e-Gov Law API Watch Workflow: Claude + Google Sheets + Slack

Watch Japanese e-Gov Law changes automatically—daily, explained by Claude, logged to Google Sheets, and summarized in Slack

If you manage compliance or legal monitoring, this e-Gov Law API Watch n8n workflow keeps you informed: it checks selected Japanese laws every day, detects new revisions, generates an article-level diff, and uses Anthropic Claude to produce clear before/after explanations—then records everything in Google Sheets and posts per-law summaries to Slack.

What this workflow does

• Runs on a schedule (or manually in demo mode): executes daily to compare law revisions; in demo mode, it can compare the two newest revisions.
• Builds a watch list from Google Sheets: reads the watch state from the spreadsheet’s “Watch” tab and constructs a per-law list using the configured law IDs.
• Fetches revision history via e-Gov Law API: determines whether to baseline (first run), compare revisions (new change), or flag an invalid law ID.
• Computes an article-by-article diff: for each changed law, it fetches old and new texts and computes an article-level diff (including supplementary provisions).
• Explains changes with Claude: sends changed excerpts to Claude to generate a JSON explanation including verbatim before/after quotes, then validates the output against the diff.
• Logs and notifies: writes detailed rows to the “Changes” tab, posts one Slack summary message per law, and updates the “Watch” tab with the latest revision for next run comparisons.

Use cases

• Compliance teams tracking updates to specific Japanese laws.
• SaaS operators needing automated legal change monitoring with audit-friendly logs.
• Automation engineers building an e-Gov Law API workflow with Slack notifications and spreadsheet reporting.

Technical details

• Integrations/Nodes: HTTP Request (e-Gov Law API), Google Sheets, Slack
• Workflow logic: if, set, code, sticky note
• Required setup: create the spreadsheet, then run the “set up the sheet” branch to generate the Watch and Changes tabs and headers.