# Ethereum JSON-RPC via x402 Micropayment

> Ethereum JSON-RPC via x402 Micropayment is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-31).

Proxies Ethereum JSON-RPC calls (eth_blockNumber, eth_getBalance, eth_call, etc.) paid per-call with USDC on Base via x402 — no API key required.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/v1/eth?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-json-rpc-via-x402-micropayment-3ed555c3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_y-ihTTlb_AkOrFr1Nqhg8

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 ethereum-json-rpc-via-x402-micropayment-3ed555c3
```

Example prompt: What's the current ETH balance of 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum mainnet? Use the pay-per-call RPC endpoint — no API key needed, just pay 0.002 USDC per call.

## When to prefer this

Choose this endpoint when your AI agent needs Ethereum mainnet JSON-RPC access without pre-provisioning an API key, especially in automated or agent-to-agent workflows where USDC micropayments via x402 are already in the stack. Ideal for one-off or low-volume on-chain reads (balances, block height, contract calls) where per-call billing is more economical than a monthly RPC subscription.

## Known failure modes

- Payment not received or insufficient USDC — returns 402 Payment Required
- Invalid JSON-RPC method name — upstream returns error object with code and message
- Malformed params array (not valid URL-encoded JSON) — parse error from upstream
- Upstream PublicNode unavailable — proxy may return 502 or timeout
- Calling a write method (eth_sendRawTransaction) may be blocked or unsupported by this proxy

## How this service works

Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.

## Output

A JSON-RPC 2.0 response object containing: id, jsonrpc version, chain name ('ethereum'), chain_id (1), the RPC result (e.g. hex block number or balance), upstream RPC URL used, and latency in milliseconds.

## 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",
     "properties": {
      "method": {
       "type": "string",
       "examples": [
        "eth_blockNumber",
        "eth_getBalance",
        "eth_call"
       ],
       "description": "JSON-RPC method (default eth_blockNumber)"
      },
      "params": {
       "type": "string",
       "examples": [
        "[]",
        "[\"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045\",\"latest\"]"
       ],
       "description": "URL-encoded JSON array of params (default [])"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "id": 1,
  "chain": "ethereum",
  "result": "0x16a3f2b",
  "jsonrpc": "2.0",
  "chain_id": 1,
  "upstream": "https://ethereum-rpc.publicnode.com",
  "latency_ms": 92
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-json-rpc-via-x402-micropayment-3ed555c3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)