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.
npx agentmods add commands/buildermethods/design-os/design-shellgit clone --depth 1 https://github.com/buildermethods/design-osWhat 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 | $0.00000 | $0.01692 |
| Opus 5 | $0.00000 | $0.00846 |
| Sonnet 5 | $0.00000 | $0.00338 |
| Haiku 4.5 | $0.00000 | $0.00169 |
Grade A, and why
design-shell 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 239 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Design Shell
You are helping the user design the application shell — the persistent navigation and layout that wraps all sections. This is a screen design, not implementation code.
Step 1: Check Prerequisites
First, verify prerequisites exist:
- Read
/product/product-overview.md— Product name and description - Read
/product/product-roadmap.md— Sections for navigation - Check if
/product/design-system/colors.jsonand/product/design-system/typography.jsonexist
If overview or roadmap are missing:
"Before designing the shell, you need to define your product and sections. Please run:
/product-vision— Define your product/product-roadmap— Define your sections"
Stop here if overview or roadmap are missing.
If design tokens are missing, show a warning but continue:
"Note: Design tokens haven't been defined yet. I'll proceed with default styling, but you may want to run /design-tokens first for consistent colors and typography."
Step 2: Analyze Product Structure
Review the roadmap sections and present navigation options:
"I'm designing the shell for [Product Name]. Based on your roadmap, you have [N] sections:
- [Section 1] — [Description]
- [Section 2] — [Description]
- [Section 3] — [Description]
Let's decide on the shell layout. Common patterns:
A. Sidebar Navigation — Vertical nav on the left, content on the right Best for: Apps with many sections, dashboard-style tools, admin panels
B. Top Navigation — Horizontal nav at top, content below Best for: Simpler apps, marketing-style products, fewer sections
C. Minimal Header — Just logo + user menu, sections accessed differently Best for: Single-purpose tools, wizard-style flows
Which pattern fits [Product Name] best?"
Wait for their response.
Step 3: Gather Design Details
Use AskUserQuestion to clarify:
- "Where should the user menu (avatar, logout) appear?"
- "Do you want the sidebar collapsible on mobile, or should it become a hamburger menu?"
- "Any additional items in the navigation? (Settings, Help, etc.)"
- "What should the 'home' or default view be when the app loads?"
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.
- yesterday First seen · 239 lines · 0 tokens per session scan A e949ca680027
design-shell is a command published in the GitHub repository buildermethods/design-os (1,845 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,692 tokens. 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.
Other commands, from other repositories
checklist
Generate a custom checklist for the current feature based on user requirements.
clarify
Identify underspecified areas in the current feature spec by asking up to 5 highly targeted clarification questions and encoding answers back into the spec.
specify
Create or update the feature specification from a natural language feature description.
analyze
Perform a non-destructive cross-artifact consistency and quality analysis across spec.md, plan.md, and tasks.md after task generation.
converge
Assess the current codebase against the feature's spec, plan, and tasks, then append any remaining unbuilt work as new tasks to tasks.md so implement can complete it.
implement
Execute the implementation plan by processing and executing all tasks defined in tasks.md.