# QuickNode: JSON-RPC proxy — arb-mainnet

> QuickNode: JSON-RPC proxy — arb-mainnet is a paid API for AI agents from x402.quicknode.com, paid per call via x402, $10/call, status unknown (last checked 2026-09-15).

Provides low-latency JSON-RPC access to Arbitrum One mainnet for sending transactions, reading blockchain state, and calling smart contracts.

## Facts

- Endpoint: POST https://x402.quicknode.com/arb-mainnet
- Price: $10/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-quicknode-com-4f6ad2b7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eJapK0JHf93nLHUGQ9n-u

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 x402-quicknode-com-4f6ad2b7 -d '<json body>'
```

Example prompt: Can you check the current ETH balance for address 0xAbCd...1234 on Arbitrum One mainnet using eth_getBalance with the latest block tag?

## When to prefer this

Choose this endpoint when you need real-time, low-latency RPC access specifically to Arbitrum One mainnet — for sending transactions, reading live chain state, or interacting with Arbitrum-deployed smart contracts. Prefer this over generic Ethereum endpoints when your target contracts or assets are on Arbitrum L2 rather than Ethereum mainnet or other chains.

## Known failure modes

- Invalid JSON-RPC method name returns error code -32601 method not found
- Malformed params array returns error code -32602 invalid params
- Payment not provided or insufficient USDC results in 402 Payment Required
- Network congestion or node unavailability returns 503 or timeout
- Calling a non-existent contract address returns a revert or zero result
- Submitting a transaction with insufficient gas returns execution reverted error

## How this service works

Low-latency RPC access to the Arbitrum One mainnet for sending transactions, reading state, and interacting with smart contracts.

## Output

A JSON-RPC 2.0 response object containing the result of the requested method (e.g. block data, balance in hex wei, transaction hash, contract return data) or a structured error object with code and message if the call fails.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "id": {
   "type": [
    "number",
    "string"
   ],
   "description": "Request identifier"
  },
  "method": {
   "type": "string",
   "description": "JSON-RPC method name (e.g., eth_blockNumber, eth_call)"
  },
  "params": {
   "type": "array",
   "description": "Method parameters"
  },
  "jsonrpc": {
   "type": "string",
   "const": "2.0"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-quicknode-com-4f6ad2b7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.quicknode.com](https://www.zero.xyz/host/x402.quicknode.com/llms.txt)