# ENS Reverse Resolution – api.web3identity.com

> ENS Reverse Resolution – api.web3identity.com is a paid API for AI agents from api.web3identity.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

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

## Facts

- Endpoint: POST https://api.web3identity.com/api/reverse/0x00000000219ab540356cBB839Cbe05303d7705Fa
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-web3identity-com-276b95b7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Pzshxdy3kpA1OIlYimZMg

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 api-web3identity-com-276b95b7 -d '<json body>'
```

Example prompt: What is the ENS name for the Ethereum address 0x00000000219ab540356cBB839Cbe05303d7705Fa?

## When to prefer this

Use this endpoint when you have a raw Ethereum wallet address and need to display or identify it by its human-readable ENS name. Prefer this over on-chain direct calls when you need a fast, paid API lookup without running your own Ethereum node. Ideal for enriching address data in user interfaces, transaction history displays, or identity resolution pipelines.

## Known failure modes

- Address has no reverse ENS record set — returns null or empty string
- Invalid Ethereum address format — returns 400 or error response
- Address checksum mismatch — may return error or no result
- ENS resolver unavailable — service timeout or 503
- Payment failure — x402 payment not accepted, returns 402

## How this service works

Reverse resolve address to ENS name

## Output

Returns the ENS .eth human-readable name (e.g. 'vitalik.eth') that is set as the reverse record for the given Ethereum address, or null/empty if no reverse record is configured.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "name"
 ],
 "properties": {
  "name": {
   "type": "string",
   "example": "vitalik.eth",
   "description": "ENS name"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-web3identity-com-276b95b7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.web3identity.com](https://www.zero.xyz/host/api.web3identity.com/llms.txt)