true, get: function () { return onAnswerWritten_1.onAnswerWritten; } });
 var onCoupleLeave_1 = require("./couples/onCoupleLeave");
 Object.defineProperty(exports, "onCoupleLeave", { enumerable: true, get: function () { return onCoupleLeave_1.onCoupleLeave; } });
+var leaveCoupleCallable_1 = require("./couples/leaveCoupleCallable");
+Object.defineProperty(exports, "leaveCoupleCallable", { enumerable: true, get: function () { return leaveCoupleCallable_1.leaveCoupleCallable; } });
+var onUserDelete_1 = require("./users/onUserDelete");
+Object.defineProperty(exports, "onUserDelete", { enumerable: true, get: function () { return onUserDelete_1.onUserDelete; } });
 var onGameSessionUpdate_1 = require("./games/onGameSessionUpdate");
 Object.defineProperty(exports, "onGameSessionUpdate", { enumerable: true, get: function () { return onGameSessionUpdate_1.onGameSessionUpdate; } });
 /**
diff --git a/functions/dist/index.js.map b/functions/dist/index.js.map
index 9af30036..16e7adce 100644
--- a/functions/dist/index.js.map
+++ b/functions/dist/index.js.map
@@ -1 +1 @@
-{"version":3,"file":"index.js","sourceRoot":"","sources":["../src/index.ts"],"names":[],"mappings":";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAA,8DAA+C;AAC/C,sDAAuC;AAEvC,qEAAqE;AACrE,8EAA8E;AAC9E,gFAAgF;AAChF,IAAI,KAAK,CAAC,IAAI,CAAC,MAAM,KAAK,CAAC,EAAE,CAAC;IAC5B,KAAK,CAAC,aAAa,EAAE,CAAA;AACvB,CAAC;AAED,iEAA+D;AAAtD,sHAAA,iBAAiB,OAAA;AAC1B,6DAA2D;AAAlD,kHAAA,eAAe,OAAA;AACxB,uDAGkC;AAFhC,sHAAA,yBAAyB,OAAA;AACzB,4HAAA,+BAA+B,OAAA;AAEjC,+DAGsC;AAFpC,0HAAA,yBAAyB,OAAA;AACzB,wHAAA,uBAAuB,OAAA;AAEzB,wEAAsE;AAA7D,4HAAA,oBAAoB,OAAA;AAC7B,2DAAqE;AAA5D,8HAAA,2BAA2B,OAAA;AACpC,uEAGwC;AAFtC,0HAAA,mBAAmB,OAAA;AACnB,kIAAA,2BAA2B,OAAA;AAE7B,+DAA6D;AAApD,kHAAA,eAAe,OAAA;AACxB,yDAAuD;AAA9C,8GAAA,aAAa,OAAA;AACtB,mEAAiE;AAAxD,0HAAA,mBAAmB,OAAA;AAE5B;;;GAGG;AACU,QAAA,MAAM,GAAG,SAAS,CAAC,KAAK,CAAC,SAAS,CAAC,CAAC,GAAG,EAAE,GAAG,EAAE,EAAE;IAC3D,GAAG,CAAC,MAAM,CAAC,GAAG,CAAC,CAAC,IAAI,CAAC,EAAE,MAAM,EAAE,IAAI,EAAE,CAAC,CAAA;AACxC,CAAC,CAAC,CAAA"}
\ No newline at end of file
+{"version":3,"file":"index.js","sourceRoot":"","sources":["../src/index.ts"],"names":[],"mappings":";;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;AAAA,8DAA+C;AAC/C,sDAAuC;AAEvC,qEAAqE;AACrE,8EAA8E;AAC9E,gFAAgF;AAChF,IAAI,KAAK,CAAC,IAAI,CAAC,MAAM,KAAK,CAAC,EAAE,CAAC;IAC5B,KAAK,CAAC,aAAa,EAAE,CAAA;AACvB,CAAC;AAED,iEAA+D;AAAtD,sHAAA,iBAAiB,OAAA;AAC1B,6DAA2D;AAAlD,kHAAA,eAAe,OAAA;AACxB,uDAGkC;AAFhC,sHAAA,yBAAyB,OAAA;AACzB,4HAAA,+BAA+B,OAAA;AAEjC,+DAGsC;AAFpC,0HAAA,yBAAyB,OAAA;AACzB,wHAAA,uBAAuB,OAAA;AAEzB,wEAAsE;AAA7D,4HAAA,oBAAoB,OAAA;AAC7B,2DAAqE;AAA5D,8HAAA,2BAA2B,OAAA;AACpC,uEAGwC;AAFtC,0HAAA,mBAAmB,OAAA;AACnB,kIAAA,2BAA2B,OAAA;AAE7B,+DAA6D;AAApD,kHAAA,eAAe,OAAA;AACxB,yDAAuD;AAA9C,8GAAA,aAAa,OAAA;AACtB,qEAAmE;AAA1D,0HAAA,mBAAmB,OAAA;AAC5B,qDAAmD;AAA1C,4GAAA,YAAY,OAAA;AACrB,mEAAiE;AAAxD,0HAAA,mBAAmB,OAAA;AAE5B;;;GAGG;AACU,QAAA,MAAM,GAAG,SAAS,CAAC,KAAK,CAAC,SAAS,CAAC,CAAC,GAAG,EAAE,GAAG,EAAE,EAAE;IAC3D,GAAG,CAAC,MAAM,CAAC,GAAG,CAAC,CAAC,IAAI,CAAC,EAAE,MAAM,EAAE,IAAI,EAAE,CAAC,CAAA;AACxC,CAAC,CAAC,CAAA"}
\ No newline at end of file
diff --git a/functions/dist/users/onUserDelete.js b/functions/dist/users/onUserDelete.js
new file mode 100644
index 00000000..99555b6a
--- /dev/null
+++ b/functions/dist/users/onUserDelete.js
@@ -0,0 +1,145 @@
+"use strict";
+var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+      desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
+}) : (function(o, m, k, k2) {
+    if (k2 === undefined) k2 = k;
+    o[k2] = m[k];
+}));
+var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
+    Object.defineProperty(o, "default", { enumerable: true, value: v });
+}) : function(o, v) {
+    o["default"] = v;
+});
+var __importStar = (this && this.__importStar) || (function () {
+    var ownKeys = function(o) {
+        ownKeys = Object.getOwnPropertyNames || function (o) {
+            var ar = [];
+            for (var k in o) if (Object.prototype.hasOwnProperty.call(o, k)) ar[ar.length] = k;
+            return ar;
+        };
+        return ownKeys(o);
+    };
+    return function (mod) {
+        if (mod && mod.__esModule) return mod;
+        var result = {};
+        if (mod != null) for (var k = ownKeys(mod), i = 0; i < k.length; i++) if (k[i] !== "default") __createBinding(result, mod, k[i]);
+        __setModuleDefault(result, mod);
+        return result;
+    };
+})();
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.onUserDelete = void 0;
+const functions = __importStar(require("firebase-functions"));
+const admin = __importStar(require("firebase-admin"));
+/**
+ * Auth deletion trigger — cascades account deletion server-side.
+ *
+ * Fires when a Firebase Auth user is deleted (via client deleteAccount() or
+ * Admin SDK). The Admin SDK bypasses Firestore rules, so this function can
+ * reach everything the client cannot.
+ *
+ * Steps (all best-effort after the auth account is already gone):
+ *  1. If the user was in a couple:
+ *     a. Clear the partner's coupleId.
+ *     b. Send the partner an FCM push notification.
+ *     c. Recursively delete the couple doc + all subcollections.
+ *  2. Delete all Storage objects under users/{uid}/ (profile photo etc.).
+ *  3. Recursively delete the user doc + all subcollections
+ *     (entitlements, fcmTokens, notification_queue).
+ */
+exports.onUserDelete = functions.auth.user().onDelete(async (user) => {
+    var _a, _b, _c, _d;
+    const uid = user.uid;
+    const db = admin.firestore();
+    // ── 1. Couple unpair ──────────────────────────────────────────────────────
+    const userDocRef = db.collection('users').doc(uid);
+    const userDoc = await userDocRef.get();
+    const coupleId = userDoc.exists
+        ? (_a = userDoc.data()) === null || _a === void 0 ? void 0 : _a.coupleId
+        : undefined;
+    if (coupleId) {
+        const coupleRef = db.collection('couples').doc(coupleId);
+        const coupleDoc = await coupleRef.get();
+        if (coupleDoc.exists) {
+            const userIds = ((_c = (_b = coupleDoc.data()) === null || _b === void 0 ? void 0 : _b.userIds) !== null && _c !== void 0 ? _c : []);
+            const partnerId = userIds.find((id) => id !== uid);
+            if (partnerId) {
+                const partnerRef = db.collection('users').doc(partnerId);
+                const partnerDoc = await partnerRef.get();
+                // Only act if the partner is still recorded in this couple.
+                if (partnerDoc.exists && ((_d = partnerDoc.data()) === null || _d === void 0 ? void 0 : _d.coupleId) === coupleId) {
+                    // Clear partner's coupleId first so the onCoupleLeave trigger does
+                    // not fire a second time (it would find no partner left to notify).
+                    await partnerRef.update({ coupleId: null });
+                    // Send push notification to the partner.
+                    await notifyPartner(partnerId, partnerDoc, db).catch((err) => {
+                        console.warn(`[onUserDelete] FCM notification to partner ${partnerId} failed:`, err);
+                    });
+                }
+            }
+            // Recursively delete the couple doc + all subcollections.
+            await db.recursiveDelete(coupleRef);
+        }
+    }
+    // ── 2. Storage cleanup ────────────────────────────────────────────────────
+    try {
+        await admin.storage().bucket().deleteFiles({ prefix: `users/${uid}/` });
+    }
+    catch (err) {
+        console.warn(`[onUserDelete] Storage cleanup failed for ${uid}:`, err);
+    }
+    // ── 3. User doc + subcollections ──────────────────────────────────────────
+    await db.recursiveDelete(userDocRef);
+    console.log(`[onUserDelete] completed cleanup for user ${uid}`);
+});
+async function notifyPartner(partnerId, partnerDoc, db) {
+    var _a;
+    const messaging = admin.messaging();
+    // Collect FCM tokens (legacy field + fcmTokens subcollection).
+    const tokens = [];
+    const legacyToken = (_a = partnerDoc.data()) === null || _a === void 0 ? void 0 : _a.fcmToken;
+    if (typeof legacyToken === 'string' && legacyToken.length > 0) {
+        tokens.push(legacyToken);
+    }
+    const tokenSnap = await db.collection('users').doc(partnerId).collection('fcmTokens').get();
+    tokenSnap.docs.forEach((doc) => {
+        var _a;
+        const t = (_a = doc.data()) === null || _a === void 0 ? void 0 : _a.token;
+        if (typeof t === 'string' && t.length > 0 && !tokens.includes(t)) {
+            tokens.push(t);
+        }
+    });
+    if (tokens.length === 0)
+        return;
+    // Write an in-app notification record.
+    await db
+        .collection('users')
+        .doc(partnerId)
+        .collection('notification_queue')
+        .add({
+        type: 'partner_deleted_account',
+        title: 'Your partner deleted their account',
+        body: 'You are no longer paired. Tap to create a new invite.',
+        read: false,
+        createdAt: admin.firestore.FieldValue.serverTimestamp(),
+    });
+    const sendResults = await Promise.allSettled(tokens.map((token) => messaging.send({
+        token,
+        notification: {
+            title: 'Your partner deleted their account',
+            body: 'You are no longer paired. Tap to create a new invite.',
+        },
+        data: { type: 'partner_deleted_account' },
+    })));
+    sendResults.forEach((result, i) => {
+        if (result.status === 'rejected') {
+            console.warn(`[onUserDelete] FCM send to token ${tokens[i]} failed:`, result.reason);
+        }
+    });
+}
+//# sourceMappingURL=onUserDelete.js.map
\ No newline at end of file
diff --git a/functions/dist/users/onUserDelete.js.map b/functions/dist/users/onUserDelete.js.map
new file mode 100644
index 00000000..6e67d298
--- /dev/null
+++ b/functions/dist/users/onUserDelete.js.map
@@ -0,0 +1 @@
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\ No newline at end of file
diff --git a/functions/src/couples/leaveCoupleCallable.ts b/functions/src/couples/leaveCoupleCallable.ts
new file mode 100644
index 00000000..c34ec000
--- /dev/null
+++ b/functions/src/couples/leaveCoupleCallable.ts
@@ -0,0 +1,59 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+
+/**
+ * HTTPS callable that atomically unlinks a couple.
+ *
+ * The client cannot do this directly because Firestore rules prevent a user
+ * from writing the partner's user document. The Admin SDK bypasses those rules.
+ *
+ * Steps:
+ *  1. Verify the caller is a member of their current couple.
+ *  2. Clear coupleId on both user docs (batch — atomic).
+ *  3. Recursively delete the couple doc and all its subcollections.
+ *
+ * The existing onCoupleLeave Firestore trigger fires after step 2 and handles
+ * partner notification, so we don't duplicate that here.
+ */
+export const leaveCoupleCallable = functions.https.onCall(async (_data, context) => {
+  const callerId = context.auth?.uid
+  if (!callerId) {
+    throw new functions.https.HttpsError('unauthenticated', 'Must be signed in.')
+  }
+
+  const db = admin.firestore()
+
+  const userDoc = await db.collection('users').doc(callerId).get()
+  const coupleId = userDoc.data()?.coupleId as string | undefined
+  if (!coupleId) {
+    // Already unpaired — idempotent success.
+    return { success: true }
+  }
+
+  const coupleRef = db.collection('couples').doc(coupleId)
+  const coupleDoc = await coupleRef.get()
+
+  if (!coupleDoc.exists) {
+    // Couple doc gone — just clear caller's field.
+    await db.collection('users').doc(callerId).update({ coupleId: null })
+    return { success: true }
+  }
+
+  const userIds = (coupleDoc.data()?.userIds ?? []) as string[]
+  if (!userIds.includes(callerId)) {
+    throw new functions.https.HttpsError('permission-denied', 'Not a member of this couple.')
+  }
+
+  // Clear coupleId for all members atomically.
+  const batch = db.batch()
+  for (const uid of userIds) {
+    batch.update(db.collection('users').doc(uid), { coupleId: null })
+  }
+  await batch.commit()
+
+  // Recursively delete the couple document and every subcollection beneath it.
+  await db.recursiveDelete(coupleRef)
+
+  console.log(`[leaveCoupleCallable] user ${callerId} left couple ${coupleId}`)
+  return { success: true }
+})
diff --git a/functions/src/index.ts b/functions/src/index.ts
index 8d8c464b..513d78d9 100644
--- a/functions/src/index.ts
+++ b/functions/src/index.ts
@@ -26,6 +26,8 @@ export {
 } from './questions/assignDailyQuestion'
 export { onAnswerWritten } from './questions/onAnswerWritten'
 export { onCoupleLeave } from './couples/onCoupleLeave'
+export { leaveCoupleCallable } from './couples/leaveCoupleCallable'
+export { onUserDelete } from './users/onUserDelete'
 export { onGameSessionUpdate } from './games/onGameSessionUpdate'
 
 /**
diff --git a/functions/src/users/onUserDelete.ts b/functions/src/users/onUserDelete.ts
new file mode 100644
index 00000000..3ef0af95
--- /dev/null
+++ b/functions/src/users/onUserDelete.ts
@@ -0,0 +1,131 @@
+import * as functions from 'firebase-functions'
+import * as admin from 'firebase-admin'
+
+/**
+ * Auth deletion trigger — cascades account deletion server-side.
+ *
+ * Fires when a Firebase Auth user is deleted (via client deleteAccount() or
+ * Admin SDK). The Admin SDK bypasses Firestore rules, so this function can
+ * reach everything the client cannot.
+ *
+ * Steps (all best-effort after the auth account is already gone):
+ *  1. If the user was in a couple:
+ *     a. Clear the partner's coupleId.
+ *     b. Send the partner an FCM push notification.
+ *     c. Recursively delete the couple doc + all subcollections.
+ *  2. Delete all Storage objects under users/{uid}/ (profile photo etc.).
+ *  3. Recursively delete the user doc + all subcollections
+ *     (entitlements, fcmTokens, notification_queue).
+ */
+export const onUserDelete = functions.auth.user().onDelete(async (user) => {
+  const uid = user.uid
+  const db = admin.firestore()
+
+  // ── 1. Couple unpair ──────────────────────────────────────────────────────
+
+  const userDocRef = db.collection('users').doc(uid)
+  const userDoc = await userDocRef.get()
+  const coupleId = userDoc.exists
+    ? (userDoc.data()?.coupleId as string | undefined)
+    : undefined
+
+  if (coupleId) {
+    const coupleRef = db.collection('couples').doc(coupleId)
+    const coupleDoc = await coupleRef.get()
+
+    if (coupleDoc.exists) {
+      const userIds = (coupleDoc.data()?.userIds ?? []) as string[]
+      const partnerId = userIds.find((id) => id !== uid)
+
+      if (partnerId) {
+        const partnerRef = db.collection('users').doc(partnerId)
+        const partnerDoc = await partnerRef.get()
+
+        // Only act if the partner is still recorded in this couple.
+        if (partnerDoc.exists && partnerDoc.data()?.coupleId === coupleId) {
+          // Clear partner's coupleId first so the onCoupleLeave trigger does
+          // not fire a second time (it would find no partner left to notify).
+          await partnerRef.update({ coupleId: null })
+
+          // Send push notification to the partner.
+          await notifyPartner(partnerId, partnerDoc, db).catch((err) => {
+            console.warn(`[onUserDelete] FCM notification to partner ${partnerId} failed:`, err)
+          })
+        }
+      }
+
+      // Recursively delete the couple doc + all subcollections.
+      await db.recursiveDelete(coupleRef)
+    }
+  }
+
+  // ── 2. Storage cleanup ────────────────────────────────────────────────────
+
+  try {
+    await admin.storage().bucket().deleteFiles({ prefix: `users/${uid}/` })
+  } catch (err) {
+    console.warn(`[onUserDelete] Storage cleanup failed for ${uid}:`, err)
+  }
+
+  // ── 3. User doc + subcollections ──────────────────────────────────────────
+
+  await db.recursiveDelete(userDocRef)
+
+  console.log(`[onUserDelete] completed cleanup for user ${uid}`)
+})
+
+async function notifyPartner(
+  partnerId: string,
+  partnerDoc: admin.firestore.DocumentSnapshot,
+  db: admin.firestore.Firestore
+): Promise<void> {
+  const messaging = admin.messaging()
+
+  // Collect FCM tokens (legacy field + fcmTokens subcollection).
+  const tokens: string[] = []
+  const legacyToken = partnerDoc.data()?.fcmToken
+  if (typeof legacyToken === 'string' && legacyToken.length > 0) {
+    tokens.push(legacyToken)
+  }
+  const tokenSnap = await db.collection('users').doc(partnerId).collection('fcmTokens').get()
+  tokenSnap.docs.forEach((doc) => {
+    const t = doc.data()?.token
+    if (typeof t === 'string' && t.length > 0 && !tokens.includes(t)) {
+      tokens.push(t)
+    }
+  })
+
+  if (tokens.length === 0) return
+
+  // Write an in-app notification record.
+  await db
+    .collection('users')
+    .doc(partnerId)
+    .collection('notification_queue')
+    .add({
+      type: 'partner_deleted_account',
+      title: 'Your partner deleted their account',
+      body: 'You are no longer paired. Tap to create a new invite.',
+      read: false,
+      createdAt: admin.firestore.FieldValue.serverTimestamp(),
+    })
+
+  const sendResults = await Promise.allSettled(
+    tokens.map((token) =>
+      messaging.send({
+        token,
+        notification: {
+          title: 'Your partner deleted their account',
+          body: 'You are no longer paired. Tap to create a new invite.',
+        },
+        data: { type: 'partner_deleted_account' },
+      })
+    )
+  )
+
+  sendResults.forEach((result, i) => {
+    if (result.status === 'rejected') {
+      console.warn(`[onUserDelete] FCM send to token ${tokens[i]} failed:`, result.reason)
+    }
+  })
+}