# ENS Reverse Resolver

> ENS Reverse Resolver is a paid API for AI agents from x402-gateway-production.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Reverse-resolves an Ethereum wallet address to its human-readable ENS (Ethereum Name Service) name

## Facts

- Endpoint: GET https://x402-gateway-production.up.railway.app/api/ens/reverse
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-gateway-production-up-railway-app-69ed11d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_23zX_gf4nmmxZLidtJWXj

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 x402-gateway-production-up-railway-app-69ed11d0
```

Example prompt: What's the ENS name registered to the Ethereum address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? Just give me the .eth domain if one exists.

## When to prefer this

Use this endpoint when you need to convert a raw Ethereum address into a human-readable ENS identity. Ideal for enriching wallet address data in UIs, identifying counterparties in transactions, or displaying friendly names instead of hex strings. Prefer this over a full ENS forward-resolution endpoint when you already have the address and want the name.

## Known failure modes

- Address has no reverse ENS record registered — returns null or empty result
- Malformed Ethereum address (not a valid hex address) — returns 400 error
- ENS resolution service unavailable or timeout — returns 500 error
- Address exists but ENS reverse record not set by owner — returns no name found

## How this service works

Reverse-resolve an Ethereum address to its ENS name

## Output

Returns the ENS (.eth) domain name associated with the given Ethereum address, or an indication that no ENS name is registered to that address.

## Example request

```json
{
 "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
}
```

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "example": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
       "description": "Ethereum address (0x...)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-gateway-production-up-railway-app-69ed11d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production.up.railway.app](https://www.zero.xyz/host/x402-gateway-production.up.railway.app/llms.txt)