architecture

A command for reviewing a proposed architecture change from both the current system's context and basic design principles. Architecture is the high-level structure of a software system and how its parts fit together.

In plain words
What is it for?
Evaluating architecture proposals, including their fit, risks, alternatives, and possible sunk-cost bias.
Why use it?
It helps reveal concrete risks and whether an idea is being defended because it is correct or simply because time was already spent on the existing design.

Command for Claude Code

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.

agentmods
npx agentmods add commands/heznpc/ploidy/architecture
Clone the repo
git clone --depth 1 https://github.com/heznpc/PLOIDY

Made for: Claude Code.

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 874 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00033 $0.00874
Opus 5 $0.00016 $0.00437
Sonnet 5 $0.00007 $0.00175
Haiku 4.5 $0.00003 $0.00087

Measured 2d ago against content hash e19bb87a0ee2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

architecture 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 2d 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/architecture.md · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The user is weighing an architecture-level change:

$ARGUMENTS

You hold the existing system's context (modules, prior decisions, fail modes, operational history). That is precisely the bias the proposal is competing against — Ploidy's paper shows deep-context reviewers anchor on "fits the current shape" over "is actually correct". Run the four-step eval without asking to confirm.

1 · Write the Deep-context take

If $ARGUMENTS is a filepath (ends in .md, .txt, contains /), read that file first via the Read tool. Otherwise treat it as the proposal text.

In ~300 words:

  1. Fit — how does the proposal interact with the current system? Name the modules it touches and the abstractions it respects or violates.
  2. Concrete risks — what breaks, what gets slower, what becomes harder to test / deploy / observe?
  3. Sunk-cost check — list what in your current system you find yourself defending here. For each, state whether the defense is "this abstraction is load-bearing" or "we just spent a lot building it". If nothing, say so explicitly.
  4. Non-obvious alternatives — is there a version of the proposal that solves the same problem with less change? One sentence each.

Tag every concern HIGH / MEDIUM / LOW confidence.

2 · Spawn a Fresh sub-agent

Use the Agent tool (subagent_type="general-purpose"). It must see only the proposal text, no repo knowledge.

Prompt the subagent with exactly:

You are evaluating an architecture proposal in a codebase you have never seen. Only the proposal text is available:

<PROPOSAL TEXT — paste the expanded $ARGUMENTS here>

Answer in under 250 words:

  1. Stated in your own words, what problem is this trying to solve? If the problem is unclear, say so — do not guess.
  2. What assumptions is the proposal making about the existing system? List each; mark ones that sound uncommon.
  3. What are generic architectural alternatives (event-driven, batch, read-model, CQRS, etc.) that the proposal does not mention? One sentence each.
  4. Where is the proposal most likely to be overcomplicating? Be specific about which piece.

Do not ask for repo links. Do not request more context.

Read the full file on GitHub · 103 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. 2d ago First seen · 103 lines · 33 tokens per session scan A e19bb87a0ee2

Subscribe to this mod's changes

architecture is a command published in the GitHub repository heznpc/PLOIDY (0 stars, last pushed 6d ago), licensed MIT. It adds 33 tokens to every session and 874 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 2026-08-31.