learn-architecture

A read-only teaching command for software architecture and design topics, explaining the theory, Python examples, and practical trade-offs.

In plain words
What is it for?
Use it to learn topics such as dependency injection, the strategy pattern, design principles, or the repository pattern, including how they apply to your code.
Why use it?
It helps developers understand how a design works and when to use it without changing their code.

Command

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/mktoronto/python-clean-architecture/learn-architecture
Clone the repo
git clone --depth 1 https://github.com/MKToronto/python-clean-architecture
Per session 25 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,407 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 $0.00025 $0.02407
Opus 5 $0.00013 $0.01203
Sonnet 5 $0.00005 $0.00481
Haiku 4.5 $0.00003 $0.00241

Measured 2d ago against content hash 13a3efd8c450, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

learn-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.

commands/learn-architecture.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Teach the user an architecture or design topic from this skill's knowledge base. This command explains and deepens understanding — it does not refactor, review, or scaffold. The goal is for the user to understand both the theory and how it works in practice, including the trade-offs and comparisons an interviewer (or a thoughtful teammate) would probe.

The user may have given a topic in $ARGUMENTS (e.g. strategy, dependency injection, the 7 principles, drill me on repository). It may also contain a mode hint like drill or lesson.

Hard rule — this command never edits

This is a read-only, teaching command. It reads the user's code and the bundled example to explain — it must never create, modify, or delete any file as part of teaching. Showing "before/after" snippets, pointing at a violation, or saying "here's how you'd fix it" is explanation, not editing — present it in your reply, never apply it.

The only exception: the user explicitly asks you to apply a change to their code during the session (e.g. "go ahead and refactor that file", "apply that fix"). Even then:

  • Stop and confirm first. Use AskUserQuestion to show exactly which file(s) and what change, and get an explicit yes before any edit. A vague "sure" or momentum from the lesson is not consent — confirm the specific change.
  • This confirmation is mandatory even in auto-accept / auto-edit mode. Do not rely on the permission prompt to gate the edit — proactively ask via AskUserQuestion yourself, because that prompt may be suppressed. No silent edits, ever.
  • Prefer to redirect. Applying refactors is the job of the action commands. Point the user to /make-pythonic, /extract-god-class, /decouple, /add-endpoint, or /scaffold-api instead — only edit from this command if they decline the redirect and still want it here.

Step 1 — Pick the mode

Unless the arguments already make it obvious, use AskUserQuestion to ask "How do you want to learn this?" with two options:

Read the full file on GitHub · 123 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 · 123 lines · 25 tokens per session scan A 13a3efd8c450

Subscribe to this mod's changes

learn-architecture is a command published in the GitHub repository MKToronto/python-clean-architecture (8 stars, last pushed 2mo ago), licensed MIT. It adds 25 tokens to every session and 2,407 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.