From 971d4b3c12da889bac10b122a81716b394796584 Mon Sep 17 00:00:00 2001
From: mattie ruth backman <mattieruth@gmail.com>
Date: Fri, 9 Jan 2026 10:44:33 -0500
Subject: [PATCH] Improved and introduced error handling for too-large messages

---
 transports/daily/src/transport.ts             | 13 ++++++++++++-
 .../src/smallWebRTCTransport.ts               | 19 +++++++++++++++++--
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/transports/daily/src/transport.ts b/transports/daily/src/transport.ts
index 2dd8d43..760e82e 100644
--- a/transports/daily/src/transport.ts
+++ b/transports/daily/src/transport.ts
@@ -20,6 +20,7 @@ import Daily, {
 import {
   DeviceArray,
   DeviceError,
+  MessageTooLargeError,
   Participant,
   PipecatClientOptions,
   RTVIError,
@@ -597,7 +598,17 @@ export class DailyTransport extends Transport {
   }
 
   public sendMessage(message: RTVIMessage) {
-    this._daily.sendAppMessage(message, "*");
+    try {
+      this._daily.sendAppMessage(message, "*");
+    } catch (error: unknown) {
+      if (
+        error instanceof Error &&
+        error.message.includes("Message data too large")
+      ) {
+        throw new MessageTooLargeError(error.message);
+      }
+      throw error;
+    }
   }
 
   private handleAppMessage(ev: DailyEventObjectAppMessage) {
diff --git a/transports/small-webrtc-transport/src/smallWebRTCTransport.ts b/transports/small-webrtc-transport/src/smallWebRTCTransport.ts
index d2f3bdb..65e95e1 100644
--- a/transports/small-webrtc-transport/src/smallWebRTCTransport.ts
+++ b/transports/small-webrtc-transport/src/smallWebRTCTransport.ts
@@ -1,7 +1,10 @@
 import cloneDeep from "lodash/cloneDeep";
 import {
+  APIRequest,
+  isAPIRequest,
   logger,
   makeRequest,
+  MessageTooLargeError,
   RTVIError,
   RTVIMessage,
   PipecatClientOptions,
@@ -10,8 +13,6 @@ import {
   TransportStartError,
   TransportState,
   UnsupportedFeatureError,
-  APIRequest,
-  isAPIRequest,
 } from "@pipecat-ai/client-js";
 import { MediaManager } from "../../../lib/media-mgmt/mediaManager";
 import { DailyMediaManager } from "../../../lib/media-mgmt/dailyMediaManager";
@@ -422,6 +423,20 @@ export class SmallWebRTCTransport extends Transport {
       logger.warn(`Datachannel is not ready. Message not sent: ${message}`);
       return;
     }
+    const getSizeInBytes = (obj: any) => {
+      const jsonString = JSON.stringify(obj);
+      const encoder = new TextEncoder();
+      const bytes = encoder.encode(jsonString);
+      return bytes.length;
+    };
+
+    const objectSize = getSizeInBytes(message);
+    const maxSize = this.pc?.sctp?.maxMessageSize ?? 64 * 1024;
+    if (objectSize > maxSize) {
+      throw new MessageTooLargeError(
+        "Message data too large. Max size is " + maxSize,
+      );
+    }
     this.dc?.send(JSON.stringify(message));
   }