diff --git a/apps/admin-web/src/pages/AdminGrayReleaseConfigPage.tsx b/apps/admin-web/src/pages/AdminGrayReleaseConfigPage.tsx
index 6fa1b786a..5a7e62262 100644
--- a/apps/admin-web/src/pages/AdminGrayReleaseConfigPage.tsx
+++ b/apps/admin-web/src/pages/AdminGrayReleaseConfigPage.tsx
@@ -64,7 +64,7 @@ const FIXED_GATE_TARGETS: GateTargetOption[] = [
     key: 'game-distribution:publish',
     label: '游戏发布',
     description:
-      '游戏发布入口灰度：未配置或关闭时对已登录作者默认开放，开启后只放行白名单 / 灰度命中',
+      '未配置或关闭时不开放，启用后按白名单 / 用户标签 / 灰度比例放行',
   },
 ];
 
diff --git a/apps/ai-game-creator-shell/src-tauri/src/game_distribution_publish.rs b/apps/ai-game-creator-shell/src-tauri/src/game_distribution_publish.rs
index dc0417d65..da397f1fa 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/game_distribution_publish.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/game_distribution_publish.rs
@@ -12,6 +12,8 @@ use crate::http_client::agc_main_site_client_builder;
 use crate::platform_session::{
     current_platform_session, validate_platform_session_identity, PlatformSessionSnapshot,
 };
+use base64::Engine;
+
 use reqwest::header::{HeaderName, HeaderValue, CONTENT_TYPE};
 use reqwest::{Method, StatusCode};
 use serde::{Deserialize, Serialize};
@@ -33,6 +35,8 @@ const HTTP_TIMEOUT: Duration = Duration::from_secs(60);
 const COVER_QUEUE_POLL_INTERVAL: Duration = Duration::from_millis(1_600);
 const COVER_QUEUE_TIMEOUT: Duration = Duration::from_secs(20 * 60);
 const COVER_QUEUE_MAX_POLLS: usize = 800;
+const COVER_PREVIEW_MAX_BYTES: usize = 8 * 1024 * 1024;
+
 const PACKAGE_UPLOAD_PROGRESS_EVENT: &str = "game-package-upload-progress";
 
 #[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq)]
@@ -62,6 +66,8 @@ struct CoverGenerationPayload {
     #[serde(default)]
     image_src: Option<String>,
     #[serde(default)]
+    object_key: Option<String>,
+    #[serde(default)]
     asset_object_id: Option<String>,
     #[serde(default)]
     asset: Option<CoverAssetPayload>,
@@ -287,6 +293,48 @@ fn read_cover_asset_id(payload: &CoverGenerationPayload) -> Option<String> {
         .filter(|value| !value.is_empty())
 }
 
+fn cover_preview_data_url(media_type: &str, bytes: &[u8]) -> Result<String, String> {
+    let media_type = media_type
+        .split(';')
+        .next()
+        .unwrap_or(media_type)
+        .trim()
+        .to_ascii_lowercase();
+    if !media_type.starts_with("image/") {
+        return Err("游戏封面预览不是受支持的图片类型".to_string());
+    }
+    if bytes.is_empty() || bytes.len() > COVER_PREVIEW_MAX_BYTES {
+        return Err("游戏封面预览超过安全大小限制".to_string());
+    }
+    let encoded = base64::engine::general_purpose::STANDARD.encode(bytes);
+    Ok(format!("data:{media_type};base64,{encoded}"))
+}
+
+async fn resolve_cover_preview_data_url(
+    snapshot: &PlatformSessionSnapshot,
+    payload: &CoverGenerationPayload,
+) -> Result<String, String> {
+    current_scoped_session(snapshot)?;
+    let client = build_client()?;
+    let source = json!({
+        "objectKey": payload.object_key.as_deref(),
+        "imageSrc": payload.image_src.as_deref(),
+    });
+    let download = crate::assets::resolve_canvas_resource_download_with_limit_route_and_fence(
+        &client,
+        snapshot.api_base_url.as_str(),
+        snapshot.access_token.as_str(),
+        &source,
+        COVER_PREVIEW_MAX_BYTES,
+        "/api/assets/read-url",
+        || Ok(()),
+    )
+    .await?
+    .ok_or_else(|| "游戏封面预览内容为空".to_string())?;
+    current_scoped_session(snapshot)?;
+    cover_preview_data_url(&download.media_type, &download.bytes)
+}
+
 async fn resolve_cover_queue(
     client: &reqwest::Client,
     snapshot: &PlatformSessionSnapshot,
@@ -349,6 +397,7 @@ async fn resolve_cover_queue(
                 .map_err(|error| format!("封面生成结果格式无效：{error}"))?;
             return Ok(CoverGenerationPayload {
                 image_src: completed.image_src.or(initial.image_src),
+                object_key: completed.object_key.or(initial.object_key),
                 asset_object_id: completed.asset_object_id.or(initial.asset_object_id),
                 asset: completed.asset.or(initial.asset),
                 task_id: completed.task_id.or(initial.task_id),
@@ -462,9 +511,16 @@ pub(crate) async fn generate_game_distribution_cover(
     let payload = resolve_cover_queue(&client, &snapshot, initial).await?;
     let asset_object_id =
         read_cover_asset_id(&payload).ok_or_else(|| "生成游戏封面未返回平台素材 ID".to_string())?;
+    let preview_url = match resolve_cover_preview_data_url(&snapshot, &payload).await {
+        Ok(value) => value,
+        Err(error) => {
+            app_log!("游戏封面生成成功但预览下载失败：{error}");
+            String::new()
+        }
+    };
     Ok(GameDistributionCoverGenerationResult {
         asset_object_id,
-        preview_url: payload.image_src.unwrap_or_default().trim().to_string(),
+        preview_url,
         task_id: payload.task_id.unwrap_or_default().trim().to_string(),
         model: payload
             .model
@@ -811,4 +867,14 @@ mod tests {
             Some("asset-from-top-level")
         );
     }
+    #[test]
+    fn cover_preview_data_url_accepts_images_and_rejects_invalid_payloads() {
+        assert_eq!(
+            cover_preview_data_url("image/png; charset=binary", &[0, 1, 2])
+                .expect("image data URL"),
+            "data:image/png;base64,AAEC"
+        );
+        assert!(cover_preview_data_url("text/plain", &[0, 1, 2]).is_err());
+        assert!(cover_preview_data_url("image/png", &[]).is_err());
+    }
 }
diff --git a/docs/project-memory/plans/【实施计划】游戏分发阶段C-AGC发布资料AI生成-2026-09-23.md b/docs/project-memory/plans/【实施计划】游戏分发阶段C-AGC发布资料AI生成-2026-09-23.md
index 646340772..f012f3802 100644
--- a/docs/project-memory/plans/【实施计划】游戏分发阶段C-AGC发布资料AI生成-2026-09-23.md
+++ b/docs/project-memory/plans/【实施计划】游戏分发阶段C-AGC发布资料AI生成-2026-09-23.md
@@ -49,6 +49,8 @@ AGC 发布面板完成三项收敛：
 ## 6. 本次缺陷修复记录
 
 - 2026-09-23：AGC 生成游戏封面请求补充 `generationInputs.source = "ai-game-creator-client"`。队列 worker 依据该来源选择 `GameCreatorResourceEditor` 结果契约；未标记来源时会按 `Standard` 紧凑化并省略 `result`，导致生成完成后无法回传 `assetObjectId`。对应前端定向测试已锁定请求字段与平台素材 ID 回填链路。
+- 2026-10-02：生成结果中的 `imageSrc/objectKey` 是私有素材引用，不再直接交给 WebView `<img>`；AGC Rust 发布 facade 经鉴权 `read-url` 有界下载为 `data:` 图片预览，预览失败不阻断已登记素材发布。
+
 ## 7. 本轮核对（2026-09-28）
 
 六项交付结果都在合并后的工作树里，并有本轮实测：
diff --git a/server-rs/crates/api-server/src/frontend_runtime_config.rs b/server-rs/crates/api-server/src/frontend_runtime_config.rs
index dea103eca..51dd3388b 100644
--- a/server-rs/crates/api-server/src/frontend_runtime_config.rs
+++ b/server-rs/crates/api-server/src/frontend_runtime_config.rs
@@ -16,8 +16,8 @@ use crate::{
 pub struct FrontendRuntimeConfigResponse {
     pub image_editor_agent_sidebar_enabled: bool,
     pub agc_template_library_enabled: bool,
-    /// 游戏发布灰度：运营未配置 `game-distribution:publish` 时对已登录作者默认开放，
-    /// 显式收紧后只有白名单/灰度命中的作者拿到 `true`；匿名一律 `false`（发布必须先登录）。
+    /// 游戏发布灰度：未配置 `game-distribution:publish` 或 `enabled=false` 时不开放；
+    /// 显式配置后按 enabled、白名单、标签和灰度比例判定，匿名一律 `false`（发布必须先登录）。
     pub game_distribution_publish_enabled: bool,
 }
 
diff --git a/server-rs/crates/module-runtime/src/application.rs b/server-rs/crates/module-runtime/src/application.rs
index 8e7bd07c8..a644d5166 100644
--- a/server-rs/crates/module-runtime/src/application.rs
+++ b/server-rs/crates/module-runtime/src/application.rs
@@ -84,7 +84,7 @@ pub fn creation_entry_feature_gate_key(creation_type_id: &str) -> String {
 
 pub const IMAGE_EDITOR_AGENT_SIDEBAR_GATE_KEY: &str = "image-editor:agent-sidebar";
 pub const AGC_TEMPLATE_LIBRARY_GATE_KEY: &str = "agc:template-library";
-/// 游戏分发发布开关：`gate 行缺失`或 `enabled=false` 都表示**未开放**（灰度默认关闭）；
+/// 游戏分发发布开关：gate 行缺失或 `enabled=false` 都表示**未开放**；
 /// 只有 `enabled=true` 且白名单 / 灰度比例 / 用户标签命中时才允许发布。
 pub const GAME_DISTRIBUTION_PUBLISH_GATE_KEY: &str = "game-distribution:publish";
 
diff --git a/src/services/frontendRuntimeConfigService.ts b/src/services/frontendRuntimeConfigService.ts
index c047cad3a..27d7ffa36 100644
--- a/src/services/frontendRuntimeConfigService.ts
+++ b/src/services/frontendRuntimeConfigService.ts
@@ -6,8 +6,8 @@ export type FrontendRuntimeConfig = {
   imageEditorAgentSidebarEnabled: boolean;
   agcTemplateLibraryEnabled: boolean;
   /**
-   * 游戏发布灰度开关：后端未配置 `game-distribution:publish` 时对已登录作者默认开放，
-   * 显式收紧后只有白名单/灰度命中的作者为 `true`，匿名恒为 `false`。
+   * 游戏发布灰度：未配置 `game-distribution:publish` 或 `enabled=false` 时不开放；
+   * 显式配置后只有白名单/灰度命中的作者为 `true`，匿名恒为 `false`。
    */
   gameDistributionPublishEnabled: boolean;
 };