diff --git a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
index 7c0e04ceb..2dcb0a52e 100644
--- a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
+++ b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/SandboxManager.java
@@ -16,6 +16,8 @@
 package io.agentscope.harness.agent.sandbox;
 
 import io.agentscope.core.agent.RuntimeContext;
+import io.agentscope.harness.agent.sandbox.snapshot.RemoteSandboxSnapshot;
+import io.agentscope.harness.agent.sandbox.snapshot.SandboxSnapshot;
 import java.util.Objects;
 import java.util.Optional;
 import org.slf4j.Logger;
@@ -103,6 +105,7 @@ public SandboxAcquireResult acquire(
                                 "[sandbox] Priority 3: resuming from persisted state (scope={})",
                                 scopeKey.get());
                         SandboxState state = client.deserializeState(stateJson.get());
+                        reInjectRemoteSnapshot(state, sandboxContext);
                         Sandbox sandbox = client.resume(state);
                         return SandboxAcquireResult.selfManaged(sandbox, lease);
                     }
@@ -225,4 +228,24 @@ public void clearState(SandboxContext sandboxContext, RuntimeContext runtimeCont
             log.warn("[sandbox] Failed to clear sandbox state: {}", e.getMessage(), e);
         }
     }
+
+    /**
+     * Re-wires a deserialized {@link RemoteSandboxSnapshot} with a live
+     * {@link io.agentscope.harness.agent.sandbox.snapshot.RemoteSnapshotClient} from the
+     * {@link SandboxContext#getSnapshotSpec()}.
+     *
+     * <p>After JSON deserialization, {@code RemoteSandboxSnapshot} has only the {@code id}
+     * — the {@code RemoteSnapshotClient} must be re-injected before any I/O operations
+     * (snapshot restore during sandbox start).
+     */
+    private void reInjectRemoteSnapshot(SandboxState state, SandboxContext sandboxContext) {
+        SandboxSnapshot snapshot = state.getSnapshot();
+        if (snapshot instanceof RemoteSandboxSnapshot && sandboxContext.getSnapshotSpec() != null) {
+            SandboxSnapshot rewired = sandboxContext.getSnapshotSpec().build(snapshot.getId());
+            state.setSnapshot(rewired);
+            log.debug(
+                    "[sandbox] Re-wired RemoteSandboxSnapshot client for snapshot id={}",
+                    snapshot.getId());
+        }
+    }
 }
diff --git a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/snapshot/RemoteSandboxSnapshot.java b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/snapshot/RemoteSandboxSnapshot.java
index bace902fc..393fc76c6 100644
--- a/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/snapshot/RemoteSandboxSnapshot.java
+++ b/agentscope-harness/src/main/java/io/agentscope/harness/agent/sandbox/snapshot/RemoteSandboxSnapshot.java
@@ -15,6 +15,10 @@
  */
 package io.agentscope.harness.agent.sandbox.snapshot;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
 import io.agentscope.harness.agent.sandbox.SandboxException;
 import java.io.InputStream;
 
@@ -28,16 +32,22 @@
  * {@link RemoteSnapshotClient} cannot be serialized. When persisting session state,
  * only the {@code id} is needed — the client is re-injected from the builder at resume time.
  */
+@JsonIgnoreProperties(ignoreUnknown = true)
 public class RemoteSandboxSnapshot implements SandboxSnapshot {
-
-    private final RemoteSnapshotClient client;
+    @JsonIgnore private final RemoteSnapshotClient client;
     private final String id;
 
+    @JsonCreator
+    private RemoteSandboxSnapshot(@JsonProperty("id") String id) {
+        this.id = id;
+        this.client = null;
+    }
+
     /**
      * Creates a remote snapshot.
      *
      * @param client the remote storage client to delegate operations to
-     * @param id unique identifier for this snapshot
+     * @param id     unique identifier for this snapshot
      */
     public RemoteSandboxSnapshot(RemoteSnapshotClient client, String id) {
         this.client = client;
@@ -78,6 +88,7 @@ public InputStream restore() throws Exception {
      * <p>Checks existence via {@link RemoteSnapshotClient#exists}.
      */
     @Override
+    @JsonIgnore
     public boolean isRestorable() throws Exception {
         try {
             return client.exists(id);
@@ -92,6 +103,7 @@ public String getId() {
     }
 
     @Override
+    @JsonIgnore
     public String getType() {
         return "remote";
     }