initial project setup with README and ignore

app/core/exceptions.py

@@ -0,0 +1,70 @@
+"""Custom exceptions for the API."""
+
+from fastapi import HTTPException, status
+
+
+class APIException(HTTPException):
+    """Base API exception with structured error format."""
+    
+    def __init__(
+        self,
+        status_code: int,
+        message: str,
+        field: str = None,
+        code: str = None,
+        detail: str = None
+    ):
+        self.message = message
+        self.field = field
+        self.code = code or self._get_default_code(status_code)
+        super().__init__(status_code=status_code, detail=detail or message)
+    
+    def _get_default_code(self, status_code: int) -> str:
+        """Get default error code based on status code."""
+        codes = {
+            400: "BAD_REQUEST",
+            401: "UNAUTHORIZED",
+            403: "FORBIDDEN",
+            404: "NOT_FOUND",
+            409: "CONFLICT",
+            422: "VALIDATION_ERROR",
+            429: "RATE_LIMIT_EXCEEDED",
+            500: "INTERNAL_SERVER_ERROR",
+            503: "SERVICE_UNAVAILABLE"
+        }
+        return codes.get(status_code, "UNKNOWN_ERROR")
+
+
+class ValidationError(APIException):
+    """Validation error exception."""
+    
+    def __init__(self, message: str, field: str = None):
+        super().__init__(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            message=message,
+            field=field,
+            code="VALIDATION_ERROR"
+        )
+
+
+class NotFoundError(APIException):
+    """Resource not found exception."""
+    
+    def __init__(self, message: str = "Resource not found"):
+        super().__init__(
+            status_code=status.HTTP_404_NOT_FOUND,
+            message=message,
+            code="NOT_FOUND"
+        )
+
+
+class RateLimitError(APIException):
+    """Rate limit exceeded exception."""
+    
+    def __init__(self, message: str = "Rate limit exceeded"):
+        super().__init__(
+            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
+            message=message,
+            code="RATE_LIMIT_EXCEEDED"
+        )
+