Claude Code adds mods that customize behavior and UI via TypeScript plugins

Claude Code can now be modified with mods that change its behavior, customize the UI, and add features, written in a few lines of TypeScript or generated by Claude. Mods ship inside plugins and are installed with /plugin in the CLI or desktop app. A TypeScript function can intercept internal events such as tool calls, prompts, model requests, and renders, and add custom UI and commands.