# EIP-2612 Permit Nonce Lookup

> EIP-2612 Permit Nonce Lookup is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-01).

Returns the current EIP-2612 permit nonce for a given ERC-20 token owner address on a specified EVM chain

## Facts

- Endpoint: POST https://twin.unykorn.org/erc20-nonce?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eip-2612-permit-nonce-lookup-25c940bf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tje-PcpyYnshHmNAxt_yV

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 eip-2612-permit-nonce-lookup-25c940bf -d '<json body>'
```

Example prompt: What is the current EIP-2612 permit nonce for owner address 0xAbC...123 on the USDC contract 0xDef...456 on Base? I need it to construct a valid permit signature.

## When to prefer this

Use this endpoint when you need to programmatically retrieve the current EIP-2612 permit nonce for a specific owner and ERC-20 contract before constructing an off-chain gasless approval signature. It supports 10 major EVM chains in one unified API, making it ideal for DeFi agents and bots that need to build valid permit signatures across Ethereum, Base, Polygon, Arbitrum, Optimism, BSC, Avalanche, Gnosis, Linea, or Scroll without running their own nodes.

## Known failure modes

- Invalid Ethereum address format for owner or contract returns a validation error
- Unsupported chain name outside the allowed enum returns an error
- Contract address does not implement EIP-2612 may return an error or unexpected result
- Network congestion or node unavailability may cause timeouts
- Payment failure (insufficient USDC balance) blocks the call under x402 protocol

## How this service works

EIP-2612 permit nonce for an owner — Genesis402 / UnyKorn Operator Network

## Output

Returns a JSON object with ok status, a type field of 'erc20-nonce', the current permit nonce value for the specified owner and contract, a transaction receipt including tx_hash, amount paid in USD, a receipt ID, and the ISO 8601 timestamp when the data was generated.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "chain": {
     "enum": [
      "ethereum",
      "base",
      "polygon",
      "arbitrum",
      "optimism",
      "bsc",
      "avalanche",
      "gnosis",
      "linea",
      "scroll"
     ],
     "type": "string"
    },
    "owner": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]{40}$"
    },
    "contract": {
     "type": "string",
     "pattern": "^0x[0-9a-fA-F]{40}$"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "erc20-nonce",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.002,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eip-2612-permit-nonce-lookup-25c940bf/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)