diff --git a/src/tui/tui-event-handlers.test.ts b/src/tui/tui-event-handlers.test.ts
new file mode 100644
index 000000000..767681c5e
--- /dev/null
+++ b/src/tui/tui-event-handlers.test.ts
@@ -0,0 +1,124 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { createEventHandlers } from "./tui-event-handlers.js";
+import type { AgentEvent, TuiStateAccess } from "./tui-types.js";
+
+type MockChatLog = {
+  startTool: ReturnType<typeof vi.fn>;
+  updateToolResult: ReturnType<typeof vi.fn>;
+  addSystem: ReturnType<typeof vi.fn>;
+  updateAssistant: ReturnType<typeof vi.fn>;
+  finalizeAssistant: ReturnType<typeof vi.fn>;
+};
+
+describe("tui-event-handlers: handleAgentEvent", () => {
+  const makeState = (overrides?: Partial<TuiStateAccess>): TuiStateAccess => ({
+    agentDefaultId: "main",
+    sessionMainKey: "agent:main:main",
+    sessionScope: "global",
+    agents: [],
+    currentAgentId: "main",
+    currentSessionKey: "agent:main:main",
+    currentSessionId: "session-1",
+    activeChatRunId: "run-1",
+    historyLoaded: true,
+    sessionInfo: {},
+    initialSessionApplied: true,
+    isConnected: true,
+    autoMessageSent: false,
+    toolsExpanded: false,
+    showThinking: false,
+    connectionStatus: "connected",
+    activityStatus: "idle",
+    statusTimeout: null,
+    lastCtrlCAt: 0,
+    ...overrides,
+  });
+
+  const makeContext = (state: TuiStateAccess) => {
+    const chatLog: MockChatLog = {
+      startTool: vi.fn(),
+      updateToolResult: vi.fn(),
+      addSystem: vi.fn(),
+      updateAssistant: vi.fn(),
+      finalizeAssistant: vi.fn(),
+    };
+    const tui = { requestRender: vi.fn() };
+    const setActivityStatus = vi.fn();
+
+    return { chatLog, tui, state, setActivityStatus };
+  };
+
+  it("processes tool events when runId matches activeChatRunId (even if sessionId differs)", () => {
+    const state = makeState({ currentSessionId: "session-xyz", activeChatRunId: "run-123" });
+    const { chatLog, tui, setActivityStatus } = makeContext(state);
+    const { handleAgentEvent } = createEventHandlers({
+      // Casts are fine here: TUI runtime shape is larger than we need in unit tests.
+      chatLog: chatLog as any,
+      tui: tui as any,
+      state,
+      setActivityStatus,
+    });
+
+    const evt: AgentEvent = {
+      runId: "run-123",
+      stream: "tool",
+      data: {
+        phase: "start",
+        toolCallId: "tc1",
+        name: "exec",
+        args: { command: "echo hi" },
+      },
+    };
+
+    handleAgentEvent(evt);
+
+    expect(chatLog.startTool).toHaveBeenCalledWith("tc1", "exec", { command: "echo hi" });
+    expect(tui.requestRender).toHaveBeenCalledTimes(1);
+  });
+
+  it("ignores tool events when runId does not match activeChatRunId", () => {
+    const state = makeState({ activeChatRunId: "run-1" });
+    const { chatLog, tui, setActivityStatus } = makeContext(state);
+    const { handleAgentEvent } = createEventHandlers({
+      chatLog: chatLog as any,
+      tui: tui as any,
+      state,
+      setActivityStatus,
+    });
+
+    const evt: AgentEvent = {
+      runId: "run-2",
+      stream: "tool",
+      data: { phase: "start", toolCallId: "tc1", name: "exec" },
+    };
+
+    handleAgentEvent(evt);
+
+    expect(chatLog.startTool).not.toHaveBeenCalled();
+    expect(chatLog.updateToolResult).not.toHaveBeenCalled();
+    expect(tui.requestRender).not.toHaveBeenCalled();
+  });
+
+  it("processes lifecycle events when runId matches activeChatRunId", () => {
+    const state = makeState({ activeChatRunId: "run-9" });
+    const { tui, setActivityStatus } = makeContext(state);
+    const { handleAgentEvent } = createEventHandlers({
+      chatLog: { startTool: vi.fn(), updateToolResult: vi.fn() } as any,
+      tui: tui as any,
+      state,
+      setActivityStatus,
+    });
+
+    const evt: AgentEvent = {
+      runId: "run-9",
+      stream: "lifecycle",
+      data: { phase: "start" },
+    };
+
+    handleAgentEvent(evt);
+
+    expect(setActivityStatus).toHaveBeenCalledWith("running");
+    expect(tui.requestRender).toHaveBeenCalledTimes(1);
+  });
+});
diff --git a/src/tui/tui-event-handlers.ts b/src/tui/tui-event-handlers.ts
index 148dca67a..66b8129e4 100644
--- a/src/tui/tui-event-handlers.ts
+++ b/src/tui/tui-event-handlers.ts
@@ -95,7 +95,9 @@ export function createEventHandlers(context: EventHandlerContext) {
   const handleAgentEvent = (payload: unknown) => {
     if (!payload || typeof payload !== "object") return;
     const evt = payload as AgentEvent;
-    if (!state.currentSessionId || evt.runId !== state.currentSessionId) return;
+    // Agent events (tool streaming, lifecycle) are emitted per-run. Filter against the
+    // active chat run id, not the session id.
+    if (!state.activeChatRunId || evt.runId !== state.activeChatRunId) return;
     if (evt.stream === "tool") {
       const data = evt.data ?? {};
       const phase = asString(data.phase, "");