Domain Availability Checker

domain-availability-checker.underscoredone.com · 1 paid endpoint · listed 2026-10-27

Give this API up to 10 domain names and it tells you whether each has a registration record at the official registry. It uses RDAP, the structured replacement for WHOIS, so there is no free-text parsing. Each domain comes back as 'registered', 'unregistered', or 'indeterminate' when the registry has no RDAP for that ending. 'Unregistered' means no record was found, which usually means available - but reserved and premium names also return no record. Registration status only; no pricing.

Paid endpoints

Latest checks

Income on Base (7 days)

This provider's payout address is shared by several providers, so its income is not shown as its own.

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<a href="https://logicnodes.io/observatory/p/domain-availability-checker.underscoredone.com"><img src="https://logicnodes.io/observatory/badge/domain-availability-checker.underscoredone.com.svg" alt="x402 status"></a>

Claim it for free with x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.

Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/domain-availability-checker.underscoredone.com