# ENS Forward/Reverse Resolution by Synthora

> ENS Forward/Reverse Resolution by Synthora is a paid API for AI agents from rpc-ens.hergertsynthora.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Resolves ENS names to Ethereum addresses (forward) and Ethereum addresses to ENS names (reverse lookup)

## Facts

- Endpoint: POST https://rpc-ens.hergertsynthora.com/service
- 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-forward-reverse-resolution-by-synthora-136cc8d8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kK-Ke5IQBdnFrB2cFSVfD

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-forward-reverse-resolution-by-synthora-136cc8d8 -d '<json body>'
```

Example prompt: What Ethereum address does vitalik.eth resolve to? Also, can you reverse-resolve 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 to see if it has an ENS name?

## When to prefer this

Use this endpoint when you need to resolve ENS names to addresses or reverse-resolve addresses to ENS names within an AI agent or automated workflow. Particularly useful when you want a signed, verifiable result and need pay-per-use pricing with no subscription commitment. The first 3 calls per wallet are free, making it low-risk to try. Prefer this over raw RPC calls when you need a simple HTTP POST interface without managing an Ethereum node.

## Known failure modes

- ENS name does not exist or has no resolver set — returns an error indicating unresolvable name
- Address has no reverse ENS record — returns null or empty name
- Upstream ENS node is unreachable — returns failure with no charge applied
- Invalid input format (malformed ENS name or non-checksummed address) — validation error
- Rate limit exceeded beyond the 3 free calls without a wallet header — payment or header required

## How this service works

ENS forward/reverse resolution: name->address and address->name. Deterministic, Ed25519-signed.

## Output

Returns the resolved Ethereum address for a given ENS name (forward lookup) or the ENS name for a given Ethereum address (reverse lookup), cryptographically signed with Ed25519 for authenticity. On upstream failure, no charge is applied.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "rpc-ens",
  "result": {
   "op": "ens"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ens-forward-reverse-resolution-by-synthora-136cc8d8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rpc-ens.hergertsynthora.com](https://www.zero.xyz/host/rpc-ens.hergertsynthora.com/llms.txt)