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

# RPC

> A fast Polygon JSON-RPC endpoint, authenticated with your Radion API key. Available on paid plans.

Radion RPC gives you a Polygon JSON-RPC endpoint at `https://rpc.radion.app`. It is the same node infrastructure that powers Radion's ingestion. You send standard JSON-RPC calls and authenticate with your Radion API key.

RPC is a **paid** feature. The free plan cannot use it. See [Get access](#get-access).

## Base URL

```
https://rpc.radion.app
```

You call it like any Polygon node. Send a JSON-RPC request over HTTP `POST`, with your API key in the `X-API-Key` header.

```bash title="eth_blockNumber" theme={null}
curl "https://rpc.radion.app" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'
```

```json title="Response" theme={null}
{ "jsonrpc": "2.0", "id": 1, "result": "0x4a8f2c1" }
```

## Use it with a client

Point any Ethereum client at the endpoint. Set your API key as a header.

```ts title="viem" wrap theme={null}
import { createPublicClient, http } from "viem";
import { polygon } from "viem/chains";

const client = createPublicClient({
  chain: polygon,
  transport: http("https://rpc.radion.app", {
    fetchOptions: { headers: { "X-API-Key": "YOUR_API_KEY" } },
  }),
});

const block = await client.getBlockNumber();
```

```ts title="ethers" wrap theme={null}
import { JsonRpcProvider, FetchRequest } from "ethers";

const request = new FetchRequest("https://rpc.radion.app");
request.setHeader("X-API-Key", "YOUR_API_KEY");

const provider = new JsonRpcProvider(request);
const block = await provider.getBlockNumber();
```

## What you can call

Standard Polygon JSON-RPC methods, such as `eth_blockNumber`, `eth_getBalance`, `eth_call`, `eth_getLogs`, and `eth_getTransactionReceipt`. Read [Methods](/rpc/methods) for what is allowed and what is capped.

## Get access

RPC is on the **Starter**, **Pro**, and **Enterprise** plans. The free plan gets a `403 Forbidden`.

Upgrade in the [dashboard](https://radion.app/dashboard), then use the same API key you use for the REST API. See [Authentication](/rpc/authentication).