# How To Use Presto with viem.sh

To use Presto with [viem.sh](http://viem.sh/) library using a custom RPC endpoint, follow these steps:

1. Install the [viem.sh](http://viem.sh/) library by running `npm install viem.sh` in your project directory.
2. Create your rollup ([How to Create a Rollup](/overview/main-functionality/how-to-create-a-rollup.md)), open it, and get the RPC URL ([What Is RPC](/overview/features-for-developers/what-is-rpc.md)).<br>

   <figure><img src="/files/cqybA1LuVZsN77ykORt7" alt=""><figcaption></figcaption></figure>
3. Set up a provider to connect to your Presto L2 network using your custom RPC endpoint.
4. Make sure to replace `YOUR_CUSTOM_RPC_ENDPOINT` with the URL of your custom RPC endpoint.

```jsx
const { viem } = require('viem.sh');

const provider = new viem.providers.JsonRpcProvider('YOUR_CUSTOM_RPC_ENDPOINT');

async function getBlockByNumber(blockNumber) {
  try {
    const block = await provider.getBlock(blockNumber);
    console.log(block);
  } catch (error) {
    console.log(error);
  }
}

getBlockByNumber(12345);
```


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If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs-presto.gateway.fm/overview/features-for-developers/how-to-use-presto-with-viem.sh.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.