diff --git a/internal/types/message/messages.go b/internal/types/message/messages.go
index 4edfa7a7..f6b6f112 100644
--- a/internal/types/message/messages.go
+++ b/internal/types/message/messages.go
@@ -16,12 +16,12 @@ type Message struct {
 /////////////////////////////
 
 type SystemInit struct {
-	Event           string                `json:"event,omitempty"`
-	MemberId        string                `json:"member_id"`
-	ControlHost     ControlHost           `json:"control_host"`
-	ScreenSize      ScreenSize            `json:"screen_size"`
-	Members         map[string]MemberData `json:"members"`
-	ImplicitHosting bool                  `json:"implicit_hosting"`
+	Event           string                 `json:"event,omitempty"`
+	SessionId       string                 `json:"session_id"`
+	ControlHost     ControlHost            `json:"control_host"`
+	ScreenSize      ScreenSize             `json:"screen_size"`
+	Sessions        map[string]SessionData `json:"sessions"`
+	ImplicitHosting bool                   `json:"implicit_hosting"`
 }
 
 type SystemAdmin struct {
@@ -64,10 +64,10 @@ type SignalVideo struct {
 }
 
 /////////////////////////////
-// Member
+// Session
 /////////////////////////////
 
-type MemberID struct {
+type SessionID struct {
 	Event string `json:"event,omitempty"`
 	ID    string `json:"id"`
 }
@@ -84,7 +84,7 @@ type SessionState struct {
 	*types.SessionState
 }
 
-type MemberData struct {
+type SessionData struct {
 	Event   string              `json:"event,omitempty"`
 	ID      string              `json:"id"`
 	Profile types.MemberProfile `json:"profile"`
diff --git a/internal/websocket/filechooserdialog.go b/internal/websocket/filechooserdialog.go
index 10465040..08bd0762 100644
--- a/internal/websocket/filechooserdialog.go
+++ b/internal/websocket/filechooserdialog.go
@@ -22,7 +22,7 @@ func (manager *WebSocketManagerCtx) fileChooserDialogEvents() {
 
 		activeSession = host
 
-		go manager.sessions.Broadcast(message.MemberID{
+		go manager.sessions.Broadcast(message.SessionID{
 			Event: event.FILE_CHOOSER_DIALOG_OPENED,
 			ID:    host.ID(),
 		}, nil)
@@ -34,7 +34,7 @@ func (manager *WebSocketManagerCtx) fileChooserDialogEvents() {
 
 		activeSession = nil
 
-		go manager.sessions.Broadcast(message.MemberID{
+		go manager.sessions.Broadcast(message.SessionID{
 			Event: event.FILE_CHOOSER_DIALOG_CLOSED,
 		}, nil)
 	})
@@ -45,7 +45,7 @@ func (manager *WebSocketManagerCtx) fileChooserDialogEvents() {
 			return
 		}
 
-		if err := session.Send(message.MemberID{
+		if err := session.Send(message.SessionID{
 			Event: event.FILE_CHOOSER_DIALOG_OPENED,
 			ID:    activeSession.ID(),
 		}); err != nil {
diff --git a/internal/websocket/handler/session.go b/internal/websocket/handler/session.go
index 6bb0a16f..fec66c55 100644
--- a/internal/websocket/handler/session.go
+++ b/internal/websocket/handler/session.go
@@ -8,7 +8,7 @@ import (
 
 func (h *MessageHandlerCtx) SessionCreated(session types.Session) error {
 	h.sessions.Broadcast(
-		message.MemberData{
+		message.SessionData{
 			Event:   event.SESSION_CREATED,
 			ID:      session.ID(),
 			Profile: session.GetProfile(),
@@ -20,7 +20,7 @@ func (h *MessageHandlerCtx) SessionCreated(session types.Session) error {
 
 func (h *MessageHandlerCtx) SessionDeleted(session types.Session) error {
 	h.sessions.Broadcast(
-		message.MemberID{
+		message.SessionID{
 			Event: event.SESSION_DELETED,
 			ID:    session.ID(),
 		}, nil)
diff --git a/internal/websocket/handler/system.go b/internal/websocket/handler/system.go
index f38e86e1..ac3f71b1 100644
--- a/internal/websocket/handler/system.go
+++ b/internal/websocket/handler/system.go
@@ -24,10 +24,10 @@ func (h *MessageHandlerCtx) systemInit(session types.Session) error {
 	}
 
 	// TODO: Sessions.
-	members := map[string]message.MemberData{}
+	sessions := map[string]message.SessionData{}
 	for _, session := range h.sessions.List() {
 		sessionId := session.ID()
-		members[sessionId] = message.MemberData{
+		sessions[sessionId] = message.SessionData{
 			ID:      sessionId,
 			Profile: session.GetProfile(),
 			State:   session.GetState(),
@@ -37,16 +37,14 @@ func (h *MessageHandlerCtx) systemInit(session types.Session) error {
 	return session.Send(
 		message.SystemInit{
 			Event: event.SYSTEM_INIT,
-			// TODO: Session ID.
-			MemberId:    session.ID(),
+			SessionId:   session.ID(),
 			ControlHost: controlHost,
 			ScreenSize: message.ScreenSize{
 				Width:  size.Width,
 				Height: size.Height,
 				Rate:   size.Rate,
 			},
-			// TODO: Sessions.
-			Members:         members,
+			Sessions:        sessions,
 			ImplicitHosting: h.sessions.ImplicitHosting(),
 		})
 }