# Modifying & Unsubscribing

* **Modifying Subscriptions:** The subscription stream allows bi-directional communication. You can update your subscription filters dynamically by sending a new Subscribe request. For more details  please check [<mark style="color:yellow;">Modifying Subscribe Request</mark>](https://docs.shyft.to/solana-yellowstone-grpc/docs/getting-started/modify-grpc-subscribe-request) in "Getting Started" section.
* **Unsubscribing:** Send an empty subscription request to stop receiving updates on all streams. This will keep the connection open for future subscriptions.

### Modifying a Subscribe Request

Solana Yellowstone gRPC streams, while ideal for real-time data, often need **dynamic adjustments**. You can **modify existing subscriptions without disconnecting the stream**, allowing for real-time changes to filters or tracked addresses based on application needs or market shifts. This ensures **uninterrupted data flow** and **immediate responsiveness** to live blockchain events. For more details do checkout the [<mark style="color:yellow;">Modifying your Subscribe Request</mark>](https://docs.shyft.to/solana-yellowstone-grpc/docs/getting-started/modify-grpc-subscribe-request) section in the [<mark style="color:yellow;">Getting Started</mark>](https://docs.shyft.to/solana-yellowstone-grpc/docs/getting-started) Section.

{% hint style="success" %}
The complete code for updating subscribe requests is available on [GitHub](https://github.com/Shyft-to/solana-defi/tree/main/general-grpc-examples/Typescript/modifying_subscribe_request) and on [Replit here](https://replit.com/@shyft-to/modifying-subscribe-request-grpc?v=1).
{% endhint %}

{% tabs %}
{% tab title="TypeScript" %}
{% code overflow="wrap" %}

```typescript
import Client, {
  CommitmentLevel,
  SubscribeRequestAccountsDataSlice,
  SubscribeRequestFilterAccounts,
  SubscribeRequestFilterBlocks,
  SubscribeRequestFilterBlocksMeta,
  SubscribeRequestFilterEntry,
  SubscribeRequestFilterSlots,
  SubscribeRequestFilterTransactions,
} from "@triton-one/yellowstone-grpc";
import { SubscribeRequestPing } from "@triton-one/yellowstone-grpc/dist/grpc/geyser";

interface SubscribeRequest {
  accounts: { [key: string]: SubscribeRequestFilterAccounts };
  slots: { [key: string]: SubscribeRequestFilterSlots };
  transactions: { [key: string]: SubscribeRequestFilterTransactions };
  transactionsStatus: { [key: string]: SubscribeRequestFilterTransactions };
  blocks: { [key: string]: SubscribeRequestFilterBlocks };
  blocksMeta: { [key: string]: SubscribeRequestFilterBlocksMeta };
  entry: { [key: string]: SubscribeRequestFilterEntry };
  commitment?: CommitmentLevel;
  accountsDataSlice: SubscribeRequestAccountsDataSlice[];
  ping?: SubscribeRequestPing;
}

const subscribedWalletsA: string[] = [
  "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
  "5n2WeFEQbfV65niEP63sZc3VA7EgC4gxcTzsGGuXpump",
  "4oJh9x5Cr14bfaBtUsXN1YUZbxRhuae9nrkSyWGSpump",
  "GBpE12CEBFY9C74gRBuZMTPgy2BGEJNCn4cHbEPKpump",
  "oraim8c9d1nkfuQk9EzGYEUGxqL3MHQYndRw1huVo5h",
];

const subscribedWalletsB: string[] = [
  "6EF8rrecthR5Dkzon8Nwu78hRvfCKubJ14M5uBEwF6P",
];

const subscribeRequest1: SubscribeRequest = {
  accounts: {},
  slots: {},
  transactions: {
    modifying_A: {
      vote: false,
      failed: false,
      signature: undefined,
      accountInclude: subscribedWalletsA,
      accountExclude: [],
      accountRequired: [],
    },
  },
  transactionsStatus: {},
  entry: {},
  blocks: {},
  blocksMeta: {},
  accountsDataSlice: [],
  ping: undefined,
  commitment: CommitmentLevel.PROCESSED,
};

// Subscribes to account changes for program-owned accounts of subscribedWalletsB
const subscribeRequest2: SubscribeRequest = {
  accounts: {
    modifying_B: {
      account: [],
      filters: [],
      owner: subscribedWalletsB,
    },
  },
  slots: {},
  transactions: {},
  transactionsStatus: {},
  blocks: {},
  blocksMeta: {
    block: [],
  },
  entry: {},
  accountsDataSlice: [],
  ping: undefined,
  commitment: CommitmentLevel.PROCESSED,
};

/**
 * Dynamically updates the current stream subscription with new request parameters.
 */
async function updateSubscription(stream: any, args: SubscribeRequest) {
  try {
    stream.write(args);
  } catch (error) {
    console.error("Failed to send updated subscription request:", error);
  }
}

/**
 * Handles a single streaming session.
 * Automatically switches to a second subscription request after a timeout.
 */
async function handleStream(client: Client, args: SubscribeRequest) {
  const stream = await client.subscribe();

  // Waits for the stream to close or error out
  const streamClosed = new Promise<void>((resolve, reject) => {
    stream.on("error", (error) => {
      console.error("Stream Error:", error);
      reject(error);
      stream.end();
    });
    stream.on("end", resolve);
    stream.on("close", resolve);
  });

  // Automatically switch subscription after 10 seconds
  setTimeout(async () => {
    console.log("🔁 Switching to second subscription request...");
    await updateSubscription(stream, subscribeRequest2);
  }, 10000);

  // Handle incoming data
  stream.on("data", async (data) => {
    try {
      console.log("📦 Streamed Data:", data);
      // You can add more processing logic here
    } catch (error) {
      console.error("Error processing stream data:", error);
    }
  });

  // Send initial subscription request
  await new Promise<void>((resolve, reject) => {
    stream.write(args, (err: any) => (err ? reject(err) : resolve()));
  }).catch((reason) => {
    console.error("Initial stream write failed:", reason);
    throw reason;
  });

  await streamClosed;
}

/**
 * Starts the stream and continuously attempts to reconnect on errors.
 */
async function subscribeCommand(client: Client, args: SubscribeRequest) {
  while (true) {
    try {
      await handleStream(client, args);
    } catch (error) {
      console.error("Stream error. Retrying in 1 second...", error);
      await new Promise((resolve) => setTimeout(resolve, 1000));
    }
  }
}

const client = new Client(process.env.GRPC_URL, process.env.X_TOKEN, undefined);

// Start streaming with the first subscription
subscribeCommand(client, subscribeRequest1);
```

{% endcode %}
{% endtab %}
{% endtabs %}

### Unsubscribing to Subscribed Channels

This unsubscribes to your currently Subscribed Channels. However please note that this does not close the connection, and you may hit [<mark style="color:yellow;">**IP related limits**</mark>](https://docs.shyft.to/solana-yellowstone-grpc/grpc-docs#why-am-i-getting-maximum-ip-limit-reached-for-token-error) due to this too.

```json
{
  "slots": {},
  "accounts": {},
  "transactions": {},
  "blocks": {},
  "blocksMeta": {},
  "accountsDataSlice": []
}
```

This action will <mark style="color:yellow;">unsubscribe</mark> from all currently subscribed channels. Please note that, it won't disrupt the connection itself, which means you can still establish <mark style="color:yellow;">new subscriptions</mark> in the future without needing to <mark style="color:yellow;">re-connect</mark> to the service.

### Closing a gRPC Connection

Once the subscription stream is active, we can close it using `stream.cancel()` method. Please visit [<mark style="color:yellow;">closing a connection</mark>](#closing-a-grpc-connection) in "[<mark style="color:yellow;">Getting Started</mark>](https://docs.shyft.to/solana-yellowstone-grpc/docs/getting-started)" Section to know more.

{% hint style="success" %}
&#x20;The complete code of closing a connection is available on [Replit here](https://replit.com/@shyft-to/closing-a-grpc-connection?v=1).
{% endhint %}

{% tabs %}
{% tab title="TypeScript" %}
{% code overflow="wrap" %}

```typescript
import Client, {
  CommitmentLevel,
  SubscribeRequestAccountsDataSlice,
  SubscribeRequestFilterAccounts,
  SubscribeRequestFilterBlocks,
  SubscribeRequestFilterBlocksMeta,
  SubscribeRequestFilterEntry,
  SubscribeRequestFilterSlots,
  SubscribeRequestFilterTransactions,
} from "@triton-one/yellowstone-grpc";
import bs58 from "bs58";

const PUBLIC_KEY_TO_LISTEN = "675kPX9MHTjS2zt1qfr1NYHuzeLXfQM9H24wFSUt1Mp8"; //can be any address
const RUN_TIME = 5000; //decides how long to run
const GRPC_ENDPOINT = "https://grpc.ams.shyft.to"; //your gRPC endpoint
const X_TOKEN = ""; //your x-token

interface SubscribeRequest {
  accounts: { [key: string]: SubscribeRequestFilterAccounts };
  slots: { [key: string]: SubscribeRequestFilterSlots };
  transactions: { [key: string]: SubscribeRequestFilterTransactions };
  transactionsStatus: { [key: string]: SubscribeRequestFilterTransactions };
  blocks: { [key: string]: SubscribeRequestFilterBlocks };
  blocksMeta: { [key: string]: SubscribeRequestFilterBlocksMeta };
  entry: { [key: string]: SubscribeRequestFilterEntry };
  commitment?: CommitmentLevel | undefined;
  accountsDataSlice: SubscribeRequestAccountsDataSlice[];
}

const client = new Client(GRPC_ENDPOINT, X_TOKEN, undefined);

const req: SubscribeRequest = {
  accounts: {},
  slots: {},
  transactions: {
    raydiumLiquidityPoolV4: {
      vote: false,
      failed: false,
      signature: undefined,
      accountInclude: [PUBLIC_KEY_TO_LISTEN],
      accountExclude: [],
      accountRequired: [],
    },
  },
  transactionsStatus: {},
  entry: {},
  blocks: {},
  blocksMeta: {},
  accountsDataSlice: [],
  commitment: CommitmentLevel.PROCESSED,
};

async function handleStream(client: Client, args: SubscribeRequest) {
  console.log(`Subscribing and starting stream...`);
  const stream = await client.subscribe();
  console.log(`Streaming data and printing transactions...`);

  const streamClosed = new Promise<void>((resolve, reject) => {
    stream.on("error", (err: any) => {
      if (err.code === 1 || err.message.includes("Cancelled")) {
        //this indicates stream was cancelled by user.
        console.log("✅ Stream cancelled by user");
        resolve();
      } else {
        console.error("❌ Stream error:", err);
        reject(err);
      }
    });

    stream.on("close", () => {
      console.log("Stream closed.");
      resolve();
    });
  });

  stream.on("data", (data) => {
    if (data.transaction) {
      console.log(
        "Received: ",
        bs58.encode(data.transaction.transaction.signature),
      );
    }
  });

  // Subscribe
  stream.write(args);

  // Cancel after timeout
  setTimeout(() => {
    console.log("Cancelling stream...");
    try {
      stream.cancel();
      /*
       * stream.end() or stream.destroy();
       * Cancels the stream from the user end, and closes the stream.
       *
       * A "Cancelled on client" error (code 1) will be thrown once this is called,
       * which be caught in stream.on("error") function.
       * This is one of the ways to cancel the stream, and clear your connections, when using Shyft gRPCs.
       *
       * For more information on clearing connections, please check the FAQ section of gRPC docs
       * https://docs.shyft.to/solana-yellowstone-grpc/grpc-docs#solana-grpc-faq
       */
    } catch (error) {
      if (error.code !== "ERR_STREAM_PREMATURE_CLOSE") {
        console.error("Stream cancel error:", error);
      }
    }
  }, RUN_TIME);

  await streamClosed;
}

async function subscribeCommand(client: Client, args: SubscribeRequest) {
  await handleStream(client, args);
}

subscribeCommand(client, req);
```

{% endcode %}
{% endtab %}
{% endtabs %}