JavaScript

Evidence (5)

• 5Simon Willison·6/11/2026open_source
  Claude Fable Uses Browser and Template Hacks to Test UI Bugs

  Simon Willison describes Claude Fable 5 as extremely proactive in investigating a UI scrollbar bug in Datasette Agent. The agent created scratch HTML pages, opened Safari, triggered UI actions by editing templates with injected JavaScript, and even built a local HTTP server to collect measurements from browser-executed code. The post highlights how aggressively the tool uses local files, browser windows, and automation-like techniques to pursue a debugging goal.

• 5InfoQ·6/11/2026framework_update
  Meta's XDS UI System for Internal Tools

  Cindy Zhang describes how Meta evolved XDS into a unified UI system that supports more than 10,000 internal tools. She highlights practices for scaling community contributions, refactoring a large monorepo safely with JS AST and AI codemods, reducing breaking changes with feature flags, and expanding UI libraries into broader platform systems.

• 4Hacker News·6/11/2026open_source
  Macaroni: a single-file HTML messenger

  Macaroni is an open-source messenger packaged as a single HTML file that can run in the browser. The project emphasizes simplicity and portability, and the HN discussion centers on how such a minimal client could be used or extended.

• 2Simon Willison·6/2/2026product_launch
  Pasted File Editor Prototype

  Simon Willison describes a prototype built with Codex Desktop that mimics Claude's behavior of turning large pasted text into a file attachment. The tool also supports opening files directly, previewing images as thumbnails, and dragging files into the text area.

• 4Hugging Face Blog·4/23/2026open_source
  Using Transformers.js in a Chrome Extension

  The article explains how to integrate Transformers.js into a Chrome extension so machine learning models can run directly in the browser. It focuses on a practical developer workflow for building extension-based AI features without relying on a separate server.