v0.2.0 - htmx 4.0 Alpha Support

Adds full htmx 4.0 alpha support while maintaining backward compatibility with htmx 2.x.

What's New

• Dual version support: auto-detects htmx 2.x or 4.0 and adapts transparently
• fetch() tracking: htmx 4 replaces XHR with fetch(). Request correlation now uses ctx WeakMap
• Canonical event mapping: normalizes both 2.x (htmx:configRequest) and 4.0 (htmx:config:request) event names
• Synthetic HTTP errors: htmx 4 doesn't fire error events for 4xx/5xx. DevTools detects these from httpStatus
• Version badge: colored pill in tab bar (blue for 2.x, purple for 4.0)
• New attribute scanning: hx-action, hx-method, hx-config, hx-status, hx-optimistic, hx-preload
• LCS-based DOM diff: replaces naive set-based diff for accurate swap visualization
• Request history per element: shows all requests triggered by an element, click to jump
• Element auto-refresh: DOM tree updates in real time with debounced event subscription
• Per-tab search filters: search no longer shared between Requests/Timeline/Errors tabs
• Immutable signal updates: fixes rendering issues in Swap Visualizer

Live Demos

• htmx 2.x: https://atoolz.github.io/htmx-devtools/v2/
• htmx 4.0: https://atoolz.github.io/htmx-devtools/v4/

Install

git clone https://github.com/atoolz/htmx-devtools.git
cd htmx-devtools && npm install && npm run build:chrome

Load dist/ as unpacked extension in chrome://extensions.

v0.1.0 - Initial Release

First release of the HTMX DevTools browser extension.

Features: Request Inspector, Element Inspector, Event Timeline, Swap Visualizer, Error Panel.

Stack: TypeScript, Vite, Preact + Signals, Chrome MV3. 7 devDeps, 0 runtime deps.

Supports: htmx 2.x