Temporal Nexus Calculator MCP Server

"""Calculator service handler implementation with MCP integration.""" import uuid import logging import nexusrpc from temporalio import nexus from nexusmcp import MCPServiceHandler from nexus_mcp_calculator.service import ( CalculatorService, CalculateRequest, CalculateResponse, AddRequest, SubtractRequest, MultiplyRequest, DivideRequest, PowerRequest, SumListRequest, BasicOperationResponse, ) from nexus_mcp_calculator.workflows import ( CalculateWorkflow, AddWorkflow, SubtractWorkflow, MultiplyWorkflow, DivideWorkflow, PowerWorkflow, SumListWorkflow, ) # Set up logging logger = logging.getLogger(__name__) # Create the MCP service handler registry mcp_service_handler = MCPServiceHandler() @mcp_service_handler.register @nexusrpc.handler.service_handler(service=CalculatorService) class CalculatorHandler: """Nexus service handler for calculator operations. This handler now uses workflow_run_operations that start workflows, which execute activities for the actual calculations. This provides full visibility in the Temporal UI for both workflow and activity executions. """ @nexus.workflow_run_operation async def calculate( self, ctx: nexus.WorkflowRunOperationContext, input: CalculateRequest ) -> nexus.WorkflowHandle[CalculateResponse]: """Start a workflow to evaluate a mathematical expression. This operation starts a CalculateWorkflow which executes a CalculateActivity for the actual calculation. Both the workflow and activity are visible in the Temporal UI. """ logger.info(f"🧮 Calculator.calculate operation starting workflow for: '{input.expression}'") return await ctx.start_workflow( CalculateWorkflow.run, input, id=f"calculate-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def add( self, ctx: nexus.WorkflowRunOperationContext, input: AddRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to add two numbers together.""" logger.info(f"➕ Calculator.add operation starting workflow for: {input.a} + {input.b}") return await ctx.start_workflow( AddWorkflow.run, input, id=f"add-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def subtract( self, ctx: nexus.WorkflowRunOperationContext, input: SubtractRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to subtract two numbers.""" logger.info(f"➖ Calculator.subtract operation starting workflow for: {input.a} - {input.b}") return await ctx.start_workflow( SubtractWorkflow.run, input, id=f"subtract-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def multiply( self, ctx: nexus.WorkflowRunOperationContext, input: MultiplyRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to multiply two numbers.""" logger.info(f"✖️ Calculator.multiply operation starting workflow for: {input.a} * {input.b}") return await ctx.start_workflow( MultiplyWorkflow.run, input, id=f"multiply-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def divide( self, ctx: nexus.WorkflowRunOperationContext, input: DivideRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to divide two numbers.""" logger.info(f"➗ Calculator.divide operation starting workflow for: {input.a} / {input.b}") return await ctx.start_workflow( DivideWorkflow.run, input, id=f"divide-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def power( self, ctx: nexus.WorkflowRunOperationContext, input: PowerRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to raise a number to a power.""" logger.info(f"🔢 Calculator.power operation starting workflow for: {input.base} ^ {input.exponent}") return await ctx.start_workflow( PowerWorkflow.run, input, id=f"power-{uuid.uuid4()}", ) @nexus.workflow_run_operation async def sum_list( self, ctx: nexus.WorkflowRunOperationContext, input: SumListRequest ) -> nexus.WorkflowHandle[BasicOperationResponse]: """Start a workflow to sum a list of numbers.""" logger.info(f"📊 Calculator.sum_list operation starting workflow for {len(input.numbers)} numbers") return await ctx.start_workflow( SumListWorkflow.run, input, id=f"sum_list-{uuid.uuid4()}", )