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

# Cast Stream

> Fetch stream of casts with Farcaster hubs

In this guide, we'll create a stream of casts using Farcaster hubs and stream the casts published in real time.

### Create nodejs app

Create a new node.js app using the following commands:

```bash theme={"system"}
mkdir stream-casts
cd stream-casts
bun init
```

I have used bun but feel free to use npm, yarn, pnpm, or anything of your choice! Once the app is created, run this command to install the "@farcaster/hub-nodejs" package:

```bash theme={"system"}
bun add @farcaster/hub-nodejs
```

### Build the stream

Now, let's get to building our stream. In the index.ts file add the following to initialise the client:

<CodeGroup>
  ```typescript index.ts theme={"system"}
  import {
    createDefaultMetadataKeyInterceptor,
    getSSLHubRpcClient,
    HubEventType
  } from '@farcaster/hub-nodejs';

  const hubRpcEndpoint = "hub-grpc-api.neynar.com";
  const client = getSSLHubRpcClient(hubRpcEndpoint, {
    interceptors: [
        createDefaultMetadataKeyInterceptor('x-api-key', 'YOUR_NEYNAR_API_KEY'),
    ],
    'grpc.max_receive_message_length': 20 * 1024 * 1024, 
  });
  ```
</CodeGroup>

You need to replace "YOUR\_NEYNAR\_API\_KEY" with your API key. You can get it from your [neynar app page](https://dev.neynar.com/app).

Once our client is initialized we can use it to subscribe to specific events, in our case we want to subscribe to the `MERGE_MESSAGE` event. You can check out the full details about the types of events in [The Snapchain Events Documentation](https://snapchain.farcaster.xyz/reference/datatypes/events#events). So, add the following in your code:

<CodeGroup>
  ```typescript index.ts theme={"system"}
  client.$.waitForReady(Date.now() + 5000, async (e) => {
    if (e) {
      console.error(`Failed to connect to ${hubRpcEndpoint}:`, e);
      process.exit(1);
    } else {
      console.log(`Connected to ${hubRpcEndpoint}`);

      const subscribeResult = await client.subscribe({
        eventTypes: [HubEventType.MERGE_MESSAGE],
      });

      client.close();
    }
  });
  ```
</CodeGroup>

Finally, let's use the subscribeResult to stream and console log the cast texts:

<CodeGroup>
  ```typescript index.ts theme={"system"}
      if (subscribeResult.isOk()) {
        const stream = subscribeResult.value;

        for await (const event of stream) {
          if (event.mergeMessageBody.message.data.type === 1) {
            console.log(event.mergeMessageBody.message.data.castAddBody.text);
          }
        }
      }
  ```
</CodeGroup>

We have to filter out the data by its type since the merge message events provide all protocol events like casts, reactions, profile updates, etc. 1 is for casts published.

Here's what the completed code looks like:

```typescript theme={"system"}
import {
  createDefaultMetadataKeyInterceptor,
  getSSLHubRpcClient,
  HubEventType
} from '@farcaster/hub-nodejs';

const hubRpcEndpoint = "hub-grpc-api.neynar.com";
const client = getSSLHubRpcClient(hubRpcEndpoint, {
  interceptors: [
      createDefaultMetadataKeyInterceptor('x-api-key', 'YOUR_NEYNAR_API_KEY'),
  ],
  'grpc.max_receive_message_length': 20 * 1024 * 1024, 
});

client.$.waitForReady(Date.now() + 5000, async (e) => {
  if (e) {
    console.error(`Failed to connect to ${hubRpcEndpoint}:`, e);
    process.exit(1);
  } else {
    console.log(`Connected to ${hubRpcEndpoint}`);

    const subscribeResult = await client.subscribe({
      eventTypes: [HubEventType.MERGE_MESSAGE],
    });

    if (subscribeResult.isOk()) {
      const stream = subscribeResult.value;

      for await (const event of stream) {
        if (event.mergeMessageBody.message.data.type === 1) {
          console.log(event.mergeMessageBody.message.data.castAddBody.text);
        }
      }
    }

    client.close();
  }
});
```

### Run the stream in your terminal

Finally, you can run the script using `bun run index.ts` and it will provide you with a stream like this:

<Frame>
  <img src="https://mintcdn.com/neynar/4PNY113y9N9T-r9z/images/docs/bc0fa74-image.png?fit=max&auto=format&n=4PNY113y9N9T-r9z&q=85&s=96463bef2c786dfd41e26eee07c6ae18" alt="Cast Stream" width="2296" height="1344" data-path="images/docs/bc0fa74-image.png" />
</Frame>

## Share with us!

Lastly, make sure to share what you built with us on Farcaster by tagging [@neynar](https://warpcast.com/neynar) and if you have any questions, reach out to us on [warpcast](https://warpcast.com/~/channel/neynar) or [Slack](https://neynar.com/slack)!