Palette Engine as an API

Embed perceptually uniform
colour science in your product

The same OKLCH-based palette engine that powers Resonance is available as a REST API. Pass brand adjectives, get back a complete, WCAG-compliant colour system in milliseconds.

View Docs

quick-start.sh

curl -X POST https://resonanceapp.one/api/v1/generate \
  -H "Authorization: Bearer rsnc_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "adjective1": "bold",
    "adjective2": "trustworthy",
    "industry": "technology",
    "mood": "balanced",
    "warmth": 40,
    "contrast": "moderate"
  }'

API Reference

Endpoints

POST/api/v1/generateGenerate a full WCAG-compliant brand palette from adjectives

GET/api/v1/usageReturn current quota usage for the authenticated key

GET/api/v1/validateCheck key status, quota, and capabilities — no credit consumed

Authentication

All requests must include your API key in the Authorization header as Bearer rsnc_.... Keys start with the prefix rsnc_ and are provisioned after your request is approved.

POST /api/v1/generate — Request Body

Field	Type	Required	Description
adjective1	string	required	Primary brand personality adjective (e.g. "bold", "calm", "playful")
adjective2	string	required	Secondary brand personality adjective (e.g. "trustworthy", "innovative")
industry	enum	optional	technology \| healthcare \| finance \| education \| food \| fashion \| fitness \| entertainment \| travel \| realestate \| legal \| nonprofit \| other
mood	enum	optional	energetic \| calm \| balanced \| bold \| playful — defaults to balanced
warmth	number	optional	0–100 warmth bias (0 = cool blue-green, 100 = warm orange-red). Defaults to 50.
contrast	enum	optional	subtle \| moderate \| high — controls WCAG target level. Defaults to moderate.

Response Schema

response.json

{
  "meta": {
    "version": "1",
    "generatedAt": "2026-03-01T00:00:00.000Z",
    "durationMs": 12,
    "inputs": { "adjective1": "bold", "adjective2": "trustworthy", ... },
    "quota": { "limit": 5000, "used": 1, "remaining": 4999 }
  },
  "palette": {
    "accent": "#00d4aa",
    "neutralHue": 192,
    "light": {
      "tokens": {
        "background": "#f8fafb",
        "foreground": "#0f1a1c",
        "primary": "#00a88a",
        "primaryForeground": "#ffffff",
        "muted": "#e8f0f1",
        "mutedForeground": "#4a6870"
      },
      "wcag": {
        "body_text":      { "ratio": 14.2, "rating": "AAA" },
        "primary_button": { "ratio": 4.8,  "rating": "AA"  }
      }
    },
    "dark": { ... },
    "accessibilityVariants": [...],
    "chromaticWarnings": [],
    "grayscaleScore": 87
  },
  "exports": {
    "css": ":root { --background: #f8fafb; --foreground: #0f1a1c; ... }",
    "tailwind": { "background": "#f8fafb", "foreground": "#0f1a1c", ... }
  }
}

GET /api/v1/usage

usage.sh

# Check your current quota
curl https://resonanceapp.one/api/v1/usage \
  -H "Authorization: Bearer rsnc_YOUR_API_KEY"

# Response
{
  "keyPrefix": "rsnc_abc1",
  "tier": "starter",
  "quota": { "limit": 5000, "used": 42, "remaining": 4958 },
  "active": true
}

GET /api/v1/validate

Health-check your key and inspect its capabilities without consuming a generation credit. Ideal for startup checks, CI pipelines, and dashboard status widgets.

validate.sh

# Validate your key without consuming a credit
curl https://resonanceapp.one/api/v1/validate \
  -H "Authorization: Bearer rsnc_YOUR_API_KEY"
# Response
{
  "valid": true,
  "keyPrefix": "rsnc_abc1",
  "tier": "starter",
  "active": true,
  "quota": {
    "limit": 5000,
    "used": 42,
    "remaining": 4958,
    "percentUsed": 1,
    "resetsAt": "2026-04-01T00:00:00.000Z"
  },
  "capabilities": {
    "generate": true,
    "cssExport": true,
    "tailwindExport": true,
    "webhooks": false,
    "whiteLabel": false,
    "unlimitedQuota": false
  },
  "createdAt": "2026-03-01T08:00:00.000Z"
}

JavaScript / TypeScript Example

palette-client.ts

// Node.js / TypeScript
const response = await fetch("https://resonanceapp.one/api/v1/generate", {
  method: "POST",
  headers: {
    "Authorization": "Bearer rsnc_YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    adjective1: "bold",
    adjective2: "trustworthy",
    industry: "technology",
    mood: "balanced",
  }),
});

const { palette } = await response.json();
const { background, foreground, primary } = palette.light.tokens;

Error Codes

Status	Error Code	Meaning
400	invalid_input	Request body failed validation — check the details field
401	unauthorized	Missing or invalid API key
429	quota_exceeded	Monthly quota exhausted — upgrade tier or wait for reset
500	generation_failed	Palette generation error — retry or contact support

Simple, transparent pricing

All plans include a 14-day free trial. No credit card required to request access.

Starter

For freelancers and indie developers embedding palette generation in their tools

$49/month

5,000 palette generations/month
OKLCH + WCAG scoring included
REST API with JSON responses
Email support
Rate limit: 60 req/min

Request API Access

We review every request and respond within one business day.

Embed perceptually uniformcolour science in your product