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Overview

Connect to receive real-time market data for all markets within a specific event, including bid/ask prices, volume, and open interest.

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Connection

wss://api.bison.markets/ws/kalshi/event/{eventTicker}
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eventTicker
string
required
The Kalshi event ticker (e.g., KXBTC-100K)

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Example Connection

const eventTicker = "KXBTC-100K";
const ws = new WebSocket(
  `wss://api.bison.markets/ws/kalshi/event/${eventTicker}`
);

ws.onopen = () => {
  console.log(`Connected to ${eventTicker} market data`);
  
  // Send heartbeat every 30 seconds
  setInterval(() => {
    if (ws.readyState === WebSocket.OPEN) {
      ws.send(JSON.stringify({ type: "ping" }));
    }
  }, 30000);
};

ws.onmessage = (event) => {
  const data = JSON.parse(event.data);
  
  // Ignore ping/pong messages
  if (data.type === "ping" || data.type === "pong") {
    return;
  }
  
  console.log("Market update:", data);
  updateMarketDisplay(data);
};

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Ticker Update Format

Ticker updates contain the latest market data: 
{
  "market_ticker": "KXBTC-100K-DEC31",
  "yes_bid_uusdc": 720000,
  "yes_ask_uusdc": 750000,
  "no_bid_uusdc": 250000,
  "no_ask_uusdc": 280000,
  "last_price_uusdc": 735000,
  "volume": 15000,
  "open_interest": 50000
}

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Response Fields

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market_ticker
string
Market ticker being updated
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yes_bid_uusdc
number
Best bid price for YES in µUSDC
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yes_ask_uusdc
number
Best ask price for YES in µUSDC
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no_bid_uusdc
number
Best bid price for NO in µUSDC
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no_ask_uusdc
number
Best ask price for NO in µUSDC
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last_price_uusdc
number
Last traded price in µUSDC
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volume
number
Total traded volume
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open_interest
number
Current open interest (outstanding contracts)
All price fields are in µUSDC (microUSDC). To convert to USDC: priceUSDC = priceUusdc / 1,000,000For example, 750000 µUSDC = 0.75 USDC (75% probability).

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Example: Building a Price Display

const eventTicker = "KXBTC-100K";
const ws = new WebSocket(
  `wss://api.bison.markets/ws/kalshi/event/${eventTicker}`
);

// Store market data
const markets = new Map();

ws.onmessage = (event) => {
  const data = JSON.parse(event.data);
  
  if (data.type === "ping" || data.type === "pong") {
    return;
  }
  
  // Update market data
  markets.set(data.market_ticker, {
    yesBid: data.yes_bid_uusdc / 1_000_000,
    yesAsk: data.yes_ask_uusdc / 1_000_000,
    noBid: data.no_bid_uusdc / 1_000_000,
    noAsk: data.no_ask_uusdc / 1_000_000,
    lastPrice: data.last_price_uusdc / 1_000_000,
    volume: data.volume,
    openInterest: data.open_interest,
  });
  
  // Update your UI
  renderMarketData(data.market_ticker, markets.get(data.market_ticker));
};

function renderMarketData(ticker, data) {
  console.log(`${ticker}:`);
  console.log(`  YES: ${data.yesBid} bid / ${data.yesAsk} ask`);
  console.log(`  NO:  ${data.noBid} bid / ${data.noAsk} ask`);
  console.log(`  Last: ${data.lastPrice}, Volume: ${data.volume}`);
}

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Use Cases

Live Price Feeds

Display real-time bid/ask spreads for markets in an event

Trading Dashboards

Build comprehensive market overviews with live data

Price Alerts

Trigger notifications when prices reach certain thresholds

Market Analytics

Track volume and liquidity changes in real-time