GST Helper: Local-First Tool for Preparing Selected GSTR-1 Values from Invoices

GST Helper is an open-source, local-first app that reads outward-sales invoice PDFs to help small businesses prepare selected GSTR-1 values. It covers regular B2B invoices in Table 4A, the B2B HSN/SAC summary in Table 12, and documents issued in Table 13, with page evidence shown for each extracted value. The tool produces a reference PDF tied to the saved review, so users can check figures before entering them on the GST Portal. It does not file returns, connect to the portal, or prepare the full GSTR-1, and other sections must be handled separately. The project was built as a submission to the Hacktoberfest Open-Source AI Challenge and is available on GitHub.