Best of Anthropic — December 2025

1. 1
   Article

   Collections·21w

   Anthropic Acquires Bun to Enhance AI Coding Products' Performance and Stability

   Anthropic acquired Bun, the high-performance JavaScript runtime with 7 million monthly downloads and 83,000 GitHub stars. Despite $26 million in VC funding, Bun generated no revenue. The runtime will remain open source under MIT license and integrate into Anthropic's AI coding products like Claude Code and Claude Agent SDK. The acquisition provides Bun with resources to expand its team and accelerate development while supporting Anthropic's AI-driven development infrastructure, as Claude Code reaches $1 billion in run-rate revenue.

   319

   38
2. 2
   Video

   Awesome·20w

   Claude buys Bun, and this is really bad for devs...

   Anthropic acquired Bun, the JavaScript runtime built as a faster alternative to Node.js. While Bun will remain open source and MIT licensed, concerns arise about whether future development priorities will serve the JavaScript community or primarily benefit Claude's AI coding capabilities. The acquisition highlights broader tensions around AI companies claiming to replace developers while simultaneously hiring engineers and acquiring development tools. The piece questions the credibility of predictions about AI replacing software engineers within months, comparing them to historically inaccurate tech forecasts.

   45

   7
3. 3
   Video

   Fireship·20w

   Anthropic just bought your favorite JS runtime...

   Anthropic acquired Bun, the high-performance JavaScript/TypeScript runtime and toolkit. Created by Jared Sumner to address slow build times in the JS ecosystem, Bun has grown to 7+ million monthly downloads and 83,000+ GitHub stars. The acquisition positions Bun as infrastructure for Anthropic's AI products like Claude Code, which already uses Bun for its CLI. The team promises Bun will remain open source and MIT licensed, though concerns exist about Anthropic's open source track record.

   28

   1
4. 4
   Article

   Simon Willison·19w

   OpenAI are quietly adopting skills, now available in ChatGPT and Codex CLI

   OpenAI has quietly implemented support for skills in ChatGPT and their Codex CLI tool, following Anthropic's approach from October. Skills are simple folders containing Markdown files and optional resources that LLM tools can read and execute. ChatGPT's Code Interpreter now includes a /home/oai/skills folder with skills for handling spreadsheets, docx, and PDFs. The Codex CLI added experimental skills support two weeks ago, allowing users to place custom skills in ~/.codex/skills. The author successfully tested both implementations, creating a PDF with ChatGPT and building a Datasette plugin with Codex CLI using a custom skill. The rapid adoption by OpenAI suggests skills may become a standard pattern for extending LLM capabilities.

   19