openclaw - 💡(How to fix) Fix [Bug]: WebChat loses previously visible assistant text after new user messages (regression in 2026.5.2) [1 comments, 2 participants]

# Bug Report: Assistant text disappears from WebChat history after new user messages, leaving only tool cards

## Title

WebChat drops previously visible assistant text after later user messages; only `Tool call` / `Tool output` remain

## Version

OpenClaw **2026.5.2**

## Regression

This started **after upgrading to 2026.5.2**.
It **did not happen before the upgrade**.

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## Summary

In WebChat, a previously visible assistant reply can partially disappear after the user sends a later message.

What remains in the UI is often only:

- `Tool call`
- `Tool output`

The natural-language assistant explanation that was visible before is no longer shown.

This has happened repeatedly, not as a one-off.

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## Observed behavior

The user reports the following pattern:

1. Before sending a new message, the previous assistant reply is still visible in the WebChat UI.
2. After sending a new message, part or all of that previous assistant text disappears.
3. The UI often keeps only the tool-related cards.
4. Sometimes multiple user messages appear grouped together while the assistant replies between them are gone.
5. This can happen even when the previous assistant reply is already old (for example, about 10 minutes old), so it does **not** look like a simple "previous reply was still streaming" problem.

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## Expected behavior

Completed assistant replies should remain visible in WebChat history.

If a turn contains:

- assistant text
- tool call(s)
- tool output(s)

then the UI should preserve the full completed turn instead of dropping the assistant text when later user messages arrive.

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## Actual behavior

After a later user message is sent, previously visible assistant text may disappear from the chat history UI, while tool cards remain.

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## Scope / impact

- Makes historical reasoning and explanations hard to review
- Creates the impression that the assistant never replied
- Especially damaging in tool-heavy workflows, because only the tool trace remains visible

Severity suggestion: **Medium-High**

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## Important finding

This does **not** appear to be a policy/rules issue.

I did **not** find any rule or instruction requiring WebChat to hide assistant text and only show tool cards.
This looks like a **WebChat rendering / history reconstruction / message stitching bug**, not intended behavior.

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## Evidence

### Session transcript exists

The conversation history is being persisted to a transcript file:

`/Users/yoc/.openclaw/agents/main/sessions/087c33cf-6d89-4b75-8981-0c8a0a231e43.jsonl`

This suggests the issue is not "history only saved to file and intentionally not shown in UI".
The data exists; the WebChat UI appears to be rendering it incorrectly.

### Related log paths

- Session transcript:
  `/Users/yoc/.openclaw/agents/main/sessions/087c33cf-6d89-4b75-8981-0c8a0a231e43.jsonl`
- Gateway logs directory:
  `/Users/yoc/.openclaw/logs/`
- Current day log:
  `/tmp/openclaw/openclaw-2026-05-04.log`

### Additional clue

Session history shows many assistant turns ending in tool use / tool-related steps. These turns may be reconstructed incorrectly by the WebChat frontend after later messages arrive.

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## Suspected cause

Likely one of the following:

### 1. Final assistant text is not stably attached to the stored turn

The UI may initially show it, but later history refresh/rebuild drops it and leaves only tool cards.

### 2. WebChat incorrectly reconstructs turns that contain both tools and final assistant text

The tool trace survives, but the final natural-language reply is lost.

### 3. A completed assistant turn is being folded or replaced incorrectly when a later user message is appended

This would explain why older visible text disappears only after a new user message is sent.

### 4. Parent/child turn stitching bug

If the frontend collapses messages by parentId / chain incorrectly, it may merge user turns and drop assistant text between them.

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## Reproduction outline

1. Use WebChat on OpenClaw 2026.5.2
2. Have the assistant perform one or more tool calls and then produce a natural-language explanation
3. Confirm the assistant text is visible
4. Send a later user message
5. Observe that the earlier assistant text may disappear while `Tool call` / `Tool output` remain

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## Why this looks like a regression

- User reports it did **not** happen before upgrading to **2026.5.2**
- It started happening after the upgrade
- The issue has repeated multiple times since then

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## What to check

1. WebChat history reconstruction for turns containing:
   - tool use
   - tool results
   - final assistant text
2. Message list refresh behavior when a new user message is appended
3. Whether final assistant text is persisted separately from tool-only turns
4. Whether transcript replay matches what the live UI originally rendered
5. Any 2026.5.2 frontend changes related to tool-card rendering, turn folding, or transcript replay

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## One-line conclusion

After upgrading to **OpenClaw 2026.5.2**, WebChat appears to intermittently drop previously visible assistant text from history and retain only tool cards; this looks like a **frontend/history rendering regression**, not an intentional rule or policy.