Apply Pinnacle WebSocket snapshot and deltas in a Node Map

Answer: After subscribe, apply snapshot part frames into a Map keyed by market id (eventId:key), then apply each delta changes[] (upsert / remove). Full client: Python/Node guide. Needs Builder (€99/mo).

Core merge logic#

import WebSocket from "ws";

const markets = new Map(); // id -> market object
const KEY = process.env.PINNFEED_KEY;

function applyChange(ch) {
  if (ch.op === "upsert" || ch.type === "upsert") {
    const m = ch.market || ch.value;
    markets.set(m.id, m);
  } else if (ch.op === "remove" || ch.type === "remove") {
    markets.delete(ch.id || ch.marketId);
  }
}

const ws = new WebSocket("wss://pinnfeed.io/v1/stream", {
  headers: { "x-api-key": KEY },
  perMessageDeflate: true,
});

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

ws.on("message", (buf) => {
  const msg = JSON.parse(buf.toString());
  if (msg.type === "ping") return ws.send(JSON.stringify({ type: "pong" }));
  if (msg.type === "snapshot" || msg.part != null) {
    for (const m of msg.markets || []) markets.set(m.id, m);
  }
  if (msg.type === "delta" && Array.isArray(msg.changes)) {
    for (const ch of msg.changes) applyChange(ch);
  }
});

Field names follow the WebSocket docs. Paid plans: 3-day trial; a card is required and it is charged after day 3 unless you cancel. Educational content for adults (18+).

Questions people ask#

Do I merge events the same way?#

Yes — keep a second Map for events if you need home/away metadata; snapshot and delta frames can carry both.

Why Builder?#

Free/Hobby keys get 403 plan_lacks_ws on the WebSocket. REST pollers work on Free; push needs Builder or Pro.