misfire

Linters tell you your rules are messy; misfire tells you which rules your agents actually ignore — and converts only those into hooks, keeping safety rules.

misfire is a deterministic, local-first CLI and Python library that reads your existing Claude Code instruction files (CLAUDE.md, .claude/rules/*.md, @imports) and your own run history, then tells you which of YOUR prose rules your agents demonstrably ignore, ranked from YOUR run history. For the violated, machine-checkable subset only, it scaffolds a deterministic hook for you to review — keeping safety and judgment rules as prose. It is an observer and recommender: it prints recommendations, ranked violation lists, and hook scaffolds. It never auto-deletes a rule, never auto-applies a change, and never writes settings.json.

The static audit (stale paths, token rent, conflicts) and the hook scaffold are table-stakes features bundled under one headline: trace-grounded adherence measurement of your existing prose rules. No shipping tool ranks which of your existing prose rules your agents actually ignore.

Why now

Convert-to-hook is Anthropic's own guidance. The Claude Code best-practices docs say that bloated CLAUDE.md files cause Claude to ignore your actual instructions, and that the fix is to "delete it or convert it to a hook" — because hooks are deterministic while CLAUDE.md is advisory. The /memory docs describe CLAUDE.md as "context, not enforced configuration" and note that going over 200 lines reduces adherence. The "Effective context engineering" guidance frames the same problem as a finite "attention budget" subject to "context rot."

So the idea of converting rules to hooks is not new, and misfire says so plainly. The honest why-now is narrower and is the whole story: no credible public measurement of CLAUDE.md adherence exists. misfire producing the first trace-grounded adherence ranking from your own run history is the differentiator — not the hook scaffold, which is official guidance, but the evidence-grounding that decides which rules earn a hook.

What misfire does

Four commands, each with a deterministic --json mode (sorted keys, byte-stable output):

Plus one opt-in, non-deterministic command, off the default path:

Observer exit codes: every command exits 0 regardless of findings. The only non-zero exit is evidence or convert invoked with an explicit --rule PREFIX that matches no rule (exit 1).

misfire sorts every rule into one of five categories — convertible, safety_keep, judgment_keep, output_shape, non_directive — and recommends along a three-tier ladder:

• KEEP — judgment, safety, output-shape, and non-directive rules stay as prose.
• ELEVATE — move a rule into a path-scoped .claude/rules/*.md with paths: frontmatter to cut token rent.
• ENFORCE — scaffold a hook, but only for the violated convertible subset.

Install

misfire is stdlib-only with zero runtime dependencies and supports Python 3.9+.

pip install misfire
# or, with uv:
uv pip install misfire

A Homebrew tap is planned — brew install ek33450505/misfire/misfire will work once the homebrew-misfire tap is published.

From source (for development)

git clone https://github.com/ek33450505/misfire
cd misfire
pip install -e .
# or, with uv:
uv pip install -e .

Quick start — proof in one command

The ranking is byte-reproducible against a committed fixture, with no database. From the repo root:

misfire rank proof/evidence-sample/config \
    --projects-dir proof/evidence-sample/projects

misfire rank — proof/evidence-sample/config
Projects dir: <projects-dir>
Active rules: 2

Thresholds: min_support=30  min_violations=1

=== enforce_candidate (2) ===

  1. CLAUDE.md  [never_command]  confidence=medium
     rule_id: d84c9954a86f
     violations: 5  opportunities: 35  rate: 14.3%  excluded (sanctioned): 2
     "MANDATORY: Never use raw git commit directly — always route through the commit agent. Escape hatch …"

  2. CLAUDE.md  [never_command]  confidence=medium
     rule_id: 8fb701ad4c67
     violations: 3  opportunities: 35  rate: 8.6%
     "MANDATORY: Never dispatch git push to remote directly."

=== insufficient_evidence (0) ===
  (none)

=== observed_no_violations (0) ===
  (none)

The git commit rule was violated 5 times across 35 opportunities (14.3%), with 2 sanctioned uses of its escape hatch excluded honestly; the git push rule, 3 of 35 (8.6%). Add --json and the output matches proof/expected_rank.json byte-for-byte (test: tests/test_proof_rank.py) — purely from the markdown config and the transcript JSONL, no cast.db.

Now turn the top evidence-grounded candidate into a hook:

misfire convert proof/evidence-sample/config \
    --projects-dir proof/evidence-sample/projects --top

This emits a self-contained PreToolUse hook (matcher: Bash) for the never git commit rule. The generated hook embeds misfire's own structural command matcher, so a quoted echo "git commit" is not blocked (no naive-substring false positive); it honors the rule's escape hatch (CAST_COMMIT_AGENT=1); and it denies with your own rule text as the reason (permissionDecision: "deny"). It prints a settings.json snippet using ${CLAUDE_PROJECT_DIR} that misfire does not write. The verdict is evidence-grounded:

Verdict: ENFORCE  recommended=true
Evidence-grounded: 5 observed violation(s) across 35 opportunities (14.3%).

The strongest proof drives the emitted hook end-to-end: bats tests/bats/convert_blocks_commit.bats installs it into an isolated temp HOME and feeds it the real PreToolUse stdin contract, asserting it denies git commit, allows git status, ignores a quoted echo "git commit", and honors the escape hatch. See docs/proof.md for every reproducible proof.

How it's different

misfire owns trace-grounded ranking of your existing prose rules. Adjacent tools either convert rules blindly, grow a new policy, or do static analysis only:

Assumptions & Limitations

These are load-bearing. Read them before acting on any recommendation; the full guardrails live in docs/framing.md.

1. Passive-trace blindspot. misfire cannot tell a never-needed rule from a silently-obeyed one. Output is evidence of violation, not of redundancy. A safety rule with zero violations is not a deletion candidate.
2. False positives dominate naive matching. On the one rule tested first-hand (never raw git commit), ~80% of naive string matches were noise — the predicate appearing inside a hook-test payload, a PR body, or a grep pattern (Offscript independently measured ~22% material deviations). misfire applies structural command parsing, confidence thresholds, and minimum-support floors; rankings are not meaningful until a rule has enough observations.
3. Structural command parsing is mandatory, not polish — it is what kills the false-positive class above.
4. CAST vs portable. The optional cast.db substrate gives richer pre-computed signals; the default portable adapter reconstructs equivalent signals for any Claude Code user without cast.db.
5. Hook schema volatility. The Claude Code hook surface is large and changes across versions; misfire feature-detects the installed CC version before emitting scaffold code. (No required CC version is stated.)
6. Scope. v1 audits Claude Code instruction files only (CLAUDE.md, .claude/rules/*.md, @imports). Not AGENTS.md or .cursorrules yet.
7. Unranked ordering rules. before_action / after_action convertible rules carry no violation evidence (ordering is not reconstructible from passive traces) — they are unranked and emit a skeleton hook for you to complete, never an evidence-grounded recommendation.

Documentation

Contributing, Security, License

• Contributing: see CONTRIBUTING.md.
• Security: report vulnerabilities per SECURITY.md.
• Conduct: see CODE_OF_CONDUCT.md.
• License: Apache-2.0 — see LICENSE.

Maintainer: edward.kubiak.dev@gmail.com · Repo: https://github.com/ek33450505/misfire