fix(harness): preserve explicit sandbox snapshot specs

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-agentrun/src/main/java/io/agentscope/extensions/sandbox/agentrun/AgentRunFilesystemSpec.java

@@ -105,7 +105,9 @@ public AgentRunFilesystemSpec maxRetries(int maxRetries) {
         return this;
     }
 
+    @Override
     public AgentRunFilesystemSpec snapshotSpec(SandboxSnapshotSpec snapshotSpec) {
+        super.snapshotSpec(snapshotSpec);
         this.snapshotSpec = snapshotSpec;
         return this;
     }

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-agentrun/src/test/java/io/agentscope/extensions/sandbox/agentrun/AgentRunFilesystemSpecTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.extensions.sandbox.agentrun;
+
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import io.agentscope.harness.agent.sandbox.snapshot.NoopSnapshotSpec;
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshotSpec;
+import org.junit.jupiter.api.Test;
+
+class AgentRunFilesystemSpecTest {
+
+    @Test
+    void snapshotSpecPreservesExplicitOverride() {
+        SandboxSnapshotSpec snapshotSpec = new NoopSnapshotSpec();
+        AgentRunFilesystemSpec spec = new AgentRunFilesystemSpec();
+
+        assertSame(spec, spec.snapshotSpec(snapshotSpec));
+        assertSame(snapshotSpec, spec.getSnapshotSpecOverride());
+        assertSame(snapshotSpec, spec.snapshotSpec());
+    }
+}

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-daytona/src/main/java/io/agentscope/extensions/sandbox/daytona/DaytonaFilesystemSpec.java

@@ -80,7 +80,9 @@ public DaytonaFilesystemSpec workspaceRoot(String workspaceRoot) {
         return this;
     }
 
+    @Override
     public DaytonaFilesystemSpec snapshotSpec(SandboxSnapshotSpec snapshotSpec) {
+        super.snapshotSpec(snapshotSpec);
         this.snapshotSpec = snapshotSpec;
         return this;
     }

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-daytona/src/test/java/io/agentscope/extensions/sandbox/daytona/DaytonaFilesystemSpecTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.extensions.sandbox.daytona;
+
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import io.agentscope.harness.agent.sandbox.snapshot.NoopSnapshotSpec;
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshotSpec;
+import org.junit.jupiter.api.Test;
+
+class DaytonaFilesystemSpecTest {
+
+    @Test
+    void snapshotSpecPreservesExplicitOverride() {
+        SandboxSnapshotSpec snapshotSpec = new NoopSnapshotSpec();
+        DaytonaFilesystemSpec spec = new DaytonaFilesystemSpec();
+
+        assertSame(spec, spec.snapshotSpec(snapshotSpec));
+        assertSame(snapshotSpec, spec.getSnapshotSpecOverride());
+        assertSame(snapshotSpec, spec.snapshotSpec());
+    }
+}

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-e2b/src/main/java/io/agentscope/extensions/sandbox/e2b/E2bFilesystemSpec.java

@@ -95,7 +95,9 @@ public E2bFilesystemSpec maxRetries(int maxRetries) {
         return this;
     }
 
+    @Override
     public E2bFilesystemSpec snapshotSpec(SandboxSnapshotSpec snapshotSpec) {
+        super.snapshotSpec(snapshotSpec);
         this.snapshotSpec = snapshotSpec;
         return this;
     }

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-e2b/src/test/java/io/agentscope/extensions/sandbox/e2b/E2bFilesystemSpecTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.extensions.sandbox.e2b;
+
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import io.agentscope.harness.agent.sandbox.snapshot.NoopSnapshotSpec;
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshotSpec;
+import org.junit.jupiter.api.Test;
+
+class E2bFilesystemSpecTest {
+
+    @Test
+    void snapshotSpecPreservesExplicitOverride() {
+        SandboxSnapshotSpec snapshotSpec = new NoopSnapshotSpec();
+        E2bFilesystemSpec spec = new E2bFilesystemSpec();
+
+        assertSame(spec, spec.snapshotSpec(snapshotSpec));
+        assertSame(snapshotSpec, spec.getSnapshotSpecOverride());
+        assertSame(snapshotSpec, spec.snapshotSpec());
+    }
+}

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-kubernetes/src/main/java/io/agentscope/extensions/sandbox/kubernetes/KubernetesFilesystemSpec.java

@@ -86,7 +86,9 @@ public KubernetesFilesystemSpec serverPort(int serverPort) {
         return this;
     }
 
+    @Override
     public KubernetesFilesystemSpec snapshotSpec(SandboxSnapshotSpec snapshotSpec) {
+        super.snapshotSpec(snapshotSpec);
         this.snapshotSpec = snapshotSpec;
         return this;
     }

agentscope-extensions/agentscope-extensions-sandbox/agentscope-extensions-sandbox-kubernetes/src/test/java/io/agentscope/extensions/sandbox/kubernetes/KubernetesFilesystemSpecTest.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2024-2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.agentscope.extensions.sandbox.kubernetes;
+
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+import io.agentscope.harness.agent.sandbox.snapshot.NoopSnapshotSpec;
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshotSpec;
+import org.junit.jupiter.api.Test;
+
+class KubernetesFilesystemSpecTest {
+
+    @Test
+    void snapshotSpecPreservesExplicitOverride() {
+        SandboxSnapshotSpec snapshotSpec = new NoopSnapshotSpec();
+        KubernetesFilesystemSpec spec = new KubernetesFilesystemSpec();
+
+        assertSame(spec, spec.snapshotSpec(snapshotSpec));
+        assertSame(snapshotSpec, spec.getSnapshotSpecOverride());
+        assertSame(snapshotSpec, spec.snapshotSpec());
+    }
+}

agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/impl/docker/DockerFilesystemSpec.java

@@ -86,7 +86,9 @@ public DockerFilesystemSpec additionalRunArgs(List<String> additionalRunArgs) {
         return this;
     }
 
+    @Override
     public DockerFilesystemSpec snapshotSpec(SandboxSnapshotSpec snapshotSpec) {
+        super.snapshotSpec(snapshotSpec);
         this.snapshotSpec = snapshotSpec;
         return this;
     }

agentscope-harness/src/test/java/io/agentscope/harness/agent/HarnessAgentDistributedSandboxTest.java

@@ -31,6 +31,7 @@
 import io.agentscope.harness.agent.filesystem.spec.RemoteFilesystemSpec;
 import io.agentscope.harness.agent.sandbox.impl.docker.DockerFilesystemSpec;
 import io.agentscope.harness.agent.sandbox.snapshot.LocalSnapshotSpec;
+import io.agentscope.harness.agent.sandbox.snapshot.NoopSnapshotSpec;
 import java.nio.file.Path;
 import java.util.List;
 import java.util.Map;
@@ -70,8 +71,14 @@ void sandboxMode_withDistributedSession_builds() {
     }
 
     @Test
-    void sandboxMode_snapshotSpecOnFilesystemSpec() {
+    void sandboxMode_explicitSnapshotSpecOverridesDistributedStore() {
         AgentStateStore distributedSession = mock(AgentStateStore.class);
+        DistributedStore distributedStore =
+                DistributedStore.builder()
+                        .agentStateStore(distributedSession)
+                        .baseStore(mock(BaseStore.class))
+                        .sandboxSnapshotSpec(new NoopSnapshotSpec())
+                        .build();
         DockerFilesystemSpec spec = new DockerFilesystemSpec();
         spec.isolationScope(IsolationScope.AGENT);
         spec.snapshotSpec(new LocalSnapshotSpec(workspace.resolve("snapshots")));
@@ -82,11 +89,12 @@ void sandboxMode_snapshotSpecOnFilesystemSpec() {
                                 .name("agent")
                                 .model(stubModel("ok"))
                                 .workspace(workspace)
-                                .stateStore(distributedSession)
+                                .distributedStore(distributedStore)
                                 .filesystem(spec)
                                 .build());
 
         assertEquals(IsolationScope.AGENT, spec.getIsolationScope());
+        assertInstanceOf(LocalSnapshotSpec.class, spec.getSnapshotSpecOverride());
         assertInstanceOf(LocalSnapshotSpec.class, spec.toSandboxContext().getSnapshotSpec());
     }