[BUG] WebSocket connection timeout of 800ms too short — causes premature SSE fallback on slow networks

[vipul674]

Description of the Bug

In frontend/src/components/chat/ChatPanel.tsx, the WebSocket connection has a timeout of only 800ms:

const wsTimeout = setTimeout(() => {
    // WebSocket didn't connect fast enough, fall back to SSE
    setIsWsConnected(false);
    startSSE();
}, 800);

An 800ms timeout is too aggressive for WebSocket connections. WebSocket connections require:

1. DNS resolution (can take 100-500ms on slow networks)
2. TCP handshake
3. HTTP upgrade handshake
4. Server-side processing time

On slow networks, cold-start servers, or under load, this can easily exceed 800ms, causing the application to unnecessarily fall back to SSE streaming. This means users lose the benefits of real-time WebSocket streaming (lower latency, full-duplex) even though WebSocket would have worked fine given an extra second or two.

Steps to Reproduce

1. Connect to the application over a slow network (e.g., mobile 3G, throttled connection)
2. Start a chat session and send a message
3. The WebSocket connection attempt times out at 800ms
4. The client falls back to SSE, losing real-time streaming benefits
5. WebSocket would have succeeded with a longer timeout

Expected Behavior

The timeout should be increased to at least 5000ms (5 seconds) to account for network and server startup latency. A retry mechanism should also be considered before falling back.

Affected File

frontend/src/components/chat/ChatPanel.tsx (line ~283)

Suggested Fix

Increase the timeout:

const WS_TIMEOUT_MS = 5000;  // 5 seconds instead of 800ms

Consider adding a single retry attempt before falling back to SSE.

GSSoC '26

• Yes, I am participating in GirlScript Summer of Code and would like to fix this.

[github-actions]

Hi @vipul674! 👋

Thanks for opening this issue! We are thrilled to have you contribute to PDF-Assistant-RAG for GSSoC 2026.

📌 Before you start:

• Make sure you have read our Contributing Guidelines.
• Wait for a project admin to assign this issue to you before working on it.
• Remember to branch off dev and not main.

Happy Coding! 🚀

[vipul674]

@param20h I would like to work on this issue under GSSoC 2026. Please assign it to me.