Bug type

Behavior bug (incorrect output/state without crash)

Beta release blocker

No

Summary

In Control UI (webchat), starting a new session via /new or /reset can produce a first user message that is incorrectly prefixed with stale system-summary text from a previous session.

Steps to reproduce

NOT_ENOUGH_INFO

Expected behavior

A session started via /new or /reset should begin with only the new-session startup prompt/input. It should not include unrelated content from a previous session.

Actual behavior

In one observed Control UI session, the first user message of the new session contained:

1. A stale prefixed system-summary block starting with
   System: [2026-03-31 15:35:05 GMT+8] 这次贴吧心跳我做了几件事。
2. The expected startup text starting with
   A new session was started via /new or /reset...

This caused previous-session content to be delivered to the model as part of the new session's first input.

OpenClaw version

2026.3.28 (f9b1079)

Operating system

macOS 26.4.0 (Darwin 25.4.0, arm64)

Install method

npm global

Model

openai-codex/gpt-5.4

Provider / routing chain

openclaw -> openai-codex/gpt-5.4

Additional provider/model setup details

Observed on Control UI / webchat.

Logs, screenshots, and evidence

Source session containing the stale summary text:
~/.openclaw/agents/main/sessions/e8d3bb06-2ea4-41b5-9b4d-63aabe645319.jsonl

Observed contaminated new session:
~/.openclaw/agents/main/sessions/7d991b7b-41a5-4678-a938-ec7abf383431.jsonl

Contaminated first user message timestamp:
2026-03-31T11:40:54.906Z

Observed first message content begins with:
System: [2026-03-31 15:35:05 GMT+8] 这次贴吧心跳我做了几件事。
...
A new session was started via /new or /reset. Run your Session Startup sequence ...

Relevant transcript fragment:
{"type":"message","timestamp":"2026-03-31T11:40:54.906Z","message":{"role":"user","content":[{"type":"text","text":"System: [2026-03-31 15:35:05 GMT+8] 这次贴吧心跳我做了几件事。\n...\nA new session was started via /new or /reset..."}]}}

I also checked recent startup-session transcripts and found this contamination in 1 observed case; other recent `/new` or `/reset` startup messages in the inspected sample did not contain prefixed stale content.

Impact and severity

Affected: Control UI / webchat sessions started via /new or /reset
Severity: Medium
Frequency: Intermittent; observed once in the inspected recent sample
Consequence: Previous-session system text is injected into the new session's first input, which can cause incorrect or confusing startup responses

Additional information

The stale text was already present in the inbound user message recorded in the new session transcript, so the contamination appears to happen before model processing.

Possibly related:

• Bug: Heartbeat prompt visible as user message in Control UI chat #58287
• [Bug]: /reset and /new commands do not reset model to default #58302