# On-Chain Nonce Lookup

> On-Chain Nonce Lookup is a paid API for AI agents from store.agentexchange.work, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the current transaction nonce for a given EVM wallet address on a specified blockchain network

## Facts

- Endpoint: GET https://store.agentexchange.work/chain/nonce
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/on-chain-nonce-lookup-755ac59e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dM_iKkA8bIE3HSmBXlUim

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 on-chain-nonce-lookup-755ac59e
```

Example prompt: What's the current nonce for the wallet 0xAbCd1234...5678 on Base — I need it before I sign my next transaction.

## When to prefer this

Use this endpoint when an AI agent needs the current on-chain nonce for an EVM address before constructing or signing a transaction, especially without wanting to manage API keys or subscriptions. Pay-per-call USDC via x402 makes it ideal for autonomous agents with embedded wallets. Covers 6 major EVM networks including Base, Ethereum, Optimism, Arbitrum, Polygon, and Gnosis.

## Known failure modes

- Invalid or malformed address (non-0x format) returns an error
- Unsupported chain name returns an error — only base, ethereum, optimism, arbitrum, polygon, gnosis are valid
- Payment failure via x402 prevents the call from completing
- Network or RPC unavailability for the target chain causes a timeout or error
- Address with no transactions may return nonce of 0, which could be misinterpreted

## How this service works

An address's transaction count (nonce) via eth_getTransactionCount — the next nonce to use and total outgoing transactions, across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. The read settlement and trading agents make to build and sequence transactions. Live public RPC; one paid call at $0.001.

## Output

Returns a JSON object with the blockchain name, the queried wallet address, and the current integer nonce (transaction count) for that address on the specified chain.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "base|ethereum|optimism|arbitrum|polygon|gnosis (default base)"
      },
      "address": {
       "type": "string",
       "description": "Account address (0x...)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "nonce": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/on-chain-nonce-lookup-755ac59e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from store.agentexchange.work](https://www.zero.xyz/host/store.agentexchange.work/llms.txt)