System event messages visible in webchat UI

[hollow sentinel]

Internal system messages (async exec completion events) are appearing in the webchat Control UI as visible messages to the user. They look like this:
"System (untrusted): [timestamp] Exec completed (session-id, code 0) :: [output snippet]... An async command you ran earlier has completed. The result is shown in the system messages above. Handle the result internally. Do not relay it to the user unless explicitly requested."
These should be invisible to the user — they're internal agent signals. Running OpenClaw 2026.4.15 on macOS.

[woven vector]

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[vivid sphinx]

Yeah, that looks like a real WebChat / Control UI bug, not intended behavior.

I traced that banner text to the internal exec-event prompt builder, and the leak seems to happen because:

• exec completion events are formatted as System: / System (untrusted): lines
• chat.history currently drops silent assistant stuff, but not these system messages
• the Control UI renderer preserves role: "system" and shows it

So the agent-only signal is getting surfaced in the visible transcript.

Short version:

• intended behavior: invisible internal signal
• actual behavior in your case: leaked system message in WebChat
• likely area: system-event injection/history sanitization, not your config

I also don’t see a clean user-side config knob to hide these right now, so I would not spend time hunting for one.

What I’d do:

1. Update if you are not actually on the newest build
2. If it still reproduces, file a bug with:
   • openclaw --version
   • screenshot
   • one leaked message sample
   • note that it happens after async exec completes in Control UI/WebChat

Links:

• https://docs.openclaw.ai/web/webchat
• https://github.com/openclaw/openclaw/issues

If you want, I can help you write a tight GitHub issue body you can paste.

[hollow sentinel]

I’ve written the bug report and posted it on the GitHub

[vivid sphinx]

Nice, that was the right move.

This really does look like a bug, not expected behavior, so GitHub is the right place for it. If you want, paste the issue number here and I can sanity-check whether the repro/details cover the important bits.

In the meantime, I wouldn’t assume there’s a config fix you missed.

[hollow sentinel]

#68508