Pinnacle odds WebSocket client in Deno

Answer: Deno ships a standard WebSocket, so no package is needed. The standard constructor has no headers option, so on the server pass the key as ?key= read from an environment variable, subscribe in onopen, reply {"type":"pong"} to each ping (every 20 s), and keep a Map of markets updated from snapshot and delta frames. Run with deno run --allow-net --allow-env stream.ts. Builder or Pro key required.

stream.ts#

const KEY = Deno.env.get('PINNFEED_KEY');   // ps_live_...
if (!KEY) throw new Error('set PINNFEED_KEY');
const markets = new Map<string, any>();
let backoff = 1000;

function connect() {
  const ws = new WebSocket(`wss://pinnfeed.io/v1/stream?key=${encodeURIComponent(KEY!)}`);
  ws.onopen = () => {
    backoff = 1000;
    ws.send(JSON.stringify({ type: 'subscribe', sports: ['basketball'], markets: ['spread', 'total'], main: true }));
  };
  ws.onmessage = (ev) => {
    const msg = JSON.parse(ev.data);
    if (msg.type === 'ping') return ws.send('{"type":"pong"}');
    if (msg.type === 'snapshot') {
      if (msg.part === 1) markets.clear();
      for (const m of msg.markets) markets.set(m.id, m);
      if (msg.final) console.log('snapshot ready:', markets.size, 'markets');
    } else if (msg.type === 'delta') {
      for (const ch of msg.changes) {
        if (ch.kind !== 'market') continue;
        if (ch.op === 'remove') markets.delete(ch.id);
        else markets.set(ch.market.id, ch.market);
      }
    } else if (msg.type === 'error') console.error(msg.code, msg.message);
  };
  ws.onclose = (ev) => {
    console.log('closed', ev.code, ev.reason);
    if (ev.code === 4001) return;                 // key revoked: stop
    setTimeout(connect, backoff);
    backoff = Math.min(backoff * 2, 30000);
  };
}
connect();

The key in the URL never leaves your server here, but keep it out of logs. Close codes: 4002 no subscribe in 30 s, 4008 slow consumer (buffer over 16 MB), 4001 key revoked.

Plans#

WebSocket on Builder (€99/mo, 3 connections) and Pro. 3-day trial; a card is required and it is charged after day 3 unless you cancel. Same pattern in TypeScript/Node and Bun.

Educational content for adults (18+).

Questions people ask#

Can I use Deno Deploy?#

Deploy is request-driven; for a 24/7 stream, run the script on a VM or container. For scheduled REST, see Supabase Edge Functions.

Why not set the x-api-key header?#

The web-standard constructor has no headers argument. The URL key works the same on the server.

Does Deno support compression?#

PinnFeed only compresses when the client negotiates permessage-deflate; see compression.