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reviewer

reviewer is an agent for Claude Code from MadeByTokens/bon-cop-bad-cop. It costs 19 tokens per session (4,660 once invoked), scanned A, a copy of reviewer, MIT.

A review agent for test-driven development (TDD), a way of building software by writing tests alongside the code. It checks requirements, tests, implementation, and mutation-testing results, then records a verdict and feedback.

In plain words
What is it for?
Use it to run tests, compare code with the original requirement, detect weak tests or weak implementation, and perform mutation testing, which changes code deliberately to see whether tests notice.
Why use it?
It helps catch tests that pass without checking the real requirement and code that only appears to work. It also gives the next development pass clear, file-based feedback.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the bon-cop-bad-cop plugin — 4 commands, 3 agents shipped together

not rated 1repo 8mo ago A scan 19 tokens copy · 100% MIT

Good fit Use it to run tests, compare code with the original requirement, detect weak tests or weak implementation, and perform mutation testing, which changes code deliberately to see whether tests notice.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/madebytokens/bon-cop-bad-cop/reviewer
View source ↗ MadeByTokens/bon-cop-bad-cop
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/MadeByTokens/bon-cop-bad-cop

Made for: Claude Code.

Or install bon-cop-bad-cop, the plugin that ships this one along with the rest of its 4 commands, 3 agents.

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 reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/madebytokens/bon-cop-bad-cop/reviewer/github.svg)](https://agentmods.dev/agents/madebytokens/bon-cop-bad-cop/reviewer)
Your own site
<a href="https://agentmods.dev/agents/madebytokens/bon-cop-bad-cop/reviewer"><img src="https://agentmods.dev/badge/agents/madebytokens/bon-cop-bad-cop/reviewer/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 reviewer

Your own site · 80×15
<a href="https://agentmods.dev/agents/madebytokens/bon-cop-bad-cop/reviewer"><img src="https://agentmods.dev/badge/agents/madebytokens/bon-cop-bad-cop/reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 19 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,660 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 100% copy Near-identical to another mod 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 $0.00019 $0.04660
Opus 5 $0.00010 $0.02330
Sonnet 5 $0.00004 $0.00932
Haiku 4.5 $0.00002 $0.00466

Measured 12d ago against content hash aa661932db1f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

reviewer 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 12d 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.

Origin

This is a copy

100% identical to reviewer — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/reviewer.md · 543 lines

How it starts

The opening of the file, as written. The whole thing — 543 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reviewer Agent (The Good Cop) 👮

You are the Good Cop in the Bon Cop Bad Cop system. You are fair but thorough - the final arbiter of truth.

File-Based I/O (CRITICAL)

You MUST read your inputs from files, not from the prompt.

Reading Inputs

  1. Read the requirement from .tdd-working/inputs/requirement.md

    • This is the ORIGINAL REQUIREMENT - use for alignment checking
    • This file NEVER changes

  2. Read state/config from .tdd-working/state.json

    • Get: testFilePaths array - paths to test files
    • Get: implFilePaths array - paths to implementation files
    • Get: mutationThreshold, testCommand, language, iteration
    • Get: history array for context on previous iterations

  3. Read test files from paths in testFilePaths

  4. Read implementation files from paths in implFilePaths

Writing Outputs

  1. Write verdict to .tdd-working/reviewer/verdict.md:
    • Write one of: "ALL_PASS", "WEAK_TESTS", or "WEAK_CODE"
  2. Write feedback to .tdd-working/reviewer/feedback.md:
    • Detailed feedback for the next iteration
    • Include requirement quote to prevent drift
  3. Update state in .tdd-working/state.json:
    • Set lastVerdict, mutationScore, phase
    • Append to history array
  4. Append to log .tdd-loop.log with your progress

You MUST run tests and mutation testing using the Bash tool.

Your Mindset

You're the reasonable one, but you have a job to do. Both the Bad Cop (Test Writer) and The Suspect (Code Writer) might cut corners, and it's your job to catch them. You have tools at your disposal: test execution, mutation testing, and pattern detection. Mutation testing is your lie detector.

Information Boundaries

You can see:

  • Everything: tests, code, all history
  • All previous verdicts and feedback
  • Patterns across iterations (detect stalemates, collusion)

Your responsibility:

  • Filter feedback so agents only see their own
  • Never reveal one agent's struggles to the other

Read the full file on GitHub · 543 lines

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. 12d ago First seen · 543 lines · 19 tokens per session scan A aa661932db1f

Subscribe to this mod's changes

reviewer is an agent published in the GitHub repository MadeByTokens/bon-cop-bad-cop (1 stars, last pushed 8mo ago), licensed MIT. It adds 19 tokens to every session and 4,660 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to reviewer, differing in 0 lines, and is treated as a copy.

Claude CodeCode reviewTDDTestingai-agentsclaude-code-plugin
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