Quick Start: Your First Stream

Build your first real-time crypto price streaming application in 5 minutes

See it in action: Check out our Live Streaming Dashboard to see real-time price updates across multiple chains before you build your own.

Tutorial overview

In this tutorial, you’ll learn how to:

• Connect to the DexPaprika streaming API
• Receive real-time price updates
• Handle connection errors gracefully
• Build a simple price display

Time to complete: 5 minutes Prerequisites: Basic JavaScript knowledge

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Step 1: Choose Your Asset

For this tutorial, we’ll stream the price of Ethereum (WETH).

Finding Token Addresses

Use the REST API to find token addresses:

1. Search by name or symbol using the Search Endpoint:

curl "https://api.dexpaprika.com/search?query=WETH"

2. Get network list using the Networks Endpoint:

curl "https://api.dexpaprika.com/networks"

Common Token Addresses

Or use these verified addresses for popular tokens:

Ethereum

Chain: ethereum
WETH: 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2
USDC: 0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48

Solana

Chain: solana
SOL: So11111111111111111111111111111111111111112
USDC: EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v

BSC

Chain: bsc
BNB: 0xbb4cdb9cbd36b01bd1cbaebf2de08d9173bc095c
USDT: 0x55d398326f99059ff775485246999027b3197955

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Step 2: Test with cURL

First, let’s verify the stream works with a simple cURL command:

curl -N "https://streaming.dexpaprika.com/stream?method=t_p&chain=ethereum&address=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&limit=3"

You should see output like:

data: {"a":"0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2","c":"ethereum","p":"3997.5514026436525223","t":1761733397}
event: t_p

data: {"a":"0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2","c":"ethereum","p":"3998.1234567890123456","t":1761733398}
event: t_p

The limit=3 parameter closes the stream after 3 events - perfect for testing!

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Step 3: JavaScript Implementation

Here’s how to connect to the streaming API using JavaScript:

// Connect to streaming API
const url = new URL('https://streaming.dexpaprika.com/stream');
url.searchParams.set('method', 't_p');
url.searchParams.set('chain', 'ethereum');
url.searchParams.set('address', '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2');

const eventSource = new EventSource(url.toString());

// Handle price updates
eventSource.addEventListener('t_p', (event) => {
    const data = JSON.parse(event.data);
    const price = parseFloat(data.p);
    console.log(`WETH Price: $${price.toFixed(2)}`);
});

// Handle errors with reconnection
eventSource.onerror = () => {
    console.log('Connection lost, reconnecting...');
    eventSource.close();
    // Implement reconnection logic here
};

🎯 Live Example: See this code in action in our Interactive Streaming Dashboard - watch 6 tokens stream live across Ethereum, Solana, and BSC with real-time updates, connection status, and latency monitoring.

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Step 4: Customize Your Stream

Stream Different Tokens

Modify the URL parameters to stream any token:

// Bitcoin on Ethereum
url.searchParams.set('chain', 'ethereum');
url.searchParams.set('address', '0x2260fac5e5542a773aa44fbcfedf7c193bc2c599');

// SOL on Solana
url.searchParams.set('chain', 'solana');
url.searchParams.set('address', 'So11111111111111111111111111111111111111112');

// BNB on BSC
url.searchParams.set('chain', 'bsc');
url.searchParams.set('address', '0xbb4cdb9cbd36b01bd1cbaebf2de08d9173bc095c');

Add Multiple Assets

To stream multiple assets, switch to the POST method:

Show View implementation

async function streamMultipleAssets() {
    const assets = [
        { chain: 'ethereum', address: '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2', method: 't_p' },
        { chain: 'solana', address: 'So11111111111111111111111111111111111111112', method: 't_p' }
    ];

    const response = await fetch('https://streaming.dexpaprika.com/stream', {
        method: 'POST',
        headers: {
            'Accept': 'text/event-stream',
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(assets)
    });

    const reader = response.body.getReader();
    const decoder = new TextDecoder();

    while (true) {
        const { value, done } = await reader.read();
        if (done) break;

        const text = decoder.decode(value, { stream: true });
        // Parse SSE events from text
        console.log(text);
    }
}

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Understanding the Code

Key Components

EventSource API

The EventSource API is the browser’s built-in way to handle SSE:

const eventSource = new EventSource(url);
eventSource.addEventListener('t_p', handler);

It automatically handles:

• Persistent connections
• Automatic reconnection
• Event parsing

Error Handling

The onerror callback handles disconnections:

eventSource.onerror = () => {
    // Implement exponential backoff
    const delay = baseDelay * Math.pow(2, attempts);
    setTimeout(reconnect, delay);
};

Price Updates

Each event contains:

{
    "a": "address",     // Token contract address
    "c": "chain",       // Blockchain network
    "p": "price",       // USD price as string
    "t": timestamp      // Unix timestamp
}

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Implementation Notes

Browser Support

• EventSource API works in all modern browsers
• For direct browser connections, you’ll need to handle CORS (use a backend proxy)
• No issues when streaming from server-side (Node.js, Python, etc.)

Best Practices

• Implement exponential backoff for reconnection
• Handle both connection errors and SSE error events
• Parse prices as floats to maintain precision
• Close connections properly on page unload

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See It Live

🚀 Live Streaming Dashboard

Experience the API in action! Our interactive demo streams 6 cryptocurrencies in real-time across Ethereum, Solana, and BSC. Watch live price updates, connection status, latency metrics, and update statistics. Built with React and deployed on Vercel - perfect reference implementation showing POST /stream with multiple assets.

What you’ll see:

• Real-time price updates every ~1 second
• Multi-chain token streaming (ETH, SOL, BSC)
• Live connection status and latency
• Price change indicators and trends
• Total updates and uptime metrics

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Next Steps

Congratulations! You’ve built your first streaming application. Here’s what to explore next:

React Integration

Create reusable React components for streaming.

Stream Multiple Assets

Learn POST /stream to efficiently track multiple tokens.

Portfolio Tracker

Track your entire portfolio value in real-time.

Production Best Practices

Learn error handling, monitoring, and scaling.

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Get Help

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API Reference

Read the complete API documentation.