See also: Hooks Reference — the full hooks table with events and matchers.

Middleware Layer

Middleware hooks are thin shell scripts between the model and its tools. They intercept Claude Code events (file writes, session start/stop, prompt submissions) and inject feedback or context — without any agent or skill involvement.

Why middleware exists

Agents write code, re-read their own code, declare it good, stop.

This is the failure mode the middleware layer was built to interrupt. Without external feedback, an agent edits a file, reads it back, decides it looks correct, and stops — without running tests or verification.

The four hooks

Hook	Event	Purpose
post-write-build-verify.sh	PostToolUse (Edit|Write)	Compile/lint on source writes; hash-cached to skip unchanged files. Never blocks — feedback only.
post-write-loop-detection.sh	PostToolUse (Edit|Write)	Warns at 4 edits to same file, escalates at 8. Cleared per session.
pre-completion-check.sh	Stop	Blocks session end without verification evidence. 3-attempt guard. LEAN: soft nudge only. MINIMAL: skipped.
project-context-loader.sh	SessionStart	Injects directory tree, tool availability, package scripts. Resets per-session state.

Key properties

• Cheap — each hook runs in milliseconds.
• Composable — hooks are independent. Adding or removing one doesn't affect others.
• Pruneable — measured via dead-weight audit. If a hook stops paying its delta, it can be removed.
• Zero awareness — agents have no awareness of middleware. They see feedback in context but don't know its source.

Opt-out matrix

Env var	Effect
MEOWKIT_BUILD_VERIFY=off	Skip build verify
MEOWKIT_LOOP_DETECT=off	Skip loop detection
MEOWKIT_PRECOMPLETION=off	Skip pre-completion check
MEOWKIT_AUTOBUILD_MODE=LEAN	PreCompletion: soft nudge; BuildVerify: still runs
MEOWKIT_AUTOBUILD_MODE=MINIMAL	Skip BuildVerify + PreCompletion

Next steps

• Hooks reference — full event + handler table
• How it works — architecture overview
• Configuration — all env vars