Diffity (Code Review)

What is Diffity?

Diffity is a browser-based code review tool that integrates with gwt. It provides:

• Diff viewing — see your changes in a rich browser UI
• Comments — leave review comments on specific lines
• AI integration — have AI read, process, and resolve comments automatically

Prerequisites

Diffity requires Node.js. gwt detects whether npx is available at runtime — no configuration flag needed.

Check availability with gwt doctor:

  ✓ diffity (ready)

or:

  ✗ diffity (npx not found — install Node.js for code review features)

Usage

Opening a diff

gwt diff                # Diff against HEAD
gwt diff main           # Diff against a specific reference
gwt diff --uncommitted  # Show only uncommitted changes

This opens the diff viewer in your browser.

Via the gateway

When the gateway is running, Diffity is accessible at http://diff.localhost:<port> — no need to run gwt diff separately.

How it fits together

1. gwt gateway start — if npx is available, registers Diffity as a gateway app automatically
2. gwt diff — opens the diff viewer directly, using the gateway port if the gateway is running
3. Code review workflow — leave comments in the browser, then use the AI integration to process them

Without Node.js

If Node.js is not installed, gwt works perfectly fine — you just don’t get the browser-based diff viewer. The gwt diff command will show a helpful message pointing you to the installation steps.