1.6A Brief History: Who Invented This Pattern?

The CLI-skill pattern -- a thin SKILL.md teaching an agent to drive a capable binary -- was pioneered in 2025 by Jason Huggins, the creator of Selenium (2004), with his Vibium project and its vibe-check skill. The idea: instead of streaming browser state to the agent through a protocol server, give the agent a CLI and a markdown file explaining how to use it.

In early 2026, Microsoft adopted the pattern for Playwright. They shipped @playwright/cli with an install --skills flag that generates exactly this kind of SKILL.md -- and began recommending it over their own MCP server for coding-agent workflows. This book centers on the Playwright CLI because, as of July 2026, it is the stack that won: first-party, cross-browser, backed by the most popular automation engine in the industry. Vibium shipped V1 in June 2026 and remains a promising but unproven bet -- it gets an honest case study in Part VII.