diff --git a/apps/client/src/network/handlers/CommonHandler.ts b/apps/client/src/network/handlers/CommonHandler.ts
index 9f08170..840f99c 100644
--- a/apps/client/src/network/handlers/CommonHandler.ts
+++ b/apps/client/src/network/handlers/CommonHandler.ts
@@ -4,7 +4,7 @@
  * connect イベントをアプリ用の id 通知に変換する
  */
 import type { Socket } from "socket.io-client";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type { ConnectionLifecyclePayloadOf } from "@repo/shared";
 import { createClientSocketEventBridge } from "./socketEventBridge";
 
diff --git a/apps/client/src/network/handlers/GameHandler.ts b/apps/client/src/network/handlers/GameHandler.ts
index c5f42c6..51bc03a 100644
--- a/apps/client/src/network/handlers/GameHandler.ts
+++ b/apps/client/src/network/handlers/GameHandler.ts
@@ -4,7 +4,7 @@
  * シーン層が利用する通信操作を集約する
  */
 import type { Socket } from "socket.io-client";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type {
   BombHitReportPayload,
   BombPlacedAckPayload,
diff --git a/apps/client/src/network/handlers/LobbyHandler.ts b/apps/client/src/network/handlers/LobbyHandler.ts
index 6e9c994..1b1d70e 100644
--- a/apps/client/src/network/handlers/LobbyHandler.ts
+++ b/apps/client/src/network/handlers/LobbyHandler.ts
@@ -4,7 +4,7 @@
  * ルーム更新購読とゲーム開始要求送信を提供する
  */
 import type { Socket } from "socket.io-client";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type { ServerToClientPayloadOf } from "@repo/shared";
 import { createClientSocketEventBridge } from "./socketEventBridge";
 
diff --git a/apps/client/src/network/handlers/TitleHandler.ts b/apps/client/src/network/handlers/TitleHandler.ts
index 06b18d8..456cdc0 100644
--- a/apps/client/src/network/handlers/TitleHandler.ts
+++ b/apps/client/src/network/handlers/TitleHandler.ts
@@ -4,7 +4,7 @@
  * ルーム参加フローの送受信イベントを集約する
  */
 import type { Socket } from "socket.io-client";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type { ClientToServerPayloadOf, ServerToClientPayloadOf } from "@repo/shared";
 import { createClientSocketEventBridge } from "./socketEventBridge";
 
diff --git a/apps/server/src/logging/constants/eventNames.ts b/apps/server/src/logging/constants/eventNames.ts
index fdeeb92..0aed1a4 100644
--- a/apps/server/src/logging/constants/eventNames.ts
+++ b/apps/server/src/logging/constants/eventNames.ts
@@ -2,7 +2,7 @@
  * eventNames
  * ログ出力で利用するイベント名定数群を提供する
  */
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 
 /** GameUseCaseログで利用するイベント名定数 */
 export const gameUseCaseLogEvents = {
diff --git a/apps/server/src/logging/contracts/payloadByScope.ts b/apps/server/src/logging/contracts/payloadByScope.ts
index 0480671..8620418 100644
--- a/apps/server/src/logging/contracts/payloadByScope.ts
+++ b/apps/server/src/logging/contracts/payloadByScope.ts
@@ -2,7 +2,7 @@
  * payloadByScope
  * スコープごとのログペイロード型契約を提供する
  */
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import { gameDomainLogEvents, gameUseCaseLogEvents, roomDomainLogEvents, roomUseCaseLogEvents } from "../constants/eventNames";
 import { logResults } from "../constants/results";
 import { logScopes } from "../constants/scopes";
diff --git a/apps/server/src/network/handlers/connectionEventLogger.ts b/apps/server/src/network/handlers/connectionEventLogger.ts
index f5ccc84..0fec54f 100644
--- a/apps/server/src/network/handlers/connectionEventLogger.ts
+++ b/apps/server/src/network/handlers/connectionEventLogger.ts
@@ -2,7 +2,7 @@
  * connectionEventLogger
  * 接続ハンドラで利用するログ記録処理を共通化する
  */
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import { logEvent } from "@server/logging/logger";
 import { logResults, logScopes } from "@server/logging/index";
 
diff --git a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
index bad3082..f8cac06 100644
--- a/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
+++ b/apps/server/src/network/handlers/game/createGameOutputAdapter.ts
@@ -3,7 +3,7 @@
  * ゲーム系ユースケースから利用する送信関数群を生成する
  */
 import { Server } from "socket.io";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type {
   BombPlacedAckPayload,
   BombPlacedPayload,
diff --git a/apps/server/src/network/handlers/game/gameEventOrchestrators.ts b/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
index a522685..ac74bf6 100644
--- a/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
+++ b/apps/server/src/network/handlers/game/gameEventOrchestrators.ts
@@ -4,7 +4,7 @@
  * 受信ハンドラからユースケース実行責務を分離する
  * ランタイム未解決時はNetworkスコープでignored_missing_roomを記録する
  */
-import { protocol, type BombHitReportPayload, type PingPayload, type PlaceBombPayload, type playerTypes } from "@repo/shared";
+import { contracts as protocol, type BombHitReportPayload, type PingPayload, type PlaceBombPayload, type playerTypes } from "@repo/shared";
 import { readyForGameCoordinator } from "@server/application/coordinators/readyForGameCoordinator";
 import { startGameCoordinator } from "@server/application/coordinators/startGameCoordinator";
 import { movePlayerUseCase } from "@server/domains/game/application/useCases/movePlayerUseCase";
diff --git a/apps/server/src/network/handlers/game/registerGameHandlers.ts b/apps/server/src/network/handlers/game/registerGameHandlers.ts
index 22b807c..46a7dee 100644
--- a/apps/server/src/network/handlers/game/registerGameHandlers.ts
+++ b/apps/server/src/network/handlers/game/registerGameHandlers.ts
@@ -3,7 +3,7 @@
  * ゲーム関連イベントの受信ハンドラを登録する
  */
 import { Socket } from "socket.io";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type {
   GameEventRoomUseCasePort,
   GameEventRuntimeUseCasePort,
diff --git a/apps/server/src/network/handlers/orchestratorEventLogger.ts b/apps/server/src/network/handlers/orchestratorEventLogger.ts
index 7cfb0a5..ca7487b 100644
--- a/apps/server/src/network/handlers/orchestratorEventLogger.ts
+++ b/apps/server/src/network/handlers/orchestratorEventLogger.ts
@@ -2,7 +2,7 @@
  * orchestratorEventLogger
  * オーケストレータ層で利用するイベントログ記録を共通化する
  */
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import { logEvent } from "@server/logging/logger";
 import { logResults, logScopes } from "@server/logging/index";
 
diff --git a/apps/server/src/network/handlers/payloadGuard.ts b/apps/server/src/network/handlers/payloadGuard.ts
index dd1ab88..3bd6936 100644
--- a/apps/server/src/network/handlers/payloadGuard.ts
+++ b/apps/server/src/network/handlers/payloadGuard.ts
@@ -2,7 +2,7 @@
  * payloadGuard
  * 受信ペイロード検証と不正時ログ記録を共通化するガード生成を担う
  */
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import { logEvent } from "@server/logging/logger";
 import { logResults, logScopes } from "@server/logging/index";
 
diff --git a/apps/server/src/network/handlers/registerConnectionHandlers.ts b/apps/server/src/network/handlers/registerConnectionHandlers.ts
index 0703ca3..fc5d64b 100644
--- a/apps/server/src/network/handlers/registerConnectionHandlers.ts
+++ b/apps/server/src/network/handlers/registerConnectionHandlers.ts
@@ -3,7 +3,7 @@
  * 接続時にルームとゲームの各ハンドラを登録する
  */
 import { Socket } from "socket.io";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import { disconnectCoordinator } from "@server/application/coordinators/disconnectCoordinator";
 import { registerGameHandlers } from "./game/registerGameHandlers";
 import { registerRoomHandlers } from "./room/registerRoomHandlers";
diff --git a/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts b/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
index 90aacab..00610cd 100644
--- a/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
+++ b/apps/server/src/network/handlers/room/createRoomOutputAdapter.ts
@@ -3,7 +3,7 @@
  * ルーム系ユースケースから利用する送信関数を生成する
  */
 import { Server } from "socket.io";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type { roomTypes } from "@repo/shared";
 import type { RoomOutputPort } from "@server/domains/room/application/ports/roomUseCasePorts";
 import { createEmitToRoom } from "@server/network/adapters/socketEmitters";
diff --git a/apps/server/src/network/handlers/room/registerRoomHandlers.ts b/apps/server/src/network/handlers/room/registerRoomHandlers.ts
index 7fdd565..bb3f083 100644
--- a/apps/server/src/network/handlers/room/registerRoomHandlers.ts
+++ b/apps/server/src/network/handlers/room/registerRoomHandlers.ts
@@ -3,7 +3,7 @@
  * ルーム参加イベントの受信ハンドラを登録する
  */
 import { Socket } from "socket.io";
-import { protocol } from "@repo/shared";
+import { contracts as protocol } from "@repo/shared";
 import type {
   JoinRoomEventRoomUseCasePort,
   JoinRoomEventRuntimeUseCasePort,
diff --git a/apps/server/src/network/handlers/socketEventBridge.ts b/apps/server/src/network/handlers/socketEventBridge.ts
index 977ef98..3ead355 100644
--- a/apps/server/src/network/handlers/socketEventBridge.ts
+++ b/apps/server/src/network/handlers/socketEventBridge.ts
@@ -14,16 +14,16 @@
 /** サーバー向けの型付きソケットイベント bridge を生成する */
 export const createServerSocketOnBridge = (socket: Socket) => {
   const bridgeTarget: SocketBridgeTarget = {
-    on: (event, callback) => {
-      socket.on(event, callback);
+    on: <TPayload>(event: string, callback: (payload: TPayload) => void) => {
+      socket.on(event, callback as (payload: unknown) => void);
     },
-    once: (event, callback) => {
-      socket.once(event, callback);
+    once: <TPayload>(event: string, callback: (payload: TPayload) => void) => {
+      socket.once(event, callback as (payload: unknown) => void);
     },
-    off: (event, callback) => {
-      socket.off(event, callback);
+    off: <TPayload>(event: string, callback: (payload: TPayload) => void) => {
+      socket.off(event, callback as (payload: unknown) => void);
     },
-    emit: (event, payload) => {
+    emit: (event: string, payload?: unknown) => {
       if (payload === undefined) {
         socket.emit(event);
         return;
diff --git a/packages/shared/src/domains/app/app.const.ts b/packages/shared/src/domains/app/app.const.ts
index 215be5d..f72fd2a 100644
--- a/packages/shared/src/domains/app/app.const.ts
+++ b/packages/shared/src/domains/app/app.const.ts
@@ -1,8 +1,9 @@
 /**
  * app.const
- * アプリ状態領域で利用する定数と派生型を定義する
- * 画面遷移フェーズの単一情報源を提供する
+ * アプリ状態領域で利用する定数を定義する
+ * 画面遷移フェーズ値を外部利用向けに提供する
  */
+import type { ScenePhase as ScenePhaseType } from "./app.type";
 
 /** クライアント画面遷移で利用するフェーズ定数 */
 export const ScenePhase = {
@@ -10,7 +11,4 @@
   LOBBY: "lobby",
   PLAYING: "playing",
   RESULT: "result",
-} as const;
-
-/** クライアント画面遷移で利用するフェーズ型 */
-export type ScenePhase = (typeof ScenePhase)[keyof typeof ScenePhase];
+} as const satisfies Record<string, ScenePhaseType>;
diff --git a/packages/shared/src/domains/app/app.type.ts b/packages/shared/src/domains/app/app.type.ts
index 041ba11..b334be3 100644
--- a/packages/shared/src/domains/app/app.type.ts
+++ b/packages/shared/src/domains/app/app.type.ts
@@ -1,8 +1,8 @@
 /**
  * app.type
- * アプリ状態領域で利用する共有型を再公開する
- * 定数定義から導出した型を外部参照向けに提供する
+ * アプリ状態領域で利用する共有型を定義する
+ * 画面遷移フェーズ契約を外部参照向けに提供する
  */
 
-/** 画面遷移フェーズ型を再公開する */
-export type { ScenePhase } from "./app.const";
+/** クライアント画面遷移で利用するフェーズ型 */
+export type ScenePhase = "title" | "lobby" | "playing" | "result";
diff --git a/packages/shared/src/domains/room/room.const.ts b/packages/shared/src/domains/room/room.const.ts
index 9617d26..ee3ece3 100644
--- a/packages/shared/src/domains/room/room.const.ts
+++ b/packages/shared/src/domains/room/room.const.ts
@@ -1,15 +1,13 @@
 /**
  * room.const
- * ルーム領域で利用する定数と派生型を定義する
- * 進行フェーズの単一情報源を提供する
+ * ルーム領域で利用する定数を定義する
+ * 進行フェーズ値を外部利用向けに提供する
  */
+import type { RoomPhase as RoomPhaseType } from "./room.type";
 
 /** ルーム進行フェーズで利用する定数 */
 export const RoomPhase = {
   WAITING: "waiting",
   PLAYING: "playing",
   RESULT: "result",
-} as const;
-
-/** ルーム進行フェーズで利用する型 */
-export type RoomPhase = (typeof RoomPhase)[keyof typeof RoomPhase];
+} as const satisfies Record<string, RoomPhaseType>;
diff --git a/packages/shared/src/domains/room/room.type.ts b/packages/shared/src/domains/room/room.type.ts
index aa9657d..ce8c529 100644
--- a/packages/shared/src/domains/room/room.type.ts
+++ b/packages/shared/src/domains/room/room.type.ts
@@ -3,7 +3,9 @@
  * ルーム領域で利用する共有型を定義する
  * 参加状態とイベントペイロード契約を集約する
  */
-import type { RoomPhase } from "./room.const";
+
+/** ルーム進行フェーズ状態型 */
+export type RoomPhase = "waiting" | "playing" | "result";
 
 /** ルーム所属プレイヤー情報 */
 export interface RoomMember {