David Crawshaw on the Inevitability of Open-Source DevTools in the AI Era

In early August 2026, David Crawshaw, co-founder of exe.dev, published an article titled *Devtools must be open source*, which garnered over 500 upvotes and heated discussions on Hacker News. The core arguments are as follows: AI Agents can directly modify source code to achieve tool personalization and automatically rebase upstream code, drastically reducing the maintenance cost of forks; the expansion ceiling of plugin APIs has relatively depreciated, and source code is the ultimate expansion system. The article takes the integration of meat.dev by Shelley Agent and a comparison with VS Code's extension API as examples, and points out the customization boundaries of closed-source Agents such as Claude Code. Combined with the fork practices of Zed and Ghostty, as well as the closed-source IDE options like Cursor, it discusses whether DevTools should list "source code access right" as a first-class requirement in 2026.