diff --git a/desktop/renderer/src/components/SidePanel.vue b/desktop/renderer/src/components/SidePanel.vue
index 39874c3..c5fb22b 100644
--- a/desktop/renderer/src/components/SidePanel.vue
+++ b/desktop/renderer/src/components/SidePanel.vue
@@ -219,16 +219,22 @@ onMounted(() => {
   gateway.refreshWeixinStatus();
 });
 
-/** Only create a new session if the current one already has messages. */
+/**
+ * Ensure the active chat is a fresh session bound to the currently-selected agent.
+ * Starts a new session when the current chat already has messages, OR when it
+ * belongs to a different agent than the one now selected — otherwise switching
+ * agents on an empty chat would keep routing to (and displaying) the old agent.
+ */
 function ensureEmptySession() {
-  if (chatStore.messages.length > 0) {
-    chatStore.newSession(agentStore.currentAgentId);
+  const targetAgentId = agentStore.currentAgentId;
+  if (chatStore.messages.length > 0 || chatStore.currentSessionAgentId !== targetAgentId) {
+    chatStore.newSession(targetAgentId);
   }
-  // Tag the (new or existing) session with the current agent
+  // Tag the (new or existing) session with the current agent.
   const key = chatStore.sessionKey;
   const s = sessionStore.sessions.find((s) => s.key === key);
-  if (s && !s.agentId) {
-    s.agentId = agentStore.currentAgentId;
+  if (s) {
+    s.agentId = targetAgentId;
   }
 }
 
diff --git a/desktop/renderer/src/components/chat/ChatMessageList.vue b/desktop/renderer/src/components/chat/ChatMessageList.vue
index 1c9d76b..e0d1041 100644
--- a/desktop/renderer/src/components/chat/ChatMessageList.vue
+++ b/desktop/renderer/src/components/chat/ChatMessageList.vue
@@ -467,6 +467,7 @@
 import { ref, computed, nextTick, watch } from "vue";
 import { useRouter } from "vue-router";
 import { useChatStore } from "@/stores/chat";
+import { useAgentStore } from "@/stores/agents";
 import {
   renderMarkdown,
   stripAnsi,
@@ -485,15 +486,23 @@ import searchGif from "@/assets/openclaw_search_preview_transparent.gif";
 import bookGif from "@/assets/book.gif";
 import binocularsGif from "@/assets/binoculars.gif";
 import mapGif from "@/assets/map.gif";
-import avatarImg from "@/assets/normal.png";
+import defaultAvatar from "@/assets/normal.png";
 
 defineProps<{
   studioMode?: boolean;
 }>();
 
 const chatStore = useChatStore();
+const agentStore = useAgentStore();
 const router = useRouter();
 
+/** Avatar of the agent bound to the current session (falls back to the default). */
+const avatarImg = computed(() => {
+  const agentId = chatStore.currentSessionAgentId;
+  const agent = agentStore.agents.find((a) => a.id === agentId);
+  return agent?.avatar || defaultAvatar;
+});
+
 function openModelSettings() {
   router.push({ name: "settings", params: { section: "models" } });
 }
diff --git a/desktop/renderer/src/stores/chat.test.ts b/desktop/renderer/src/stores/chat.test.ts
index d5976c5..8dffb40 100644
--- a/desktop/renderer/src/stores/chat.test.ts
+++ b/desktop/renderer/src/stores/chat.test.ts
@@ -437,6 +437,20 @@ describe("useChatStore — draft sessions", () => {
       ),
     ).toBe(true);
   });
+
+  it("encodes a non-default agent into the session key so the gateway routes to it", () => {
+    const store = useChatStore();
+    store.newSession("coder");
+    expect(store.sessionKey).toMatch(/^agent:coder:session-/);
+    expect(store.currentSessionAgentId).toBe("coder");
+  });
+
+  it("keeps a bare session key for the default (main) agent", () => {
+    const store = useChatStore();
+    store.newSession("main");
+    expect(store.sessionKey).toMatch(/^session-/);
+    expect(store.currentSessionAgentId).toBe("main");
+  });
 });
 // ── Message content extraction tests ──
 
diff --git a/desktop/renderer/src/stores/chat.ts b/desktop/renderer/src/stores/chat.ts
index 9ea365d..b8c4f1e 100644
--- a/desktop/renderer/src/stores/chat.ts
+++ b/desktop/renderer/src/stores/chat.ts
@@ -1,5 +1,5 @@
 import { defineStore } from "pinia";
-import { ref } from "vue";
+import { ref, computed } from "vue";
 import { useSessionStore } from "./sessions";
 import { scanPii, redactPii } from "@/utils/pii-scanner";
 
@@ -152,6 +152,18 @@ export const useChatStore = defineStore("chat", () => {
   const pendingPrompt = ref<string | null>(null);
   const pendingSessionAgentId = ref<string | undefined>(undefined);
 
+  /**
+   * The agent bound to the currently-active session.
+   * Non-default agents are encoded into the session key as `agent:<id>:...`;
+   * for a freshly-created session not yet synced, fall back to the pending
+   * agent; otherwise the session belongs to the default (main) agent.
+   */
+  const currentSessionAgentId = computed(() => {
+    const match = /^agent:([^:]+):/.exec(sessionKey.value);
+    if (match) return match[1];
+    return pendingSessionAgentId.value || "main";
+  });
+
   /** Per-agent last message preview text */
   const lastMessageMap = ref<Record<string, string>>({});
 
@@ -1025,7 +1037,11 @@ export const useChatStore = defineStore("chat", () => {
     _syncToSessionStore();
     _saveCurrentState();
 
-    const key = `session-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+    const suffix = `session-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+    // Encode the agent into the session key so the gateway routes the message
+    // to the selected agent. Bare keys (and "main") are normalised to the
+    // default (main) agent server-side, so only non-default agents are prefixed.
+    const key = agentId && agentId !== "main" ? `agent:${agentId}:${suffix}` : suffix;
     pendingSessionAgentId.value = agentId;
     sessionKey.value = key;
     resolvedSessionKey.value = null;
@@ -1213,6 +1229,7 @@ export const useChatStore = defineStore("chat", () => {
   return {
     sessionKey,
     resolvedSessionKey,
+    currentSessionAgentId,
     messages,
     loading,
     sending,