add to line 715 of main.js

viewer-limit.js

  async function limitConcurrentViewers(maxCount) {
    if (!session.whepInput || !session.salt) {
      throw new Error("Missing session.whepInput or session.salt");
    }
	
	const WORKER_URL = "https://hash-counter-worker.vdo.workers.dev";
	const WINDOW_MS = 5 * 60 * 1000;

    const hashValue = `${session.whepInput}${session.salt}`;
    let intervalId;

    const handleLimit = (count) => {
      if (count < maxCount) {
        return;
      }
      if (typeof warnUser === "function") {
        warnUser("Too many viewers; try again later");
      }
      console.assert(false, "Too many viewers; try again later");
      throw new Error("Too many viewers; try again later");
    };

    const requestCount = async () => {
      const response = await fetch(
        `${WORKER_URL}?hash=${encodeURIComponent(hashValue)}`,
        { cache: "no-store" }
      );
      if (!response.ok) {
        throw new Error(`Worker responded with ${response.status}`);
      }
      const data = await response.json();
      const count = Number(data.requestCount);
      if (!Number.isFinite(count)) {
        throw new Error("Invalid worker response");
      }
      handleLimit(count);
    };

    await requestCount();
    intervalId = setInterval(requestCount, WINDOW_MS);
    return () => clearInterval(intervalId);
  }
  
  limitConcurrentViewers(3)