How It Works
Overview
Hooks remind, skills build, subagents take the work: the three kinds of pieces in Quack.
Quack is a Claude Code plugin made of three kinds of pieces. Everything runs locally with Node.
Hooks
Hooks run on their own at fixed moments. They never block your work: if one
fails, it stays silent (QUACK_DEBUG=1 prints the error).
| When | What Quack does |
|---|---|
| A session starts | Gives Claude the session rules, refreshes documentation/INDEX.md if it exists, hands a fresh chat the last diary lines, and warns when a resumed chat has a cold cache. The first session after an install or update also sends one anonymous ping. |
| You send a message | Checks how big the chat is and whether the cache expired, and shows a reminder only when it matters. |
| Claude is about to read a file | If the file has 400+ lines and Claude reads it whole, Quack points it to the code map or Grep, then to a line range. |
Skills
Skills are the commands you run:
/quack:indexbuilds the code map./quack:checkupruns the setup checkup.
Subagents
Five subagents, the duck team. Each works in its own context, with its own model and effort, and sends back only a summary. The session rules tell Claude who gets which job.
What it costs
About 750 tokens per session: roughly 340 for the session rules and roughly 400 for the short descriptions of 2 skills and 5 subagents. A single whole-file read it prevents usually saves more than that.