v0.4.3

WebExtension builds of FastMCP Browser — the MCP bridge that drives Chrome/Firefox over a loopback WebSocket (32 MCP browser tools).

What's new in v0.4.3

• Stealth humanize layer. Mouse movement now follows bezier trajectories with eased velocity, typing is emitted key-by-key with human-like cadence and a per-field typo rate, and scrolling uses natural incremental steps instead of one instant jump. All of it is wired into the existing click / type / scroll tools — no new call sites needed.
• Fingerprint patches. The content engine patches the automation-detection surfaces (navigator.webdriver, permissions, plugin/mimeTypes arrays) so pages see a consistent, non-automation environment.
• Actionability wiring. Clicks and typing now wait for the element to actually be actionable (enabled, connected) and fail with a clear error rather than silently mis-targeting a disabled or detached control.
• Snapshot robustness fixes. Compact snapshot no longer crashes on large or deeply nested pages, errors from snapshot walks are surfaced to the caller instead of swallowed, an iframe hint is included when elements live inside frames, and the DOM walk is capped to prevent runaway traversals.
• Housekeeping — MCP server version bumped to 0.4.3; README extension test count corrected (120).

Install

Unzip an archive and load it unpacked:

• Chromium (fastmcp-browser-extension-chromium.zip) → chrome://extensions → Load unpacked → the chromium folder
• Firefox (fastmcp-browser-extension-firefox.zip) → about:debugging → Load Temporary Add-on → firefox/manifest.json

The Firefox .xpi has manifest.json at the archive root. It is unsigned; standard Firefox release builds require a Mozilla-signed add-on for permanent installation. LibreWolf and Firefox Developer Edition/Nightly may allow unsigned add-ons when signature enforcement is disabled.