AI implementation for openai and claude.

backend/app/models/schemas.py

@@ -0,0 +1,24 @@
+from typing import List, Optional
+
+from pydantic import BaseModel, Field, validator
+
+
+class ChatRequest(BaseModel):
+    message: str = Field(..., min_length=1, max_length=10000)
+    provider: Optional[str] = None
+
+    @validator("message")
+    def message_not_empty(cls, v):
+        if not v.strip():
+            raise ValueError("Message cannot be empty or whitespace")
+        return v.strip()
+
+
+class ChatResponse(BaseModel):
+    message: str
+    provider: str
+
+
+class ProviderListResponse(BaseModel):
+    providers: List[str]
+    default: str