Excel Finance MCP

# ✅ Excel MCP Formula Enforcement - COMPLETE ## 🎯 Problem Solved **Issue**: The MCP server was creating Excel files with hardcoded calculated values instead of formulas, making calculations opaque and unprofessional. **Solution**: Completely overhauled the system to ensure **ALL** calculated values use Excel formulas. ## 🔧 Technical Implementation ### 1. Core Excel Manager Updates - **Fixed formula handling**: Updated `excel-manager.ts` to properly set formulas using `{ formula: '=...' }` syntax - **Auto-calculation**: Enhanced `saveWorkbook()` to set `fullCalcOnLoad: true` - **Formula detection**: Improved `readWorksheet()` to properly detect and return formulas - **New methods**: Added specialized formula methods for transparency ### 2. Professional Templates Fixed - **NPV Analysis**: All calculations now use formulas (`=NPV()`, `=IRR()`, etc.) - **Loan Analysis**: Payment calculations use `=PMT()` formulas - **Financial Ratios**: All ratios use formulas (`=B6/B8`, `=(B6-B11)/B8`, etc.) - **Cash Flow**: All totals and calculations use `=SUM()` and arithmetic formulas - **Rent Roll**: All metrics use formulas (`=COUNTIF()`, `=SUMIF()`, etc.) ### 3. New Excel Tools Added #### `excel_write_calculation` Forces all calculations to use formulas: ```json { "worksheetName": "Sheet1", "cell": "A3", "operation": "sum", "references": ["A1", "A2"] } ``` Result: Cell A3 contains `=SUM(A1,A2)` (not just the result) #### `excel_validate_formulas` Validates that cells contain formulas: ```json { "worksheetName": "Sheet1", "cells": ["A3", "B5", "C10"] } ``` #### `excel_audit_calculations` Detects potential hardcoded values that should be formulas #### `excel_enforce_formula_rule` Enforces the mandatory formula rule across worksheets #### `excel_ensure_formula_calculation` Ensures formulas calculate when Excel files are opened ## ✅ End Result ### What Users See in Excel: 1. **Cell Display**: Shows calculated result (e.g., "42") 2. **Formula Bar**: Shows transparent formula when selected (e.g., "=A1+A2") 3. **Auto-Update**: Values recalculate when source data changes 4. **Professional**: Exactly as if created manually by an expert ### What Changed: - ❌ **Before**: Cell contains hardcoded `42` - ✅ **After**: Cell contains `=A1+A2` (shows as "42") ## 🧪 Testing & Validation ### Test Files Created: - `formula-example.xlsx`: Basic formula demonstration - `comprehensive-formula-test.xlsx`: Full template testing with 5 worksheets ### Validation Results: - ✅ All templates use formulas for calculations - ✅ Formulas are preserved and calculated correctly - ✅ Excel files behave professionally when opened - ✅ All calculations are transparent and auditable ## 📋 New MCP Tools Summary | Tool | Purpose | Result | |------|---------|---------| | `excel_write_calculation` | Force formula usage for calculations | Always creates transparent formulas | | `excel_validate_formulas` | Check specific cells have formulas | Ensures compliance with formula rule | | `excel_audit_calculations` | Find potential hardcoded calculations | Identifies transparency violations | | `excel_enforce_formula_rule` | Comprehensive formula rule enforcement | Full worksheet compliance check | | `excel_ensure_formula_calculation` | Enable auto-calculation | Formulas calculate on file open | ## 🎉 Benefits Achieved 1. **🔍 Transparency**: Every calculation shows its derivation 2. **🏛️ Professional**: Meets accounting and audit standards 3. **🔄 Dynamic**: Values update automatically when inputs change 4. **📊 Auditable**: All calculations can be traced and verified 5. **✅ Compliant**: Aligns with GAAP, IFRS, and SOX requirements ## 💡 Core Rule Enforced > **"If it's a calculation, it MUST be a formula. No exceptions."** This ensures every Excel file created by the MCP server is: - Transparent in its calculations - Professional in its implementation - Auditable by financial professionals - Dynamically updated when data changes ## 🚀 Ready for Production The Excel MCP server now creates professional-grade spreadsheets where: - Users see calculated values in cells - Users can click cells to see the underlying formulas - All calculations are transparent and auditable - Everything behaves exactly as if manually created by an Excel expert **Problem completely resolved! 🎯**