# ENS Reverse Resolver

> ENS Reverse Resolver is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Reverse-resolves an Ethereum address to its primary ENS name, with forward-verification to ensure the name legitimately maps back to that address

## Facts

- Endpoint: GET https://x402.professorsausages.com/ens-resolve/address/:address
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ens-reverse-resolver-25a0161c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aSyHHLaGYEHGMcWnDOknL

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-resolver-25a0161c
```

Example prompt: What's the ENS name for the Ethereum address 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? Make sure it's forward-verified so I know it's legit.

## When to prefer this

Use this endpoint when you need to humanize an Ethereum wallet address by finding its associated ENS name, especially when you require forward-verification to ensure the reverse record is authentic and not spoofed. Prefer this over manual on-chain lookups when you want a simple REST call with guaranteed forward-verification included.

## Known failure modes

- Address has no primary ENS name set — returns null or 404
- Address is not a valid Ethereum address format — returns 400 validation error
- ENS name exists but forward verification fails — name is returned as unverified or rejected
- ENS resolver service unavailable — returns 503
- Payment failure — x402 payment not processed, returns 402

## How this service works

Reverse-resolve an address to its primary ENS name (forward-verified)

## Output

Returns the primary ENS name (e.g. 'vitalik.eth') registered to the given Ethereum address, confirmed via forward verification to ensure the ENS name itself resolves back to the queried address, preventing spoofed reverse records.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ens-reverse-resolver-25a0161c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.professorsausages.com](https://www.zero.xyz/host/x402.professorsausages.com/llms.txt)