From 981fb0fe8646e94322f19ce5c5e408730ecd6853 Mon Sep 17 00:00:00 2001
From: Dotta <bippadotta@protonmail.com>
Date: Thu, 3 Sep 2026 07:07:20 -0500
Subject: [PATCH] fix(runner): bind fast terminal turns deterministically

---
 .../src/drivers/acpx/runtime-host.test.ts     | 20 +++++++++----------
 .../src/live/runnerd-codex-transport.ts       | 18 +++++++++++++++--
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts b/packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts
index f1b3199ec8..006bcf8005 100644
--- a/packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts
+++ b/packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts
@@ -282,9 +282,7 @@ describe("ACPX runtime host", () => {
     expect(lifetimeFenceCandidates).toHaveLength(3);
     expect(new Set(lifetimeFenceCandidates).size).toBe(3);
     expect(
-      lifetimeFenceCandidates.every(
-        (port) => port >= 49_152 && port <= 65_535,
-      ),
+      lifetimeFenceCandidates.every((port) => port >= 49_152 && port <= 65_535),
     ).toBe(true);
     expect(capturedEnvironment.OPENAI_API_KEY).toBe("launch-secret");
     expect(host.persistedEnvironment().OPENAI_API_KEY).toBeUndefined();
@@ -1255,13 +1253,15 @@ describe("ACPX runtime host", () => {
     });
     // File removal precedes kernel lease release. Wait for the lease itself so
     // this assertion cannot race between those two ordered cleanup steps.
-    const contender = await vi.waitFor(() =>
-      stageManagedCodexCredential({
-        agentHomeDirectory: credentialHome,
-        environment: {
-          PAPERCLIP_ACPX_CODEX_AUTH_JSON_SECRET: '{"owner":"contender"}',
-        },
-      }),
+    const contender = await vi.waitFor(
+      () =>
+        stageManagedCodexCredential({
+          agentHomeDirectory: credentialHome,
+          environment: {
+            PAPERCLIP_ACPX_CODEX_AUTH_JSON_SECRET: '{"owner":"contender"}',
+          },
+        }),
+      { timeout: 5_000 },
     );
     await contender.close();
   });
diff --git a/packages/paperclip-runner/src/live/runnerd-codex-transport.ts b/packages/paperclip-runner/src/live/runnerd-codex-transport.ts
index b013fd1986..29bd8f830d 100644
--- a/packages/paperclip-runner/src/live/runnerd-codex-transport.ts
+++ b/packages/paperclip-runner/src/live/runnerd-codex-transport.ts
@@ -3013,7 +3013,22 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
     this.#flushPendingTraceRehydrations();
     const events = this.#core?.store.state.committedEvents ?? [];
     while (this.#eventIndex < events.length) {
-      const event = events[this.#eventIndex++];
+      const event = events[this.#eventIndex]!;
+      const eventPayload = record(event.envelope.payload).payload;
+      const terminalWhileTurnStartPending =
+        this.#turnStartResponsePending &&
+        ([
+          "turn.completed",
+          "turn.failed",
+          "turn.interrupted",
+          "turn.cancelled",
+        ].includes(event.eventType) ||
+          (event.eventType === "provider.event" &&
+            unwrapRunnerdProviderNotifications(eventPayload).some(
+              (notification) => notification.method === "turn/completed",
+            )));
+      if (terminalWhileTurnStartPending) return;
+      this.#eventIndex += 1;
       if (
         event.eventType === "harness.ready" ||
         event.eventType === "session.started" ||
@@ -3141,7 +3156,6 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
           this.#bridgedRuntimeInputs.delete(requestId);
         continue;
       }
-      const eventPayload = record(event.envelope.payload).payload;
       const sessionUpdatePayload = record(eventPayload);
       const canonicalMethod = (
         {