diff --git a/server-rs/crates/module-runtime/src/agc_model_access.rs b/server-rs/crates/module-runtime/src/agc_model_access.rs
index bf74ee07c..67c0109b7 100644
--- a/server-rs/crates/module-runtime/src/agc_model_access.rs
+++ b/server-rs/crates/module-runtime/src/agc_model_access.rs
@@ -23,13 +23,16 @@ pub const MODEL_NOT_AVAILABLE_FOR_PLAN: &str = "MODEL_NOT_AVAILABLE_FOR_PLAN";
 /// 单个模型要求的权限档。
 ///
 /// 缺省 `Basic`（失败开放）：存量目录 JSON 缺该字段、后台未人工标注都按基础档处理，
-/// 只有被后台明确标成 `Full` 的模型才会对 `Basic` 档账号产生拦截。
+/// 只有被后台明确标成 `Full` 的模型才会对 `Basic` 档账号产生拦截。未知取值同样
+/// 失败开放到 `Basic`（`#[serde(other)]`），避免将来新增档位时旧服务端整份目录解析失败、
+/// 静默回退到上游目录而丢掉人工标注。
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "lowercase")]
 pub enum AgcModelAccess {
-    #[default]
-    Basic,
     Full,
+    #[default]
+    #[serde(other)]
+    Basic,
 }
 
 impl AgcModelAccess {
@@ -246,6 +249,17 @@ mod tests {
         assert_eq!(catalog.models[0].access, AgcModelAccess::Basic);
     }
 
+    #[test]
+    fn unknown_catalog_json_access_fails_open_to_basic() {
+        // 中文注释：未知 access 取值（例如将来新增档位）不能让整份目录解析失败、
+        // 静默回退上游目录，应失败开放到 Basic。
+        let catalog: AgcModelCatalog = serde_json::from_str(
+            r#"{"revision":1,"defaultModelId":"model-a","models":[{"id":"model-a","alias":"model-a","modelId":"model-a","enabled":true,"agentMode":"codex","access":"premium"}]}"#,
+        )
+        .expect("未知 access 应失败开放到 Basic");
+        assert_eq!(catalog.models[0].access, AgcModelAccess::Basic);
+    }
+
     #[test]
     fn basic_plan_does_not_see_full_models_and_gets_first_basic_default() {
         let mut catalog = catalog_from_ids(&["model-a", "model-b", "model-c"], 1);