diff --git a/apps/api/src/services/resource_resolver.py b/apps/api/src/services/resource_resolver.py
index d46349408..c4debe784 100644
--- a/apps/api/src/services/resource_resolver.py
+++ b/apps/api/src/services/resource_resolver.py
@@ -11,16 +11,17 @@ Resource Resolver - ADR-016 K8s 資源動態驗證
 3. 模糊匹配 namespace 內的 Deployments
 4. 回傳匹配結果或候選列表
 
-版本: v1.0
+版本: v1.1
 建立: 2026-03-26 (台北時區)
 建立者: Claude Code (首席架構師)
+修改: 2026-03-26 (台北) - 新增 IResourceResolver Protocol (P2 架構改進)
 
 @see docs/adr/ADR-016-k8s-resource-naming.md
 """
 
 from dataclasses import dataclass, field
 from difflib import SequenceMatcher
-from typing import Any
+from typing import Protocol, runtime_checkable
 
 import structlog
 
@@ -64,7 +65,34 @@ class K8sResource:
 
 
 # =============================================================================
-# Resource Resolver
+# Protocol Interface (Phase 17 P2 - 架構審查)
+# =============================================================================
+
+@runtime_checkable
+class IResourceResolver(Protocol):
+    """
+    ResourceResolver 介面定義
+
+    用途:
+    - 依賴注入 (DI) 時的型別約束
+    - 測試時 Mock 的型別檢查
+    - 符合 leWOOOgo 積木化規範
+
+    @see feedback_resource_resolver_di.md
+    """
+
+    async def resolve(
+        self,
+        raw_resource: str,
+        namespace: str = "awoooi-prod",
+        resource_kind: str = "deployment",
+    ) -> ResolveResult:
+        """解析原始資源名稱為有效的 K8s 資源"""
+        ...
+
+
+# =============================================================================
+# Resource Resolver Implementation
 # =============================================================================
 
 class ResourceResolver:
@@ -405,15 +433,45 @@ class ResourceResolver:
 
 
 # =============================================================================
-# Singleton Instance
+# Dependency Injection Support (Phase 17 P2 改進)
 # =============================================================================
 
-_resolver: ResourceResolver | None = None
+_resolver: IResourceResolver | None = None
 
 
-def get_resource_resolver() -> ResourceResolver:
-    """取得 ResourceResolver 單例"""
+def get_resource_resolver() -> IResourceResolver:
+    """
+    取得 ResourceResolver 實例
+
+    支援兩種模式：
+    1. 預設: 使用內部 singleton (向後相容)
+    2. DI: 透過 set_resource_resolver() 注入自訂實例
+
+    測試時可使用 set_resource_resolver(mock_resolver) 注入 mock
+
+    Returns:
+        IResourceResolver: 實作 IResourceResolver Protocol 的實例
+    """
     global _resolver
     if _resolver is None:
         _resolver = ResourceResolver()
     return _resolver
+
+
+def set_resource_resolver(resolver: IResourceResolver | None) -> None:
+    """
+    注入 ResourceResolver 實例 (用於 DI 或測試)
+
+    Args:
+        resolver: 自訂 ResourceResolver 實例，None 則重置為預設
+
+    Example:
+        # 測試時注入 mock
+        mock_resolver = MockResourceResolver()
+        set_resource_resolver(mock_resolver)
+
+        # 測試後重置
+        set_resource_resolver(None)
+    """
+    global _resolver
+    _resolver = resolver