> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polynode.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# RPC Helper

> Make authenticated Polygon JSON-RPC requests from TypeScript, Python, or Rust.

Every SDK includes an HTTP JSON-RPC helper for `rpc.polynode.dev`. It is useful for Polygon reads that complement market data.

<CodeGroup>
  ```typescript TypeScript theme={null}
  const blockNumber = await pn.rpc('eth_blockNumber');
  const balance = await pn.rpc('eth_getBalance', ['0xabc...', 'latest']);
  console.log({ blockNumber, balance });
  ```

  ```python Python theme={null}
  block_number = pn.rpc("eth_blockNumber")
  balance = pn.rpc("eth_getBalance", ["0xabc...", "latest"])
  print(block_number, balance)
  ```

  ```rust Rust theme={null}
  let block_number = client
      .rpc_call("eth_blockNumber", serde_json::json!([]))
      .await?;
  let balance = client
      .rpc_call("eth_getBalance", serde_json::json!(["0xabc...", "latest"]))
      .await?;
  println!("{block_number} {balance}");
  ```
</CodeGroup>

The SDK helper uses HTTP. It does not provide WebSocket `eth_subscribe`. Never log raw signed transactions or private keys, and confirm chain ID, nonce, fees, and destination before using any state-changing RPC method.

See the [RPC documentation](/rpc/overview) for supported methods, limits, and transaction guidance.