# ETH Mainnet ENS Resolve

> ETH Mainnet ENS Resolve is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-29).

Resolves an ENS .eth name to its Ethereum address (forward lookup) or verifies an Ethereum address to its ENS name (reverse lookup)

## Facts

- Endpoint: POST https://api.arysphere.com/v1/ventures/x402_eth_reads_v1/eth_mainnet_ens_resolve?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eth-mainnet-ens-resolve-4cd21556
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_se_qGQe6FGJvNcozl2O6t

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability eth-mainnet-ens-resolve-4cd21556 -d '<json body>'
```

Example prompt: What Ethereum address does vitalik.eth resolve to? Also double-check it by doing the reverse lookup on that address to confirm its verified ENS name.

## When to prefer this

Use this endpoint when you need a fast, single paid call to resolve or reverse-resolve an ENS name on Ethereum mainnet without running your own Ethereum node. Prefer it over generic Ethereum RPC endpoints when you want a clean REST interface that abstracts away raw eth_call mechanics. It is ideal for agents that need to enrich wallet addresses with human-readable ENS identities or validate that a .eth name maps to an expected address.

## Known failure modes

- ENS name not registered or expired — returns null or empty result
- Address has no reverse ENS record set — returns null
- Invalid address format (not 0x + 40 hex) — schema validation error
- ENS name is not ASCII or not a .eth name — rejected by schema
- Network or RPC node outage on Ethereum mainnet — service unavailable
- Payment failure via x402/USDC — call not executed

## Output

Returns either the resolved Ethereum address (0x-prefixed, 40 hex characters) for a forward ENS lookup, or the verified reverse ENS name (ASCII .eth string) for a reverse lookup, depending on which parameter was provided.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "name": {
       "type": "string",
       "description": "an ASCII .eth name (forward), OR"
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "0x + 40 hex (reverse, verified)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eth-mainnet-ens-resolve-4cd21556/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)