Subagent history fails to load: "subagent history read failed (internal)" after /btw completes

[LOGIC-10]

Problem

After running /btw to create a sidechain subagent, the subagent runs and completes successfully (status changes from "运行中" to "空闲" in the task manager panel). However, when clicking on the completed subagent to view its conversation history, the UI shows an error:

历史加载失败：subagent history read failed (internal)

The subagent's answer is never visible to the user.

Reproduction

1. Install dsh-sidechain in DSH web (v0.1.0-rc.5)
2. In any conversation, run /btw <any question> (e.g. /btw 这个项目和原版有什么区别？一句话回答)
3. Wait for the subagent to finish (status shows "空闲")
4. Click on the subagent in the task manager panel to view its history
5. Error appears: "历史加载失败：subagent history read failed (internal)"

Expected behavior

Clicking the completed subagent should show its full conversation history, including the answer it produced.

Environment

• DSH version: v0.1.0-rc.5 (web profile)
• Plugin: dsh-sidechain v0.6.3 (from github:Buyi-wsgzg/dsh-sidechain, which redirects to omdsh-dev/dsh-sidechain)
• OS: macOS
• The subagent session was created and ran to completion; the error only occurs when reading its history.

Additional notes

• The main agent continues to work normally after the subagent finishes.
• The task manager panel correctly shows both the main agent and subagent with their statuses.
• The error message says "(internal)" which suggests a server-side error when reading the subagent's transcript/session data, rather than a network or permission issue.
• No detailed error is logged in the DSH web server output.

[Buyi-wsgzg]

Thanks for the detailed report.

I checked the exact error path. subagent history read failed (internal) is returned by DSH's subagent.history API. The dsh-sidechain panel itself reads the child transcript through session.history, so this appears to come from DSH's built-in subagent/task-manager view or its persistence layer, rather than from /btw execution itself.

Please update to DSH 0.1.0-rc.6 and dsh-sidechain v0.6.4, restart dsh web, and hard-refresh the browser. Note that v0.6.4 adds rc.6 compatibility but does not contain a specific fix for this error.

If the problem remains, please confirm whether you opened the child from DSH's built-in task manager or from the dsh-sidechain right sidebar. The relevant server log around the failed click and the child session ID would also help identify the underlying host error. Please redact any sensitive paths or content.

I’ll keep this issue open until we can confirm whether the failure is in DSH or the plugin.