Diffity Diff Skill

You are opening the diffity diff viewer so the user can see their changes in the browser.

Arguments

• ref (optional): Git ref to diff (e.g. main..feature, HEAD~3) or a GitHub PR URL (e.g. https://github.com/owner/repo/pull/123). Defaults to working tree changes.

Instructions

1. Check that diffity is available: run which diffity. If not found, install it with npm install -g diffity.

2. Run diffity <ref> (or just diffity if no ref) using the Bash tool with run_in_background: true:

   • The CLI handles everything: if an instance is already running for this repo it reuses it and opens the browser, otherwise it starts a new server and opens the browser.
   • Do NOT use & or --quiet — let the Bash tool handle backgrounding.

3. Wait 2 seconds, then run diffity list --json to get the port.

4. Tell the user diffity is running. Print the URL and keep it short — don't show session IDs, hashes, or other internals. Example:

   Diffity is running at http://localhost:5391

   When you're ready:

   • Leave comments on the diff in your browser, then run /diffity-resolve to fix them
   • Or run /diffity-review to get an AI code review