diff --git a/extensions/codex/src/app-server/event-projector.test.ts b/extensions/codex/src/app-server/event-projector.test.ts
index fbf9f8f7597..f3e67bd66c6 100644
--- a/extensions/codex/src/app-server/event-projector.test.ts
+++ b/extensions/codex/src/app-server/event-projector.test.ts
@@ -314,4 +314,34 @@ describe("CodexAppServerEventProjector", () => {
     expect(JSON.stringify(result.messagesSnapshot[2])).toContain("Codex plan");
     expect(result.itemLifecycle).toMatchObject({ compactionCount: 1 });
   });
+
+  it("continues projecting turn completion when an event consumer throws", async () => {
+    const onAgentEvent = vi.fn(() => {
+      throw new Error("consumer failed");
+    });
+    const projector = createProjector({
+      ...createParams(),
+      onAgentEvent,
+    });
+
+    await expect(
+      projector.handleNotification(
+        turnCompleted([
+          { type: "plan", id: "plan-1", text: "step one\nstep two" },
+          { type: "agentMessage", id: "msg-1", text: "final answer" },
+        ]),
+      ),
+    ).resolves.toBeUndefined();
+
+    const result = projector.buildResult(buildEmptyToolTelemetry());
+
+    expect(onAgentEvent).toHaveBeenCalledWith(
+      expect.objectContaining({
+        stream: "plan",
+        data: expect.objectContaining({ steps: ["step one", "step two"] }),
+      }),
+    );
+    expect(result.assistantTexts).toEqual(["final answer"]);
+    expect(JSON.stringify(result.messagesSnapshot)).toContain("Codex plan");
+  });
 });
diff --git a/extensions/codex/src/app-server/event-projector.ts b/extensions/codex/src/app-server/event-projector.ts
index 85f7fd18523..79fe4b4dec9 100644
--- a/extensions/codex/src/app-server/event-projector.ts
+++ b/extensions/codex/src/app-server/event-projector.ts
@@ -106,7 +106,7 @@ export class CodexAppServerEventProjector {
       case "item/autoApprovalReview/started":
       case "item/autoApprovalReview/completed":
         this.guardianReviewCount += 1;
-        this.params.onAgentEvent?.({
+        this.emitAgentEvent({
           stream: "codex_app_server.guardian",
           data: { method: notification.method },
         });
@@ -279,7 +279,7 @@ export class CodexAppServerEventProjector {
     }
     if (item?.type === "contextCompaction" && itemId) {
       this.activeCompactionItemIds.add(itemId);
-      this.params.onAgentEvent?.({
+      this.emitAgentEvent({
         stream: "compaction",
         data: {
           phase: "start",
@@ -291,7 +291,7 @@ export class CodexAppServerEventProjector {
       });
     }
     this.emitStandardItemEvent({ phase: "start", item });
-    this.params.onAgentEvent?.({
+    this.emitAgentEvent({
       stream: "codex_app_server.item",
       data: { phase: "started", itemId, type: item?.type },
     });
@@ -315,7 +315,7 @@ export class CodexAppServerEventProjector {
     if (item?.type === "contextCompaction" && itemId) {
       this.activeCompactionItemIds.delete(itemId);
       this.completedCompactionCount += 1;
-      this.params.onAgentEvent?.({
+      this.emitAgentEvent({
         stream: "compaction",
         data: {
           phase: "end",
@@ -328,7 +328,7 @@ export class CodexAppServerEventProjector {
     }
     this.recordToolMeta(item);
     this.emitStandardItemEvent({ phase: "end", item });
-    this.params.onAgentEvent?.({
+    this.emitAgentEvent({
       stream: "codex_app_server.item",
       data: { phase: "completed", itemId, type: item?.type },
     });
@@ -388,7 +388,7 @@ export class CodexAppServerEventProjector {
     if (!params.explanation && (!params.steps || params.steps.length === 0)) {
       return;
     }
-    this.params.onAgentEvent?.({
+    this.emitAgentEvent({
       stream: "plan",
       data: {
         phase: "update",
@@ -412,7 +412,7 @@ export class CodexAppServerEventProjector {
     if (!kind) {
       return;
     }
-    this.params.onAgentEvent?.({
+    this.emitAgentEvent({
       stream: "item",
       data: {
         itemId: item.id,
@@ -440,6 +440,16 @@ export class CodexAppServerEventProjector {
     });
   }
 
+  private emitAgentEvent(
+    event: Parameters<NonNullable<EmbeddedRunAttemptParams["onAgentEvent"]>>[0],
+  ): void {
+    try {
+      this.params.onAgentEvent?.(event);
+    } catch {
+      // Downstream event consumers must not corrupt the canonical Codex turn projection.
+    }
+  }
+
   private collectAssistantTexts(): string[] {
     const finalText = this.resolveFinalAssistantText();
     return finalText ? [finalText] : [];