Stop hook that blocks Claude from finishing until quality checks pass. Detects rationalization patterns (surface text heuristics), stale learning logs (filesystem mtime), and low disk space. Complements self-audit by mechanically enforcing learning capture habits. Use when Claude should be mechanica

Delivery Gate — Mechanical Quality Gate for Claude Code A Stop hook that checks three things before Claude can finish a session, using only deterministic checks — file modification timestamps, disk usage, and regex patterns on the transcript text. No AI inference. This is distinct from reasoning gates (like self audit ): delivery gate checks machine verifiable facts; self audit checks output quality across four reasoning dimensions. Together they form defense in depth: delivery gate : "Was the learning library touched today? Is disk space safe?" self audit : "Is the file content correct, complete, and honest?" This is the same pattern as CI pipeline gates — automated, deterministic checks that verify machine readable facts rather than trusting self reported status. What It Checks Check Mechanism On Hit Rationalization patterns Regex on transcript tail Warning only (never blocks) Stale learning libraries mtime on 5 configurable paths Warning if some stale; Block if =3 stale OR growth log stale + complex task Disk space < 50GB shutil.disk usage Warning Disk space < 15GB shutil.disk usage Block (exit 2) Rationalization detection warns about patterns like "skip tests for now" and "pre existing bug" — surface signals that thinking may have been cut short. It never blocks on its own, because regex heuristics can false positive. The blocking conditions are: disk critical, =3 learning libs stale , OR growth log specifically stale (all require complex task =3 edits). Why Claude Code's built in checks cover code quality (build → type → lint → test). But there's a different failure mode: the agent produces working code while the session hygiene was neglected — learning not captured, rationalized shortcuts, disk running out silently. Over many sessions of "ship and forget," the human hasn't grown. This hook enforces the habit: complex task → must touch learning libraries. Install Add to ~/.claude/settings.json : Learning Libraries Create these files in your project's memory directory. The hook checks if at least one was updated today: Customize the LIBS dict to match your own file structure. Configuration Edit quality gate.py : Variable Default Purpose RATIONALIZE 4 patterns Regex patterns for rationalization detection LIBS 5 libraries Files/dirs to check for today's updates COMPLEX THRESHOLD 3 Edit/Write calls to classify as complex DISK WARN GB 50 Warn below this DISK CRIT GB 15 Block below this Examples Simple session — allowed: Complex task, learning captured — allowed: Complex task, no learning — BLOCKED: Low disk space — BLOCKED: Limitations The hook enforces the habit of touching learning libraries, not the quality of what was recorded. If output index.md is updated but growth log is skipped, the hook passes (1 of 5 libraries touched). This is by design: mechanical gates check machine verifiable facts. For content quality verification, pair with self audit . Compatibility Python 3.8+ (uses from future import annotations ) Cross platform: Windows, macOS, Linux Zero dependencies beyond stdlib Quality This code went through 4 rounds of automated code review (CodeRabbit + Greptile) with 9 real bugs found and fixed. See Also self audit — Reasoning quality gate (completeness/consistency/groundedness/honesty) verification loop — Code quality checks (build/type/lint/test) gateguard — PreToolUse safety gate

delivery-gate