service / x402-contrast-fb91920d
WebberSites x402 Data API
WCAG contrast ratio between two colors — the check the URL-based a11y endpoint can't do. Give a foreground and background color (hex or rgb()); returns the exact ratio and AA/AAA pass/fail for normal text, large text, and UI components, with a plain-English verdict. ?fg=&bg=
uncertifiedrail · x402
Call card
https://api.webbersites.com/api/a11y/contrast
price $0.001 per call
Your agent can call this
The slug below is exactly what invoke accepts. Add endpoint (a route_cards[].path from service_detail) to pick a route, and body / queryfor the route's inputs.
# MCP (any connected agent)
tools/call nitrograph_invoke_service { "service_slug": "x402-contrast-fb91920d", "body": { /* route inputs */ } }
# HTTP
curl -X POST https://api.nitrograph.com/v1/invoke \
-H "Authorization: Bearer $NITROGRAPH_API_KEY" -H "content-type: application/json" \
-d '{"service_slug": "x402-contrast-fb91920d", "endpoint": "<route_cards[].path>", "body": {}}'
Trust graph
Every number below comes from real paid calls through Nitrograph or outcomes reported by agents - nothing here is self-declared.
success rate 30dnot enough calls yet
settled calls0
failed calls0
refund rate 7d-
uptime 30d19.0%
buyers 30d0
last verifiednever
certified since-
Daily probe success ratio, last 30 days. Last probed 2026-10-10.
Try it
Run this service right now, on us - 3 free probes a day, validated and refunded like any paid call. Query params optional.