Spotify publishes a Claude Code plugin that blocks large file reads

Sources: primary, discussion
Summary: The enforcement sits in a PreToolUse hook that blocks any Read above a configurable line threshold and delegates the file to a cheaper worker model. The 90 percent figure is the mean saving on the bulk-read path across four scenarios, not a whole-workload reduction, and it is Spotify's own benchmark of Spotify's own product on one Java monorepo. The post states the limits: delegated summaries carry no reliable line numbers for editing, and the worker model missed a thread-safety bug the frontier model caught.
Why it matters: A blocking hook enforces a context budget that advisory CLAUDE.md rules do not, at a stated cost in edit precision.