From 35226703ce7b0a032fa309d48f31a762c55b8c9a Mon Sep 17 00:00:00 2001
From: AssemblyAI <engineering.sdk@assemblyai.com>
Date: Tue, 19 May 2026 10:25:35 -0400
Subject: [PATCH] Project import generated by Copybara.

GitOrigin-RevId: 0570d5ed67c6ebb9780cf3edd4ab2ef34c721511
---
 package.json                      |  2 +-
 src/services/streaming/service.ts |  7 +++++++
 src/types/streaming/index.ts      |  2 ++
 tests/unit/streaming.test.ts      | 31 +++++++++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 6f74d41..ed50085 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "assemblyai",
-  "version": "4.33.2",
+  "version": "4.33.3",
   "description": "The AssemblyAI JavaScript SDK provides an easy-to-use interface for interacting with the AssemblyAI API, which supports async and real-time transcription, as well as the latest LeMUR models.",
   "engines": {
     "node": ">=18"
diff --git a/src/services/streaming/service.ts b/src/services/streaming/service.ts
index bb18ffc..636c561 100644
--- a/src/services/streaming/service.ts
+++ b/src/services/streaming/service.ts
@@ -205,6 +205,13 @@ export class StreamingTranscriber {
       );
     }
 
+    if (this.params.turnLeftPadMs !== undefined) {
+      searchParams.set(
+        "turn_left_pad_ms",
+        this.params.turnLeftPadMs.toString(),
+      );
+    }
+
     if (this.params.customerSupportAudioCapture) {
       console.warn(
         "`customerSupportAudioCapture=true` will record session audio. Only enable this when explicitly coordinating with AssemblyAI support.",
diff --git a/src/types/streaming/index.ts b/src/types/streaming/index.ts
index f25584c..3f5f2e9 100644
--- a/src/types/streaming/index.ts
+++ b/src/types/streaming/index.ts
@@ -40,6 +40,7 @@ export type StreamingTranscriberParams = {
   voiceFocusThreshold?: number;
   continuousPartials?: boolean;
   interruptionDelay?: number;
+  turnLeftPadMs?: number;
   customerSupportAudioCapture?: boolean;
   includePartialTurns?: boolean;
   redactPii?: boolean;
@@ -221,6 +222,7 @@ export type StreamingUpdateConfiguration = {
   prompt?: string;
   filter_profanity?: boolean;
   interruption_delay?: number;
+  turn_left_pad_ms?: number;
 };
 
 export type StreamingForceEndpoint = {
diff --git a/tests/unit/streaming.test.ts b/tests/unit/streaming.test.ts
index b05a7c3..4b86651 100644
--- a/tests/unit/streaming.test.ts
+++ b/tests/unit/streaming.test.ts
@@ -204,6 +204,37 @@ describe("streaming", () => {
     );
   });
 
+  it("should include turn_left_pad_ms in connection URL", async () => {
+    await cleanup();
+    WS.clean();
+
+    const wsUrl =
+      `${websocketBaseUrl}?token=123&sample_rate=16000` +
+      `&speech_model=u3-rt-pro` +
+      `&turn_left_pad_ms=1024`;
+    server = new WS(wsUrl);
+    rt = new StreamingTranscriber({
+      websocketBaseUrl,
+      token: "123",
+      sampleRate: 16_000,
+      speechModel: "u3-rt-pro",
+      turnLeftPadMs: 1024,
+    });
+    onOpen = jest.fn();
+    rt.on("open", onOpen);
+    await connect(rt, server);
+  });
+
+  it("should include turn_left_pad_ms in updateConfiguration message", async () => {
+    rt.updateConfiguration({ turn_left_pad_ms: 1024 });
+    await expect(server).toReceiveMessage(
+      JSON.stringify({
+        type: "UpdateConfiguration",
+        turn_left_pad_ms: 1024,
+      }),
+    );
+  });
+
   it("should include voice_focus and voice_focus_threshold in connection URL", async () => {
     await cleanup();
     WS.clean();