DESIGN.md is a specification created by Google Labs for their Stitch app that lets designers export and import design rules across projects. Google has now open-sourced the draft spec so it can be used across any tool or platform.
What it does
The format gives AI agents precise understanding of design intent. Instead of guessing what a color is for, an agent can read the DESIGN.md file and know exactly the purpose of each design token, then validate choices against WCAG accessibility standards.
Think of it as a shared visual language between designers and AI. You define your brand guidelines, colors, typography, spacing, and component rules in a structured Markdown file. AI tools that support the spec can then generate UIs that actually match your brand.
Why it matters
The key move is open-sourcing the spec. A design token format locked inside one app is limited. A universal spec that any tool can read and write becomes infrastructure. Designers avoid reinventing their design system every time they start a new project or switch tools.
This is similar to how CLAUDE.md and .cursorrules became de facto standards for giving AI coding agents project context. DESIGN.md does the same thing for design agents. If adopted widely, it could become the bridge between Figma files and AI-generated interfaces.
Where to find it
The spec is available on GitHub. Designers can also generate their own DESIGN.md files directly from within the Stitch app.