diff --git a/server/src/agentManager.ts b/server/src/agentManager.ts
index 9d0ec97..9e68ad3 100644
--- a/server/src/agentManager.ts
+++ b/server/src/agentManager.ts
@@ -117,6 +117,9 @@ export class AgentManager {
             }
             return null;
         }
+        // SSE 历史与序号属于单次 run。复用前清掉上一轮终态，避免 /run 或 /stream
+        // 重放旧 Done/Error/Stopped，让客户端误以为新任务已经结束；会话消息仍保留。
+        entry.agent.eventHistory$.next([]);
         return entry.agent;
     }
 
diff --git a/server/test/agentManager.test.ts b/server/test/agentManager.test.ts
index 1f5d71a..75eaaf8 100644
--- a/server/test/agentManager.test.ts
+++ b/server/test/agentManager.test.ts
@@ -22,6 +22,9 @@ function mkFakeAgent(events: AgentEvent[] = []) {
             get value() {
                 return history;
             },
+            next(events: AgentEvent[]) {
+                history = events;
+            },
         },
         eventStream$: {
             subscribe(fn: (e: AgentEvent) => void) {
@@ -69,16 +72,18 @@ describe("AgentManager（FR-30 / SPEC-033）", () => {
         expect(entry.subscribers.size).toBeGreaterThanOrEqual(0);
     });
 
-    it("热缓存：终态后 takeWarm 命中返回同一 agent；过期/错配 → null 并 destroy", async () => {
+    it.each(["Done", "Error", "Stopped"] as const)("热缓存：%s 后 takeWarm 清空运行事件并返回同一 agent；错配 → null 并 destroy", async (type) => {
         const m = mkManager();
         const agent = mkFakeAgent();
         m.register(agent as never, "s1", "/w");
-        agent.emit(mkEvent({ type: "Done", message: "完成" }));
+        agent.emit(mkEvent({ type, message: "完成" }));
         await new Promise((r) => setTimeout(r, 0));
 
         // 命中：同会话同工作区
+        expect(agent.eventHistory$.value.map((e) => e.type)).toEqual([type]);
         const warm = m.takeWarm("s1", "/w");
         expect(warm).toBe(agent);
+        expect(agent.eventHistory$.value).toEqual([]); // 新 run 不重放上一轮终态
         // 取走后再取 → null
         expect(m.takeWarm("s1", "/w")).toBeNull();
 
diff --git a/server/test/warmReplay.test.ts b/server/test/warmReplay.test.ts
new file mode 100644
index 0000000..135e6f7
--- /dev/null
+++ b/server/test/warmReplay.test.ts
@@ -0,0 +1,216 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+    AnyAgent,
+    Config,
+    EventStream,
+    projectKeyOf,
+    type ChatMessage,
+} from "@any-code/domain";
+import {
+    AgentManager,
+    getAgentManager,
+    TERMINAL,
+    type StreamFrame,
+} from "../src/agentManager.js";
+import { createApp } from "../src/index.js";
+import { workspaceJobs } from "../src/shared.js";
+import { runningSessions, runningWorkspaces } from "../src/singleFlight.js";
+
+const workspacePath = "/warm-replay-workspace";
+const sessionId = "warm-replay-session";
+const globals = globalThis as unknown as {
+    __anycodeAgentManager?: AgentManager;
+};
+
+/** Real event ordering, with task completion controlled by the test and no model or disk access. */
+function createFakeAgent() {
+    const stream = new EventStream();
+    const session = { messages: [] as ChatMessage[] };
+    const service = { appendEvent: vi.fn().mockResolvedValue(undefined) };
+    stream.submit({ type: "System", message: "cold-start initialization" });
+    return {
+        eventHistory$: stream.history$,
+        eventStream$: stream.event$,
+        getSession: () => session,
+        getService: () => service,
+        getProjectKey: () => projectKeyOf(workspacePath),
+        submit: vi.fn((task: string) => {
+            session.messages.push({ role: "user", content: task });
+            stream.submit({ type: "User", message: task });
+        }),
+        complete(answer: string) {
+            session.messages.push({ role: "assistant", content: answer });
+            stream.submit({ type: "Assistant", message: answer });
+            stream.submit({ type: "Done", message: "task completed" });
+        },
+        stop: vi.fn(),
+        destroy: vi.fn(() => stream.clear()),
+    };
+}
+
+/** Like the Web client, stop consuming at the first terminal event. */
+function observe(response: Response) {
+    const frames: StreamFrame[] = [];
+    let ended = false;
+    const finished = (async () => {
+        const reader = response.body!.getReader();
+        const decoder = new TextDecoder();
+        let buffer = "";
+        try {
+            while (true) {
+                const { value, done } = await reader.read();
+                if (done) return;
+                buffer += decoder.decode(value, { stream: true });
+                let boundary: number;
+                while ((boundary = buffer.indexOf("\n\n")) >= 0) {
+                    const block = buffer.slice(0, boundary);
+                    buffer = buffer.slice(boundary + 2);
+                    if (!block.startsWith("data: ")) continue;
+                    const frame = JSON.parse(block.slice(6)) as StreamFrame;
+                    frames.push(frame);
+                    if (TERMINAL.has(frame.event.type)) return;
+                }
+            }
+        } finally {
+            ended = true;
+            reader.releaseLock();
+        }
+    })();
+    return {
+        frames,
+        finished,
+        get ended() {
+            return ended;
+        },
+    };
+}
+
+describe("warm agent SSE replay", () => {
+    let manager: AgentManager;
+    let agent: ReturnType<typeof createFakeAgent>;
+    let app: ReturnType<typeof createApp>;
+    let requests: AbortController[];
+
+    beforeEach(() => {
+        // Only interval timers are faked: SSE keepalives and the warm-cache sweeper.
+        vi.useFakeTimers({ toFake: ["setInterval", "clearInterval"] });
+        vi.spyOn(Config, "load").mockReturnValue({
+            maxConcurrentRuns: 3,
+        } as Config);
+        globals.__anycodeAgentManager = new AgentManager();
+        manager = getAgentManager();
+        agent = createFakeAgent();
+        vi.spyOn(AnyAgent, "create").mockResolvedValue(
+            agent as unknown as AnyAgent
+        );
+        app = createApp();
+        requests = [];
+        runningSessions().clear();
+        runningWorkspaces().clear();
+    });
+
+    afterEach(() => {
+        for (const controller of requests) controller.abort();
+        manager.stopAll();
+        delete globals.__anycodeAgentManager;
+        workspaceJobs.clear();
+        runningSessions().clear();
+        runningWorkspaces().clear();
+        vi.clearAllTimers();
+        vi.useRealTimers();
+        vi.restoreAllMocks();
+    });
+
+    async function run(task: string) {
+        const controller = new AbortController();
+        requests.push(controller);
+        const response = await app.request(`/api/sessions/${sessionId}/run`, {
+            method: "POST",
+            headers: { "content-type": "application/json" },
+            body: JSON.stringify({ task, workspacePath }),
+            signal: controller.signal,
+        });
+        expect(response.status).toBe(200);
+        await vi.waitFor(() =>
+            expect(agent.submit).toHaveBeenCalledWith(task, undefined)
+        );
+        return observe(response);
+    }
+
+    async function finishFirstRun() {
+        const first = await run("first task");
+        agent.complete("first answer");
+        await first.finished;
+        await vi.waitFor(() => expect(manager.get(sessionId)).toBeUndefined());
+        return first;
+    }
+
+    it("replays cold-start events, then reuses the agent with fresh sequences and intact messages", async () => {
+        const first = await finishFirstRun();
+        expect(first.frames.map((f) => [f.seq, f.event.type])).toEqual([
+            [0, "System"],
+            [1, "User"],
+            [2, "Assistant"],
+            [3, "Done"],
+        ]);
+        expect(first.frames[0].event.message).toBe("cold-start initialization");
+        expect(agent.destroy).not.toHaveBeenCalled();
+
+        const second = await run("second task");
+        await vi.waitFor(() => expect(second.frames.length).toBeGreaterThan(0));
+        expect(
+            second.frames.map((f) => [f.seq, f.event.type, f.event.message])
+        ).toEqual([[0, "User", "second task"]]);
+        expect(second.ended).toBe(false);
+        expect(agent.getSession().messages.map((m) => m.content)).toEqual([
+            "first task",
+            "first answer",
+            "second task",
+        ]);
+        expect(AnyAgent.create).toHaveBeenCalledOnce();
+        expect(manager.get(sessionId)?.agent).toBe(agent);
+
+        agent.complete("second answer");
+        await second.finished;
+        expect(
+            second.frames.map((f) => [f.seq, f.event.type, f.event.message])
+        ).toEqual([
+            [0, "User", "second task"],
+            [1, "Assistant", "second answer"],
+            [2, "Done", "task completed"],
+        ]);
+        expect(second.ended).toBe(true);
+    });
+
+    it("reattaches to only the current warm run and waits for its actual terminal event", async () => {
+        await finishFirstRun();
+        const second = await run("second task");
+        const controller = new AbortController();
+        requests.push(controller);
+        const response = await app.request(
+            `/api/sessions/${sessionId}/stream?since=-1`,
+            {
+                signal: controller.signal,
+            }
+        );
+        expect(response.status).toBe(200);
+        const attached = observe(response);
+        await vi.waitFor(() =>
+            expect(attached.frames.length).toBeGreaterThan(0)
+        );
+        expect(
+            attached.frames.map((f) => [f.seq, f.event.type, f.event.message])
+        ).toEqual([[0, "User", "second task"]]);
+        expect(attached.ended).toBe(false);
+
+        agent.complete("second answer");
+        await Promise.all([second.finished, attached.finished]);
+        expect(attached.frames).toEqual(second.frames);
+        expect(attached.frames.map((f) => [f.seq, f.event.type])).toEqual([
+            [0, "User"],
+            [1, "Assistant"],
+            [2, "Done"],
+        ]);
+        expect(AnyAgent.create).toHaveBeenCalledOnce();
+    });
+});