The one seam between presence and whatever carries the agent's traffic.
Presence knows nothing about the transport. A host that relays MCP tool calls into the page implements this; so would one that runs the agent in-process.
Deliver the user's answer to a prompt.
Optional
User-side events the agent may want on its next tool result. Optional.
Everything the agent side pushes at the view. Returns the unsubscribe.
The one seam between presence and whatever carries the agent's traffic.
Remarks
Presence knows nothing about the transport. A host that relays MCP tool calls into the page implements this; so would one that runs the agent in-process.