auth_manual.html

<button id="connect-button" onclick="window.launchNwc()">Connect NWC</button>
<button id="reset-button" onclick="window.resetNwc()">Reset</button>

<script type="module">
  import { webln, nwc } from "https://esm.sh/@getalby/sdk@4.0.0"; // jsdelivr.net, skypack.dev also work
  import {
    generateSecretKey,
    getPublicKey,
  } from "https://esm.sh/nostr-tools@2.9.4"; // jsdelivr.net, skypack.dev also work
  import {
    bytesToHex,
    hexToBytes,
  } from "https://esm.sh/@noble/hashes@1.3.1/utils"; // jsdelivr.net, skypack.dev also work

  const params = new URL(window.location.href).searchParams;
  const walletPubkey = params.get("pubkey");
  const relayUrl = params.get("relay");
  const lud16 = params.get("lud16");
  const secret = window.localStorage.getItem("demo_secret");

  if (walletPubkey && relayUrl) {
    try {
      if (!secret) {
        throw new Error("No secret saved locally");
      }
      window.document.getElementById("connect-button").remove();
      const nwcClient = new nwc.NWCClient({
        secret,
        walletPubkey,
        relayUrl,
        lud16,
      });
      const weblnProvider = new webln.NostrWebLNProvider({
        client: nwcClient,
      });
      await weblnProvider.enable();
      const result = await weblnProvider.getInfo();
      alert("Info response: " + JSON.stringify(result) + " lud16: " + lud16);
    } catch (error) {
      console.error(error);
      alert("Something went wrong: " + error);
    }
  } else {
    window.document.getElementById("reset-button").remove();
  }

  window.resetNwc = async () => {
    window.localStorage.removeItem("demo_secret");
    window.location.href = window.origin;
  };

  window.launchNwc = async () => {
    try {
      if (!window.origin.startsWith("http")) {
        alert(
          "Please use a webserver from this directory e.g. python3 -m http.server",
        );
      }

      const secret = bytesToHex(generateSecretKey());
      const pubkey = getPublicKey(hexToBytes(secret));
      window.localStorage.setItem("demo_secret", secret);
      const authorizationBasePath = prompt(
        "Auth URL",
        "https://my.albyhub.com/apps/new",
      );
      const authUrl = await nwc.NWCClient.getAuthorizationUrl(
        authorizationBasePath,
        {
          name: "Deeplink " + Date.now(),
          returnTo: window.location.href,
        },
        pubkey,
      );
      window.location = authUrl;
    } catch (error) {
      console.error(error);
      alert("Something went wrong: " + error);
    }
  };
</script>