Quickstart

This guide takes you from a fresh install to a running conformance check in three steps.

1. Extract your identity

Navigate to your project root and run:

dna start

DNA scans your codebase and extracts what it already believes about design:

Palette — CSS custom properties and Tailwind color tokens, with tier inference (primitive vs. semantic) from the alias graph
Type scale — font sizes in use, annotated for review
Spacing grid — the grid unit (default 4px) and optionally a declared spacing scale
Component directories — auto-detected for inventory and similar

Everything is written to .dna/identity.yaml with per-rule provenance — every value carries { from, at } so you know which side held authority and when.

DNA also writes a starter ds-lint.config.json (if none exists) so dna check has something to check immediately.

Nothing to extract → nothing written. DNA never fabricates an identity. If it can't find design values, it says so and exits cleanly.

2. Run your first check

dna check

On a fresh extraction, this should be clean — DNA checked against the code it just extracted from. Now make a change that violates the identity (use a raw hex color instead of a CSS variable) and run it again:

✗ color-family-allowlist · src/components/Button.module.css:14
  rgba(182, 141, 66, 0.1) — not in the palette
  → use var(--brand)

✗ off-grid-spacing · src/components/Sidebar.module.css:31
  gap: 2px — not divisible by the 4px grid
  → nearest on-grid: 4px

2 errors · 0 warnings

Three possible outcomes per run — never just pass/fail:

Outcome	Meaning
pass	Checked N files, all conformant — shown with counts
nothing-to-check	No identity, no config, or no in-scope files — never shown as green
fail	Violations found — listed with file, line, value, and a fix hint

3. Install the pre-commit hook

dna hook install

This installs a git pre-commit hook that runs dna check before every commit. Violations block the commit.

4. Wire your AI IDE (optional)

# Claude Code
claude mcp add dna -- dna mcp

# Or manually — add to your IDE's MCP config:
# { "command": "dna", "args": ["mcp"] }

Once connected, your AI assistant gains five tools: dna_check, dna_resolve, dna_inventory, dna_similar, and dna_start_preview. It will call them on its own initiative when working on design-relevant files — checking the inventory before building, resolving raw values to tokens before writing them, and checking after every edit. No manual prompting needed.

See MCP Overview for the full setup guide.

Next steps

Understand how the identity file works in Design Identity
See all available rules in the Rules Reference
Explore all CLI commands in the CLI Overview