A design interview and documentation command for deciding a project’s architecture, data model, platform, and behavior. Architecture describes how parts of a system fit together.

Designing components and boundaries, database schemas, runtime behavior, synchronization, build-versus-buy choices, tradeoffs, and a behavioral specification.

It helps make important technical decisions explicit and keeps future changes localized rather than spreading through the whole project.

How robconery/cassini-workshop configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to robconery/cassini-workshop. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/robconery/cassini-workshop/main/.claude/commands/design.md

Clone the repo

git clone --depth 1 https://github.com/robconery/cassini-workshop

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.

README.md

[![agentmods](https://agentmods.dev/badge/commands/robconery/cassini-workshop/design/github.svg)](https://agentmods.dev/commands/robconery/cassini-workshop/design)

Your own site

<a href="https://agentmods.dev/commands/robconery/cassini-workshop/design"><img src="https://agentmods.dev/badge/commands/robconery/cassini-workshop/design/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.

Your own site · 80×15

<a href="https://agentmods.dev/commands/robconery/cassini-workshop/design"><img src="https://agentmods.dev/badge/commands/robconery/cassini-workshop/design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 723 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.

Model	Per session	Once invoked
Fable 5.1	$0.00021	$0.00723
Opus 5.5	$0.00008	$0.00289
Sonnet 5.5	$0.00004	$0.00145
Haiku 4.5	$0.00002	$0.00072

Measured 2mo ago against content hash 6ea78fe896e7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

design 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 2mo 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 design — 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.

.claude/commands/design.md · 69 lines

How it starts

The opening of the file, as written. The whole thing — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.

design

🎯 Design for change. Every architectural decision here is judged by one question: when this changes, how big is the diff? Pick the boundaries, seams, and data shapes that make the next change small and local.

Decide how to build what /explore defined. This is a solution-space interview. Output: an architecture, a data model, and a behavioral spec.

Scope

IN: components & boundaries, data model, database (schema and platform), runtime, sync vs async, build-vs-buy, key tradeoffs, behavioral requirements.
OUT: the problem/why (that's /explore — read it, don't redo it), task breakdown (/plan), prose docs/README (/document).

Preflight

Read docs/PROJECT.md (the brief — design must serve it), plus docs/ARCHITECTURE.md, docs/SPEC.md, CLAUDE.md, docs/MEMORY.md. Summarize current state in 1–2 lines. Re-entrant: refine, don't restart.
If PROJECT.md still has open scope questions, surface them — designing on an undefined problem is wasted work; offer to bounce back to /explore.

Skills

Pull in the relevant skill rather than improvising:

DB schema → postgres-dba (or sqlite-dev if local/Bun + SQLite).
Module/class boundaries → solid-principles, design-principles.
Pattern choice → gof-patterns. TS conventions → typescript-best-practices.

Interview

Up to ~10 questions, adaptive, batched (4 at a time). Bank:

Data model — core entities and relationships?
Database platform, and why (durability, scale, ops)?
Runtime / language / framework — and any locked constraints?
Major components and their boundaries?
Sync or async? Where are the seams?
External services / APIs — build or buy?
Auth & trust boundaries, if any?
Hardest technical risk, and the fallback?
What are we explicitly not building for now (YAGNI)?
Non-functionals that bite: scale, latency, offline, cost ceiling?

Produce

docs/ARCHITECTURE.md (owned): components, data flow, the data model, database platform + schema, key decisions with their rationale and the alternative rejected.
docs/SPEC.md (owned): behavioral requirements in prose — what the system must do, observably. This is what /plan slices into stories; keep it testable, not vague.
docs/PROJECT.md: update the decisions log only (don't rewrite it).
docs/MEMORY.md: append dated entries for each architectural decision — the choice, the why, the rejected alternative.

Read the full file on GitHub · 69 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.

2mo ago First seen · 69 lines · 21 tokens per session scan A 6ea78fe896e7

Subscribe to this mod's changes

design is a command published in the GitHub repository robconery/cassini-workshop (1 stars, last pushed 4mo ago), licensed MIT. It adds 21 tokens to every session and 723 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to design, differing in 0 lines, and is treated as a copy.

Planning ai-workshop cassini cloudflare-workers mcp sqlite

cassini-workshop: Command for Claude Code

Borrowing it

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

This is a copy

How it starts

design

Scope

Preflight

Skills

Interview

Produce

What this file has done since we first saw it

Other commands, from other repositories

hyperliquid-risk

speckit.archive.run

setup-sandbox

session-recap

self-improve

update-agentskills