Add onRichContent callback

[giannagerton]

Summary

Adds an experimental onRichContent callback so the SDK can hand off agent-driven UI components (e.g. an item card) to whoever's consuming it.

• New RichContentClientEvent/RichContentData schema in @elevenlabs/types (AsyncAPI + generated types)
• onRichContent callback in @elevenlabs/client, dispatched from BaseConversation the same way every other server-pushed event is — no reply sent back, the agent's turn doesn't wait on it
• Re-exported through @elevenlabs/react's HookCallbacks

Backs the embedded widget, which is the only client the server sends components to today — this callback won't fire for other consumers yet. props is agent-authored; treat it as untrusted when rendering.

Summary

RFC

Adds an experimental onRichContent callback so the SDK can hand off agent driven UI to the widget.

• New RichContentClientEvent/RichContentData schema in @elevenlabs/types
• onRichContent callback in @elevenlabs/client, dispatched from BaseConversation. No reply sent back, the agent's turn doesn't wait on it
• Re-exported through @elevenlabs/react's HookCallbacks

---

Note

Medium Risk
New experimental surface that forwards untrusted props to app code; misuse when rendering could introduce XSS, but core conversation and auth paths are unchanged.

Overview
Adds rich_content to the agent WebSocket contract and wires it through @elevenlabs/types, @elevenlabs/client, and @elevenlabs/react as an experimental onRichContent callback.

When the server sends a display component (e.g. item_card), the client invokes the callback with { rich_content_id, component, props, event_id }. Unlike client_tool_call, the SDK does not send a response, so the agent turn is not blocked on the client.

BaseConversation dispatches rich_content in onMessage via handleRichContent; tests cover payload forwarding, no sendMessage, and missing callback. The changeset notes props should be treated as agent-authored and untrusted when rendering into a document.

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[giannagerton]

• Render rich content components in the transcript #915
• Add onRichContent callback #912 👈 (View in Graphite)
• main

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