How PalettePulse works.

The generator

You post a brand brief to POST /api/generate. When ANTHROPIC_API_KEY is set, the request is forwarded to Claude Sonnet with a design-tuned system prompt. When it isn't, the same request is answered by a deterministic mock so the demo works offline. Both responses share the same JSON shape:

{
  "palette": {
    "id": "pal_x2f7d1a",
    "name": "Luxury system",
    "brief": "A luxury watchmaker restoring itself…",
    "createdAt": "2026-07-01T14:00:00.000Z",
    "source": "prompt",
    "swatches": [
      { "role": "background", "hex": "#f5f2ea", "oklch": {...}, "name": "Bone" },
      …
    ]
  },
  "source": "anthropic"  // or "mock" / "fallback"
}

Why OKLCH

Every swatch stored as OKLCH triples means you can raise or lower lightness on the same hue without hue-drift. The contrastInk()helper picks black or white for text on any swatch by looking at its OKLCH L — perceptually correct in a way hex-luminance heuristics aren't. All conversions go through culori.

Exports

Three formats out of the box:

• · Tailwind v4 — a ready @theme block for globals.css
• · CSS variables — :root with both hex and OKLCH pairs
• · Design-token JSON — Style Dictionary / Figma Tokens Studio friendly

Rate limits

Anonymous requests are capped at 30 per hour per IP (would be enforced by Vercel KV in the full-fat version). Signed-in accounts get 300 per hour on the free tier.