E Tax

This automates the entire Japanese tax filing process through the National Tax Agency's 確定申告書等作成コーナー web interface. It takes calculated tax data from the shinkoku system and drives a browser to fill out forms for income tax, business financial statements, and consumption tax returns. The skill intelligently picks between Claude in Chrome, Antigravity Browser Sub-Agent, or Playwright CLI depending on what's available in your environment. It includes proper interrupt and resume protocol with .data file saving, handles QR code authentication gates where you need to physically scan with your phone, and runs sanity checks before submission. The documentation is exhaustively detailed with complete screen flow maps and field-level input logic. If you're doing Japanese business tax filing and already have the calculations done, this eliminates hours of manual web form data entry.