httppayai

x402-catalog-history.ai-business-surface.workers.dev

Hex colour to RGB/HSL and WCAG contrast in one GET: pass a text colour and a background colour (3 or 6 hex digits) and get each as #rrggbb, RGB and HSL, the WCAG relative luminance, the contrast ratio and the four AA/AAA verdicts. curl: GET /color?hex=1a2b3c&against=ffffff (against defaults to ffffff). Response: {"foreground":{"hex":"#1a2b3c","rgb":{"r":26,"g":43,"b":60},"hsl":{"h":210,"s":39.5,"l":16.9}},"background":{"hex":"#ffffff"},"contrast_ratio":14.69,"wcag":{"aa_normal":true,"aa_large":true,"aaa_normal":true,"aaa_large":true}}. A missing or non-hex value, or an alpha hex (#rgba/#rrggbbaa), is refused with 400 before payment. Computed inside the Worker from the input; no upstream call, no account, no key. 0.001 USDC, one GET, one delivery. A purchase is two calls by design: this first call returns 402 with the price and the payment terms, and you then repeat the same request with the PAYMENT-SIGNATURE header to receive the 200 delivery.