BC Calculator MCP Server

Instructions

Implementation Reference

• src/ts/index.ts:157-260 (handler)

  The handleCalculate function that executes the 'calculate' tool logic: validates input arguments, sanitizes the expression, acquires a BC process from the pool, sets precision, evaluates the expression, and returns the result with execution time.
  async function handleCalculate(args: unknown): Promise<any> { const startTime = Date.now(); // Validate arguments if (!args || typeof args !== 'object') { return { content: [{ type: 'text', text: 'Invalid arguments: expected an object' }], isError: true }; } const { expression, precision = globalPrecision } = args as { expression?: string; precision?: number; }; if (!expression) { return { content: [{ type: 'text', text: 'Missing required argument: expression' }], isError: true }; } // Validate precision if (precision !== undefined && (precision < 0 || precision > 100)) { return { content: [{ type: 'text', text: 'Invalid precision: must be between 0 and 100' }], isError: true }; } try { // Validate input expression const validation = InputValidator.validate(expression); if (!validation.valid) { return { content: [{ type: 'text', text: `Validation error: ${validation.error}` }], isError: true }; } // Acquire process from pool const process = await pool.acquireProcess(); try { // Set precision if different from current await process.setPrecision(precision); // Evaluate expression const result = await process.evaluate(validation.sanitized!); // Release process back to pool pool.releaseProcess(process); const executionTime = Date.now() - startTime; return { content: [{ type: 'text', text: JSON.stringify({ result, expression, precision, executionTimeMs: executionTime }, null, 2) }] }; } catch (error) { // Always release process even on error pool.releaseProcess(process); throw error; } } catch (error) { if (error instanceof BCCalculatorError) { return { content: [{ type: 'text', text: `BC Calculator Error [${error.code}]: ${error.message}` }], isError: true }; } return { content: [{ type: 'text', text: `Calculation error: ${error instanceof Error ? error.message : String(error)}` }], isError: true }; } }
• src/python/bc_calculator_mcp/__main__.py:130-200 (handler)

  The handle_calculate function that executes the 'calculate' tool logic in Python: validates input, sanitizes expression, acquires BC process, sets precision, evaluates, and returns result.
  async def handle_calculate(args: dict[str, Any]) -> list[TextContent]: """Handle basic calculation requests""" import time start_time = time.time() # Get arguments with defaults expression = args.get("expression") precision = args.get("precision", global_precision) if not expression: return [TextContent( type="text", text="Missing required argument: expression" )] # Validate precision if precision is not None and (precision < 0 or precision > 100): return [TextContent( type="text", text="Invalid precision: must be between 0 and 100" )] try: # Validate input expression validation = InputValidator.validate(expression) if not validation.valid: return [TextContent( type="text", text=f"Validation error: {validation.error}" )] # Acquire process from pool process = await pool.acquire_process() try: # Set precision if different from current await process.set_precision(precision) # Evaluate expression result = await process.evaluate(validation.sanitized or expression) # Release process back to pool pool.release_process(process) execution_time = (time.time() - start_time) * 1000 return [TextContent( type="text", text=json.dumps({ "result": result, "expression": expression, "precision": precision, "executionTimeMs": execution_time }, indent=2) )] except Exception as error: # Always release process even on error pool.release_process(process) raise except BCCalculatorError as error: return [TextContent( type="text", text=f"BC Calculator Error [{error.code.value}]: {error.message}" )] except Exception as error: return [TextContent( type="text", text=f"Calculation error: {str(error)}" )]
• src/ts/index.ts:46-66 (schema)

  Input schema definition for the 'calculate' tool, specifying expression as required string and optional precision number.
  { name: 'calculate', description: 'Evaluate mathematical expressions using BC calculator with arbitrary precision arithmetic. ' + 'Supports basic operations (+, -, *, /, ^, %), comparisons, and math library functions ' + '(sqrt, sine, cosine, arctan, log, exp).', inputSchema: { type: 'object', properties: { expression: { type: 'string', description: 'Mathematical expression to evaluate (e.g., "2+2", "sqrt(144)", "355/113")' }, precision: { type: 'number', description: 'Number of decimal places for the result (0-100, default: 20)', minimum: 0, maximum: 100 } }, required: ['expression'] }
• src/python/bc_calculator_mcp/__main__.py:42-65 (schema)

  Input schema definition for the 'calculate' tool in Python.
  Tool( name="calculate", description=( "Evaluate mathematical expressions using BC calculator with arbitrary precision arithmetic. " "Supports basic operations (+, -, *, /, ^, %), comparisons, and math library functions " "(sqrt, sine, cosine, arctan, log, exp)." ), inputSchema={ "type": "object", "properties": { "expression": { "type": "string", "description": 'Mathematical expression to evaluate (e.g., "2+2", "sqrt(144)", "355/113")' }, "precision": { "type": "number", "description": "Number of decimal places for the result (0-100, default: 20)", "minimum": 0, "maximum": 100 } }, "required": ["expression"] } ),
• src/ts/index.ts:124-152 (registration)

  Tool dispatch/registration in the CallToolRequestSchema handler switch statement, mapping 'calculate' to handleCalculate.
  switch (name) { case 'calculate': return await handleCalculate(args); case 'calculate_advanced': return await handleCalculateAdvanced(args); case 'set_precision': return await handleSetPrecision(args); default: return { content: [{ type: 'text', text: `Unknown tool: ${name}` }], isError: true }; } } catch (error) { return { content: [{ type: 'text', text: `Error: ${error instanceof Error ? error.message : String(error)}` }], isError: true }; } });