zFiniazFINIA
Machine API / all services

Check WCAG contrast for a colour pair

Calculate WCAG 2.x sRGB contrast for one caller-supplied colour pair; no interface-wide accessibility claim is made.

0.001 USDC / call · Base · x402 v2 exact

Version 1.0.0. Demand unvalidated. Catalogue availability does not prove paid fulfilment.

Request

POST https://api.zfinia.com/x402/v1/accessibility-contrast-calculator

{
  "foreground": "#000000",
  "background": "#ffffff",
  "large_text": false
}
  1. Send the example as an application/json POST without payment to receive HTTP 402.
  2. Inspect Payment-Required and confirm the network, asset, recipient and amount using your own x402 client.
  3. Your client authorizes payment and retries the same POST. A successful paid response returns the result. A 402 is not a delivery.

GET is an unpaid payment challenge probe. Paid delivery uses POST.

Full input and output contractInspect unpaid challengeHow to verify before paying

Machine clients: website catalogue JSON · MCP challenge handoff. MCP does not hold a buyer wallet or make payments for you.