Google's open-source DESIGN.md gives AI agents a prompt-ready blueprint for brand-consistent design

Google has released the DESIGN.md format from its AI design tool Stitch as open source. The format stores design rules in a machine-readable file that works across projects and platforms. Each DESIGN.md file pairs design tokens—exact values like colors or font sizes in YAML—with plain-text notes explaining why those values exist.

AI agents can use the format, for example, to generate interface designs that fit a brand's look and check their work against WCAG accessibility rules. Google is also shipping a CLI tool with commands for validating, comparing, and exporting design files to formats like Tailwind or W3C DTCG.

The project is available under an Apache 2.0 license on GitHub and is still in alpha. You can also generate custom files for free right in Stitch, the AI design tool Google launched in mid-March, with the full spec documented on the Stitch site. Anthropic recently made a similar move into design, rolling out Claude Design, an AI agent for front-end design, slides, and more.