Establishes the connection with a client and negotiates protocol capabilities.
This method is called once at the beginning of the connection to:
The agent should respond with its supported protocol version and capabilities.
See protocol docs: Initialization
Creates a new conversation session with the agent.
Sessions represent independent conversation contexts with their own history and state.
The agent should:
May return an auth_required error if the agent requires authentication.
See protocol docs: Session Setup
OptionalloadLoads an existing session to resume a previous conversation.
This method is only available if the agent advertises the loadSession capability.
The agent should:
See protocol docs: Loading Sessions
Authenticates the client using the specified authentication method.
Called when the agent requires authentication before allowing session creation. The client provides the authentication method ID that was advertised during initialization.
After successful authentication, the client can proceed to create sessions with
newSession without receiving an auth_required error.
See protocol docs: Initialization
Processes a user prompt within a session.
This method handles the whole lifecycle of a prompt:
See protocol docs: Prompt Turn
Cancels ongoing operations for a session.
This is a notification sent by the client to cancel an ongoing prompt turn.
Upon receiving this notification, the Agent SHOULD:
session/update notificationssession/prompt request with StopReason::CancelledSee protocol docs: Cancellation
The Agent interface defines the interface that all ACP-compliant agents must implement.
Agents are programs that use generative AI to autonomously modify code. They handle requests from clients and execute tasks using language models and tools.