# QuickNode JSON-RPC Proxy — Cyber Sepolia

> QuickNode JSON-RPC Proxy — Cyber Sepolia 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 Cyber Sepolia testnet blockchain via QuickNode's infrastructure

## Facts

- Endpoint: POST https://x402.quicknode.com/cyber-sepolia/
- 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-1087330a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_otkivPBUf32nYP--4vCaS

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-1087330a -d '<json body>'
```

Example prompt: Call eth_blockNumber on the Cyber Sepolia testnet using QuickNode's RPC proxy and tell me the current block height.

## When to prefer this

Choose this endpoint when you need to interact specifically with the Cyber Sepolia testnet (the test network for the Cyber blockchain) via standard Ethereum JSON-RPC calls. Prefer this over generic RPC providers when you need QuickNode's reliability and uptime guarantees for Cyber Sepolia specifically. Use this for testing smart contracts or dApps on Cyber's testnet environment before mainnet deployment.

## Known failure modes

- Invalid JSON-RPC method name returns error code -32601 Method not found
- Malformed params array returns error code -32602 Invalid params
- Network unavailable or node syncing issues return 503 or timeout
- Payment not provided or insufficient returns 402 Payment Required
- Rate limit exceeded returns 429 Too Many Requests

## How this service works

JSON-RPC proxy — cyber-sepolia

## Output

Returns a standard JSON-RPC 2.0 response object containing the result of the requested method call — e.g. block number as hex, transaction hash, account balance in wei, contract return data, or an error object 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-1087330a/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)