diff --git a/backend/routers/developer.py b/backend/routers/developer.py
index 730f89e1ad..f5c8d722af 100644
--- a/backend/routers/developer.py
+++ b/backend/routers/developer.py
@@ -6,7 +6,7 @@
 from typing import List, Optional
 
 from fastapi import APIRouter, HTTPException, Depends, Query
-from pydantic import BaseModel, Field, ValidationError
+from pydantic import BaseModel, Field, ValidationError, field_validator
 
 import database.folders as folders_db
 import database.memories as memories_db
@@ -104,20 +104,103 @@ def delete_key(key_id: str, uid: str = Depends(get_current_user_id)):
 # ******************************************************
 
 
+def _coerce_required_memory_id(value) -> str:
+    if not value and value != 0:
+        raise ValueError('id is required')
+    return str(value)
+
+
+def _coerce_optional_memory_datetime(value) -> Optional[datetime]:
+    if value in [None, '']:
+        return None
+    if isinstance(value, datetime):
+        return value
+    if isinstance(value, str):
+        try:
+            return datetime.fromisoformat(value.replace('Z', '+00:00'))
+        except ValueError:
+            return None
+    if isinstance(value, (int, float)) and not isinstance(value, bool):
+        try:
+            return datetime.fromtimestamp(value, tz=timezone.utc)
+        except (OSError, OverflowError, ValueError):
+            return None
+    return None
+
+
 class CleanerMemory(BaseModel):
     # Core fields (aligned with MemoryResponse)
     id: str
-    content: str
-    category: MemoryCategory
+    content: str = ''
+    category: MemoryCategory = MemoryCategory.interesting
     visibility: Optional[str] = 'private'
-    tags: List[str] = []
-    created_at: datetime
-    updated_at: datetime
-    manually_added: bool
+    tags: List[str] = Field(default_factory=list)
+    created_at: Optional[datetime] = None
+    updated_at: Optional[datetime] = None
+    manually_added: bool = False
     scoring: Optional[str] = None
-    reviewed: bool
+    reviewed: bool = False
     user_review: Optional[bool] = None
-    edited: bool
+    edited: bool = False
+
+    @field_validator('id', mode='before')
+    def coerce_id(cls, value):
+        return _coerce_required_memory_id(value)
+
+    @field_validator('content', mode='before')
+    def coerce_content(cls, value):
+        if value is None:
+            return ''
+        return str(value)
+
+    @field_validator('category', mode='before')
+    def coerce_category(cls, value):
+        if isinstance(value, MemoryCategory):
+            return value
+        try:
+            return MemoryCategory(value)
+        except (TypeError, ValueError):
+            return MemoryCategory.interesting
+
+    @field_validator('visibility', mode='before')
+    def coerce_visibility(cls, value):
+        return value if value in ['public', 'private'] else 'private'
+
+    @field_validator('tags', mode='before')
+    def coerce_tags(cls, value):
+        if not isinstance(value, list):
+            return []
+        return [str(tag) for tag in value if tag is not None]
+
+    @field_validator('scoring', mode='before')
+    def coerce_scoring(cls, value):
+        if value is None:
+            return None
+        return str(value)
+
+    @field_validator('created_at', 'updated_at', mode='before')
+    def coerce_datetime(cls, value):
+        return _coerce_optional_memory_datetime(value)
+
+    @field_validator('user_review', mode='before')
+    def coerce_user_review(cls, value):
+        if isinstance(value, bool):
+            return value
+        if value in [None, '']:
+            return None
+        if isinstance(value, str):
+            return value.lower() in ['true', '1', 'yes']
+        return bool(value)
+
+    @field_validator('manually_added', 'reviewed', 'edited', mode='before')
+    def coerce_bool(cls, value):
+        if isinstance(value, bool):
+            return value
+        if value in [None, '']:
+            return False
+        if isinstance(value, str):
+            return value.lower() in ['true', '1', 'yes']
+        return bool(value)
 
 
 class CreateMemoryRequest(BaseModel):
@@ -176,8 +259,11 @@ def get_memories(
     # hardening already applied to GET /v3/memories.
     valid_memories = []
     for memory in memories:
+        if not isinstance(memory, dict) or not memory.get('id'):
+            logger.warning('Skipping malformed memory in Developer API memory list')
+            continue
         if memory.get('is_locked', False):
-            content = memory.get('content', '')
+            content = str(memory.get('content') or '')
             memory['content'] = (content[:70] + '...') if len(content) > 70 else content
         try:
             valid_memories.append(CleanerMemory.model_validate(memory))
diff --git a/backend/tests/unit/test_dev_api_folder_filters.py b/backend/tests/unit/test_dev_api_folder_filters.py
index d4189c183c..0a9ea2d974 100644
--- a/backend/tests/unit/test_dev_api_folder_filters.py
+++ b/backend/tests/unit/test_dev_api_folder_filters.py
@@ -11,6 +11,8 @@
 from types import ModuleType
 from unittest.mock import MagicMock
 
+import pytest
+
 os.environ.setdefault('OPENAI_API_KEY', 'sk-test-not-real')
 os.environ.setdefault('ENCRYPTION_SECRET', 'omi_ZwB2ZNqB2HHpMK6wStk7sTpavJiPTFg7gXUHnc4tFABPU6pZ2c2DKgehtfgi4RZv')
 
@@ -361,6 +363,19 @@ def _build_test_app():
     return app, TestClient(app)
 
 
+def _build_memories_test_app():
+    """Build a minimal FastAPI app for Developer API memories routes."""
+    from fastapi import FastAPI
+    from fastapi.testclient import TestClient
+    from routers.developer import router as developer_router
+    from dependencies import get_uid_with_memories_read
+
+    app = FastAPI()
+    app.include_router(developer_router)
+    app.dependency_overrides[get_uid_with_memories_read] = lambda: 'uid1'
+    return app, TestClient(app, raise_server_exceptions=False)
+
+
 class TestDevApiHttpLayer:
     """HTTP layer tests using FastAPI TestClient."""
 
@@ -461,3 +476,118 @@ def test_dev_get_folders_returns_200_with_list_body(self):
         assert len(body) == 1
         assert body[0]['id'] == 'f1'
         assert body[0]['name'] == 'Work'
+
+
+class TestDevApiMemoriesHttpLayer:
+    """HTTP layer tests for Developer API memory list resilience."""
+
+    def setup_method(self):
+        import database.memories as memories_db
+
+        memories_db.get_memories = MagicMock()
+
+    def test_memories_page_tolerates_legacy_malformed_record(self):
+        """A single legacy record must not turn an offset page into HTTP 500."""
+        import database.memories as memories_db
+
+        now = datetime(2025, 1, 15, 10, 0, 0, tzinfo=timezone.utc)
+        memories_db.get_memories.return_value = [
+            {
+                'id': 'mem-ok',
+                'content': 'normal memory',
+                'category': 'manual',
+                'visibility': 'private',
+                'tags': ['source'],
+                'created_at': now,
+                'updated_at': now,
+                'manually_added': True,
+                'scoring': '01_998_1736935200',
+                'reviewed': True,
+                'user_review': True,
+                'edited': False,
+            },
+            {
+                'id': 'mem-legacy',
+                'content': 'legacy memory',
+                'category': 'unexpected-legacy-category',
+                'visibility': None,
+                'tags': None,
+                'created_at': 'not-a-date',
+                'updated_at': {'bad': 'date'},
+                'user_review': 'yes',
+            },
+            {
+                'id': 'mem-locked-legacy',
+                'content': None,
+                'category': None,
+                'is_locked': True,
+                'scoring': 123,
+            },
+            {
+                'content': 'no id should be skipped',
+                'category': 'manual',
+            },
+        ]
+
+        _, client = _build_memories_test_app()
+        resp = client.get('/v1/dev/user/memories?limit=3&offset=7')
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body) == 3
+        legacy = body[1]
+        assert legacy['id'] == 'mem-legacy'
+        assert legacy['content'] == 'legacy memory'
+        assert legacy['category'] == 'interesting'
+        assert legacy['visibility'] == 'private'
+        assert legacy['tags'] == []
+        assert legacy['created_at'] is None
+        assert legacy['updated_at'] is None
+        assert legacy['manually_added'] is False
+        assert legacy['reviewed'] is False
+        assert legacy['user_review'] is True
+        assert legacy['edited'] is False
+
+        locked_legacy = body[2]
+        assert locked_legacy['id'] == 'mem-locked-legacy'
+        assert locked_legacy['content'] == ''
+        assert locked_legacy['category'] == 'interesting'
+        assert locked_legacy['scoring'] == '123'
+
+    def test_cleaner_memory_coerces_edge_values(self):
+        """CleanerMemory validators should be resilient outside the endpoint pre-filter too."""
+        from routers.developer import CleanerMemory
+
+        memory = CleanerMemory(
+            id='mem-edge',
+            content=None,
+            category=None,
+            created_at=1736935200,
+            updated_at=[],
+            manually_added='1',
+            reviewed='true',
+            user_review='no',
+            edited='',
+        )
+
+        assert memory.id == 'mem-edge'
+        assert memory.content == ''
+        assert memory.category == 'interesting'
+        assert memory.created_at == datetime(2025, 1, 15, 10, 0, 0, tzinfo=timezone.utc)
+        assert memory.updated_at is None
+        assert memory.manually_added is True
+        assert memory.reviewed is True
+        assert memory.user_review is False
+        assert memory.edited is False
+
+    def test_cleaner_memory_rejects_empty_id(self):
+        """CleanerMemory should not serialize malformed responses with an empty id."""
+        from pydantic import ValidationError
+        from routers.developer import CleanerMemory
+
+        with pytest.raises(ValidationError):
+            CleanerMemory(
+                id=None,
+                content='legacy memory',
+                category='manual',
+            )
diff --git a/backend/tests/unit/test_dev_api_memories_pagination.py b/backend/tests/unit/test_dev_api_memories_pagination.py
index 1f6621a893..2c20db0713 100644
--- a/backend/tests/unit/test_dev_api_memories_pagination.py
+++ b/backend/tests/unit/test_dev_api_memories_pagination.py
@@ -1,9 +1,9 @@
-"""Regression test for GET /v1/dev/user/memories resilience (issue #7492).
+"""Regression tests for GET /v1/dev/user/memories resilience (issue #7492).
 
 The endpoint declares response_model=List[CleanerMemory] and returned raw Firestore dicts, so a
-single malformed/legacy record (missing a required field or an out-of-enum category) made FastAPI
-raise ResponseValidationError -> HTTP 500 for the whole page (only the offsets containing that record
-failed). The handler now validates each record and skips+logs invalid ones, mirroring GET /v3/memories.
+single malformed/legacy record could make FastAPI raise ResponseValidationError -> HTTP 500 for the
+whole page. The handler now validates each record individually, skips records without required
+identity fields, and coerces legacy optional fields to safe defaults.
 """
 
 import os
@@ -80,6 +80,7 @@ def __getattr__(self, name):
         sys.modules[_mod_name] = _AutoMockModule(_mod_name)
 
 sys.modules['firebase_admin.auth'].InvalidIdTokenError = type('InvalidIdTokenError', (Exception,), {})
+sys.modules['utils.apps'].update_personas_async = MagicMock()
 
 # utils.other.endpoints must expose real callables (used in route signatures); provide stand-ins.
 _endpoints = ModuleType('utils.other.endpoints')
@@ -129,9 +130,24 @@ def _valid_memory(mid):
     }
 
 
-def _invalid_memory(mid):
-    # Legacy/malformed record missing a required CleanerMemory field ('edited').
+def _missing_id_memory(mid):
+    # Malformed record missing the required identity field.
     m = _valid_memory(mid)
+    del m['id']
+    return m
+
+
+def _legacy_memory(mid):
+    # Legacy record with missing/invalid optional fields that should be coerced.
+    m = _valid_memory(mid)
+    m['category'] = 'old-category'
+    m['visibility'] = None
+    m['tags'] = None
+    m['created_at'] = 'not-a-date'
+    m['updated_at'] = {'bad': 'date'}
+    m['manually_added'] = ''
+    m['reviewed'] = None
+    m['user_review'] = 'yes'
     del m['edited']
     return m
 
@@ -144,7 +160,7 @@ def _build():
 
 
 def test_invalid_record_is_skipped_not_500():
-    page = [_valid_memory('good1'), _invalid_memory('bad1'), _valid_memory('good2')]
+    page = [_valid_memory('good1'), _missing_id_memory('bad1'), _valid_memory('good2')]
     with patch.object(memories_db, 'get_memories', return_value=page):
         client = _build()
         resp = client.get('/v1/dev/user/memories')
@@ -152,6 +168,25 @@ def test_invalid_record_is_skipped_not_500():
     assert [m['id'] for m in resp.json()] == ['good1', 'good2']
 
 
+def test_legacy_optional_fields_are_defaulted_not_500():
+    page = [_legacy_memory('legacy1')]
+    with patch.object(memories_db, 'get_memories', return_value=page):
+        client = _build()
+        resp = client.get('/v1/dev/user/memories')
+    assert resp.status_code == 200
+    [memory] = resp.json()
+    assert memory['id'] == 'legacy1'
+    assert memory['category'] == 'interesting'
+    assert memory['visibility'] == 'private'
+    assert memory['tags'] == []
+    assert memory['created_at'] is None
+    assert memory['updated_at'] is None
+    assert memory['manually_added'] is False
+    assert memory['reviewed'] is False
+    assert memory['user_review'] is True
+    assert memory['edited'] is False
+
+
 def test_all_valid_records_returned():
     page = [_valid_memory('a'), _valid_memory('b')]
     with patch.object(memories_db, 'get_memories', return_value=page):