# QuickNode JSON-RPC Proxy — Arbitrum Mainnet

> QuickNode JSON-RPC Proxy — Arbitrum Mainnet is a paid API for AI agents from x402.quicknode.com, paid per call via x402, $10/call, status unknown (last checked 2026-09-14).

Proxies JSON-RPC calls to the Arbitrum One mainnet blockchain, enabling smart contract interactions, balance lookups, transaction submission, and block data retrieval.

## Facts

- Endpoint: POST https://x402.quicknode.com/arbitrum-mainnet/
- Price: $10/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quicknode-32700e03
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4lnb4O0L9MIXWx2c746gr

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 quicknode-32700e03 -d '<json body>'
```

Example prompt: Call eth_getBalance on Arbitrum mainnet for address 0xAbC123...def456 using JSON-RPC 2.0 and tell me the current ETH balance.

## When to prefer this

Choose this endpoint when you need programmatic, pay-per-call access to the Arbitrum One mainnet via standard JSON-RPC without managing your own node infrastructure or API key subscriptions. Ideal for agents that need on-demand blockchain queries billed per call via x402 micropayments.

## Known failure modes

- Invalid JSON-RPC method name returns error code -32601 Method not found
- Malformed params array causes -32602 Invalid params error
- Payment of $10 USDC not provided results in 402 Payment Required response
- Network congestion or node unavailability returns 503 or timeout
- Invalid contract ABI encoding in eth_call params returns execution revert error
- Requesting a pruned historical block beyond node retention returns null or error

## How this service works

JSON-RPC proxy — arbitrum-mainnet

## Output

A standard JSON-RPC 2.0 response object containing the result field with the requested blockchain data (e.g. balance in wei, block object, transaction receipt, contract return data) or an error object with code and message if the call fails.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "jsonrpc",
  "method"
 ],
 "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"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "id": {
   "type": [
    "number",
    "string"
   ]
  },
  "error": {
   "type": "object",
   "properties": {
    "code": {
     "type": "integer"
    },
    "message": {
     "type": "string"
    }
   }
  },
  "result": {
   "description": "RPC result (type varies by method)"
  },
  "jsonrpc": {
   "type": "string",
   "const": "2.0"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quicknode-32700e03/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)