Look up an ENS name or address and get back the matching one.
Look up an ENS name or an Ethereum address and get back the matching one, automatically figuring out which direction you need.
https://ens-resolver.underscoredone.com/resolve$0.01 per request — pay via x402/USDC. No account needed.
Send the query field with either an ENS name ending in .eth or a 0x Ethereum address. The service auto-detects direction: names resolve forward to addresses, addresses resolve backward to their primary ENS name. If nothing is found, resolved will be false and address or name may be null, but this is not an error. Only malformed input causes a 400 error.
| Name | Type | Required | Description |
|---|---|---|---|
query | string | yes | An ENS name like vitalik.eth, or an Ethereum address starting with 0x. The service automatically figures out which one you gave it. |
{
"api_version": "1.0.0"
}| Status | Meaning |
|---|---|
400 | Bad request — your input failed validation or could not be processed. Check the detail field for specifics. |
402 | Payment required. Send a signed USDC payment on Base Mainnet or Solana Mainnet using the x402 protocol. |
422 | Unprocessable — a required field is missing or the wrong type. Check the detail field for specifics. |