arch-learn

arch-learn is a command for Claude Code from jed1978/ddd-architecture-coach. It costs 37 tokens per session (234 once invoked), scanned A, original, MIT.

A command for recording an architecture lesson in the project's .claude/arch-learnings.md file. DDD, or domain-driven design, is a way to organise software around the business areas it serves.

In plain words
What is it for?
Use it to append a user-provided lesson, label whether it applies to the whole project or a specific business area, and warn when it belongs in personal memory instead.
Why use it?
It gives architecture decisions and lessons a shared project record instead of leaving them only in chat or in one developer's memory.

Command for Claude Code

Written for Claude Code: $ARGUMENTS substitution. Also seen: mentions Claude Code.

Good fit Use it to append a user-provided lesson, label whether it applies to…

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/jed1978/ddd-architecture-coach/arch-learn
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/jed1978/ddd-architecture-coach

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 arch-learn

README.md
[![agentmods](https://agentmods.dev/badge/commands/jed1978/ddd-architecture-coach/arch-learn.svg)](https://agentmods.dev/commands/jed1978/ddd-architecture-coach/arch-learn)
Your own site
<a href="https://agentmods.dev/commands/jed1978/ddd-architecture-coach/arch-learn"><img src="https://agentmods.dev/badge/commands/jed1978/ddd-architecture-coach/arch-learn.svg" alt="Measured on agentmods" height="20"></a>
Per session 37 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 234 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 $0.00037 $0.00234
Opus 5 $0.00018 $0.00117
Sonnet 5 $0.00007 $0.00047
Haiku 4.5 $0.00004 $0.00023

Measured 6d ago against content hash 07f370a47a2e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

arch-learn 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.

assets/commands/arch-learn.md · 16 lines

What it actually says

請啟動 DDD Architecture Coach(ddd-architecture-coach skill)並寫入一條 learning

執行步驟:

  1. 把 $ARGUMENTS 視為使用者要記錄的 learning 內容
  2. 讀取 .claude/arch-learnings.md(若不存在,依 SKILL.md Memory/State/Learnings 三層分工原則建立)
  3. 判斷 applies_to 範圍:
    • 內容明顯為個人偏好(跨專案)→ 提醒使用者應寫入 Claude Code memory,不要寫入 arch-learnings
    • 本專案 phase / BC 級規範 → append 到 arch-learnings.md,source: user_triggered
  4. 確認後寫入並回報新 learning 的位置

$ARGUMENTS

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 · 16 lines · 37 tokens per session scan A 07f370a47a2e

Subscribe to this mod's changes

arch-learn is a command published in the GitHub repository jed1978/ddd-architecture-coach (5 stars, last pushed 4mo ago), licensed MIT. It adds 37 tokens to every session and 234 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.