diff --git a/docs/features/assistant-workbar/progress.md b/docs/features/assistant-workbar/progress.md
index 1e9e25c9..a6f85d14 100644
--- a/docs/features/assistant-workbar/progress.md
+++ b/docs/features/assistant-workbar/progress.md
@@ -46,9 +46,13 @@
 
 ## 2026-09-08 OpenCode 复用与原生控件恢复
 
-- `OpenCodeRuntime` 复用缓存的 embedded server 前执行有超时的健康检查；健康则保留
-  client，检查失败、抛错或超时则清除 client、会话映射、会话初始化及待答问题，关闭旧
-  server 后重建。并发调用共享检查与重建，调用方取消只结束自身等待。
+- `OpenCodeRuntime` 仅在没有活动请求时探测缓存的 embedded server；活动对话或
+  Compact 期间直接复用服务，避免新会话的一次短探测失败关闭其他会话正在使用的进程。
+  空闲探测失败时仍清除旧 client 和会话映射并重建；并发调用共享检查与重建。
+  进程退出或服务关闭会中止绑定它的对话与 Compact，事件流重连等待也可立即取消，
+  请求明确报错，不自动重放已执行命令。本次修复后的真实模型验证共 6 次：正常并发、
+  已复现场景下的共享服务保护均正常完成；主动结束测试进程后旧请求明确失败，新请求
+  在替换服务上完成。此前“新会话完成、旧会话持续等待”的故障不再出现。
 - 请求级 MCP 注册与断开通过实例内 `mutateMcp` 队列串行执行。仅实际发出 `mcp.add`
   的名称进入清理列表；注册尚在排队时取消不追加断开。断开的 1 秒超时从出队后开始。
 - `App` 按本机/远程、连接方式、项目和 Runtime 选择组成 scope 缓存原生清单，用请求
diff --git a/src/main/agent/opencode-runtime.test.ts b/src/main/agent/opencode-runtime.test.ts
index aed8b011..c5422aa8 100644
--- a/src/main/agent/opencode-runtime.test.ts
+++ b/src/main/agent/opencode-runtime.test.ts
@@ -1227,6 +1227,179 @@ describe("OpenCodeRuntime embedded launcher", () => {
     }
   });
 
+  it("does not replace a shared server while another conversation is running", async () => {
+    const setup = runClient([
+      { type: "session.idle", properties: { sessionID: "session-1" } },
+    ]);
+    let release!: () => void;
+    const gate = new Promise<void>((resolve) => { release = resolve; });
+    vi.mocked(setup.event.subscribe).mockImplementationOnce(async () => ({
+      stream: (async function* () {
+        await gate;
+        yield { type: "session.idle", properties: { sessionID: "session-1" } };
+      })(),
+    }) as never);
+    const child = fakeChild();
+    const replacement = fakeChild(43);
+    const { deps, checkServerHealth, spawnMock } = dependencies(child, {
+      createClient: () => setup.client,
+    });
+    spawnMock.mockReturnValueOnce(child).mockReturnValue(replacement);
+    const runtime = new OpenCodeRuntime(options(), deps);
+    const first = collectRun(runtime);
+    try {
+      await vi.waitFor(() => expect(setup.session.promptAsync).toHaveBeenCalledOnce());
+      checkServerHealth.mockResolvedValueOnce(false);
+      const peerEvents: RuntimeEvent[] = [];
+      for await (const event of runtime.run(
+        {
+          requestId: "peer", conversationId: "peer-conversation",
+          prompt: "test", workMode: "execute",
+        },
+        new AbortController().signal,
+      )) peerEvents.push(event);
+      await expect(runtime.testConnection()).resolves.toMatchObject({ available: true });
+      expect(peerEvents.at(-1)).toMatchObject({ type: "done" });
+      expect(checkServerHealth).toHaveBeenCalledOnce();
+      expect(child.kill).not.toHaveBeenCalled();
+      expect(spawnMock).toHaveBeenCalledOnce();
+      release();
+      await expect(first).resolves.toContainEqual(expect.objectContaining({ type: "done" }));
+      await expect(runtime.testConnection()).resolves.toMatchObject({ available: true });
+      expect(child.kill).toHaveBeenCalledOnce();
+      expect(spawnMock).toHaveBeenCalledTimes(2);
+    } finally {
+      release();
+      await first.catch(() => undefined);
+      await runtime.dispose();
+    }
+  });
+
+  it.each(["exit", "dispose"])(
+    "settles an active request when its embedded server ends through %s",
+    async (ending) => {
+      const setup = runClient([]);
+      vi.mocked(setup.event.subscribe).mockImplementation(async (_input, options) => ({
+        stream: (async function* () {
+          const signal = options!.signal!;
+          await new Promise<void>((_resolve, reject) => {
+            signal.addEventListener("abort", () => reject(signal.reason), { once: true });
+          });
+          yield { type: "session.idle", properties: { sessionID: "session-1" } };
+        })(),
+      }) as never);
+      const child = fakeChild();
+      const { deps } = dependencies(child, { createClient: () => setup.client });
+      const runtime = new OpenCodeRuntime(options(), deps);
+      const controller = new AbortController();
+      let settled = false;
+      const events: RuntimeEvent[] = [];
+      const result = (async () => {
+        try {
+          for await (const event of runtime.run(
+            { requestId: "active", conversationId: "active", prompt: "test", workMode: "execute" },
+            controller.signal,
+          )) events.push(event);
+        } catch (error) {
+          return error;
+        } finally {
+          settled = true;
+        }
+      })();
+      try {
+        await vi.waitFor(() => expect(setup.session.promptAsync).toHaveBeenCalledOnce());
+        if (ending === "exit") closeChild(child, 1);
+        else await runtime.dispose();
+        await vi.waitFor(() => expect(settled).toBe(true), { timeout: 300 });
+        await expect(result).resolves.toMatchObject({
+          message: expect.stringMatching(/OpenCode 服务.*(?:退出|关闭)/u),
+        });
+        expect(controller.signal.aborted).toBe(false);
+        expect(events.some((event) => event.type === "done")).toBe(false);
+      } finally {
+        controller.abort();
+        await result;
+        await runtime.dispose();
+      }
+    },
+  );
+
+  it("cancels an event-stream retry delay when its server exits", async () => {
+    const setup = runClient([]);
+    let retrying = false;
+    vi.mocked(setup.event.subscribe).mockImplementation(async (_input, options) => ({
+      stream: (async function* () {
+        retrying = true;
+        await (options as { sseSleepFn: (milliseconds: number) => Promise<void> })
+          .sseSleepFn(30_000);
+        yield { type: "session.idle", properties: { sessionID: "session-1" } };
+      })(),
+    }) as never);
+    const child = fakeChild();
+    const { deps } = dependencies(child, { createClient: () => setup.client });
+    const runtime = new OpenCodeRuntime(options(), deps);
+    const result = collectRun(runtime).catch((error: unknown) => error);
+    try {
+      await vi.waitFor(() => expect(retrying).toBe(true));
+      closeChild(child, 1);
+      await expect(result).resolves.toMatchObject({
+        message: expect.stringContaining("OpenCode 服务已退出"),
+      });
+    } finally {
+      await runtime.dispose();
+    }
+  });
+
+  it.each(["complete", "exit"])(
+    "protects an active Compact until it ends through %s",
+    async (ending) => {
+      const setup = runClient([
+        { type: "session.idle", properties: { sessionID: "session-1" } },
+      ]);
+      let release!: () => void;
+      const summarize = vi.fn((_input, options: { signal: AbortSignal }) =>
+        new Promise((resolve, reject) => {
+          release = () => resolve({ data: true });
+          options.signal.addEventListener("abort", () => reject(options.signal.reason), { once: true });
+        }));
+      Object.assign(setup.client, {
+        v2: { session: { context: vi.fn().mockResolvedValue({
+          data: { data: [{ type: "assistant", model: { providerID: "test", id: "test" } }] },
+        }) } },
+      });
+      Object.assign(setup.client.session, { summarize });
+      const child = fakeChild();
+      const { deps, checkServerHealth } = dependencies(child, { createClient: () => setup.client });
+      const runtime = new OpenCodeRuntime(options(), deps);
+      try {
+        await collectRun(runtime);
+        const compact = runtime.compactConversation({
+          requestId: "compact", conversationId: "conversation-1",
+          runtimeSelection: { provider: "opencode" }, history: [], historyMessageIds: [],
+        }, new AbortController().signal).catch((error: unknown) => error);
+        await vi.waitFor(() => expect(summarize).toHaveBeenCalledOnce());
+        const probes = checkServerHealth.mock.calls.length;
+        await expect(runtime.testConnection()).resolves.toMatchObject({ available: true });
+        expect(checkServerHealth).toHaveBeenCalledTimes(probes);
+        expect(child.kill).not.toHaveBeenCalled();
+        if (ending === "exit") {
+          closeChild(child, 1);
+          await expect(compact).resolves.toMatchObject({
+            message: expect.stringContaining("OpenCode 服务已退出"),
+          });
+        } else {
+          release();
+          await expect(compact).resolves.toMatchObject({ result: { compacted: true } });
+          await runtime.testConnection();
+          expect(checkServerHealth).toHaveBeenCalledTimes(probes + 1);
+        }
+      } finally {
+        release?.();
+        await runtime.dispose();
+      }
+    },
+  );
+
   it.each(["unhealthy", "rejected", "hung"])(
     "replaces a %s cached server once for concurrent callers",
     async (failure) => {
diff --git a/src/main/agent/opencode-runtime.ts b/src/main/agent/opencode-runtime.ts
index 3b9c3a4d..eb0a2c6b 100644
--- a/src/main/agent/opencode-runtime.ts
+++ b/src/main/agent/opencode-runtime.ts
@@ -20,6 +20,7 @@ import {
 } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { dirname, join, resolve } from "node:path";
+import { setTimeout as delay } from "node:timers/promises";
 import { parse as parseYaml, stringify as stringifyYaml } from "yaml";
 import type {
   AgentQuestionAnswer,
@@ -168,6 +169,8 @@ type OpenCodeProviderDescriptor = {
 type OpenCodeServer = {
   url: string;
   authorization: string;
+  signal: AbortSignal;
+  activeRequests: number;
   close: () => Promise<void>;
 };
 
@@ -287,6 +290,14 @@ function executionDeadlineLabel(milliseconds: number): string {
     : `${milliseconds} 毫秒`;
 }
 
+function eventSubscriptionOptions(signal: AbortSignal) {
+  return {
+    signal,
+    sseSleepFn: (milliseconds: number) =>
+      delay(milliseconds, undefined, { signal }),
+  };
+}
+
 function awaitWithAbort<T>(
   operation: Promise<T>,
   signal: AbortSignal,
@@ -1171,10 +1182,24 @@ export class OpenCodeRuntime implements AgentRuntime {
           }
           stdout?.resume();
           stderr?.resume();
+          const lifetime = new AbortController();
+          child.once("close", (code: number | null) => {
+            lifetime.abort(new Error(
+              `OpenCode 服务已退出（code ${code ?? "unknown"}），请重试当前请求`,
+            ));
+          });
+          child.once("error", () => {
+            lifetime.abort(new Error(
+              "OpenCode 服务发生错误并已关闭，请重试当前请求",
+            ));
+          });
           resolveServer({
             url,
             authorization,
+            signal: lifetime.signal,
+            activeRequests: 0,
             close: async () => {
+              lifetime.abort(new Error("OpenCode 服务已关闭，请重试当前请求"));
               try {
                 const exited = this.waitForExit(child);
                 this.terminate(child);
@@ -1315,6 +1340,10 @@ export class OpenCodeRuntime implements AgentRuntime {
     signal?: AbortSignal,
   ): Promise<OpencodeClient> {
     if (this.client && this.server) {
+      // A short probe must not replace a server still serving another request.
+      if (this.server.activeRequests > 0 && !this.server.signal.aborted) {
+        return this.client;
+      }
       const probeSignal = AbortSignal.any([
         ...(signal ? [signal] : []),
         AbortSignal.timeout(STARTUP_PROBE_TIMEOUT_MS),
@@ -2027,6 +2056,27 @@ export class OpenCodeRuntime implements AgentRuntime {
       throw new Error("当前模型连接未启用图像输入");
     }
     const client = await this.getClient(signal);
+    const server = this.server;
+    const requestSignal = server
+      ? AbortSignal.any([signal, server.signal])
+      : signal;
+    if (server) server.activeRequests += 1;
+    try {
+      requestSignal.throwIfAborted();
+      yield* this.runWithClient(request, requestSignal, client);
+    } catch (error) {
+      requestSignal.throwIfAborted();
+      throw error;
+    } finally {
+      if (server) server.activeRequests -= 1;
+    }
+  }
+
+  private async *runWithClient(
+    request: AgentExecutionRequest,
+    signal: AbortSignal,
+    client: OpencodeClient,
+  ): AsyncGenerator<RuntimeEvent, void, void> {
     const directory = this.options.defaultWorkspace;
     const runtimeControl =
       request.runtimeControl?.provider === "opencode"
@@ -2290,7 +2340,10 @@ export class OpenCodeRuntime implements AgentRuntime {
       const subscription = await this.controlRequest(
         "订阅事件流",
         (controlSignal) =>
-          client.event.subscribe({ directory }, { signal: controlSignal }),
+          client.event.subscribe(
+            { directory },
+            eventSubscriptionOptions(controlSignal),
+          ),
         AbortSignal.any([signal, subscriptionController.signal]),
       );
 
@@ -2942,10 +2995,11 @@ export class OpenCodeRuntime implements AgentRuntime {
             configuredTimeout,
           );
     deadlineTimer?.unref?.();
-    const executionSignal = deadline
+    let executionSignal = deadline
       ? AbortSignal.any([signal, deadline.signal])
       : signal;
     let releaseConversation: (() => void) | undefined;
+    let server: OpenCodeServer | undefined;
     try {
       releaseConversation = await this.acquireConversationRun(
         request.conversationId,
@@ -2954,6 +3008,13 @@ export class OpenCodeRuntime implements AgentRuntime {
       const client = this.sessions.has(request.conversationId)
         ? await this.getClient(executionSignal)
         : undefined;
+      if (client) {
+        server = this.server;
+        if (server) {
+          server.activeRequests += 1;
+          executionSignal = AbortSignal.any([executionSignal, server.signal]);
+        }
+      }
       const sessionId = this.sessions.get(request.conversationId);
       if (!sessionId || !client) {
         return {
@@ -3012,7 +3073,7 @@ export class OpenCodeRuntime implements AgentRuntime {
         (controlSignal) =>
           client.event.subscribe(
             { directory: this.options.defaultWorkspace },
-            { signal: controlSignal },
+            eventSubscriptionOptions(controlSignal),
           ),
         subscriptionSignal,
       );
@@ -3094,11 +3155,13 @@ export class OpenCodeRuntime implements AgentRuntime {
       if (deadline?.signal.aborted && !signal.aborted) {
         throw deadline.signal.reason;
       }
+      executionSignal.throwIfAborted();
       throw error;
     } finally {
       if (deadlineTimer) {
         clearTimeout(deadlineTimer);
       }
+      if (server) server.activeRequests -= 1;
       releaseConversation?.();
     }
   }