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
OptionalloadWhether the agent supports session/load.
OptionalmcpMCP capabilities supported by the agent.
OptionalpromptPrompt capabilities supported by the agent.
Optionalsession
Capabilities supported by the agent.
Advertised during initialization to inform the client about available features and content types.
See protocol docs: Agent Capabilities