Get Viewer Information

MEDKit exposes the current extension user after medkit.loaded() resolves. A real Twitch ID is present only when the viewer has shared it with the extension.

Read the current user

import Muxy from "@muxy/extensions-js";
Muxy.setup({ clientID: import.meta.env.VITE_MUXY_CLIENT_ID });
const medkit = new Muxy.SDK();
await medkit.loaded();

const user = await medkit.getUser();

console.log({
  channelID: user.channelID,
  role: user.role,
  sharedTwitchID: user.twitchID ?? null,
  opaqueID: user.twitchOpaqueID,
  bufferMilliseconds: user.buffer,
});

Useful fields in the 2.4.18 User type include:

Field	Meaning
channelID	Current Twitch channel ID
twitchID	Shared Twitch ID, or null when unavailable
twitchOpaqueID	Twitch's opaque identifier for the current extension user
role	Current extension role
buffer, latency, bitrate	Current player context when Twitch supplies it
theme, volume, videoMode	Current viewer UI/player context
twitchJWT	Backend authorization JWT; treat as a secret
helixToken	Token for supported Twitch front-end API calls; treat as a secret

Use onUserUpdate(callback) when a page must react to a refreshed authorization context. Do not log, persist, or send either token to analytics.

Enumerate users who shared their Twitch ID

getExtensionUsers(next?) is admin-only. It returns at most 1,000 entries, may return duplicates across asynchronous pages, and uses "0" as the terminal cursor.

async function getSharedTwitchIDs(medkit) {
  const ids = new Set();
  let cursor;

  do {
    const page = await medkit.getExtensionUsers(cursor);

    for (const user of page.results) {
      ids.add(user.twitch_id);
    }

    cursor = page.next;
  } while (cursor !== "0");

  return [...ids];
}

await medkit.loaded();
const sharedTwitchIDs = await getSharedTwitchIDs(medkit);
console.log(`Received ${sharedTwitchIDs.length} unique Twitch IDs`);

Run bulk enumeration from an approved admin workflow. Add cancellation, backoff, and a page limit before using it against a large extension population.