diff --git a/src/memory_manager/core/services.py b/src/memory_manager/core/services.py
new file mode 100644
index 0000000..4116787
--- /dev/null
+++ b/src/memory_manager/core/services.py
@@ -0,0 +1,133 @@
+"""Core services for memory management."""
+from typing import List, Optional
+from memory_manager.db.models import MemoryCategory, MemoryEntry, Commit
+from memory_manager.db.repository import MemoryRepository
+
+
+class MemoryService:
+    def __init__(self, repository: MemoryRepository):
+        self.repository = repository
+
+    async def create_entry(
+        self,
+        title: str,
+        content: str,
+        category: str,
+        tags: List[str],
+        agent_id: str = "unknown",
+        project_path: str = ".",
+        parent_id: Optional[int] = None,
+    ) -> MemoryEntry:
+        category_enum = MemoryCategory(category)
+        return await self.repository.create_entry(
+            title=title,
+            content=content,
+            category=category_enum,
+            tags=tags,
+            agent_id=agent_id,
+            project_path=project_path,
+            parent_id=parent_id,
+        )
+
+    async def get_entry(self, entry_id: int) -> Optional[MemoryEntry]:
+        return await self.repository.get_entry(entry_id)
+
+    async def list_entries(
+        self,
+        category: Optional[str] = None,
+        agent_id: Optional[str] = None,
+        limit: int = 100,
+        offset: int = 0,
+    ) -> List[MemoryEntry]:
+        category_enum = MemoryCategory(category) if category else None
+        return await self.repository.list_entries(
+            category=category_enum,
+            agent_id=agent_id,
+            limit=limit,
+            offset=offset,
+        )
+
+    async def update_entry(
+        self,
+        entry_id: int,
+        title: Optional[str] = None,
+        content: Optional[str] = None,
+        category: Optional[str] = None,
+        tags: Optional[List[str]] = None,
+    ) -> Optional[MemoryEntry]:
+        category_enum = MemoryCategory(category) if category else None
+        return await self.repository.update_entry(
+            entry_id=entry_id,
+            title=title,
+            content=content,
+            category=category_enum,
+            tags=tags,
+        )
+
+    async def delete_entry(self, entry_id: int) -> bool:
+        return await self.repository.delete_entry(entry_id)
+
+    async def search_entries(
+        self,
+        query: str,
+        category: Optional[str] = None,
+        tags: Optional[List[str]] = None,
+    ) -> List[MemoryEntry]:
+        category_enum = MemoryCategory(category) if category else None
+        return await self.repository.search_entries(
+            query=query,
+            category=category_enum,
+            tags=tags,
+        )
+
+
+class CommitService:
+    def __init__(self, repository: MemoryRepository):
+        self.repository = repository
+
+    async def create_commit(
+        self,
+        message: str,
+        agent_id: str = "unknown",
+        project_path: str = ".",
+    ) -> Commit:
+        return await self.repository.create_commit(
+            message=message,
+            agent_id=agent_id,
+            project_path=project_path,
+        )
+
+    async def get_commits(self, limit: int = 50) -> List[Commit]:
+        return await self.repository.get_commits(limit=limit)
+
+    async def get_commit(self, commit_hash: str) -> Optional[Commit]:
+        return await self.repository.get_commit(commit_hash)
+
+    async def diff_commits(self, hash1: str, hash2: str) -> dict:
+        entries1 = await self.repository.get_commit_entries(hash1)
+        entries2 = await self.repository.get_commit_entries(hash2)
+
+        snapshot1 = {e.memory_entry_id: e.entry_snapshot for e in entries1}
+        snapshot2 = {e.memory_entry_id: e.entry_snapshot for e in entries2}
+
+        all_ids = set(snapshot1.keys()) | set(snapshot2.keys())
+        diff_result = {
+            "hash1": hash1,
+            "hash2": hash2,
+            "added": [],
+            "removed": [],
+            "modified": [],
+        }
+
+        for entry_id in all_ids:
+            if entry_id not in snapshot1:
+                diff_result["added"].append(snapshot2[entry_id])
+            elif entry_id not in snapshot2:
+                diff_result["removed"].append(snapshot1[entry_id])
+            elif snapshot1[entry_id] != snapshot2[entry_id]:
+                diff_result["modified"].append({
+                    "before": snapshot1[entry_id],
+                    "after": snapshot2[entry_id],
+                })
+
+        return diff_result