diff --git a/.github/workflows/docker-deploy.yml b/.github/workflows/docker-deploy.yml
index 31f85735b..a15f6f73f 100644
--- a/.github/workflows/docker-deploy.yml
+++ b/.github/workflows/docker-deploy.yml
@@ -73,9 +73,25 @@ jobs:
       - name: Build docs image
         run: docker build --progress=plain -t nexent/nexent-docs:${{ github.event.inputs.app_version }} -t nexent/nexent-docs -f deploy/images/dockerfiles/docs/Dockerfile .
 
+  build-sandbox:
+    runs-on: ${{ fromJson(inputs.runner_label_json) }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Build sandbox image
+        run: docker build --build-arg MIRROR=https://pypi.tuna.tsinghua.edu.cn/simple --build-arg APT_MIRROR=tsinghua -t nexent/nexent-sandbox:${{ github.event.inputs.app_version }} -t nexent/nexent-sandbox -f deploy/images/dockerfiles/sandbox/Dockerfile .
+
+  build-mcp:
+    runs-on: ${{ fromJson(inputs.runner_label_json) }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Build MCP image
+        run: docker build --build-arg MIRROR=https://pypi.tuna.tsinghua.edu.cn/simple --build-arg APT_MIRROR=tsinghua -t nexent/nexent-mcp:${{ github.event.inputs.app_version }} -t nexent/nexent-mcp -f deploy/images/dockerfiles/mcp/Dockerfile .
+
   deploy:
     runs-on: ${{ fromJson(inputs.runner_label_json) }}
-    needs: [ build-main, build-data-process, build-web, build-docs ]
+    needs: [ build-main, build-data-process, build-web, build-docs, build-sandbox, build-mcp ]
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
diff --git a/deploy/env/.env.example b/deploy/env/.env.example
index 6ce269eb2..b3b377987 100644
--- a/deploy/env/.env.example
+++ b/deploy/env/.env.example
@@ -257,7 +257,7 @@ IND_AIDP_IMAGE_SIGNING_KEY=
 
 # Default sandbox isolation level: local / docker / wasm.
 # 'local' preserves backward-compatibility for existing deployments.
-NEXENT_SANDBOX_DEFAULT_LEVEL=local
+NEXENT_SANDBOX_DEFAULT_LEVEL=docker
 
 # Default sandbox container lifecycle scope: session / system.
 # session = one container per agent_run, destroyed on run end (strictest isolation).