refactors

backend/mappers.py

@@ -1,11 +1,12 @@
 """Response mappers for converting models to API response schemas."""
 
-from models import Exchange, Invite
+from models import Exchange, Invite, PriceHistory
 from schemas import (
     AdminExchangeResponse,
     ExchangeResponse,
     ExchangeUserContact,
     InviteResponse,
+    PriceHistoryResponse,
 )
 
 
@@ -89,3 +90,19 @@ class InviteMapper:
             spent_at=invite.spent_at,
             revoked_at=invite.revoked_at,
         )
+
+
+class PriceHistoryMapper:
+    """Mapper for PriceHistory model to response schemas."""
+
+    @staticmethod
+    def to_response(record: PriceHistory) -> PriceHistoryResponse:
+        """Convert a PriceHistory model to PriceHistoryResponse schema."""
+        return PriceHistoryResponse(
+            id=record.id,
+            source=record.source,
+            pair=record.pair,
+            price=record.price,
+            timestamp=record.timestamp,
+            created_at=record.created_at,
+        )