Method GetSessionSnapshot

pkg/server/session_manager.go:290–331

GetSessionSnapshot returns the full, self-contained state of a session: its stored fields plus, when an active runtime is attached, its live runtime state (streaming, current agent) and the sequence number of the most recent event on its /events stream. It is the resync primitive for the control pla

(ctx context.Context, id string)

// plane: a client reads the snapshot, then tails /events?since=<LastEventSeq>
// to continue without a gap.
func (sm *SessionManager) GetSessionSnapshot(ctx context.Context, id string) (*api.SessionSnapshotResponse, error) {
	// Prefer the live in-memory session (it has the freshest messages and
	// title) and fall back to the store when the session is not attached.
	var sess *session.Session
	streaming := false
	agent := ""
	if rs, ok := sm.runtimeSessions.Load(id); ok {
		sess = rs.session
		agent = rs.runtime.CurrentAgentName(ctx)
		// Probe streaming state without interfering: TryLock succeeds only
		// when no RunStream is in progress.
		if rs.streaming.TryLock() {
			rs.streaming.Unlock()
		} else {
			streaming = true
		}
	}
	if sess == nil {
		var err error
		sess, err = sm.sessionStore.GetSession(ctx, id)
		if err != nil {
			return nil, err
		}
	}

	lastSeq, _ := sm.LastEventSeq(id)

	return &api.SessionSnapshotResponse{
		ID:            sess.ID,
		Title:         sess.Title,
		CreatedAt:     sess.CreatedAt,
		WorkingDir:    sess.WorkingDir,
		Messages:      sess.GetAllMessages(),
		ToolsApproved: sess.ToolsApproved,
		Permissions:   sess.Permissions,
		InputTokens:   sess.InputTokens,
		OutputTokens:  sess.OutputTokens,
		Streaming:     streaming,
		Agent:         agent,
		LastEventSeq:  lastSeq,
	}, nil
}

// CreateSession creates a new session from a template.
func (sm *SessionManager) CreateSession(ctx context.Context, sessionTemplate *session.Session) (*session.Session, error) {