GST Purchase Reconciliation Engine

A high-performance, privacy-first web application designed to reconcile Books of Accounts against GSTR-2B portal data. Built to handle complex financial datasets entirely within the client's browser, ensuring sensitive financial records never touch an external server.

Features

• Zero-Server Processing: Utilizes the HTML5 FileReader API and SheetJS to process massive .xlsx and .csv files locally.
• Smart Key Normalization: Advanced string parsing algorithms to match inconsistent invoice formats (e.g., "INV-2023/01" vs "INV202301").
• Automated Column Mapping: Regex-powered auto-detection of standard accounting column headers, with a manual UI fallback.
• Granular Tolerance Thresholds: Configurable numeric tolerance levels to filter out minor rounding differences automatically.
• Dynamic ITC Summary: Real-time calculation of Input Tax Credit (ITC) categorization across IGST, CGST, SGST, and Cess.

Tech Stack

• Frontend: HTML5, Vanilla JavaScript (ES6+), CSS3
• Libraries: SheetJS (xlsx)
• Backend Framework (Serving): Python, Flask
• Deployment Environment: Google Cloud Run (Dockerized)