Workflow Orchestration Agents: Architecture Blueprint & Production Stack

import asyncio
from typing import Dict, Any
from pydantic import BaseModel, Field
import httpx

class CreatePurchaseOrderPayload(BaseModel):
    vendor_id: str = Field(description="SAP Vendor ID string")
    material_code: str = Field(description="Material inventory item code")
    quantity: int = Field(gt=0, description="Purchase quantity")
    total_value_usd: float = Field(gt=0.0)

class MCPToolResponse(BaseModel):
    status: str
    po_number: str
    message: str

async def execute_mcp_sap_tool(tool_name: str, arguments: Dict[str, Any]) -> MCPToolResponse:
    """Executes standardized MCP tool call against internal SAP Gateway microservice."""
    if tool_name != "sap_create_purchase_order":
        raise ValueError(f"Unknown MCP Tool: {tool_name}")

    # Validate tool arguments against Pydantic schema
    payload = CreatePurchaseOrderPayload(**arguments)
    
    # Safety Check: Mandatory human approval if PO value exceeds $50,000
    if payload.total_value_usd > 50000.0:
        return MCPToolResponse(
            status="PENDING_HUMAN_APPROVAL",
            po_number="N/A",
            message=f"PO value ${payload.total_value_usd:.2f} exceeds threshold. Pushed to manager review."
        )

    # Dispatch to SAP REST API endpoint via OAuth 2.0
    async with httpx.AsyncClient() as client:
        res = await client.post(
            "https://sap-gateway.internal/api/v1/purchase_orders",
            json=payload.model_dump(),
            headers={"Authorization": "Bearer SECURE_MCP_TOKEN"},
            timeout=15.0
        )
        data = res.json()
        return MCPToolResponse(
            status="SUCCESS",
            po_number=data.get("po_id", "PO-991048"),
            message="Purchase order generated successfully in SAP S/4HANA."
        )

# Example Execution Run
if __name__ == "__main__":
    sample_args = {
        "vendor_id": "VEND-88401",
        "material_code": "MAT-MICRO-88",
        "quantity": 500,
        "total_value_usd": 18500.0
    }
    result = asyncio.run(execute_mcp_sap_tool("sap_create_purchase_order", sample_args))
    print(f"MCP Action Result: {result.status} | PO #: {result.po_number}")