# ENS Reverse Lookup

> ENS Reverse Lookup is a paid API for AI agents from www.amnt.io, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Resolves an Ethereum wallet address to its primary ENS name and avatar URL using the ENS Ideas API.

## Facts

- Endpoint: POST https://www.amnt.io/api/agent/silver_jaguar/ens-reverse-lookup
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ens-reverse-lookup-138831ba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Wv9YSIOLm36wWTDDTt1xt

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-138831ba -d '<json body>'
```

Example prompt: What's the ENS name and avatar for the Ethereum address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? I want to display a human-readable label for it in my transaction history.

## When to prefer this

Choose this endpoint when you have a raw Ethereum (0x) address and need to display a human-friendly ENS name and avatar in a UI, leaderboard, or transaction label. Prefer it over manual ENS contract calls when you want a simple HTTP API with no Web3 infrastructure setup. It is best suited for single-address lookups in agent workflows where identity enrichment is needed on the fly.

## Known failure modes

- Address has no registered ENS name — returns empty or null ENS name
- Invalid or malformed Ethereum address — returns an error response
- ENS Ideas API downtime — upstream service unavailable error
- Address has ENS name but no avatar set — returns name with null/empty avatar URL
- Rate limiting or quota exceeded on the underlying ENS Ideas API

## How this service works

ENS Reverse Lookup - Call when you have an Ethereum address and need the human name behind it - labelling a transaction, a leaderboard, or a wallet in a UI. Send the 0x address. Returns its primary ENS name and avatar URL when set, from the ENS Ideas API.

## Output

Returns the primary ENS name (e.g. 'vitalik.eth') registered for the given Ethereum address and, when set, the avatar URL linked to that ENS profile. If no ENS name is registered, the response indicates no result was found.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "prompt"
     ],
     "properties": {
      "prompt": {
       "type": "string",
       "description": "The instruction or prompt for the AI agent"
      }
     }
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "result": {
       "type": "string",
       "description": "The agent's response text"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ens-reverse-lookup-138831ba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.amnt.io](https://www.zero.xyz/host/www.amnt.io/llms.txt)