# Ethereum Signer Recovery

> Ethereum Signer Recovery is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Recovers the Ethereum address that produced a given message signature, enabling signature verification and identity validation on EVM chains.

## Facts

- Endpoint: POST https://twin.unykorn.org/eth-recover-signer?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-signer-recovery-5fe82c40
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zpn_Hd8WnnSRD73OGkOxO

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 ethereum-signer-recovery-5fe82c40 -d '<json body>'
```

Example prompt: Can you recover the Ethereum address that signed this message 'Hello World' with signature 0x4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b01?

## When to prefer this

Choose this endpoint when you need a pay-per-call, no-infrastructure-required ecrecover operation accessible via HTTP from an AI agent. Ideal when you do not want to run your own Ethereum node or library, need a neutral third-party receipt for audit purposes, or are operating in an agent pipeline that already uses x402 micropayment rails. Prefer alternatives (local ethers.js / web3.py) for high-volume or latency-critical workloads where $0.003/call cost accumulates.

## Known failure modes

- Invalid or malformed signature (not a valid hex string starting with 0x) returns an error
- Message exceeding 49152 character limit is rejected
- Signature of incorrect length (not 65 bytes / 132 hex chars) fails ecrecover
- Payment failure via x402 protocol results in 402 response before processing
- Network timeout on the UnyKorn operator node

## How this service works

Recover which address signed a message — Genesis402 / UnyKorn Operator Network

## Output

Returns a JSON object with an ok flag, the endpoint type identifier 'eth-recover-signer', the recovered Ethereum signer address, and a payment receipt containing the transaction hash, USD amount charged, and a unique receipt ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "message": {
     "type": "string",
     "maxLength": 49152
    },
    "signature": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]*$"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "eth-recover-signer",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.003,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-signer-recovery-5fe82c40/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)