# EVM Account Nonce Lookup

> EVM Account Nonce Lookup is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns the transaction count (nonce) for an Ethereum address across 7 EVM chains, distinguishing pending vs confirmed to reveal stuck mempool transactions and provide the correct next nonce for transaction construction.

## Facts

- Endpoint: GET https://api.x402node.dev/chain/account-nonce
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-account-nonce-lookup-f334d4cf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Q5tToUEgpgCPinOc-Crhm

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 evm-account-nonce-lookup-f334d4cf
```

Example prompt: What's the current confirmed and pending nonce for wallet address 0xAbC123... on Base — I want to make sure there are no stuck mempool transactions before I submit my next tx.

## When to prefer this

Use this endpoint when an agent needs to construct, sign, or broadcast EVM transactions and must know the correct nonce to avoid rejection or collision. Also ideal for detecting stuck pending transactions in the mempool across 7 EVM chains, where a single-chain RPC call would be insufficient or setting up your own multi-chain RPC infrastructure is impractical.

## Known failure modes

- Invalid or malformed Ethereum address returns a 4xx error
- Unsupported chain identifier returns an error indicating valid chain options
- RPC backend unavailability for a specific chain may return a 5xx error
- Address with no transaction history returns nonce of 0 (not an error)
- Payment not included or insufficient results in HTTP 402 response

## How this service works

Transaction count (nonce) for an address across 7 EVM chains, including pending vs confirmed to reveal stuck mempool transactions - agents need the correct nonce to build and send transactions and to detect pending txs. nonce, transaction count, account nonce, pending transactions, next nonce, tx count Accepts payment on Base or Solana — either network works.

## Output

Returns the confirmed transaction count (nonce), the pending transaction count including mempool transactions, and the difference indicating any stuck or unconfirmed transactions for the queried address on the specified EVM chain.

## Example request

```json
{
 "chain": "base",
 "address": "0x742d35Cc6634C0532925a3b844Bc9e7595f42bE1"
}
```

## 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": "ethereum, base (default), arbitrum, optimism, polygon, bsc, avalanche"
      },
      "address": {
       "type": "string",
       "description": "Address (required)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-account-nonce-lookup-f334d4cf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)