Give Cursor a design system

Cursor's Agent is excellent at code and blind to your brand. Connect the Identity Forge MCP server and it can choose a kit, apply the tokens and DESIGN.md, and build against them instead of inventing a new look each time.

Updated July 13, 2026

Why Cursor needs a design system

Cursor's Agent and Composer generate whole features fast, but each generation can make fresh styling decisions. Without a fixed system, spacing, colors, and component shapes drift across files. A design system gives the Agent one set of semantic tokens and a written DESIGN.md, so later components follow the same rules as the first.

Cursor supports MCP natively. The Agent can use tools to search, fetch, and apply a kit while it works, in addition to reading the files the kit installs.

The kit you'll install

Below is the free ambient-sage kit, rendered from the exact tokens the Agent writes into your project:

Ambient Sage

After Work Chill

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Plus Jakarta Sans · 28 semantic tokens · light + dark

A live preview of Ambient Sage's real system: fonts, semantic colors, surfaces, and treatments.

Install it (MCP)

  1. 1

    Write the MCP config

    Run this in your project root to merge the server into .cursor/mcp.json.

    npx --yes --package=https://identityforge.io/downloads/identityforge-0.3.0.tgz identityforge install --client cursor
  2. 2

    Enable the server in Cursor

    Open Settings → MCP (or the MCP panel) and toggle the identityforge server on. Restart Cursor if the tools don't appear.

  3. 3

    Sign in (optional for free kits)

    npx --yes --package=https://identityforge.io/downloads/identityforge-0.3.0.tgz identityforge login
  4. 4

    Prompt the Agent to theme your app

    Give product, audience, and mood; it shortlists with search_themes, reads the brief with get_design_md, applies with apply_theme.

    Use Identity Forge to pick a minimal, warm theme for a
    wellness app, apply it, and follow the DESIGN.md.

The `.cursor/mcp.json` entry

The install command writes this stdio server. You can also paste it by hand:

{
  "mcpServers": {
    "identityforge": {
      "command": "npx",
      "args": ["-y", "identityforge@latest", "mcp"]
    }
  }
}
.cursor/mcp.json: the identityforge MCP server entry

Reinforce it with a Cursor rule (optional)

To make the Agent consistent even outside a kit-apply turn, add a short project rule (.cursor/rules) telling it to style only against the semantic tokens and to follow DESIGN.md. This pairs well with the kit: the tokens define the values, the rule enforces that generated code always uses them.

Always style against the semantic design tokens defined in the
project (bg-background, text-foreground, bg-primary, bg-muted,
border-border, …) and follow the rules and motifs in DESIGN.md.
Never hardcode raw hex colors or introduce a new font.
.cursor/rules: keep generated UI on the design system

Prefer no MCP? Direct paths

  1. 1

    CLI apply

    Writes DESIGN.md + a tokens file into the current directory; ask Cursor to wire them in.

    identityforge apply ambient-sage
  2. 2

    shadcn registry

    Installs the kit's CSS variables directly if you use shadcn/ui.

    npx shadcn add https://identityforge.io/r/ambient-sage.json

See the same setup for Claude Code and Windsurf, or start from the pillar guide.

FAQ

How do I give Cursor a design system?

Run `… identityforge install --client cursor` to add the Identity Forge MCP server to .cursor/mcp.json, enable it under Settings → MCP, then ask Cursor's Agent to pick and apply a kit. It writes a DESIGN.md and semantic tokens into the project.

Where does the config go?

Into `.cursor/mcp.json` at your project root. After installing, enable the identityforge server in Cursor's MCP settings.

Should I use a Cursor rule too?

It helps. A short .cursor/rules note telling the Agent to style only against the semantic tokens and follow DESIGN.md keeps generated code on-system even when you're not explicitly applying a kit.

Can I do this without MCP?

Yes. `identityforge apply <slug>` writes DESIGN.md and tokens into the current directory, or `npx shadcn add https://identityforge.io/r/<slug>.json` installs the kit's CSS variables for shadcn/ui projects.