# ENS Reverse Lookup

> ENS Reverse Lookup is a paid API for AI agents from api.strale.io, paid per call via x402, $0.0216/call, status unknown (last checked 2026-09-13).

Resolves an Ethereum wallet address to its associated ENS (Ethereum Name Service) domain name

## Facts

- Endpoint: GET https://api.strale.io/x402/v2/ens-reverse-lookup
- Price: $0.0216/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-803ff9ca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_j5XGfe1_cAAISOUBOiHts

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-803ff9ca
```

Example prompt: What ENS name is registered to the Ethereum address 0x1234abcd...? Do a reverse lookup and tell me the human-readable domain associated with it.

## When to prefer this

Use this endpoint when you need to resolve a raw Ethereum wallet address to a human-readable ENS name, especially in agent workflows requiring identity enrichment, transaction labeling, or user verification in Web3 contexts. Prefer this over generic blockchain APIs when you need a cryptographic audit trail of the lookup result.

## Known failure modes

- Address has no reverse ENS record set — returns null or empty result
- Invalid address format (not a valid 0x Ethereum address) — returns validation error
- ENS resolver temporarily unavailable — returns service error
- Address is valid but reverse record points to a different forward resolution — returned name may not forward-resolve back to the same address

## How this service works

The trust layer for AI agents — 250+ independently tested data capabilities across 27 countries. Execute capabilities via REST, MCP, A2A, or x402 micropayments. Every call returns an audit record with cryptographic chain hashing.

## Output

Returns the ENS domain name (e.g. 'vitalik.eth') reverse-resolved from the given Ethereum wallet address, along with a cryptographically hashed audit record confirming the result's provenance and integrity.

## 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": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "Ethereum wallet address (0x...)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ens-reverse-lookup-803ff9ca/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)