ExperimentalThe ID of the session this update pertains to.
The actual update content.
Optional_The _meta property is reserved by ACP to allow clients and agents to attach additional metadata to their interactions. Implementations MUST NOT make assumptions about values at these keys.
See protocol docs: Extensibility
Notification containing a session update from the agent.
Agents can send session updates at any point while the session exists.
See protocol docs: Agent Reports Output