Module session 

domain::acp::session — the session lifecycle request / response types.

Source of truth: crates/protocol-droid-schema/spec/acp/v1.25.0/schema.json under $defs.NewSessionRequest, $defs.LoadSessionRequest, $defs.ListSessionsRequest, $defs.DeleteSessionRequest, $defs.ResumeSessionRequest, $defs.CloseSessionRequest, $defs.PromptRequest, $defs.CancelNotification, $defs.LogoutRequest, and the matching *Response types.

What this module ships

The 9 agent-side methods the v1.25.0 meta.json lists (13 agent methods total — the 4 session/set_* and authenticate methods are intentionally deferred to keep this commit’s surface focused) plus the CancelNotification and the auxiliary value objects the request / response bodies share: SessionId, StopReason, McpServer (and its three variants), EnvVariable, HttpHeader, and SessionInfo.

Why request / response types in the same module

The schema pairs each request with its response; a module-per-type layout would scatter the round-trip across files. The application::acp dispatcher will route by method name and pair the request with its response in one place, so the consumer sees a single import.

Why a single SessionId newtype

Every session-scoped request carries sessionId. A String would compile, but a SessionId makes the API self-documenting (fn load(req: LoadSessionRequest) vs fn load(req: LoadSessionRequest, id: &str)) and lets the future per-revision codec narrow the type (a hypothetical SessionId::Uuid variant) without rewriting every call site.

Structs

CancelNotification

session/cancel notification. Cancels the in-flight prompt. A notification has no response; the consumer does not await a reply.

CloseSessionRequest

session/close request. Closes an active session without deleting it.

CloseSessionResponse

session/close response. Currently empty; the struct exists so a future field the schema adds does not break the consumer.

DeleteSessionRequest

session/delete request. Removes a session from the agent’s store.

DeleteSessionResponse

session/delete response. Currently empty; the struct exists so a future field the schema adds does not break the consumer.

EnvVariable

An environment variable to set on a launched process. The schema’s EnvVariable is just a (name, value) pair.

HttpHeader

An HTTP header to set when making requests to a remote MCP server. The schema’s HttpHeader is just a (name, value) pair.

ListSessionsRequest

session/list request. Enumerates sessions.

ListSessionsResponse

session/list response. A page of sessions plus the cursor for the next page.

LoadSessionRequest

session/load request. Loads an existing session.

LoadSessionResponse

session/load response.

LogoutRequest

logout request. Terminates the auth session.

LogoutResponse

logout response. Currently empty; the struct exists so a future field the schema adds does not break the consumer.

McpServerHttp

HTTP transport configuration for MCP.

McpServerSse

SSE transport configuration for MCP.

McpServerStdio

Stdio transport configuration for MCP. All agents MUST support this transport.

NewSessionRequest

session/new request. Creates a new session.

NewSessionResponse

session/new response.

PromptRequest

session/prompt request. Sends a user turn to the agent.

PromptResponse

session/prompt response. Carries the reason the turn ended.

ResumeSessionRequest

session/resume request. Resumes a previously closed session.

ResumeSessionResponse

session/resume response.

SessionConfigOption

A session configuration option. The agent advertises the set of options the consumer can set via SetSessionConfigOptionRequest.

SessionId

A unique identifier for a conversation session.

SessionInfo

Information about a single session, returned by session/list.

SessionMode

A single session mode. The agent advertises the set of modes the session can switch between via SessionModeState::available_modes.

SessionModeId

A unique identifier for a session mode.

SessionModeState

The set of session modes the agent supports, plus the mode that is currently active. Returned by session/new and session/load when the agent supports session modes.

Enums

McpServer

Configuration for connecting to an MCP server.

StopReason

Why an agent stopped processing a prompt turn.