Design OS is a product-planning and interface-design tool that guides an idea through product definition, data modeling, design-system choices, screen design, and implementation handoff. Teams use it to give coding agents a clear specification before development begins. Its catalogue add-ons support the guided planning and design workflow.
Borrowing it
Nothing to install: this file belongs to buildermethods/design-os. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/buildermethods/design-os/main/AGENTS.mdgit clone --depth 1 https://github.com/buildermethods/design-osWrote 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.
[](https://agentmods.dev/instructions/buildermethods/design-os/agents-md)<a href="https://agentmods.dev/instructions/buildermethods/design-os/agents-md"><img src="https://agentmods.dev/badge/instructions/buildermethods/design-os/agents-md/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.
<a href="https://agentmods.dev/instructions/buildermethods/design-os/agents-md"><img src="https://agentmods.dev/badge/instructions/buildermethods/design-os/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.02035 | $0.02035 |
| Opus 5.5 | $0.00814 | $0.00814 |
| Sonnet 5.5 | $0.00407 | $0.00407 |
| Haiku 4.5 | $0.00203 | $0.00203 |
Grade A, and why
design-os AGENTS.md 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.
How it starts
The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Directives for Design OS
Design OS is a product planning and design tool that helps users define their product vision, sketch out their data shape, design their UI, and prepare export packages for implementation in a separate codebase.
Important: Design OS is a planning tool, not the end product codebase. The screen designs and components generated here are meant to be exported and integrated into your actual product's codebase.
Understanding Design OS Context
When working in Design OS, be aware of two distinct contexts:
1. Design OS Application
The React application that displays and manages planning files. When modifying the Design OS UI itself:
- Files live in
src/(components, pages, utilities) - Uses the Design OS design system (stone palette, DM Sans, etc.)
- Provides the interface for viewing specs, screen designs, exports, etc.
2. Product Design (Screen Designs & Exports)
The product you're planning and designing. When creating screen designs and exports:
- Screen design components live in
src/sections/[section-name]/andsrc/shell/ - Product definition files live in
product/ - Exports are packaged to
product-plan/for integration into a separate codebase - Follow the design requirements specified in each section's spec
Getting Started — The Planning Flow
Design OS follows a structured planning sequence:
1. Product Vision (/product-vision)
Define your product overview, roadmap sections, and data shape — all in one conversational flow. After answering clarifying questions, all three files are generated automatically.
Output: product/product-overview.md, product/product-roadmap.md, product/data-shape/data-shape.md
Use /product-roadmap, /data-shape individually to update those files after initial creation.
2. Design System (/design-tokens)
Choose your color palette (from Tailwind) and typography (from Google Fonts). These tokens are applied to all screen designs.
Output: product/design-system/colors.json, product/design-system/typography.json
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 · 213 lines · 2,035 tokens per session scan A eca2f3bb640d
design-os AGENTS.md is an instructions file published in the GitHub repository buildermethods/design-os (1,876 stars, last pushed 1mo ago), licensed MIT. It adds 2,035 tokens to every session, about $0.0081 per session on Opus 5.5. 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.
design-os AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| design-os AGENTS.mdbuildermethods/design-os | Instructions file | 1.9k | 1mo ago | MIT | A | 2,035 | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |