relay-companion/overlay/deep-link.cjs

Install Relay for Claude Code, Cowork, and Codex, then sign in from the Relay pill.

"use strict";

const MESSAGE_ID = /^[A-Za-z0-9][A-Za-z0-9_.:-]{0,199}$/;
const CHAT_ID = /^chat_[A-Za-z0-9]{1,199}$/;
const HANDOFF_ID = /^[A-Za-z0-9_-]{16,120}$/;

function safeAckOrigin(value) {
  if (!value) return "";
  let url;
  try {
    url = new URL(String(value));
  } catch {
    return "";
  }
  const local = ["localhost", "127.0.0.1", "::1", "[::1]"].includes(url.hostname);
  const trustedHostedReader = url.hostname === "sendrelays.com"
    || url.hostname.endsWith(".sendrelays.com")
    || url.hostname.endsWith(".awsapprunner.com");
  if ((!local && url.protocol !== "https:") || (local && !["http:", "https:"].includes(url.protocol))) return "";
  if (!local && !trustedHostedReader) return "";
  if (url.username || url.password || url.pathname !== "/" || url.search || url.hash) return "";
  return url.origin;
}

function parseRelayDeepLink(value) {
  let url;
  try {
    url = new URL(String(value || ""));
  } catch {
    return null;
  }
  if (url.protocol !== "relay:" || url.hostname !== "open") return null;
  const messageId = String(url.searchParams.get("message") || "").trim();
  const chatId = String(url.searchParams.get("chat") || "").trim();
  const rawHost = String(url.searchParams.get("host") || "").trim().toLowerCase();
  const handoffId = String(url.searchParams.get("handoff") || "").trim();
  const rawAckOrigin = String(url.searchParams.get("ack") || "").trim();
  const ackOrigin = safeAckOrigin(rawAckOrigin);
  if (
    !MESSAGE_ID.test(messageId)
    || (chatId && !CHAT_ID.test(chatId))
    || (handoffId && !HANDOFF_ID.test(handoffId))
    || (rawAckOrigin && !ackOrigin)
    || !["relay", "codex", "claude"].includes(rawHost)
  ) return null;
  return {
    messageId,
    host: rawHost,
    ...(chatId ? { chatId } : {}),
    ...(handoffId ? { handoffId } : {}),
    ...(ackOrigin ? { ackOrigin } : {}),
  };
}

function relayDeepLinkFromArgv(argv) {
  for (const value of Array.isArray(argv) ? argv : []) {
    const parsed = parseRelayDeepLink(value);
    if (parsed) return { url: String(value), ...parsed };
  }
  return null;
}

function relayDeepLinkFailureStatus(error) {
  const status = Number(error?.status || error?.statusCode || 0);
  const code = String(error?.code || "").toLowerCase();
  return [401, 403, 404].includes(status) || /(authorization|credential|signed.?out|unauth)/.test(code)
    ? "account_required"
    : "unavailable";
}

module.exports = { parseRelayDeepLink, relayDeepLinkFromArgv, relayDeepLinkFailureStatus, safeAckOrigin };