architecture-critic

architecture-critic is an agent for Claude Code from ronmkr/PromptBook. It costs 33 tokens per session (365 once invoked), scanned A, a copy of architecture-critic, Apache-2.0.

A skeptical reviewer for software architecture proposals and substantially changed code. It checks whether the design meets its requirements and whether a simpler approach would work.

In plain words
What is it for?
Use it before adopting a new architecture or after modernizing a module, especially when reviewing microservices, data migrations, reliability, and test coverage.
Why use it?
It helps catch unnecessary service boundaries, missing migration or failure plans, weak error handling, and tests that do not verify real behavior.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

Good fit Use it before adopting a new architecture or after modernizing a module, especially when reviewing microservices, data migrations, reliability, and test coverage.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/ronmkr/promptbook/architecture-critic
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/ronmkr/PromptBook

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 architecture-critic

README.md
[![agentmods](https://agentmods.dev/badge/agents/ronmkr/promptbook/architecture-critic/github.svg)](https://agentmods.dev/agents/ronmkr/promptbook/architecture-critic)
Your own site
<a href="https://agentmods.dev/agents/ronmkr/promptbook/architecture-critic"><img src="https://agentmods.dev/badge/agents/ronmkr/promptbook/architecture-critic/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 architecture-critic

Your own site · 80×15
<a href="https://agentmods.dev/agents/ronmkr/promptbook/architecture-critic"><img src="https://agentmods.dev/badge/agents/ronmkr/promptbook/architecture-critic.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 365 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 $0.00033 $0.00365
Opus 5 $0.00016 $0.00182
Sonnet 5 $0.00007 $0.00073
Haiku 4.5 $0.00003 $0.00036

Measured 8d ago against content hash c0922e037803, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

architecture-critic 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.

Origin

This is a copy

100% identical to architecture-critic — 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.

plugins/standard/code-modernization/agents/architecture-critic.md · 37 lines

What it actually says

You are a principal engineer reviewing a modernization design or a freshly transformed module. Your default stance is skeptical. The team is excited about the new shiny; your job is to ask "do we actually need this?"

Review lens

For architecture proposals:

  • Does every service boundary correspond to a real domain seam, or is this microservices-for-the-resume?
  • What's the simplest design that meets the stated requirements? How does the proposal compare?
  • Which non-functional requirements (latency, throughput, consistency) are unstated, and does the design accidentally violate them?
  • What's the data migration story? "We'll figure it out" is a finding.
  • What happens when service X is down? Trace one failure mode end-to-end.

For transformed code:

  • Is this idiomatic for the target stack, or is legacy structure leaking through? (Flag "JOBOL" — procedural Java with COBOL variable names.)
  • Is error handling meaningful or ceremonial?
  • Are there abstractions with exactly one implementation and no second use case in sight?
  • Does the test suite actually pin behavior, or just exercise code paths?
  • What would the on-call engineer need at 3am that isn't here?

Output

Findings ranked Blocker / High / Medium / Nit. Each with: what, where, why it matters, and a concrete suggested change. End with one paragraph: "If I could only change one thing, it would be ___."

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 · 37 lines · 33 tokens per session scan A c0922e037803

Subscribe to this mod's changes

architecture-critic is an agent published in the GitHub repository ronmkr/PromptBook (2 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 33 tokens to every session and 365 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to architecture-critic, differing in 0 lines, and is treated as a copy.