diff --git a/app/api/schemas/admin.py b/app/api/schemas/admin.py
index 467ba5b..f1f602b 100644
--- a/app/api/schemas/admin.py
+++ b/app/api/schemas/admin.py
@@ -80,9 +80,25 @@ class IntentPayload(StrictPayload):
     version: int = Field(default=1, ge=1)
 
 
+#: `agent_reply_template.chk_template_scene` 允许的取值。**必须逐字对齐**：
+#: 此前 `ReplyPayload.scene` 只校验长度（`min_length=1, max_length=32`），
+#: 于是传一个不在列内的场景会**穿过接口校验、撞上数据库 CHECK 约束**，
+#: 最终以 `500` 冒出（`(3819, "Check constraint 'chk_template_scene' is violated.")`）——
+#: 那本该是一次 `422` 参数校验失败。2026-09-13 由接口逐条测试发现。
+ReplyScene = Literal[
+    "disclaimer",
+    "low_confidence",
+    "compliance_block",
+    "transfer",
+    "model_failure",
+    "system_busy",
+    "clarification",
+]
+
+
 class ReplyPayload(StrictPayload):
     template_code: str = Field(min_length=1, max_length=64)
-    scene: str = Field(min_length=1, max_length=32)
+    scene: ReplyScene
     title: str = Field(min_length=1, max_length=128)
     content_text: str = Field(min_length=1, max_length=32000)
     variables: list[str] = Field(default_factory=list)