Borrowing it
Nothing to install: this file belongs to slbug/claude-ruby-grape-rails. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/slbug/claude-ruby-grape-rails/main/.github/instructions/hooks-review.instructions.mdgit clone --depth 1 https://github.com/slbug/claude-ruby-grape-railsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/slbug/claude-ruby-grape-rails/hooks-review)<a href="https://agentmods.dev/instructions/slbug/claude-ruby-grape-rails/hooks-review"><img src="https://agentmods.dev/badge/instructions/slbug/claude-ruby-grape-rails/hooks-review/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/slbug/claude-ruby-grape-rails/hooks-review"><img src="https://agentmods.dev/badge/instructions/slbug/claude-ruby-grape-rails/hooks-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.02870 | $0.02870 |
| Opus 5.5 | $0.01148 | $0.01148 |
| Sonnet 5.5 | $0.00574 | $0.00574 |
| Haiku 4.5 | $0.00287 | $0.00287 |
Grade B, and why
claude-ruby-grape-rails hooks-review.instructions.md scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 25d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Recursive force deletemediumDestructive command
rm -rf with a variable or a broad path is one typo away from removing the wrong tree.
- `rm -rf` only for validated `mktemp -d` outputs Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 228 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Shell Script and Hook Review Rules
Scope: shell hook scripts under plugins/**/hooks/scripts/*.sh, Ruby hook
scripts under plugins/**/hooks/scripts/*.rb (e.g.
compress-verify-output.rb, skill-discovery-observer.rb), and shipped
binaries under plugins/**/bin/*. Shell-specific rules below apply to
.sh scripts; Ruby hooks follow the cross-cutting hook conventions
(# Policy: header, opt-in env var short-circuit before side effects,
file mode 0o600 on telemetry artifacts, symlink-refusal on
${CLAUDE_PLUGIN_DATA} before mkdir_p/writes).
Audience: Agents, Not Humans
Imperative-only. Hook script source code follows normal code-comment conventions — rule applies to markdown review checklist itself.
Shell Hardening
- All executable hook scripts must use
set -o nounsetandset -o pipefail - Library files (
*-lib.sh) sourced by other scripts may omit these since the caller's settings apply - Do NOT add
set -e/set -o errexitunless the script must abort on any failure. Current strict-abort hooks:block-dangerous-ops.sh,block-out-of-bounds-writes.sh,active-plan-marker.sh. Most hooks intentionally handle failures gracefully — advisory hooks warn/skip, guardrails fail closed via explicit checks, not errexit - Use
command -vto check for dependencies (jq, grep, etc) before use - Use
${var:?}in deletion commands to prevent empty-variable disasters - Each script should have a
# Policy:comment near the top documenting its failure behavior (advisory, fail-closed, or security-sensitive) - Use
read_hook_inputfrom workspace-root-lib.sh for stdin JSON parsing - Use
resolve_workspace_rootfor safe repo root resolution
Deletion Safety
rm -fonly formktempoutputs or exact fixed plugin-owned pathsrm -rfonly for validatedmktemp -doutputsrmdirfor expected-empty lock directories- For variable-based cleanup, validate the path/prefix first
Hook Output Patterns
- PostToolUse stdout is verbose-mode only — use
exit 2+ stderr to feed messages to Claude - SessionStart stdout IS added to Claude's context
- SubagentStart uses
hookSpecificOutput.additionalContext - PostToolUseFailure uses
hookSpecificOutput.additionalContext - PreCompact uses stderr for context reminders; exit 2 blocks compaction during active work/full phases
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 25d ago Changed · +7 lines · +76 tokens per session da70661e7a39
- 1mo ago First seen · 221 lines · 2,794 tokens per session scan B 4bfb02a5eb3c
claude-ruby-grape-rails hooks-review.instructions.md is an instructions file published in the GitHub repository slbug/claude-ruby-grape-rails (7 stars, last pushed 26d ago), licensed MIT. It adds 2,870 tokens to every session, about $0.0115 per session on Opus 5.5. A static security scan graded it B with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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