https://api.x402node.dev/identity/username-check
Check if a username is taken across 10 developer platforms (GitHub, GitLab, Reddit, HackerNews, dev.to, Medium, npm, PyPI, StackOverflow, ProductHunt). Returns per-platform {taken, status, url}. Use ?username=alice or ?username=alice and platforms=github,reddit. Built for AI agents helping pick handles, brand audits.
Start with a quote-only recipe. Payment signing stays in your project.
const response = await fetch("https://api.x402node.dev/identity/username-check", {
method: "GET",
});
console.log(response.status);
console.log(Object.fromEntries(response.headers));
console.log((await response.text()).slice(0, 1000));
// A valid 402 is a quote, not a completed paid call.This sends no payment. Inspect the 402 response before adding a wallet-enabled client.
- Live 402 quote confirmed
GET returned a protocol-valid 402 quote (402). No payment was made.
- Origin reachable
HEAD https://api.x402node.dev/ returned 404.
- Observed in cdp-bazaar
The registry record was observed and retained with provenance.
- Observed in 402-index
Discovered through bazaar.
- Registry record checked
Registry health: healthy.
EVIDENCE
Each record has an exact-route quote outcome. Unresolved templates and potentially mutating methods are labeled instead of being invoked without provider-specific test input. A quote is still separate from a settled paid call.