diff --git a/mateclaw-server/src/main/java/vip/mate/agent/graph/plan/node/StepExecutionNode.java b/mateclaw-server/src/main/java/vip/mate/agent/graph/plan/node/StepExecutionNode.java
index d19066e3..59c4ca8a 100644
--- a/mateclaw-server/src/main/java/vip/mate/agent/graph/plan/node/StepExecutionNode.java
+++ b/mateclaw-server/src/main/java/vip/mate/agent/graph/plan/node/StepExecutionNode.java
@@ -30,10 +30,13 @@ import vip.mate.planning.service.PlanningService;
 import vip.mate.agent.context.ChatOrigin;
 import vip.mate.skill.runtime.SkillCatalogRenderer;
 import vip.mate.tool.builtin.DelegateAgentTool;
+import vip.mate.tool.builtin.DelegationContext;
+import vip.mate.tool.builtin.ToolExecutionContext;
 
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * 步骤执行节点
@@ -221,7 +224,7 @@ public class StepExecutionNode implements NodeAction {
         if (delegateAgentTool != null && assignedAgentId != null
                 && !assignedAgentId.equals(parseLongOrNull(agentId))) {
             return executeDelegatedStep(accessor, stepIndex, step, planId, assignedAgentId,
-                    chatOrigin, events, iterationEventsOn);
+                    conversationId, chatOrigin, events, iterationEventsOn);
         }
 
         if (iterationEventsOn) {
@@ -658,7 +661,7 @@ public class StepExecutionNode implements NodeAction {
      */
     private Map<String, Object> executeDelegatedStep(
             PlanStateAccessor accessor, int stepIndex, String step, Long planId,
-            Long assignedAgentId, ChatOrigin chatOrigin,
+            Long assignedAgentId, String conversationId, ChatOrigin chatOrigin,
             List<GraphEventPublisher.GraphEvent> events, boolean iterationEventsOn) {
 
         if (iterationEventsOn) {
@@ -672,12 +675,28 @@ public class StepExecutionNode implements NodeAction {
 
         log.info("[StepExecution] Delegating step {} to agent {}", stepIndex + 1, assignedAgentId);
 
+        // Seed the delegation context with the plan's REAL conversation id (from
+        // graph state) so the delegated child conversation is parented to it and
+        // stays hidden from the user's conversation list. The ChatOrigin in the
+        // plan-execute path carries no conversationId, so delegateByAgentId can't
+        // derive the parent on its own — we provide it here.
+        boolean seeded = false;
+        if (conversationId != null && !conversationId.isBlank()
+                && DelegationContext.parentConversationId() == null
+                && ToolExecutionContext.conversationId() == null) {
+            DelegationContext.enter(conversationId, Set.of(), conversationId, null, 0);
+            seeded = true;
+        }
         String result;
         try {
             result = delegateAgentTool.delegateByAgentId(assignedAgentId, step, chatOrigin);
         } catch (Exception e) {
             log.error("[StepExecution] Delegated step {} threw: {}", stepIndex, e.getMessage(), e);
             result = "[错误] 委派执行异常：" + e.getMessage();
+        } finally {
+            if (seeded) {
+                DelegationContext.exit();
+            }
         }
 
         String finalResult = result != null ? result : "";
diff --git a/mateclaw-server/src/main/java/vip/mate/tool/builtin/DelegateAgentTool.java b/mateclaw-server/src/main/java/vip/mate/tool/builtin/DelegateAgentTool.java
index 4fd4de33..b12a0ec8 100644
--- a/mateclaw-server/src/main/java/vip/mate/tool/builtin/DelegateAgentTool.java
+++ b/mateclaw-server/src/main/java/vip/mate/tool/builtin/DelegateAgentTool.java
@@ -340,8 +340,30 @@ public class DelegateAgentTool {
         if (target == null || !Boolean.TRUE.equals(target.getEnabled())) {
             return "[错误] 未找到 id=" + agentId + " 的已启用 Agent。";
         }
-        ToolContext ctx = (parentOrigin != null ? parentOrigin : ChatOrigin.EMPTY).toToolContext();
-        return delegateToAgent(target.getName(), task, false, ctx);
+        ChatOrigin origin = parentOrigin != null ? parentOrigin : ChatOrigin.EMPTY;
+        ToolContext ctx = origin.toToolContext();
+        // A graph-node-initiated delegation (e.g. a plan step) runs outside any
+        // tool-execution / delegation context, so resolveParentConversationId()
+        // would return null and the child conversation would be created with a
+        // null parent — leaking it into the user's top-level conversation list
+        // (the list filters on parentConversationId IS NULL). Seed a depth-0
+        // delegation frame carrying the parent conversation id from the
+        // ChatOrigin so the child is correctly parented and hidden, mirroring how
+        // a tool-initiated delegation gets its conv id from ToolExecutionContext.
+        String parentConvId = origin.conversationId();
+        boolean seedContext = parentConvId != null && !parentConvId.isBlank()
+                && ToolExecutionContext.conversationId() == null
+                && DelegationContext.parentConversationId() == null;
+        if (seedContext) {
+            DelegationContext.enter(parentConvId, Set.of(), parentConvId, null, 0);
+        }
+        try {
+            return delegateToAgent(target.getName(), task, false, ctx);
+        } finally {
+            if (seedContext) {
+                DelegationContext.exit();
+            }
+        }
     }
 
     // ==================== Parallel delegation ====================