rein: Command for Claude Code

.claude/commands/rein-review.md

rein-review is a command for Claude Code from jstxn/rein. It costs 27 tokens per session (416 once invoked), scanned A, original, MIT.

A pre-commit review of the current code changes. A diff is the record of what was added, removed, or changed.

In plain words
What is it for?
Inspect staged and unstaged changes before committing, checking each changed file and the integrity of tests and fixtures.
Why use it?
It catches unrelated edits, leftover debugging code, weakened tests, and work that has grown beyond its intended scope.

Command for Claude Code

Written for Claude Code: installed under .claude/.

This is jstxn/rein's own configuration. It tells Claude Code how to work on rein itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything rein configures →

View source ↗ jstxn/rein
Reuse

Borrowing it

Nothing to install: this file belongs to jstxn/rein. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/jstxn/rein/main/.claude/commands/rein-review.md
Clone the repo
git clone --depth 1 https://github.com/jstxn/rein

Made for: Claude Code.

Wrote 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.

agentmods badge for rein-review

README.md
[![agentmods](https://agentmods.dev/badge/commands/jstxn/rein/rein-review/github.svg)](https://agentmods.dev/commands/jstxn/rein/rein-review)
Your own site
<a href="https://agentmods.dev/commands/jstxn/rein/rein-review"><img src="https://agentmods.dev/badge/commands/jstxn/rein/rein-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.

agentmods 80×15 button for rein-review

Your own site · 80×15
<a href="https://agentmods.dev/commands/jstxn/rein/rein-review"><img src="https://agentmods.dev/badge/commands/jstxn/rein/rein-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 416 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.00416
Opus 5 $0.00014 $0.00208
Sonnet 5 $0.00005 $0.00083
Haiku 4.5 $0.00003 $0.00042

Measured 11d ago against content hash 6804dee3e55f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

rein-review scanned grade A with 0 findings 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 11d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/commands/rein-review.md · 53 lines

What it actually says

rein-review

Use this after implementation and before committing to review your own diff for problems that verification commands alone will not catch.

When To Use

  • Before any commit that touches more than a trivial change
  • After a multi-file implementation pass
  • When you are about to declare work complete

When Not To Use

  • The change is a single-line typo fix with no surrounding edits
  • rein-verify has already been run and covers diff review (avoid duplication)

Steps

  1. Read the full diff (staged and unstaged).
  2. For every changed file, verify you read it before editing it.
  3. Check for unrelated changes:
    • files modified that are not part of the task
    • formatting-only changes in files you did not need to touch
    • import reordering or whitespace changes outside the task scope
  4. Check for debug leftovers:
    • console.log, print, debugger statements
    • commented-out code that should be removed
    • TODO/FIXME comments added without justification
  5. Check for test and fixture integrity:
    • tests removed or weakened without explanation
    • assertions loosened (exact match to contains, strict to loose)
    • test data changed to make failures disappear
    • new tests that only assert the happy path
  6. Check for scope drift:
    • refactors beyond what the task required
    • new abstractions or helpers for one-time use
    • feature additions not in the original scope
  7. If any issue is found, fix it before committing.
  8. If all checks pass, state what was reviewed and confirm the diff is clean.

Output

Emit a short review note with:

  • files reviewed
  • issues found (if any) and how they were resolved
  • confirmation that the diff is limited to the task scope
  • any caveats or remaining concerns
Changes

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.

  1. 11d ago First seen · 53 lines · 27 tokens per session scan A 6804dee3e55f

Subscribe to this mod's changes

rein-review is a command published in the GitHub repository jstxn/rein (12 stars, last pushed 4mo ago), licensed MIT. It adds 27 tokens to every session and 416 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.