Create app.py

app.py

@@ -0,0 +1,80 @@
+import os
+import httpx
+from fastapi import FastAPI, HTTPException
+from fastapi.middleware.cors import CORSMiddleware
+from pydantic import BaseModel
+
+app = FastAPI(
+    title="SAP Purchase Order API Demo",
+    description=(
+        "Fetches purchase order data from SAP Sandbox API.\n\n"
+        "Designed for integration with OpenAI Agentkit UI — "
+        "Agentkit auto-discovers endpoints from `/openapi.json`."
+    ),
+    version="1.0.0",
+)
+
+# Allow all origins for Agentkit / external calls
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Read secret from Hugging Face environment
+SAP_API_KEY = os.getenv("SAP_API_KEY")
+SAP_BASE_URL = (
+    "https://sandbox.api.sap.com/s4hanacloud/sap/opu/odata4/"
+    "sap/api_purchaseorder_2/srvd_a2x/sap/purchaseorder/0001/PurchaseOrder?$top=50"
+)
+
+# --- Models ---
+
+class PurchaseOrderItem(BaseModel):
+    PurchaseOrder: str | None = None
+    Supplier: str | None = None
+    CreatedByUser: str | None = None
+    CreatedDateTime: str | None = None
+
+
+class PurchaseOrderResponse(BaseModel):
+    source: str
+    count: int
+    data: list[PurchaseOrderItem] | dict
+
+
+# --- Routes ---
+
+@app.get("/health", summary="Health check", tags=["System"])
+async def health_check():
+    """Simple endpoint to verify the backend is running."""
+    return {"status": "ok", "message": "SAP Purchase Order API backend is running"}
+
+
+@app.get(
+    "/purchase-orders",
+    response_model=PurchaseOrderResponse,
+    summary="Get Purchase Orders",
+    tags=["Purchase Orders"],
+    description="Fetch top 50 purchase orders from SAP Sandbox API.",
+)
+async def get_purchase_orders():
+    """Fetches purchase orders from SAP Sandbox API"""
+    if not SAP_API_KEY:
+        raise HTTPException(status_code=500, detail="SAP_API_KEY not found in environment")
+
+    headers = {"APIKey": SAP_API_KEY}
+
+    try:
+        async with httpx.AsyncClient(timeout=30.0) as client:
+            resp = await client.get(SAP_BASE_URL, headers=headers)
+            resp.raise_for_status()
+            data = resp.json()
+            po_items = data.get("value", [])
+            return {"source": "SAP Sandbox", "count": len(po_items), "data": po_items}
+    except httpx.HTTPStatusError as e:
+        raise HTTPException(status_code=e.response.status_code, detail=f"SAP API error: {e.response.text}")
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))