diff --git a/src/memory_manager/api/schemas.py b/src/memory_manager/api/schemas.py
new file mode 100644
index 0000000..17f6a27
--- /dev/null
+++ b/src/memory_manager/api/schemas.py
@@ -0,0 +1,69 @@
+"""Pydantic schemas for API."""
+from datetime import datetime
+from typing import List, Optional
+from pydantic import BaseModel, Field
+
+
+class MemoryEntryCreate(BaseModel):
+    title: str = Field(..., min_length=1, max_length=255)
+    content: str = Field(..., min_length=1)
+    category: str = Field(...)
+    tags: List[str] = Field(default_factory=list)
+    agent_id: Optional[str] = Field(default="unknown")
+    project_path: Optional[str] = Field(default=".")
+    parent_id: Optional[int] = None
+
+
+class MemoryEntryUpdate(BaseModel):
+    title: Optional[str] = Field(None, min_length=1, max_length=255)
+    content: Optional[str] = Field(None, min_length=1)
+    category: Optional[str] = None
+    tags: Optional[List[str]] = None
+
+
+class MemoryEntryResponse(BaseModel):
+    id: int
+    title: str
+    content: str
+    category: str
+    tags: List[str]
+    agent_id: str
+    project_path: str
+    created_at: datetime
+    updated_at: datetime
+    parent_id: Optional[int] = None
+
+    class Config:
+        from_attributes = True
+
+
+class CommitCreate(BaseModel):
+    message: str = Field(..., min_length=1)
+    agent_id: Optional[str] = Field(default="unknown")
+    project_path: Optional[str] = Field(default=".")
+
+
+class CommitResponse(BaseModel):
+    id: int
+    hash: str
+    message: str
+    agent_id: str
+    project_path: str
+    created_at: datetime
+
+    class Config:
+        from_attributes = True
+
+
+class DiffResponse(BaseModel):
+    hash1: str
+    hash2: str
+    added: List[dict]
+    removed: List[dict]
+    modified: List[dict]
+
+
+class StatsResponse(BaseModel):
+    total_entries: int
+    total_commits: int
+    category_counts: dict