diff --git a/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.test.ts b/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.test.ts
index 2d14fa9518de..11e479c185ac 100644
--- a/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.test.ts
+++ b/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.test.ts
@@ -69,6 +69,7 @@ import * as ProviderReplayHarness from "../testkit/ProviderReplayHarness.ts";
 import * as ProviderAdapter from "@t3tools/provider-core/server/ProviderAdapter";
 import type * as ProviderContinuationRequests from "@t3tools/provider-core/server/ProviderContinuationRequests";
 import * as ModelManifest from "../../provider/ModelManifest.ts";
+import * as PortScanner from "../../preview/PortScanner.ts";
 import { resolveProviderCompatibility } from "../../provider/providerCompatibility.ts";
 import * as CodexAdapterV2 from "./CodexAdapterV2.ts";
 import { withCodexReplayChildMetadata } from "./CodexAdapterV2.testkit.ts";
@@ -879,6 +880,66 @@ describe("CodexAdapterV2 process exit", () => {
       ),
     ),
   );
+
+  it.effect("counts the app-server as a running agent until its session closes", () => {
+    let runningAgents = 0;
+    const factoryLayer = CodexAdapterV2.layerAppServerClientFactory.pipe(
+      Layer.provide(
+        Layer.mock(PortScanner.PortDiscovery)({
+          trackAgent: () => {
+            runningAgents += 1;
+            return () => {
+              runningAgents -= 1;
+            };
+          },
+        }),
+      ),
+      Layer.provide(
+        Layer.succeed(ProviderEventLoggers.ProviderEventLoggers, {
+          native: undefined,
+          canonical: undefined,
+        }),
+      ),
+      Layer.provide(
+        Layer.succeed(
+          ChildProcessSpawner.ChildProcessSpawner,
+          ChildProcessSpawner.make(() =>
+            Effect.succeed(
+              ChildProcessSpawner.makeHandle({
+                pid: ChildProcessSpawner.ProcessId(999_999_999),
+                exitCode: Effect.never,
+                isRunning: Effect.succeed(true),
+                kill: () => Effect.void,
+                unref: Effect.succeed(Effect.void),
+                stdin: Sink.drain,
+                stdout: Stream.never,
+                stderr: Stream.empty,
+                all: Stream.empty,
+                getInputFd: () => Sink.drain,
+                getOutputFd: () => Stream.empty,
+              }),
+            ),
+          ),
+        ),
+      ),
+    );
+    return Effect.gen(function* () {
+      const factory = yield* CodexAdapterV2.CodexAppServerClientFactory;
+      yield* Effect.scoped(
+        factory
+          .open({
+            instanceId: CodexAdapterV2.CODEX_DEFAULT_INSTANCE_ID,
+            threadId: ThreadId.make("thread-codex-agent"),
+            providerSessionId: ProviderSessionId.make("session-codex-agent"),
+            runtimePolicy: CODEX_TEST_RUNTIME_POLICY,
+            settings: DEFAULT_CODEX_SETTINGS,
+            environment: {},
+          })
+          .pipe(Effect.tap(() => Effect.sync(() => assert.equal(runningAgents, 1)))),
+      );
+      assert.equal(runningAgents, 0);
+    }).pipe(Effect.provide(factoryLayer));
+  });
 });
 
 describe("CodexAdapterV2 session initialize", () => {
diff --git a/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.ts b/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.ts
index f81a3809b35f..256bee07ab42 100644
--- a/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.ts
+++ b/apps/server/src/orchestration-v2/Adapters/CodexAdapterV2.ts
@@ -1516,13 +1516,16 @@ function isSensitiveCodexProtocolKey(key: string): boolean {
 export const layerAppServerClientFactory: Layer.Layer<
   CodexAppServerClientFactory,
   never,
-  ChildProcessSpawner.ChildProcessSpawner | ProviderEventLoggers.ProviderEventLoggers
+  | ChildProcessSpawner.ChildProcessSpawner
+  | PortScanner.PortDiscovery
+  | ProviderEventLoggers.ProviderEventLoggers
 > = Layer.effect(
   CodexAppServerClientFactory,
   Effect.gen(function* () {
     const spawner = yield* ChildProcessSpawner.ChildProcessSpawner;
     const { native: nativeEventLogger } = yield* ProviderEventLoggers.ProviderEventLoggers;
     const agentScope = yield* AgentScope;
+    const portDiscovery = yield* PortScanner.PortDiscovery;
 
     return CodexAppServerClientFactory.of({
       open: Effect.fn("CodexAdapterV2.open")(function* (input) {
@@ -1550,6 +1553,10 @@ export const layerAppServerClientFactory: Layer.Layer<
               }),
           ),
         );
+        // Its shells carry each thread's T3CODE_THREAD_ID, so port discovery reads listeners' threads.
+        yield* Effect.acquireRelease(Effect.sync(portDiscovery.trackAgent), (release) =>
+          Effect.sync(release),
+        );
         const protocolLogger = makeCodexAppServerProtocolLogger({
           nativeEventLogger,
           threadId: input.threadId,