diff --git a/src/agents/subagent-spawn.thread-binding.test.ts b/src/agents/subagent-spawn.thread-binding.test.ts
index 103c900938c..21c07c7db31 100644
--- a/src/agents/subagent-spawn.thread-binding.test.ts
+++ b/src/agents/subagent-spawn.thread-binding.test.ts
@@ -60,11 +60,6 @@ describe("spawnSubagentDirect thread binding delivery", () => {
       registerSubagentRunMock: hoisted.registerSubagentRunMock,
       emitSessionLifecycleEventMock: hoisted.emitSessionLifecycleEventMock,
       hookRunner: hoisted.hookRunner,
-      getSessionBindingService: () => ({ listBySession: () => [] }),
-      resolveConversationDeliveryTarget: () => ({
-        to: "room:!room:example",
-        threadId: "$thread-root",
-      }),
       resolveSubagentSpawnModelSelection: () => "openai-codex/gpt-5.4",
       resolveSandboxRuntimeStatus: () => ({ sandboxed: false }),
     });
@@ -108,7 +103,7 @@ describe("spawnSubagentDirect thread binding delivery", () => {
     );
   });
 
-  it("keeps completion announcements when no bound delivery origin is resolved", async () => {
+  it("keeps completion announcements when only a generic binding is available", async () => {
     hoisted.hookRunner.hasHooks.mockImplementation(
       (hookName?: string) => hookName === "subagent_spawning",
     );
@@ -131,7 +126,21 @@ describe("spawnSubagentDirect thread binding delivery", () => {
       registerSubagentRunMock: hoisted.registerSubagentRunMock,
       emitSessionLifecycleEventMock: hoisted.emitSessionLifecycleEventMock,
       hookRunner: hoisted.hookRunner,
-      getSessionBindingService: () => ({ listBySession: () => [] }),
+      getSessionBindingService: () => ({
+        listBySession: () => [
+          {
+            status: "active",
+            conversation: {
+              channel: "feishu",
+              accountId: "work",
+              conversationId: "oc_dm_chat_1",
+            },
+          },
+        ],
+      }),
+      resolveConversationDeliveryTarget: () => ({
+        to: "channel:oc_dm_chat_1",
+      }),
       resolveSubagentSpawnModelSelection: () => "openai-codex/gpt-5.4",
       resolveSandboxRuntimeStatus: () => ({ sandboxed: false }),
     });
diff --git a/src/agents/subagent-spawn.ts b/src/agents/subagent-spawn.ts
index 9557531cc33..1c8b55bf673 100644
--- a/src/agents/subagent-spawn.ts
+++ b/src/agents/subagent-spawn.ts
@@ -41,13 +41,11 @@ import {
   emitSessionLifecycleEvent,
   getGlobalHookRunner,
   loadConfig,
-  getSessionBindingService,
   mergeSessionEntry,
   mergeDeliveryContext,
   normalizeDeliveryContext,
   pruneLegacyStoreKeys,
   resolveAgentConfig,
-  resolveConversationDeliveryTarget,
   resolveDisplaySessionKey,
   resolveGatewaySessionStoreTarget,
   resolveInternalSessionKey,
@@ -340,9 +338,7 @@ async function ensureThreadBindingForSubagentSpawn(params: {
           "Unable to create or bind a thread for this subagent session. Session mode is unavailable for this target.",
       };
     }
-    const deliveryOrigin =
-      normalizeDeliveryContext(result.deliveryOrigin) ??
-      resolveThreadBindingDeliveryOrigin(params.childSessionKey);
+    const deliveryOrigin = normalizeDeliveryContext(result.deliveryOrigin);
     return {
       status: "ok",
       ...(deliveryOrigin ? { deliveryOrigin } : {}),
@@ -355,30 +351,6 @@ async function ensureThreadBindingForSubagentSpawn(params: {
   }
 }
 
-function resolveThreadBindingDeliveryOrigin(childSessionKey: string): DeliveryContext | undefined {
-  const activeBindings = getSessionBindingService()
-    .listBySession(childSessionKey)
-    .filter((binding) => binding.status === "active");
-  if (activeBindings.length !== 1) {
-    return undefined;
-  }
-  const binding = activeBindings[0];
-  if (!binding) {
-    return undefined;
-  }
-  const target = resolveConversationDeliveryTarget({
-    channel: binding.conversation.channel,
-    conversationId: binding.conversation.conversationId,
-    parentConversationId: binding.conversation.parentConversationId,
-  });
-  return normalizeDeliveryContext({
-    channel: binding.conversation.channel,
-    accountId: binding.conversation.accountId,
-    to: target.to,
-    threadId: target.threadId,
-  });
-}
-
 function hasRoutableDeliveryOrigin(
   origin?: DeliveryContext,
 ): origin is DeliveryContext & { channel: string; to: string } {