architecture

architecture is a skill for Claude Code from owainlewis/blueprint. It costs 39 tokens per session (1,131 once invoked), scanned A, original, MIT.

A documentation helper for creating or updating ARCHITECTURE.md, a file that explains how a software system is organised and how its main parts depend on one another.

In plain words
What is it for?
Use it to document the system boundary, trust boundaries, source of truth, major components, dependency direction, important data flows, and rules contributors must preserve.
Why use it?
Architecture documentation can become outdated after code changes. This helper checks the implementation so the document describes the system that actually exists.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

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 skills/owainlewis/blueprint/architecture
Any agent
npx skills add owainlewis/blueprint --skill architecture
Clone the repo
git clone --depth 1 https://github.com/owainlewis/blueprint

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/owainlewis/blueprint/architecture.svg)](https://agentmods.dev/skills/owainlewis/blueprint/architecture)
Your own site
<a href="https://agentmods.dev/skills/owainlewis/blueprint/architecture"><img src="https://agentmods.dev/badge/skills/owainlewis/blueprint/architecture.svg" alt="Measured on agentmods" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,131 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 5.1 $0.00039 $0.01131
Opus 5 $0.00019 $0.00566
Sonnet 5 $0.00008 $0.00226
Haiku 4.5 $0.00004 $0.00113

Measured 6d ago against content hash 1cfe9ed95d46, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, 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 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.

skills/architecture/SKILL.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Architecture

Create or update root ARCHITECTURE.md so a new teammate can understand the system that exists in code today.

The document should reveal the few rules that give the system its shape: where truth lives, which way dependencies point, how important work moves through the system, and which boundaries a change must preserve.

Process

  1. Read the request, repository instructions, and any existing ARCHITECTURE.md.
  2. Inspect the implementation. Start with manifests, entry points, configuration, schemas, migrations, infrastructure, tests, and the code behind a few critical flows. Follow evidence rather than trying to read every file.
  3. Identify the load-bearing facts: the system boundary, trust boundaries, source of truth, main parts, dependency direction, important protocols or data, and the one rule a contributor must not break.
  4. Create or update root ARCHITECTURE.md. Preserve useful verified content from an existing document, remove stale claims, and organize the body around the system rather than a generic template.
  5. Verify each concrete claim against code, configuration, schemas, infrastructure, or executable tests. Treat existing prose as a claim, not evidence.
  6. Run the review pass and stop with the document ready for human review. Do not propose future behavior, write a design, plan work, or change implementation.

Document shape

Start every document with this small common frame:

# <System> architecture

## Executive summary

Explain what the system does, name its source of truth, show how its main parts work together, and state the most important architectural rule.

### System architecture

Show the users, outside systems, runtime parts, and data stores in one small diagram when this makes the boundary clearer.

### Dependency hierarchy

Show which way important dependencies point. State the rule in prose below the diagram.

Shape the remaining sections around the repository itself. Prefer names such as Protocol, Request lifecycle, Event pipeline, Storage model, or the real component names. Do not add sections that have nothing useful to say.

Read the full file on GitHub · 97 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. 6d ago First seen · 97 lines · 39 tokens per session scan A 1cfe9ed95d46

Subscribe to this mod's changes

architecture is a skill published in the GitHub repository owainlewis/blueprint (378 stars, last pushed 8d ago), licensed MIT. It adds 39 tokens to every session and 1,131 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 2026-08-30.

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