principal-reviewer

principal-reviewer is an agent for Claude Code from thapr0digy/skills. It costs 38 tokens per session (300 once invoked), scanned A, original, MIT.

A read-only code-review agent that examines only the changes in a task against a supplied rubric, with particular attention to performance, scalability, and maintainability.

In plain words
What is it for?
Use it to inspect a Git diff, apply the project's review criteria, and return severity-ranked findings with concrete fixes.
Why use it?
It provides a focused review of changed code without modifying files or reporting unrelated pre-existing problems.

Agent for Claude Code

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

Part of the principal-review plugin — 1 skill, 1 agent shipped together

Good fit Use it to inspect a Git diff, apply the project's review criteria, and return severity-ranked findings with concrete fixes.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/thapr0digy/skills/principal-reviewer
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/thapr0digy/skills

Made for: Claude Code.

Or install principal-review, the plugin that ships this one along with the rest of its 1 skill, 1 agent.

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 principal-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/thapr0digy/skills/principal-reviewer/github.svg)](https://agentmods.dev/agents/thapr0digy/skills/principal-reviewer)
Your own site
<a href="https://agentmods.dev/agents/thapr0digy/skills/principal-reviewer"><img src="https://agentmods.dev/badge/agents/thapr0digy/skills/principal-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 principal-reviewer

Your own site · 80×15
<a href="https://agentmods.dev/agents/thapr0digy/skills/principal-reviewer"><img src="https://agentmods.dev/badge/agents/thapr0digy/skills/principal-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 38 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 300 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 $0.00038 $0.00300
Opus 5 $0.00019 $0.00150
Sonnet 5 $0.00008 $0.00060
Haiku 4.5 $0.00004 $0.00030

Measured 6d ago against content hash af871babc18b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

principal-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 6d 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.

plugins/principal-review/agents/principal-reviewer.md · 25 lines

What it actually says

You are a principal engineer reviewing only the code that changed in this task.

Inputs (from your dispatch prompt)

  • The working directory to review.
  • The absolute path to the rubric.

Procedure

  1. Read the rubric file at the path you were given. It is the single source of the criteria - apply it, do not invent extra rules.
  2. Get the diff: run git -C <cwd> diff HEAD and git -C <cwd> status --porcelain to see changed and untracked files. Read the changed regions in full for context.
  3. Detect the language(s) from the changed files and apply the matching cheat-sheet plus the core criteria.
  4. Judge only the changed code. Do not report pre-existing issues in untouched code.

Output

Return findings in the rubric's finding format, severity-ranked, most severe first. Each finding: { file:line, category, why it fails at scale or maintainability, concrete fix }. If the changed code passes, return exactly: No findings - changes meet the principal-review bar. Be specific and terse; every finding must name a concrete fix.

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. 6d ago First seen · 25 lines · 38 tokens per session scan A af871babc18b

Subscribe to this mod's changes

principal-reviewer is an agent published in the GitHub repository thapr0digy/skills (2 stars, last pushed 10d ago), licensed MIT. It adds 38 tokens to every session and 300 once invoked, about $0.0002 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 2026-09-04.

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