diff --git a/packages/server/src/services/hermes/group-chat/agent-clients.ts b/packages/server/src/services/hermes/group-chat/agent-clients.ts
index a80bdb1..33c985c 100644
--- a/packages/server/src/services/hermes/group-chat/agent-clients.ts
+++ b/packages/server/src/services/hermes/group-chat/agent-clients.ts
@@ -72,6 +72,12 @@ export function groupContextTokensWithFixedOverhead(
     return Math.floor(fixedContextTokens) + estimateGroupHistoryMessageTokens(history)
 }
 
+export function groupBridgeReasoningDeltaFromEvent(event: Record<string, unknown>): string | null {
+    if (String(event.event || '') !== 'reasoning.delta') return null
+    const text = String(event.text || '')
+    return text ? text : null
+}
+
 interface MemberData {
     id: string
     name: string
@@ -698,10 +704,12 @@ class AgentClient {
                     approval_id: (ev as any).approval_id,
                     choice: (ev as any).choice,
                 })
-            } else if (eventType === 'reasoning.delta' || eventType === 'thinking.delta') {
-                const text = String((ev as any)?.text || '')
-                reasoning += text
-                this.emitMessageReasoningDelta(roomId, getCurrentMessageId(), text)
+            } else {
+                const text = groupBridgeReasoningDeltaFromEvent(ev as Record<string, unknown>)
+                if (text) {
+                    reasoning += text
+                    this.emitMessageReasoningDelta(roomId, getCurrentMessageId(), text)
+                }
             }
         }
         return reasoning
diff --git a/packages/server/src/services/hermes/group-chat/index.ts b/packages/server/src/services/hermes/group-chat/index.ts
index 4b9108b..5050919 100644
--- a/packages/server/src/services/hermes/group-chat/index.ts
+++ b/packages/server/src/services/hermes/group-chat/index.ts
@@ -142,6 +142,12 @@ function normalizeMentionDepth(depth: unknown): number {
     return Number.isFinite(value) && value > 0 ? Math.floor(value) : 0
 }
 
+function maxAgentMentionDepth(): number {
+    const value = Number(process.env.HERMES_GROUP_CHAT_MAX_AGENT_MENTION_DEPTH)
+    if (!Number.isFinite(value) || value <= 0) return 4
+    return Math.min(10, Math.floor(value))
+}
+
 function groupRunOrder(id: string): { baseId: string; phase: number } {
     const value = String(id || '')
     const partMatch = value.match(/^(.*)_part_(\d+)(?:_(toolcall|toolresult)_.+)?$/)
@@ -965,10 +971,14 @@ export class GroupChatServer {
         ack?.({ id: savedMsg.id })
 
         const mentionDepth = normalizeMentionDepth(data.mentionDepth)
-        const shouldRouteMentions = savedMsg.role === 'user'
+        const isAgentReply = savedMsg.role === 'assistant' && member?.source === 'agent'
+        const shouldRouteMentions = savedMsg.role === 'user' ||
+            (isAgentReply && mentionDepth < maxAgentMentionDepth())
 
         if (shouldRouteMentions) {
-            // Server-side @mention routing — parse user mentions and invoke agents directly.
+            // Server-side @mention routing — parse mentions and invoke agents directly.
+            // Agent replies are allowed to mention other agents, but mentionDepth
+            // bounds chained agent-to-agent handoffs so one prompt cannot loop forever.
             this.agentClients.processMentions(roomId, {
                 content: contentToText(savedMsg.content),
                 input: Array.isArray(data.content) ? data.content : undefined,
diff --git a/tests/server/group-chat-context-cache.test.ts b/tests/server/group-chat-context-cache.test.ts
index 1988504..49bc931 100644
--- a/tests/server/group-chat-context-cache.test.ts
+++ b/tests/server/group-chat-context-cache.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest'
 import { countTokens } from '../../packages/server/src/lib/context-compressor'
 import {
   estimateGroupHistoryMessageTokens,
+  groupBridgeReasoningDeltaFromEvent,
   groupContextTokensWithFixedOverhead,
 } from '../../packages/server/src/services/hermes/group-chat/agent-clients'
 
@@ -22,4 +23,19 @@ describe('group chat fixed context cache helpers', () => {
     expect(groupContextTokensWithFixedOverhead(undefined, [{ content: 'hello' }])).toBeUndefined()
     expect(groupContextTokensWithFixedOverhead(null, [{ content: 'hello' }])).toBeUndefined()
   })
+
+  it('keeps spinner thinking events out of persisted group-chat reasoning', () => {
+    expect(groupBridgeReasoningDeltaFromEvent({
+      event: 'thinking.delta',
+      text: '(◕‿◕✿) pondering...',
+    })).toBeNull()
+    expect(groupBridgeReasoningDeltaFromEvent({
+      event: 'reasoning.delta',
+      text: 'real reasoning',
+    })).toBe('real reasoning')
+    expect(groupBridgeReasoningDeltaFromEvent({
+      event: 'reasoning.delta',
+      text: '',
+    })).toBeNull()
+  })
 })
diff --git a/tests/server/group-chat-member-sync.test.ts b/tests/server/group-chat-member-sync.test.ts
index 27e9e13..72035d2 100644
--- a/tests/server/group-chat-member-sync.test.ts
+++ b/tests/server/group-chat-member-sync.test.ts
@@ -270,15 +270,15 @@ describe('Group Chat member/agent identity sync', () => {
     expect(ctx.body).toEqual({ rooms })
   })
 
-  it('routes @mentions only from user messages, not agent replies', () => {
+  it('routes @mentions from users and bounded agent replies', () => {
     const server = Object.create(GroupChatServer.prototype) as any
     const emit = vi.fn()
     server.rooms = new Map([
       ['room-1', {
         hasOnlineMember: vi.fn(() => true),
         getOnlineMemberBySocketId: vi.fn((socketId: string) => socketId === 'agent-socket'
-          ? { userId: 'agent-1', name: '丫鬟' }
-          : { userId: 'human-1', name: 'Human' }),
+          ? { userId: 'agent-1', name: '丫鬟', source: 'agent' }
+          : { userId: 'human-1', name: 'Human', source: 'human' }),
       }],
     ])
     server.socketUserMap = new Map([
@@ -297,9 +297,23 @@ describe('Group Chat member/agent identity sync', () => {
 
     server.handleMessage({ id: 'human-socket' }, { roomId: 'room-1', content: '@all hi', role: 'user' }, vi.fn())
     expect(server.agentClients.processMentions).toHaveBeenCalledTimes(1)
+    expect(server.agentClients.processMentions).toHaveBeenLastCalledWith('room-1', expect.objectContaining({
+      content: '@all hi',
+      senderId: 'human-1',
+      mentionDepth: 0,
+    }))
 
     server.agentClients.processMentions.mockClear()
     server.handleMessage({ id: 'agent-socket' }, { roomId: 'room-1', content: '@all agent says hi', role: 'assistant', mentionDepth: 1 }, vi.fn())
+    expect(server.agentClients.processMentions).toHaveBeenCalledTimes(1)
+    expect(server.agentClients.processMentions).toHaveBeenLastCalledWith('room-1', expect.objectContaining({
+      content: '@all agent says hi',
+      senderId: 'agent-1',
+      mentionDepth: 1,
+    }))
+
+    server.agentClients.processMentions.mockClear()
+    server.handleMessage({ id: 'agent-socket' }, { roomId: 'room-1', content: '@all too deep', role: 'assistant', mentionDepth: 4 }, vi.fn())
     expect(server.agentClients.processMentions).not.toHaveBeenCalled()
   })
 })