diff --git a/apps/api/src/models/ai.py b/apps/api/src/models/ai.py
index 50e72d70..9986ec1c 100644
--- a/apps/api/src/models/ai.py
+++ b/apps/api/src/models/ai.py
@@ -94,11 +94,18 @@ class OpenClawDecision(BaseModel):
         default="default",
         description="Kubernetes namespace",
     )
-    kubectl_command: str = Field(
+    # 2026-03-29 ogt: 允許 None，LLM 可能返回 null
+    kubectl_command: str | None = Field(
         default="",
         description="具體的 kubectl 指令",
     )
 
+    @field_validator("kubectl_command", mode="before")
+    @classmethod
+    def normalize_kubectl_command(cls, v):
+        """將 null 轉換為空字串"""
+        return v if v is not None else ""
+
     # === 風險評估欄位 ===
     risk_level: AIRiskLevel = Field(
         ...,