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

# LaserStream WebSocket: Real-Time Solana Data Streaming

> Stream real-time Solana blockchain data over WebSockets with LaserStream WebSocket — standard Solana subscriptions plus Helius extensions like transactionSubscribe, up to 200 ms faster than Agave RPC-based WebSockets.

## What is LaserStream WebSocket?

LaserStream WebSocket is the WebSocket-protocol variant of [LaserStream](/laserstream). It serves the standard Solana JSON-RPC subscription methods (`accountSubscribe`, `programSubscribe`, `logsSubscribe`, `signatureSubscribe`, `slotSubscribe`, …) alongside Helius-specific extensions like [`transactionSubscribe`](/rpc/websocket/transaction-subscribe) for advanced filtering — all on the same unified `wss://mainnet.helius-rpc.com` endpoint and on the same LaserStream backend as the [gRPC product](/laserstream).

WebSockets give you a persistent, real-time connection: instead of repeatedly polling "has anything changed?", the blockchain notifies you the moment something happens.

<CardGroup cols={2}>
  <Card title="Real-Time Updates" icon="bolt">
    Get instantly notified when Solana accounts change, transactions occur, or when new blocks are produced
  </Card>

  <Card title="Efficient Resource Usage" icon="leaf">
    One persistent connection instead of polling hundreds of HTTP requests
  </Card>

  <Card title="Low Latency" icon="clock">
    Up to 200 ms faster than standard Agave RPC-based WebSockets, served by LaserStream
  </Card>

  <Card title="Helius Extensions" icon="filter">
    `transactionSubscribe` and an enhanced `accountSubscribe` for advanced filtering on top of the standard Solana methods
  </Card>
</CardGroup>

## Endpoints

WebSockets — both the standard Solana methods and the Helius-specific extensions — are served from a single unified endpoint per network:

**Mainnet:** `wss://mainnet.helius-rpc.com/?api-key=<API_KEY>`
**Devnet:** `wss://devnet.helius-rpc.com/?api-key=<API_KEY>`

### Gatekeeper (Beta)

To test our fastest WebSocket offering, try the new Gatekeeper (Beta) endpoint:

`wss://beta.helius-rpc.com/?api-key=<API_KEY>`

## Pricing & Metering

WebSocket usage is metered at **2 credits per 0.1 MB** of streamed data. Opening a connection costs **1 credit**.

For high-volume workloads on Professional plans, [**Data Add-Ons**](/billing/plans#data-add-ons) provide monthly data allowances (5TB–100TB) at predictable costs. Data add-ons can be applied to LaserStream and WebSockets.

<Note>
  The Helius-specific methods `transactionSubscribe` and `accountSubscribe` (with Helius filters) require a **Developer**, **Business**, or **Professional** [plan](/billing/plans). Standard Solana methods like `programSubscribe`, `logsSubscribe`, and `signatureSubscribe` are available on all plans.
</Note>

## Core Concepts

### Subscription Types

<AccordionGroup>
  <Accordion title="Account Subscriptions" icon="user">
    Monitor changes to specific accounts like wallet balances, token accounts, or program data.

    **Use cases:**

    * Wallet balance tracking
    * Token account monitoring
    * Smart contract state changes
    * NFT ownership updates
  </Accordion>

  <Accordion title="Program Subscriptions" icon="code">
    Watch all accounts owned by a specific program for any changes.

    **Use cases:**

    * DEX trade monitoring
    * DeFi protocol tracking
    * NFT marketplace activity
    * Gaming asset changes
  </Accordion>

  <Accordion title="Transaction Subscriptions" icon="receipt">
    Get notified when specific transactions are confirmed or when transactions mention certain accounts.

    **Use cases:**

    * Payment confirmations
    * Transaction status tracking
    * Multi-signature approvals
    * Contract execution monitoring
  </Accordion>

  <Accordion title="Slot Subscriptions" icon="clock">
    Monitor blockchain progression and finality at the slot level.

    **Use cases:**

    * Block explorer applications
    * Network health monitoring
    * Consensus tracking
    * Performance analytics
  </Accordion>
</AccordionGroup>

### Commitment Levels

Understanding commitment levels is crucial for reliable applications:

<Tabs>
  <Tab title="Processed">
    **Fastest** - Transaction processed by a validator but not confirmed

    * Latency: \~400ms
    * Risk: Can be dropped or reordered
    * Use for: Real-time UI updates (with caution)
  </Tab>

  <Tab title="Confirmed">
    **Balanced** - Majority of cluster has voted on the slot

    * Latency: \~2-3 seconds
    * Risk: Low chance of being dropped
    * Use for: Most applications
  </Tab>

  <Tab title="Finalized">
    **Safest** - Supermajority of cluster has voted on the slot

    * Latency: \~15-30 seconds
    * Risk: Extremely unlikely to be dropped
    * Use for: Financial applications, high-value transactions
  </Tab>
</Tabs>

<Info>
  **Want to learn more about commitment levels?** Read our comprehensive blog post: [Understanding Solana Commitment Levels](https://www.helius.dev/blog/solana-commitment-levels)
</Info>

## Available WebSocket Methods

Helius supports the full set of Solana WebSocket subscription methods, plus Helius-specific extensions. All methods share the same `wss://mainnet.helius-rpc.com` endpoint.

### Helius extensions

Two methods deliver richer filtering than the Solana standard:

* [`transactionSubscribe`](/rpc/websocket/transaction-subscribe) — subscribe to transactions matching include/exclude/required account lists, vote/failed flags, and a specific signature
* [`accountSubscribe`](/rpc/websocket/account-subscribe) — Helius adds advanced filters on top of the standard `accountSubscribe` shape

### Standard Solana methods

`accountSubscribe`, `blockSubscribe`, `logsSubscribe`, `programSubscribe`, `rootSubscribe`, `signatureSubscribe`, `slotSubscribe`, `slotsUpdatesSubscribe`, `voteSubscribe` and their corresponding `*Unsubscribe` pairs.

<Card title="Complete API Reference" icon="book" href="/api-reference/rpc/websocket-methods">
  **Explore all 18+ WebSocket methods**. Each method includes detailed parameters, response formats, and examples.
</Card>

## How to Implement Reconnection Logic

WebSocket connections can disconnect for various reasons - network issues, server maintenance, or temporary outages. Production applications **must** implement reconnection logic to ensure reliability.

### Why Disconnections Happen

<AccordionGroup>
  <Accordion title="Network Issues">
    * Internet connectivity problems
    * WiFi handoffs on mobile devices
    * Corporate firewall timeouts
    * ISP routing changes
  </Accordion>

  <Accordion title="Server-Side Events">
    * Planned maintenance windows
    * Load balancer restarts
    * RPC node updates
    * Temporary overload protection
  </Accordion>

  <Accordion title="Client-Side Issues">
    * Browser tab backgrounding
    * Mobile app suspension
    * Computer sleep/hibernation
    * Process crashes or restarts
  </Accordion>
</AccordionGroup>

### Detecting Disconnections

<Tabs>
  <Tab title="JavaScript/Browser">
    ```javascript [expandable] theme={"system"}
    class ConnectionMonitor {
      constructor(ws) {
        this.ws = ws;
        this.pingInterval = null;
        this.lastPong = Date.now();
        this.isConnected = false;
        
        this.setupEventListeners();
        this.startPingMonitoring();
      }
      
      setupEventListeners() {
        this.ws.onopen = () => {
          console.log('Connected');
          this.isConnected = true;
          this.lastPong = Date.now();
        };
        
        this.ws.onclose = (event) => {
          console.log('Disconnected:', event.code, event.reason);
          this.isConnected = false;
          this.stopPingMonitoring();
        };
        
        this.ws.onerror = (error) => {
          console.error('WebSocket error:', error);
          this.isConnected = false;
        };
        
        // Listen for pong responses (server acknowledgment)
        this.ws.onmessage = (event) => {
          const data = JSON.parse(event.data);
          if (data.method === 'pong') {
            this.lastPong = Date.now();
          }
          // Handle other messages...
        };
      }
      
      startPingMonitoring() {
        this.pingInterval = setInterval(() => {
          if (this.isConnected) {
            // Send ping to check connection health
            this.ws.send(JSON.stringify({
              jsonrpc: '2.0',
              method: 'ping',
              id: Date.now()
            }));
            
            // Check if we received a pong recently
            const timeSinceLastPong = Date.now() - this.lastPong;
            if (timeSinceLastPong > 30000) { // 30 seconds timeout
              console.warn('No pong received, connection may be stale');
              this.ws.close();
            }
          }
        }, 10000); // Ping every 10 seconds
      }
      
      stopPingMonitoring() {
        if (this.pingInterval) {
          clearInterval(this.pingInterval);
          this.pingInterval = null;
        }
      }
    }
    ```
  </Tab>

  <Tab title="Node.js">
    ```javascript [expandable] theme={"system"}
    const WebSocket = require('ws');

    class NodeConnectionMonitor {
      constructor(url) {
        this.url = url;
        this.ws = null;
        this.pingInterval = null;
        this.isAlive = false;
      }
      
      connect() {
        this.ws = new WebSocket(this.url);
        
        this.ws.on('open', () => {
          console.log('Connected');
          this.isAlive = true;
          this.startHeartbeat();
        });
        
        this.ws.on('close', () => {
          console.log('Disconnected');
          this.isAlive = false;
          this.stopHeartbeat();
        });
        
        this.ws.on('error', (error) => {
          console.error('WebSocket error:', error);
          this.isAlive = false;
        });
        
        // Built-in ping/pong handling
        this.ws.on('pong', () => {
          this.isAlive = true;
        });
      }
      
      startHeartbeat() {
        this.pingInterval = setInterval(() => {
          if (!this.isAlive) {
            console.log('Connection lost, terminating');
            return this.ws.terminate();
          }
          
          this.isAlive = false;
          this.ws.ping();
        }, 30000); // Ping every 30 seconds
      }
      
      stopHeartbeat() {
        if (this.pingInterval) {
          clearInterval(this.pingInterval);
          this.pingInterval = null;
        }
      }
    }
    ```
  </Tab>
</Tabs>

### Reconnection Strategies

<Tabs>
  <Tab title="Exponential Backoff">
    ```javascript [expandable] theme={"system"}
    class ExponentialBackoffReconnector {
      constructor(url, maxRetries = 10) {
        this.url = url;
        this.maxRetries = maxRetries;
        this.retryCount = 0;
        this.baseDelay = 1000; // Start with 1 second
        this.maxDelay = 30000; // Cap at 30 seconds
        this.ws = null;
        this.subscriptions = new Map();
        this.isReconnecting = false;
      }
      
      connect() {
        if (this.isReconnecting) return;
        
        try {
          this.ws = new WebSocket(this.url);
          this.setupEventHandlers();
        } catch (error) {
          console.error('Failed to create WebSocket:', error);
          this.scheduleReconnect();
        }
      }
      
      setupEventHandlers() {
        this.ws.onopen = () => {
          console.log('Connected successfully');
          this.retryCount = 0; // Reset retry count on successful connection
          this.isReconnecting = false;
          this.resubscribeAll(); // Restore subscriptions
        };
        
        this.ws.onclose = (event) => {
          console.log('Connection closed:', event.code);
          if (!this.isReconnecting) {
            this.scheduleReconnect();
          }
        };
        
        this.ws.onerror = (error) => {
          console.error('WebSocket error:', error);
        };
      }
      
      scheduleReconnect() {
        if (this.retryCount >= this.maxRetries) {
          console.error('Max retry attempts reached. Giving up.');
          return;
        }
        
        this.isReconnecting = true;
        this.retryCount++;
        
        // Calculate delay with exponential backoff + jitter
        const delay = Math.min(
          this.baseDelay * Math.pow(2, this.retryCount - 1),
          this.maxDelay
        );
        
        // Add jitter to prevent thundering herd
        const jitteredDelay = delay + (Math.random() * 1000);
        
        console.log(`Reconnecting in ${jitteredDelay}ms (attempt ${this.retryCount}/${this.maxRetries})`);
        
        setTimeout(() => {
          this.connect();
        }, jitteredDelay);
      }
      
      subscribe(method, params, callback) {
        const id = this.generateId();
        this.subscriptions.set(id, { method, params, callback });
        
        if (this.ws && this.ws.readyState === WebSocket.OPEN) {
          this.sendSubscription(id, method, params);
        }
        
        return id;
      }
      
      resubscribeAll() {
        console.log(`Restoring ${this.subscriptions.size} subscriptions`);
        for (const [id, sub] of this.subscriptions) {
          this.sendSubscription(id, sub.method, sub.params);
        }
      }
      
      sendSubscription(id, method, params) {
        this.ws.send(JSON.stringify({
          jsonrpc: '2.0',
          id: id,
          method: method,
          params: params
        }));
      }
      
      generateId() {
        return Date.now() + Math.random();
      }
    }
    ```
  </Tab>

  <Tab title="Circuit Breaker Pattern">
    ```javascript [expandable] theme={"system"}
    class CircuitBreakerWebSocket {
      constructor(url, options = {}) {
        this.url = url;
        this.failureThreshold = options.failureThreshold || 5;
        this.recoveryTimeout = options.recoveryTimeout || 60000;
        this.checkInterval = options.checkInterval || 10000;
        
        this.state = 'CLOSED'; // CLOSED, OPEN, HALF_OPEN
        this.failureCount = 0;
        this.lastFailureTime = null;
        this.ws = null;
        this.subscriptions = new Map();
      }
      
      connect() {
        if (this.state === 'OPEN') {
          if (Date.now() - this.lastFailureTime > this.recoveryTimeout) {
            console.log('Circuit breaker moving to HALF_OPEN state');
            this.state = 'HALF_OPEN';
          } else {
            console.log('Circuit breaker is OPEN, connection blocked');
            return false;
          }
        }
        
        try {
          this.ws = new WebSocket(this.url);
          this.setupEventHandlers();
          return true;
        } catch (error) {
          this.recordFailure();
          return false;
        }
      }
      
      setupEventHandlers() {
        this.ws.onopen = () => {
          console.log('Connected - Circuit breaker CLOSED');
          this.state = 'CLOSED';
          this.failureCount = 0;
          this.resubscribeAll();
        };
        
        this.ws.onclose = () => {
          this.recordFailure();
        };
        
        this.ws.onerror = (error) => {
          console.error('WebSocket error:', error);
          this.recordFailure();
        };
      }
      
      recordFailure() {
        this.failureCount++;
        this.lastFailureTime = Date.now();
        
        console.log(`Failure recorded: ${this.failureCount}/${this.failureThreshold}`);
        
        if (this.failureCount >= this.failureThreshold) {
          console.log('Circuit breaker opened due to repeated failures');
          this.state = 'OPEN';
        }
      }
      
      startHealthCheck() {
        setInterval(() => {
          if (this.state === 'OPEN' || 
              (this.ws && this.ws.readyState !== WebSocket.OPEN)) {
            this.connect();
          }
        }, this.checkInterval);
      }
    }
    ```
  </Tab>
</Tabs>

### Testing Reconnection Logic

<Tabs>
  <Tab title="Network Simulation">
    ```javascript [expandable] theme={"system"}
    // Test disconnection scenarios
    class NetworkSimulator {
      constructor(wsManager) {
        this.wsManager = wsManager;
      }
      
      // Simulate network outage
      simulateNetworkOutage(duration = 5000) {
        console.log('Simulating network outage...');
        
        // Force close the connection
        if (this.wsManager.ws) {
          this.wsManager.ws.close(1006, 'Network outage simulation');
        }
        
        // Block reconnection temporarily
        const originalConnect = this.wsManager.connect.bind(this.wsManager);
        this.wsManager.connect = () => {
          console.log('Connection blocked during outage simulation');
        };
        
        // Restore connection after duration
        setTimeout(() => {
          console.log('Network restored');
          this.wsManager.connect = originalConnect;
          this.wsManager.connect();
        }, duration);
      }
      
      // Simulate intermittent connectivity
      simulateIntermittentConnectivity() {
        setInterval(() => {
          if (Math.random() < 0.1) { // 10% chance every 10 seconds
            console.log('Simulating connection drop...');
            this.wsManager.ws?.close(1006, 'Intermittent connectivity');
          }
        }, 10000);
      }
    }

    // Usage
    const simulator = new NetworkSimulator(wsManager);
    simulator.simulateNetworkOutage(10000); // 10 second outage
    ```
  </Tab>

  <Tab title="Automated Testing">
    ```javascript [expandable] theme={"system"}
    // Jest test example
    describe('WebSocket Reconnection', () => {
      let wsManager;
      
      beforeEach(() => {
        wsManager = new ProductionWebSocketManager({
          endpoint: 'ws://localhost:8080',
          apiKey: 'test-key'
        });
      });
      
      test('should reconnect after connection loss', async () => {
        const reconnectPromise = new Promise((resolve) => {
          wsManager.on('connected', resolve);
        });
        
        await wsManager.connect();
        
        // Simulate connection loss
        wsManager.ws.close(1006, 'Test disconnection');
        
        // Wait for reconnection
        await reconnectPromise;
        
        expect(wsManager.connectionState).toBe('CONNECTED');
        expect(wsManager.metrics.reconnections).toBeGreaterThan(0);
      });
      
      test('should restore subscriptions after reconnection', async () => {
        await wsManager.connect();
        
        const messages = [];
        const subscriptionId = wsManager.subscribe(
          'accountSubscribe',
          ['test-account', {}],
          (data) => messages.push(data)
        );
        
        // Verify subscription exists
        expect(wsManager.subscriptions.has(subscriptionId)).toBe(true);
        
        // Simulate disconnection and reconnection
        wsManager.ws.close(1006, 'Test disconnection');
        
        await new Promise(resolve => wsManager.on('connected', resolve));
        
        // Verify subscription was restored
        const subscription = wsManager.subscriptions.get(subscriptionId);
        expect(subscription.pending).toBe(true); // Should be re-subscribing
      });
    });
    ```
  </Tab>
</Tabs>

<Warning>
  **Critical for Production**: Implementing proper reconnection logic is not optional for production applications. WebSocket connections will disconnect - plan for it, test it, and monitor it in production.
</Warning>

## Troubleshooting

<AccordionGroup>
  <Accordion title="Connection Failed">
    **Symptoms**: WebSocket fails to connect initially

    **Solutions**:

    * Verify your API key is correct and has sufficient credits
    * Check the endpoint URL format: `wss://mainnet.helius-rpc.com?api-key=YOUR_KEY`
    * Ensure your firewall allows WebSocket connections on port 443
    * Test with a simple ping first to verify basic connectivity
  </Accordion>

  <Accordion title="Frequent Disconnections">
    **Symptoms**: Connection drops every few minutes

    **Solutions**:

    * WebSockets have a **10-minute inactivity timer**. Send a ping at least once per minute to keep the connection alive (see the reconnection examples above and the [WebSocket FAQ](/faqs/websockets#why-are-my-enhanced-websockets-connections-disconnecting))
    * Implement proper ping/pong heartbeat (shown in reconnection examples above)
    * Check your network stability and corporate firewall settings
    * Monitor your subscription count - too many can cause instability
    * Verify you're handling the connection lifecycle properly
  </Accordion>

  <Accordion title="Missing Messages">
    **Symptoms**: Not receiving expected subscription updates

    **Solutions**:

    * Verify your subscription is confirmed (check the response)
    * Ensure the account/program you're monitoring has actual activity
    * Monitor your connection state - missed messages often indicate disconnections
  </Accordion>

  <Accordion title="High Latency">
    **Symptoms**: Slow message delivery, delays in updates

    **Solutions**:

    * Use "confirmed" instead of "finalized" commitment
    * Reduce the number of active subscriptions
    * Optimize your message processing logic
    * Consider using multiple connections to distribute load
    * Check your network connection quality
  </Accordion>

  <Accordion title="Memory Leaks">
    **Symptoms**: Application memory usage grows over time

    **Solutions**:

    * Implement proper subscription cleanup
    * Remove event listeners when components unmount
    * Clear message logs periodically
    * Monitor subscription count and enforce limits
    * Use weak references for callback functions where possible
  </Accordion>
</AccordionGroup>

## Migration from Standard RPC

If you're currently using HTTP polling, here's how to migrate to WebSockets:

```javascript [expandable] theme={"system"}
// Old approach - HTTP polling
class HTTPAccountMonitor {
  constructor(connection, accountAddress) {
    this.connection = connection;
    this.accountAddress = accountAddress;
    this.interval = null;
    this.lastKnownBalance = null;
  }

  start() {
    this.interval = setInterval(async () => {
      try {
        const accountInfo = await this.connection.getAccountInfo(
          new PublicKey(this.accountAddress)
        );
        
        const currentBalance = accountInfo?.lamports || 0;
        
        if (this.lastKnownBalance !== currentBalance) {
          console.log(`Balance changed: ${currentBalance}`);
          this.lastKnownBalance = currentBalance;
        }
      } catch (error) {
        console.error('Failed to fetch account info:', error);
      }
    }, 2000); // Poll every 2 seconds
  }

  stop() {
    if (this.interval) {
      clearInterval(this.interval);
      this.interval = null;
    }
  }
}

// New approach - WebSocket subscription
class WebSocketAccountMonitor {
  constructor(wsManager, accountAddress) {
    this.wsManager = wsManager;
    this.accountAddress = accountAddress;
    this.subscriptionId = null;
  }

  start() {
    this.subscriptionId = this.wsManager.subscribe(
      'accountSubscribe',
      [
        this.accountAddress,
        { encoding: 'jsonParsed', commitment: 'confirmed' }
      ],
      (data) => {
        const currentBalance = data.value.lamports;
        console.log(`Balance changed: ${currentBalance}`);
        
        // Handle the change immediately - no polling delay!
      }
    );
  }

  stop() {
    if (this.subscriptionId) {
      this.wsManager.unsubscribe(this.subscriptionId);
      this.subscriptionId = null;
    }
  }
}
```

## Enhanced Capabilities

For apps requiring even more advanced features, consider using [LaserStream gRPC](/laserstream):

<CardGroup cols={2}>
  <Card title="24-Hour Historical Replay" icon="clock-rotate-left">
    Catch up on missed data when your app was offline
  </Card>

  <Card title="Multi-Node Aggregation" icon="network-wired">
    Better reliability via data from multiple validators
  </Card>

  <Card title="Higher Throughput" icon="gauge-high">
    Handle more subscriptions and higher message rates
  </Card>

  <Card title="Enterprise Features" icon="building">
    Advanced monitoring, analytics, and data pipelines
  </Card>
</CardGroup>

## Get Started

Ready to Get Started?

Check out our [WebSocket Quickstart Guide](/rpc/websocket/quickstart) for practical examples and a step-by-step implementation.