Contexts

What is a context

Contexts are used to allow child components to access parent state without having to pass it down the component tree via props. However, this means that if a component depends on a context, you must make sure that context is provided somewhere up the component tree.

// ✅ This works!
// ConnectionState depends on the RoomContext which is provided by LiveKitRoom.
<LiveKitRoom>
  <ConnectionState />
</LiveKitRoom>

// ✅ This works!
// The context provider (LiveKitRoom) does not have to be a immediate parent of the component (ConnectionState) needing the context.
<LiveKitRoom>
    <div>
        <ConnectionState />
    </div>
</LiveKitRoom>

// ❌ This will cause an error!
// ConnectionState depends on a parent component to provide the RoomContext.
<LiveKitRoom></LiveKitRoom>
<ConnectionState />

If you only use LiveKit Components without creating custom components yourself, you don't need to interact with the contexts. Just make sure that the component tree meets the context requirements of all components. If it doesn't, you'll get an error message telling you which context is missing.

The two most important contexts are:

Room context

The RoomContext provides the Room object as a context.

/* 1️⃣ LiveKitRoom provides the RoomContext. */
<LiveKitRoom serverUrl="server-url" token="user-access-token" connect={true}>
  {/* 2️⃣ ConnectionState uses the RoomContext to retrieve information about the connection state of the room. */}
  <ConnectionState />
</LiveKitRoom>

Participant context

The ParticipantContext provides a Participant object to all child components.

/* 1️⃣ ParticipantTile provides the ParticipantContext. */
<ParticipantTile>
  {/* 2️⃣ ParticipantName uses the ParticipantContext to get the participant name. */}
  <ParticipantName />
</ParticipantTile>

Accessing contexts

Context access is not required to build an application using LiveKit Components. However, if you want to build custom components that depend on a context, you can use one of the hooks we provide. For example, you can use the useRoomContext hook to access the Room object and the useParticipantContext hook to access the Participant object.