# ENS Reverse Lookup – Get Primary ENS Name for Ethereum Address

> ENS Reverse Lookup – Get Primary ENS Name for Ethereum Address is a paid API for AI agents from api.api-agent-ia.ch, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-26).

Returns the primary ENS (Ethereum Name Service) name associated with a given Ethereum address via reverse resolution

## Facts

- Endpoint: GET https://api.api-agent-ia.ch/nom-ens?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-26
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ens-reverse-lookup-get-primary-ens-name-for-ethereum-address-ccd47a55
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_TM-as5XO_f2ZbdZ6Ps_-P

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 ens-reverse-lookup-get-primary-ens-name-for-ethereum-address-ccd47a55
```

Example prompt: What is the primary ENS name registered to the Ethereum address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045?

## When to prefer this

Use this endpoint when you need to reverse-resolve an Ethereum address to its human-readable ENS name (reverse lookup). Choose this over a forward ENS resolver when your input is a 0x address and you want to find the name, not the other way around. Ideal for enriching wallet data, displaying friendly identities in UIs, or verifying ENS ownership before a transaction.

## Known failure modes

- Address has no primary ENS name set — returns empty or null name field
- Invalid Ethereum address format supplied — likely returns a 400 or error response
- ENS resolution temporarily unavailable due to upstream node issues
- Rate limiting or payment failure if x402 payment is not processed correctly

## How this service works

Does this wallet have a readable name? Returns the primary ENS name of an address on Ethereum mainnet, or null if it has none ($0.002 per call).

## Output

A JSON object containing the primary ENS name (e.g. 'vitalik.eth'), the network ('ethereum'), and the resolved Ethereum address (0x…). Returns null or an error if no ENS name is registered for the address.

## 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",
     "required": [
      "adresse"
     ],
     "properties": {
      "adresse": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "name": "vitalik.eth",
  "reseau": "ethereum",
  "adresse": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ens-reverse-lookup-get-primary-ens-name-for-ethereum-address-ccd47a55/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.api-agent-ia.ch](https://www.zero.xyz/host/api.api-agent-ia.ch/llms.txt)