Update app.py

app.py

@@ -1,93 +1,124 @@
-from mcp.server.fastmcp import FastMCP
-import httpx
+"""FastAPI-based MCP server for SAP Purchase Requisition API."""
+from __future__ import annotations
+
+import json
 import os
-import uvicorn
-
-# SAP API Configuration
-SAP_API_URL = "https://sandbox.api.sap.com/s4hanacloud/sap/opu/odata4/sap/api_purchaserequisition_2/srvd_a2x/sap/purchaserequisition/0001/PurchaseReqn"
-SAP_API_KEY = os.getenv("SAP_API_KEY", "your_sap_api_key_here")
-
-# Initialize FastMCP server
-mcp = FastMCP("SAP_PurchaseRequisition")
-
-@mcp.tool()
-async def get_purchase_requisitions(top: int = 50) -> dict:
-    """
-    Fetch purchase requisitions from SAP S/4HANA Cloud API.
-    
-    Args:
-        top: Number of records to fetch (default 50, max 100)
-    
-    Returns:
-        Dictionary containing purchase requisition data
-    """
+from typing import Optional
+
+import httpx
+from dotenv import load_dotenv
+from fastapi import FastAPI, HTTPException
+from fastapi.responses import JSONResponse
+from model_context_protocol.fastapi import FastAPIMCPServer
+
+load_dotenv()
+
+API_KEY_ENV_VAR = "SAP_API_KEY"
+SAP_PURCHASE_REQUISITION_URL = (
+    "https://sandbox.api.sap.com/s4hanacloud/sap/opu/odata4/"
+    "sap/api_purchaserequisition_2/srvd_a2x/sap/purchaserequisition/0001/"
+    "PurchaseReqn"
+)
+
+app = FastAPI(title="SAP Purchase Requisition MCP Server", version="0.1.0")
+server = FastAPIMCPServer(app)
+
+
+def _get_api_key() -> str:
+    """Load the SAP API key from the environment."""
+    api_key = os.getenv(API_KEY_ENV_VAR)
+    if not api_key:
+        raise HTTPException(
+            status_code=500,
+            detail=(
+                "The SAP API key is not configured. Set the environment variable "
+                f"{API_KEY_ENV_VAR} before calling this tool."
+            ),
+        )
+    return api_key
+
+
+async def _call_sap_api(
+    *,
+    api_key: str,
+    top: int,
+    select: Optional[str],
+    filter_: Optional[str],
+) -> dict:
+    """Fetch purchase requisition data from the SAP sandbox API."""
     headers = {
-        "APIKey": SAP_API_KEY,
-        "Accept": "application/json"
-    }
-    
-    params = {
-        "$top": min(top, 100)
+        "APIKey": api_key,
+        "Accept": "application/json",
+        "Accept-Language": "en",
     }
-    
+    params = {"$top": top}
+    if select:
+        params["$select"] = select
+    if filter_:
+        params["$filter"] = filter_
+
     async with httpx.AsyncClient(timeout=30.0) as client:
-        try:
-            response = await client.get(
-                SAP_API_URL,
-                headers=headers,
-                params=params
-            )
-            response.raise_for_status()
-            data = response.json()
-            return {
-                "status": "success",
-                "data": data,
-                "count": len(data.get("value", []))
-            }
-        except httpx.HTTPStatusError as e:
-            return {
-                "status": "error",
-                "message": f"HTTP error occurred: {e.response.status_code}",
-                "details": str(e)
-            }
-        except Exception as e:
-            return {
-                "status": "error",
-                "message": "Failed to fetch purchase requisitions",
-                "details": str(e)
+        response = await client.get(
+            SAP_PURCHASE_REQUISITION_URL,
+            headers=headers,
+            params=params,
+        )
+
+    try:
+        response.raise_for_status()
+    except httpx.HTTPStatusError as exc:
+        raise HTTPException(
+            status_code=exc.response.status_code,
+            detail=f"SAP API request failed: {exc.response.text}",
+        ) from exc
+
+    try:
+        data = response.json()
+    except ValueError as exc:  # pragma: no cover - unexpected API response
+        raise HTTPException(status_code=502, detail="SAP API returned invalid JSON") from exc
+
+    return data
+
+
+@server.tool(
+    name="list_purchase_requisitions",
+    description=(
+        "Retrieve purchase requisitions from the SAP sandbox OData endpoint. "
+        "Supports optional $select and $filter expressions to trim the payload."
+    ),
+)
+async def list_purchase_requisitions(
+    top: int = 50,
+    select: Optional[str] = None,
+    filter: Optional[str] = None,
+):
+    """Return purchase requisition data from SAP."""
+    if top <= 0 or top > 200:
+        raise HTTPException(
+            status_code=400,
+            detail="Parameter 'top' must be between 1 and 200 for sandbox usage.",
+        )
+
+    api_key = _get_api_key()
+    data = await _call_sap_api(api_key=api_key, top=top, select=select, filter_=filter)
+
+    return {
+        "content": [
+            {
+                "type": "text",
+                "text": json.dumps(data, indent=2),
             }
+        ]
+    }
+
+
+@app.get("/", response_class=JSONResponse)
+async def root():
+    """Simple health endpoint."""
+    return {"status": "ok", "mcp": "available"}
 
-@mcp.tool()
-async def get_purchase_requisition_summary(top: int = 10) -> str:
-    """
-    Get a summary of recent purchase requisitions.
-    
-    Args:
-        top: Number of records to summarize (default 10)
-    
-    Returns:
-        Formatted summary string
-    """
-    result = await get_purchase_requisitions(top)
-    
-    if result["status"] == "error":
-        return f"Error: {result['message']}"
-    
-    items = result["data"].get("value", [])
-    if not items:
-        return "No purchase requisitions found."
-    
-    summary = f"Found {result['count']} purchase requisitions:\n\n"
-    for idx, item in enumerate(items, 1):
-        pr_number = item.get("PurchaseRequisition", "N/A")
-        description = item.get("PurchaseRequisitionDescription", "No description")
-        summary += f"{idx}. PR#{pr_number}: {description}\n"
-    
-    return summary
-
-# Create ASGI app
-app = mcp.http_app()
 
 if __name__ == "__main__":
-    port = int(os.getenv("PORT", 7860))
-    uvicorn.run(app, host="0.0.0.0", port=port)
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=int(os.getenv("PORT", "8000")))