From 1f4b976495ea5a9901ae4e60b0d1fb279b585672 Mon Sep 17 00:00:00 2001
From: jamesx0416 <jamesx0416@outlook.com>
Date: Sun, 8 Mar 2026 11:20:23 +1100
Subject: [PATCH] fix: avoid duplicating streamed assistant completion text

---
 .../orchestration/Layers/ProviderRuntimeIngestion.test.ts   | 1 +
 .../src/orchestration/Layers/ProviderRuntimeIngestion.ts    | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
index 96242b846c..24409655eb 100644
--- a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
+++ b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.test.ts
@@ -834,6 +834,7 @@ describe("ProviderRuntimeIngestion", () => {
       payload: {
         itemType: "assistant_message",
         status: "completed",
+        detail: "hello live",
       },
     });
 
diff --git a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
index 022a196674..5a6f71d5e6 100644
--- a/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
+++ b/apps/server/src/orchestration/Layers/ProviderRuntimeIngestion.ts
@@ -951,6 +951,10 @@ const make = Effect.gen(function* () {
       if (assistantCompletion) {
         const assistantMessageId = assistantCompletion.messageId;
         const turnId = toTurnId(event.turnId);
+        const existingAssistantMessage = thread.messages.find((entry) => entry.id === assistantMessageId);
+        const shouldApplyFallbackCompletionText =
+          !existingAssistantMessage ||
+          existingAssistantMessage.text.length === 0;
         if (turnId) {
           yield* rememberAssistantMessageId(thread.id, turnId, assistantMessageId);
         }
@@ -963,7 +967,7 @@ const make = Effect.gen(function* () {
           createdAt: now,
           commandTag: "assistant-complete",
           finalDeltaCommandTag: "assistant-delta-finalize",
-          ...(assistantCompletion.fallbackText !== undefined
+          ...(assistantCompletion.fallbackText !== undefined && shouldApplyFallbackCompletionText
             ? { fallbackText: assistantCompletion.fallbackText }
             : {}),
         });