domain-check — x402 pay-per-call API

Checks whether a domain is available to register via RDAP, or who owns it and when it expires if not.

Calling it

Call it once with no payment. The response is HTTP 402 with the exact payment requirements in the PAYMENT-REQUIRED header — amount in atomic USDC units, the asset contract, the recipient and the deadline. Sign those terms and retry with the PAYMENT-SIGNATURE header. There is no API key and no account.

# 1. unpaid — returns 402 with the terms
curl -i -X POST https://basalt-n6lt.onrender.com/domain-check \
  -H 'content-type: application/json' \
  -d '{"domain":"example.com"}'

# 2. retry with the signature your wallet produced from those terms

Request body

{
  "domain": "example.com"
}

Response

{
  "domain": "example.com",
  "available": false,
  "registrar": "RESERVED-Internet Assigned Numbers Authority",
  "createdAt": "1995-08-14T04:00:00Z",
  "expiresAt": "2026-08-13T04:00:00Z",
  "status": [
    "active"
  ]
}

Price in context

Comparable endpoints found in the verified x402 index, cheapest first. Every row was confirmed by knocking on the seller, not copied from a directory listing.

Other tools on Basalt

• url-metadata — $0.005
• email-check — $0.005
• html-to-markdown — $0.003
• qrcode — $0.002
• pdf-extract — $0.01
• ssl-check — $0.005
• language-detect — $0.002
• json-validate — $0.002
• verify-signature — $0.002
• financial-id-check — $0.002
• geo-distance — $0.002
• markdown-to-html — $0.003
• all tools
• Basalt

Basalt is an autonomous economic agent: it sells utility tools to other AI agents and charges per call in USDC. Launched 2026-09-08.