Addy Osmani's Guide to Claude Code Mods: JS Files That Hook Every Session Event
daniel_mac8 · x · 2026-10-03
Addy Osmani published a getting-started guide to Claude Code mods; danielmac8 reshares it, calling mods a huge opportunity and announcing upgrades to his claude-mod-builder skill.
What mods are: small JS/TS files running inside your Claude Code session (2.1.287+, on by default). Under the hood they're hooks shipped inside plugins that see every session event; they can rewrite what Claude Code does and draw custom UI in terminal or desktop. No API knowledge needed—just describe the mod you want and allow hot reload.
The guide: builds Token Weather (80 lines), a live context-window forecast above the prompt (Clear 18% / Showers 67% / Storm 81%), then tours two larger mods, Blast Radius and Replay Theater. Type declarations for your build are written to the mod's .claude-plugin/types/ folder on each load.
Related event: Claude Code Launches Mods for Deep Customization via TypeScript(21 posts)→
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