# QuickNode JSON-RPC Proxy — Unichain Sepolia

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

Forwards JSON-RPC method calls to the Unichain Sepolia testnet via QuickNode's blockchain node infrastructure

## Facts

- Endpoint: POST https://x402.quicknode.com/unichain-sepolia/
- 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/quicknode-f309d7d6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iwZlzJX07HgawkplDG2-1

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-f309d7d6 -d '<json body>'
```

Example prompt: Call eth_getBalance on the Unichain Sepolia testnet for address 0xAbC123...456 using QuickNode's JSON-RPC proxy, using jsonrpc 2.0 with request id 1.

## When to prefer this

Use this endpoint when you need to interact with the Unichain Sepolia testnet specifically — for testing smart contracts, querying testnet balances, or simulating transactions before mainnet deployment. Prefer this over generic Ethereum endpoints when your target chain is Unichain Sepolia.

## 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 congestion or node unavailability returns 503 or timeout
- Payment failure (insufficient USDC) returns HTTP 402
- Invalid address format in params returns RPC error
- Testnet node sync lag may return stale data

## How this service works

JSON-RPC proxy — unichain-sepolia

## Output

Returns a standard JSON-RPC 2.0 response object containing the result of the requested method (e.g. block number as hex, balance in wei, transaction hash, call 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-f309d7d6/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)