Pinnacle odds WebSocket client in Bun

Answer: Bun's built-in WebSocket accepts a non-standard headers option, so you can send x-api-key instead of putting the key in the URL. Subscribe on open, answer each ping with {"type":"pong"}, and compare each market upsert with the previous price to log moves. Run with bun run stream.ts. Builder or Pro key required.

stream.ts#

const last = new Map<string, number>();      // market id + outcome -> decimal

const ws = new WebSocket('wss://pinnfeed.io/v1/stream', {
  headers: { 'x-api-key': process.env.PINNFEED_KEY! },   // ps_live_...
} as any);

ws.addEventListener('open', () => {
  ws.send(JSON.stringify({ type: 'subscribe', sports: ['tennis'], markets: ['moneyline'], main: true }));
});

ws.addEventListener('message', (ev) => {
  const msg = JSON.parse(String(ev.data));
  if (msg.type === 'ping') return ws.send('{"type":"pong"}');
  const list = msg.type === 'snapshot' ? msg.markets
    : msg.type === 'delta' ? msg.changes.filter((c: any) => c.kind === 'market' && c.op === 'upsert').map((c: any) => c.market)
    : [];
  for (const m of list) {
    for (const o of m.outcomes) {
      const k = `${m.id}|${o.name}`;
      const prev = last.get(k);
      if (prev && o.decimal && Math.abs(o.decimal / prev - 1) >= 0.05) {
        console.log(new Date().toISOString(), m.eventId, o.name, prev, '→', o.decimal, 'maxStake', m.maxStake);
      }
      last.set(k, o.decimal);
    }
  }
});

ws.addEventListener('close', (ev) => console.log('closed', ev.code, ev.reason));

A threshold check like m.maxStake >= 100 helps ignore thin markets. Add a reconnect with backoff for long runs: reconnect pattern.

Plans#

Builder (€99/mo) for WebSocket push, all 13 sports, 3 connections. 3-day trial; a card is required and it is charged after day 3 unless you cancel. Server-side drop alerts without a socket: /v1/drops.

Educational content for adults (18+). No tips, no guaranteed profit.

Questions people ask#

Will this code run in Node?#

Node's global WebSocket has no headers option; use the ws package there: Node example.

Why as any?#

The headers option is Bun-specific, so the DOM type definitions do not include it.

Is 5% a good alert threshold?#

It is only an example; tune it to your markets.