From c95517af312f3d921a327d1cebc48b55af3519c9 Mon Sep 17 00:00:00 2001
From: Fusion <noreply@runfusion.ai>
Date: Wed, 6 May 2026 19:26:14 -0700
Subject: [PATCH] feat(FN-3608): update dashboard chat documentation

Updated the dashboard chat documentation in the user guide with a minor addition.

Fusion-Task-Id: FN-3608
---
 .changeset/chat-stream-stuck-state.md        | 10 ++++++++++
 packages/dashboard/app/api/legacy.ts         | 11 +++++++++++
 packages/dashboard/app/hooks/useChat.ts      |  1 +
 packages/dashboard/app/hooks/useQuickChat.ts |  1 +
 4 files changed, 23 insertions(+)
 create mode 100644 .changeset/chat-stream-stuck-state.md

diff --git a/.changeset/chat-stream-stuck-state.md b/.changeset/chat-stream-stuck-state.md
new file mode 100644
index 000000000..2482b277c
--- /dev/null
+++ b/.changeset/chat-stream-stuck-state.md
@@ -0,0 +1,10 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix chat sending silently failing on flaky networks (especially mobile).
+The SSE reader in the dashboard client now treats a closed stream without
+a terminal `done`/`error` event as an error so streaming state unwinds
+instead of getting stuck. The `useChat` and `useQuickChat` hooks also now
+show a toast when a message is queued behind an in-flight response, so
+the previous stuck state is observable rather than silent.
diff --git a/packages/dashboard/app/api/legacy.ts b/packages/dashboard/app/api/legacy.ts
index 6411ca500..c3ee2e826 100644
--- a/packages/dashboard/app/api/legacy.ts
+++ b/packages/dashboard/app/api/legacy.ts
@@ -8058,6 +8058,7 @@ export function streamChatResponse(
 
   const abortController = new AbortController();
   let closedByUser = false;
+  let terminated = false;
 
   const dispatchEvent = (eventName: string, rawData: string): void => {
     if (!eventName) {
@@ -8101,6 +8102,7 @@ export function streamChatResponse(
         }
         break;
       case "done":
+        terminated = true;
         try {
           const parsed = JSON.parse(rawData) as { messageId?: unknown; message?: unknown };
           handlers.onDone?.({
@@ -8112,6 +8114,7 @@ export function streamChatResponse(
         }
         break;
       case "error":
+        terminated = true;
         try {
           const parsed = JSON.parse(rawData);
           handlers.onError?.(parsed.message || parsed);
@@ -8216,6 +8219,14 @@ export function streamChatResponse(
 
         processLines(decoder.decode(value, { stream: true }));
       }
+
+      // Server closed the stream without emitting a terminal `done` or `error`
+      // SSE event (common on flaky mobile networks, proxy idle-kill, or
+      // backgrounded tabs). Surface as an error so the client unwinds
+      // streaming state instead of getting stuck with isStreaming=true.
+      if (!terminated && !closedByUser) {
+        handlers.onError?.("Connection closed unexpectedly");
+      }
     } catch (err: unknown) {
       if (err instanceof DOMException && err.name === "AbortError") {
         if (!closedByUser) {
diff --git a/packages/dashboard/app/hooks/useChat.ts b/packages/dashboard/app/hooks/useChat.ts
index 07a9e185d..fa8f6dc04 100644
--- a/packages/dashboard/app/hooks/useChat.ts
+++ b/packages/dashboard/app/hooks/useChat.ts
@@ -492,6 +492,7 @@ export function useChat(
       if (isStreaming) {
         pendingMessageRef.current = content;
         setPendingMessage(content);
+        addToast?.("Still waiting for previous response — message queued", "warning");
         return;
       }
 
diff --git a/packages/dashboard/app/hooks/useQuickChat.ts b/packages/dashboard/app/hooks/useQuickChat.ts
index 372702592..7fba14039 100644
--- a/packages/dashboard/app/hooks/useQuickChat.ts
+++ b/packages/dashboard/app/hooks/useQuickChat.ts
@@ -557,6 +557,7 @@ export function useQuickChat(
 
         pendingMessageRef.current = content;
         setPendingMessage(content);
+        addToast?.("Still waiting for previous response — message queued", "warning");
         return Promise.resolve();
       }