# QuikNode Base Sepolia Testnet JSON-RPC

> QuikNode Base Sepolia Testnet JSON-RPC is a paid API for AI agents from x402.quiknode-cf.pro, paid per call via x402, $10/call, status unknown (last checked 2026-09-14).

Provides high-performance JSON-RPC access to the Base Sepolia testnet for deploying and testing smart contracts, sending transactions, and querying chain data.

## Facts

- Endpoint: POST https://x402.quiknode-cf.pro/base-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/x402-quiknode-cf-pro-bbfe526d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_sNcc-z-YUcPGkSsMrlxWc

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-quiknode-cf-pro-bbfe526d -d '<json body>'
```

Example prompt: Can you call eth_getBalance on Base Sepolia testnet for address 0xAbc123... using JSON-RPC 2.0?

## When to prefer this

Choose this endpoint when you need reliable, low-latency RPC access to the Base Sepolia testnet specifically — ideal for CI/CD pipelines, smart contract testing, and dApp development where a managed QuikNode node is preferable to a public free-tier RPC with rate limits.

## Known failure modes

- Invalid JSON-RPC method name returns error code -32601
- Malformed params array causes -32602 invalid params error
- Network congestion or node unavailability returns 503 or timeout
- Calling mainnet-only contract addresses returns empty or revert on testnet
- Insufficient payment (x402) results in 402 Payment Required before execution

## How this service works

High-performance JSON-RPC access to the Base Sepolia testnet (v2) for deploying and testing smart contracts, sending transactions, and querying chain data.

## Output

Returns a JSON-RPC 2.0 response object containing the result of the requested method call — such as a block number, account balance, transaction receipt, contract return value, or gas estimate — along with the matching request ID and any error details if the call failed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "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"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-quiknode-cf-pro-bbfe526d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.quiknode-cf.pro](https://www.zero.xyz/host/x402.quiknode-cf.pro/llms.txt)