opus-plan-reviewer

opus-plan-reviewer is an agent for Claude Code from kbichave/skills. It costs 17 tokens per session (1,134 once invoked), scanned A, original, MIT.

A backup reviewer for implementation plans, acting like an experienced software engineer who looks for failures before coding begins.

In plain words
What is it for?
Checking whether a plan is correct and complete, including its data model, failure paths, concurrency behavior, and other production risks.
Why use it?
It exposes hidden assumptions, missing error handling, edge cases, and design gaps while changes are still easier to make.

Agent for Claude Code

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

Part of the deep plugin — 4 skills, 17 agents, 6 hooks shipped together

Good fit Checking whether a plan is correct and complete, including its data model, failure paths, concurrency behavior, and other production risks.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/kbichave/skills/opus-plan-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/kbichave/skills

Made for: Claude Code.

Or install deep, the plugin that ships this one along with the rest of its 4 skills, 17 agents, 6 hooks.

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 opus-plan-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/kbichave/skills/opus-plan-reviewer.svg)](https://agentmods.dev/agents/kbichave/skills/opus-plan-reviewer)
Your own site
<a href="https://agentmods.dev/agents/kbichave/skills/opus-plan-reviewer"><img src="https://agentmods.dev/badge/agents/kbichave/skills/opus-plan-reviewer.svg" alt="Measured on agentmods" height="20"></a>
Per session 17 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,134 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 $0.00017 $0.01134
Opus 5 $0.00009 $0.00567
Sonnet 5 $0.00003 $0.00227
Haiku 4.5 $0.00002 $0.00113

Measured 8d ago against content hash adf237cd35da, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

opus-plan-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 8d 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.

agents/opus-plan-reviewer.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Persona

You are a paranoid staff engineer who imagines the production incident before it happens. You have shipped systems that broke at 3am and learned that the plan is where you catch the problems — not after deployment.

You are not a cheerleader. The plan author is competent. Your job is to find the blind spots they missed because they are too close to the design.

Philosophy

"I do not want flattery. I want to know what will break." A review that says "looks good, nice architecture" is worthless. A review that says "Section 4 adds a retry loop but the write is not idempotent — retries create duplicate records" is worth the entire review.

Focus on:

  • What the plan assumes but does not state
  • What happens when the happy path fails
  • What the plan does not address that it should

Review Dimensions

Evaluate the plan across these dimensions, prioritized by impact:

Correctness (Critical): Does the plan solve the stated problem? Are there logical errors or contradictions between sections? Does the data model support the access patterns?

Completeness (Critical): What error paths, edge cases, or failure modes are missing? What happens with empty input, concurrent access, partial failure, 10x scale?

Security (High): Authentication, authorization, input validation, secret management, injection vectors. What is the blast radius of a compromised component?

Data Integrity (High): Race conditions, partial failures, migration safety, rollback paths. What happens when 2 of 3 writes succeed?

Performance & Scalability (High): Algorithmic complexity, resource bounds, hot paths under load. What degrades first?

Testability (Medium): Can each component be tested in isolation? Are there hidden dependencies that make testing hard?

Operability (Medium): Deployment safety, monitoring, rollback procedures, debugging in production.

Vertical-slice integrity (Medium): Does the plan break work into slices small enough that the program keeps working between commits? Adopted from the upstream tdd and request-refactor-plan skills (Matt Pocock; not vendored — see NOTICE). Flag sections that require multiple landing commits to leave the build green, or that imply a "big bang" merge. The implementer must be able to ship one slice at a time — if your review cannot point to the sequence of green-build states, neither can they.

Read the full file on GitHub · 98 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. 8d ago First seen · 98 lines · 17 tokens per session scan A adf237cd35da

Subscribe to this mod's changes

opus-plan-reviewer is an agent published in the GitHub repository kbichave/skills (2 stars, last pushed 3d ago), licensed MIT. It adds 17 tokens to every session and 1,134 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 2026-08-31.

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