Making a gRPC connection

This illustrates how we can setup and configure a new Yellowstone gRPC connection

Once the client has been initialized. The next step is to specify what data to stream. The Yellowstone client uses Subscribe Requests ↗ to specify the data to stream.

The handleStream function is used to receive the stream (stream.on(data, func())), and also to write the subscribe request to the stream (stream.write()). You can copy and paste this code on Replit to execute.

The complete code for making a new gRPC connection is available on our GitHub, and on Replit here.

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 for the subscription request structure
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 ADDRESS_TO_STREAM_FROM = "6EF8rrecthR5Dkzon8Nwu78hRvfCKubJ14M5uBEwF6P";

/**
 * Subscribes to the gRPC stream and handles incoming data.
 * 
 * @param client - Yellowstone gRPC client
 * @param args - The Subscription request which specifies what data to stream
 */
async function handleStream(client: Client, args: SubscribeRequest) {
  const stream = await client.subscribe();

  // Promise that resolves when the stream ends or errors 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);
  });

  // Handle incoming transaction data
  stream.on("data", (data) => {
    if (data?.transaction) {
      
      console.log("Received Transaction:");
      console.log(data?.transaction);
    }
  });

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

  // Wait for the stream to close
  await streamClosed;
}

/**
 * Entry point to start the subscription stream.
 * 
 */
async function subscribeCommand(client: Client, args: SubscribeRequest) {
  await handleStream(client, args);

}

// Instantiate Yellowstone gRPC client with env credentials
const client = new Client(
  process.env.GRPC_URL, //Your Region specific gRPC URL
  process.env.X_TOKEN, // your Access Token
  undefined
);

/**
 * Subscribe Request: The `transactions` field filters transaction streams to only include those
 * that involve the specified address in `accountInclude`.
 */
const req: SubscribeRequest = {
  accounts: {},
  slots: {},
  transactions: {
    pumpFun: {
      vote: false,
      failed: false,
      signature: undefined,
      accountInclude: [ADDRESS_TO_STREAM_FROM],
      accountExclude: [],
      accountRequired: [],
    },
  },
  transactionsStatus: {},
  blocks: {},
  blocksMeta: {},
  entry: {},
  accountsDataSlice: [],
  ping: undefined,
  commitment: CommitmentLevel.CONFIRMED,
};

// Start the subscription
subscribeCommand(client, req);