Store Extension and Viewer State

Muxy stores developer-defined JSON objects at four scopes. State is intended for live application data; validate every value your application reads.

Choose a state store

Store	Scope	Read	Write
Extension	Shared by every channel using the extension	Any authorized role	Extension owner in broadcaster context
Channel	Shared by viewers of one channel	Any authorized role	Broadcaster for that channel
Viewer	One viewer on one channel	Current viewer	Current viewer
Extension viewer	One identified viewer across channels	Current identified viewer	Current identified viewer

getAllState() returns all four stores as extension, channel, viewer, and extension_viewer.

Initialize one SDK instance

Muxy.setup({ clientID: "your-extension-client-id" });
const medkit = new Muxy.SDK();
await medkit.loaded();

Read state

const allState = await medkit.getAllState();
const extensionState = await medkit.getExtensionState();
const channelState = await medkit.getChannelState();
const viewerState = await medkit.getViewerState();
const extensionViewerState = await medkit.getExtensionViewerState();

console.log({
  allState,
  extensionState,
  channelState,
  viewerState,
  extensionViewerState,
});

Example aggregate response:

{
  "extension": { "featureEnabled": true },
  "channel": { "round": 4 },
  "viewer": { "selectedCharacter": "ada" },
  "extension_viewer": { "lifetimeScore": 1200 }
}

Write state

Each setter replaces the object at that scope. Use the corresponding JSON Patch REST endpoint when you need an atomic partial update.

await medkit.setExtensionState({ featureEnabled: true });
await medkit.setChannelState({ round: 4 });
await medkit.setViewerState({ selectedCharacter: "ada" });
await medkit.setExtensionViewerState({ lifetimeScore: 1200 });

The extension and channel writes require the roles listed above. A viewer must share identity before using extension-viewer state.

React to changes

State is also delivered through Muxy PubSub. Subscribe once during application startup and remove listeners during teardown; avoid polling the REST API every frame.

For raw endpoints and role-specific examples, see the REST state API.