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

Thu, 18 Dec 2025 07:37:00 -0400

Simon Willison, Simon Willison's Weblog, Dec 18, 2025

The most recent bit of AI jargon is something that might take you back to the days of the Amazon Echo and Alexa: skills. Today's version, however, comes from Anthropic and is being (quietly) adopted by OpenAI. "A skill is just a folder with a Markdown file and some optional extra resources and scripts, so any LLM tool with the ability to navigate and read from a filesystem should be capable of using them." Here's where they show up in OpenAI. "Skills are a keeper," says Simon Willison.