diff --git a/AGENTS.md b/AGENTS.md
index 41fec57..ca07ede 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -36,6 +36,25 @@ iOS 16+ · 仅 iPhone · 仅竖屏。不做 iPad / 横屏 / 低版本 API 适配
 - 对照 Android **行为** 用 UIKit 重写，不翻译 Compose 语法
 - ViewModel 属性供读取，UI 更新由 View 在回调中主动触发
 
+## Swift 并发与 Actor
+
+工程 **Default Actor Isolation** 配置为 **`nonisolated`**（`suixinkan` 与 `suixinkanTests` 均为 `SWIFT_DEFAULT_ACTOR_ISOLATION = nonisolated`）。新类型默认不隐式绑定 `@MainActor`，与命令式 UIKit + 显式刷新风格一致。
+
+| Target | Default Actor Isolation |
+|--------|-------------------------|
+| `suixinkan` | `nonisolated` |
+| `suixinkanTests` | `nonisolated` |
+
+编写约定：
+
+- **ViewModel / Model**：保持 `nonisolated`，不依赖默认 MainActor；纯逻辑与校验可用 `nonisolated static`。
+- **需要主线程的类型**：在类型上**显式**标注 `@MainActor`（如 `APIClient`、`AuthAPI`、`ProfileAPI`、`NetworkServices`、`OSSUploadService`、`AppRouter`）。
+- **UI 更新**：在 `UIViewController` 内通过 `Task { @MainActor in ... }` 或已在主线程的回调中刷新 UI，不假设 ViewModel 调用方一定在主 Actor；`onStateChange` 回调应切回主线程再改 UI。
+- **网络与可发送类型**：请求/环境等跨边界类型保持 `nonisolated` + `Sendable`（如 `APIRequest`），避免无意引入 actor 隔离冲突。
+- **单元测试**：target 默认为 `nonisolated`；`MockURLSession` 等替身保持 `nonisolated`。需要构造 `@MainActor` 类型（`APIClient`、`AuthAPI` 等）的测试类应显式标 `@MainActor`。
+
+新增代码不要为「凑隔离」给 ViewModel 或普通 model 加 `@MainActor`；仅 UI 入口、共享网络单例等确需主线程协调处显式标注。
+
 ## 代码注释
 
 `class` / `struct` / `enum`、协议及公开 API 必须写 `///` 文档注释，说明职责与用途；复杂内部逻辑按需补充。不写废话注释、不写过时注释。
diff --git a/suixinkan.xcodeproj/project.pbxproj b/suixinkan.xcodeproj/project.pbxproj
index 77e6228..9857b4a 100644
--- a/suixinkan.xcodeproj/project.pbxproj
+++ b/suixinkan.xcodeproj/project.pbxproj
@@ -264,7 +264,7 @@
 				SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
-				SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
+				SWIFT_DEFAULT_ACTOR_ISOLATION = nonisolated;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 5.0;
@@ -300,7 +300,7 @@
 				SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
-				SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
+				SWIFT_DEFAULT_ACTOR_ISOLATION = nonisolated;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 5.0;
@@ -443,7 +443,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator";
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
-				SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
+				SWIFT_DEFAULT_ACTOR_ISOLATION = nonisolated;
 				SWIFT_EMIT_LOC_STRINGS = NO;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 5.0;
@@ -466,7 +466,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator";
 				SWIFT_APPROACHABLE_CONCURRENCY = YES;
-				SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
+				SWIFT_DEFAULT_ACTOR_ISOLATION = nonisolated;
 				SWIFT_EMIT_LOC_STRINGS = NO;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 5.0;