DESIGN.md for Codex
A practical pattern for pairing AGENTS.md engineering rules with DESIGN.md visual rules.
Design System Overview
This editorial starter was written by DesignMD to make an AI-agent workflow concrete. It is independent guidance, not an official product design file or an endorsement from the linked tool vendor.
Use it as a starting contract for repository instructions, visual tokens, component behavior, and review checks. Adapt the values to your product instead of copying them as a vendor-owned brand system.
Browse more developer tools and IDEs design systems or explore the full DESIGN.md directory.
Color System
Starter semantic tokens for this editorial workflow — not an official vendor palette. Click any swatch to copy the hex value.
Text / Primary
#111827
Accent
#8B5CF6
Surface / Background
#F5F3FF
Border / Subtle
#DDD6FE
Typography Specimen
Display
2.8rem / 700 / 1.04
The quick brown fox
Heading H1
2rem / 700 / 1.1
The quick brown fox jumps
Heading H2
1.5rem / 600 / 1.15
The quick brown fox jumps over
Heading H3
1.125rem / 600 / 1.2
The quick brown fox jumps over the lazy
Body
1rem / 400 / 1.5
The quick brown fox jumps over the lazy dog
Small / Caption
0.75rem / 400 / 1.5
The quick brown fox jumps over the lazy dog and sat down.
Monospace
const primary = "System";
Layout & Spacing Tokens
Spacing Scale
Border Radius
Elevation & Shadow
Use with AI Coding Agents
Copy one of these prompts into your AI coding agent to apply the DESIGN.md for Codex design system to your project. The DESIGN.md file in your repo root is the source of truth.
# .cursor/rules (or DESIGN.md) You are working in a project that uses the DESIGN.md for Codex design system. Read the DESIGN.md file in this project root and follow it strictly when generating UI. Match the brand's exact colors, typography, spacing scale, and border radius. Do not create generic Tailwind UI — apply the visual language from DESIGN.md. Key rules: - Use the defined color palette, not arbitrary hex values - Apply the correct font family and weight scale - Follow spacing tokens (4/8/12/16/24/32px scale) - Match component patterns: buttons, cards, inputs, badges as specified
Frequently Asked Questions
Can I use the DESIGN.md for Codex DESIGN.md with Cursor, Claude Code, or Codex?
Yes. Copy the DESIGN.md file into your project root and reference it in your agent rules. For Cursor, add it to .cursor/rules. For Claude Code, include it as CLAUDE.md. For Codex, add it to your system prompt. The agent will read it and apply the DESIGN.md for Codex visual system to any UI it generates.
Is this an official DESIGN.md for Codex file?
No — this is an independent reference created for AI coding agent compatibility. It is not officially endorsed by DESIGN.md for Codex. The visual system was analyzed and documented to help AI agents produce UI that matches the DESIGN.md for Codex aesthetic. Always verify against official DESIGN.md for Codex documentation.
What is a DESIGN.md file?
A DESIGN.md file is a Markdown document that describes a product's visual design system in a format that AI coding agents can read and follow. It captures color palettes, typography, spacing, component patterns, and usage rules — giving AI agents like Cursor, Claude Code, and Codex a source of truth for consistent UI generation.
Can I use the DESIGN.md for Codex color tokens and visual style in my own project?
The design tokens and visual patterns documented here are for reference and AI agent guidance. If you are building a project inspired by the DESIGN.md for Codex visual style, ensure your use is consistent with DESIGN.md for Codex's brand guidelines and any applicable trademark or copyright rules. This file helps AI agents understand a style — it does not grant license to use proprietary brand assets.
How do I add this to my project?
Download the DESIGN.md file (requires free account) and place it in your project root. Then tell your AI agent to read it: "Read the DESIGN.md file in this project and follow its design system when generating UI." The agent will pick it up automatically in most modern AI coding tools.