# x402 Multi-Chain EVM JSON-RPC Proxy

> x402 Multi-Chain EVM JSON-RPC Proxy is a paid API for AI agents from agentx402pay.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Provides safelisted read-only JSON-RPC access to major EVM blockchains (Base, Ethereum, Polygon, Arbitrum, Optimism) via standard methods like eth_call, eth_getBalance, and eth_getBlockByNumber

## Facts

- Endpoint: GET https://agentx402pay.com/api/rpc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-multi-chain-evm-json-rpc-proxy-aa01af29
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_E1EcCGNIuC-olPfeHfNft

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-multi-chain-evm-json-rpc-proxy-aa01af29
```

Example prompt: What's the current ETH balance of wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum mainnet?

## When to prefer this

Choose this endpoint when you need lightweight, pay-per-call read-only EVM RPC access across multiple chains without managing your own node or API keys. Ideal for agents that need occasional on-chain lookups (balances, receipts, block data, contract reads) across Base, Ethereum, Polygon, Arbitrum, or Optimism without committing to a full RPC provider subscription. Prefer this over dedicated RPC providers when building agentic workflows that already use x402 micropayment infrastructure.

## Known failure modes

- Unsupported or write RPC method requested — only safelisted read-only methods are allowed
- Invalid or malformed params JSON array causing parse error
- Unsupported chain name returns an error or defaults to Base
- Network timeout or upstream RPC node unavailability
- Payment not received or invalid x402 payment header causes 402 rejection

## How this service works

Safelisted read-only JSON-RPC proxy across major EVM chains (base, ethereum, polygon, arbitrum, optimism) — eth_call, eth_getBalance, eth_getTransactionReceipt, eth_getBlockByNumber, and more

## Output

Returns a standard JSON-RPC response object containing the result field with on-chain data such as a balance in hex wei, a transaction receipt object, block details, or a smart contract call return value. Errors are surfaced as JSON-RPC error objects with a code and message.

## 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": [
      "method"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "Chain to query: base, ethereum, polygon, arbitrum, optimism (default base)"
      },
      "method": {
       "type": "string",
       "description": "Read-only JSON-RPC method name, e.g. eth_getBalance, eth_call, eth_blockNumber"
      },
      "params": {
       "type": "string",
       "description": "JSON-encoded array of RPC params, e.g. [\"0xabc...\",\"latest\"] (default [])"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-multi-chain-evm-json-rpc-proxy-aa01af29/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentx402pay.com](https://www.zero.xyz/host/agentx402pay.com/llms.txt)