DESIGN.md — Design System Source of Truth

DESIGN.md is an open format (repo: google-labs-code/design.md, package @google/design.md) for describing a visual identity to coding agents. It combines machine-readable design tokens (YAML front matter) with human-readable rationale (Markdown prose). Tokens are normative; prose provides application context.

When this skill loads, the design system stops being something the agent guesses at and becomes something the agent reads. Every sibling design skill in the frontend plugin should defer to DESIGN.md when it exists.

MANDATORY PREPARATION

The spec is alpha and under active development. Before any non-trivial authoring work, fetch the authoritative spec and linting rules:

npx @google/design.md@latest spec --rules

Treat that output as canonical. Do not paraphrase the schema from memory for high-stakes changes — re-verify.

Detection & Mode

Before acting, decide which of three modes you are in.