openclaw - 💡(How to fix) Fix Control UI sends duplicate chat.send requests causing double messages [2 comments, 2 participants]

Bug Description

Control UI sends duplicate chat.send WebSocket requests, causing every user message to appear twice in the session history, resulting in duplicate AI responses.

Steps to Reproduce

1. Open Control UI in browser: http://localhost:18789/
2. Send any message (e.g., "你好")
3. Observe: message appears once in my session history (confirmed via sessions_history API)
4. But the AI receives and processes the message twice, causing duplicate replies
5. User sees their question appear twice, followed by two identical AI responses

Environment

• Gateway: OpenClaw Gateway v2026.4.15
• OS: Ubuntu 24.04.1 LTS (Linux 6.17.0-22-generic)
• Node: v22.22.2
• Browser: Chrome and Firefox both affected (1 WebSocket connection only)
• Gateway Port: 18789 (loopback)
• Token: Bearer token auth

Network Investigation

# Only 1 Chrome/Firefox connection to Gateway - NOT a double-connection issue
ss -tnp | grep 18789
ESTAB 0  0  127.0.0.1:54744  127.0.0.1:18789  users:(("firefox",pid=4548,fd=20))
ESTAB 0  0  127.0.0.1:18789  127.0.0.1:54744  users:(("openclaw-gatewa",pid=1499,fd=27))

Only 1 Gateway process running (pid=1499). Not a process duplication issue.

Session History Evidence

Using sessions_history API confirms messages ARE stored twice:

seq 639: role=user, "我换了浏览器..." (first)
seq 643: role=user, "我换了浏览器..." (duplicate - same timestamp!)

Both messages have identical timestamp and identical __openclaw.id, proving they came from the same original send that was duplicated at the WebSocket layer.

Root Cause Analysis (from Control UI source code)

File: dist/control-ui/assets/index-ckUmEo1l.js

The Sc function is called with identical parameters twice:

async function Sc(e, t) {
  await e.client.request(`chat.send`, {
    sessionKey: e.sessionKey,
    message: t.message,
    deliver: false,
    idempotencyKey: t.runId,
    attachments: xc(t.attachments)
  })
}

Three functions call Sc: Ec, Dc, Oc - one of these is being invoked twice for each send action. The idempotencyKey (runId) is generated via pn() and should be unique per send, but since the request itself is sent twice, the idempotency mechanism does not prevent the duplication.

Impact

• Every message sent via Control UI results in duplicate AI response
• Double token usage / API costs
• Confusing user experience
• Affects BOTH Chrome and Firefox (not browser-specific)

Workarounds Attempted

1. Restart Chrome/Firefox - issue persists
2. Restart Gateway - issue persists
3. Single tab only - confirmed 1 WebSocket connection, issue persists
4. Canvas mode - may work but not fully tested

Suggested Fix

The Control UI's send handler invokes Sc() twice for each message send. Investigate which of Ec/Dc/Oc is being called twice, and add a guard to prevent duplicate sends.