Deliver Step 9: agent-card.json, SKILL.md, USDA lookup, integrations dynamic config, Welcome/Integrations/MealPlan pages, API methods, README, routes

backend/app/services/usda_lookup.py

@@ -0,0 +1,59 @@
+"""USDA FoodData Central lookup service.
+
+Free API with 400K+ foods and research-grade nutrition data.
+API key required (free, instant signup at https://fdc.nal.usda.gov/api-key-signup).
+"""
+from __future__ import annotations
+
+import logging
+import httpx
+
+logger = logging.getLogger(__name__)
+
+USDA_BASE = "https://api.nal.usda.gov/fdc/v1"
+
+
+async def search_usda(query: str, api_key: str, page_size: int = 10) -> list[dict]:
+    """Search USDA FoodData Central for food items.
+
+    Returns a list of dicts with: fdcId, description, brandName, calories,
+    protein_g, carbs_g, fat_g, serving_size.
+    """
+    if not api_key:
+        return []
+
+    try:
+        async with httpx.AsyncClient(timeout=15) as client:
+            resp = await client.get(
+                f"{USDA_BASE}/foods/search",
+                params={
+                    "api_key": api_key,
+                    "query": query,
+                    "pageSize": page_size,
+                    "dataType": "Foundation,SR Legacy,Branded",
+                },
+            )
+            resp.raise_for_status()
+            data = resp.json()
+
+        results = []
+        for food in data.get("foods", []):
+            nutrients = {n["nutrientName"]: n["value"] for n in food.get("foodNutrients", [])}
+            results.append({
+                "fdcId": food.get("fdcId"),
+                "description": food.get("description", ""),
+                "brandName": food.get("brandName"),
+                "source": "usda",
+                "calories": nutrients.get("Energy"),
+                "protein_g": nutrients.get("Protein"),
+                "carbs_g": nutrients.get("Carbohydrate, by difference"),
+                "fat_g": nutrients.get("Total lipid (fat)"),
+                "fiber_g": nutrients.get("Fiber, total dietary"),
+                "serving_size": food.get("servingSize"),
+                "serving_unit": food.get("servingSizeUnit"),
+            })
+        return results
+
+    except Exception as e:
+        logger.warning(f"USDA search failed: {e}")
+        return []