Disclaimer — read before use
This is an experimental, unofficial plugin. It appends a user/message event with surfaceOp: replace
through DSH's internal session API and relies on DOM/projection internals. This is not a supported
public API.
A DSH upgrade, a plugin bug, or an edge case can write an event that DSH rejects when the session is
reloaded, leaving that session unable to load (the 历史加载失败 screen). The original events are not
deleted from the append-only log and can usually be recovered, but until repaired you may not be able to
open the session.
Use at your own risk. Do not use this on important sessions without a backup. The author accepts no
liability for lost access, corrupted sessions, or data loss. If you need a guaranteed-safe truncation,
use DSH's official compaction or fork instead.
dsh-rewind-back
中文 | English
A local rewind / undo button for DeepSeek Harness Web.
Hover any message, click 撤回 (rewind), and that message plus everything after it is removed from the
transcript and from the model-visible context — without leaving a trace in the model context and without
destroying the underlying session log.
Status: experimental. Built and tested against DSH 0.2.1-rc.2. The plugin uses internal session/DOM
APIs, so a DSH upgrade may break it.
Why
DSH has compaction, forking and session-level operations, but no quick way to take back one bad prompt and
everything that followed it. This plugin adds a per-message button:
- the selected message and every later message disappear from the chat;
- the model no longer sees them on the next request;
- the original text is kept in the command receipt so you can copy it and resend;
- the session log still contains every event, so nothing is physically deleted.
Features
- A 撤回 button is injected next to the copy/time actions of every message (both user bubbles and
assistant turn tails).
- Clicking it retracts the selected message and all following messages, for the whole conversation.
- The model context is truncated with a surface replacement, so the retracted messages do not count as
tokens on subsequent requests.
- The command receipt and the rewind marker itself are not sent to the model.
- The receipt can be
turn (one turn, default), always, or hidden — see Configuration.
- The UI state is restored from a session projection, so hidden messages stay hidden after a page reload.
- Also available as a command:
/rewind <n> (1 = the latest user message).
How it works
Host half (lib/index.js)
- Registers the
/rewind command.
- Appends a
user/message event carrying surfaceOp: { op: "replace", startSeq, endSeq } — the same
surface-replacement mechanism compaction uses. Session format v4 does not allow system/message outside an
open turn/step, and fabricating a turn desynchronizes the runtime's turn counter, so the replacement is a
user/message (the one surface event allowed between turns).
- The replacement's content is a single zero-width text block (
U+200B) with source.kind: "rewind-back";
the client projection hides its transcript row, and the model sees at most one zero-width token.
- Records the shadowed ranges/turns in
data.localRewind and exposes them through a localRewind
session projection.
Browser half (lib/client.js)
- Injects the button with a
MutationObserver over the chat transcript.
- Calls the host command through
remote.commands.execute (no extra HTTP endpoint).
- Reads the
localRewind projection and hides matching rows ([data-chat-anchor-key] flow rows and the
recorded [data-chat-turn] rows) with display: none.
- Applies the receipt policy: a
command row containing the rewind receipt is hidden once a later user row
exists (turn), hidden always (hidden), or left alone (always).
Only the turns explicitly recorded by the host are hidden. Do not hide turn >= fromTurn: turn numbers
only grow, so that rule would also hide every message you send after the rewind and the assistant's reply.
Install
Requirements: DSH Web 0.2.1-rc.2 (desktop app or dsh --profile web), Node.js 20+ for development.
Clone the repository somewhere stable, then link it into your DSH profile.
git clone https://github.com/GG915GG/dsh-rewind-back.git C:\src\dsh-rewind-back
# Windows: create a junction inside the profile
cmd /c mklink /J "%USERPROFILE%\.dsh\profiles\desktop\node_modules\dsh-rewind-back" "C:\src\dsh-rewind-back"
Edit %USERPROFILE%\.dsh\profiles\desktop\package.json:
{
"dependencies": {
"dsh-rewind-back": "link:C:/src/dsh-rewind-back"
},
"dsh": {
"profile": {
"bundles": [
"...",
"dsh-rewind-back"
]
}
}
}
Restart DSH completely. The host half is loaded at startup; the browser half is served by the web app.
To uninstall, remove dsh-rewind-back from dsh.profile.bundles and from dependencies, then restart DSH.
Usage
- Hover over any message; click 撤回 to retract that message and everything after it.
- Or type
/rewind 1 (latest user message), /rewind 3, etc.
- The receipt shows the original text, so it can be copied and sent again. By default it only stays in the
transcript until you send your next message.
The retracted part is gone from the visible transcript and from the model context. Because the session log is
append-only, the events are still on disk; if you really want to restore them, remove the replacement event
from the session log offline (do this only with DSH closed and after making a backup).
Configuration
The > rewind · 已撤回 … command receipt has a display policy:
# %USERPROFILE%\.dsh\profiles\desktop\cordis.patch.yml
- id: rewind-back
config:
receipt: turn # turn (default) | always | hidden
turn — visible until the next user turn starts, then gone (default);always — keep every receipt in the transcript;hidden — never show the receipt (the original text is still recoverable from the session log).
The policy is passed to the browser through the localRewind session projection. With profile HMR enabled
the new value is applied on the next recomposition; otherwise restart DSH.
Compatibility and known limitations
- Built for
0.2.1-rc.2; the manifest declares exact compatibility. Other versions may work but are not
tested.
- The button depends on DSH's current DOM (
div[data-clock], bubble structure). A front-end redesign will
break the injection; update the selectors in lib/client.js.
- The browser calls the host command with a base64-encoded prefix of the bubble text. Duplicate messages can
resolve to the newest match.
- Rewinding while a turn is still running is refused; wait for the turn to end.
- There is no built-in undo UI yet.
Development
No build step. lib/client.js is the browser bundle expected by DSH's client module loader.
node test/run.mjs
# or
npm test
The tests do not need DSH installed: test/host.test.mjs uses a fake session, and test/client.test.cjs
runs the client bundle against a minimal fake DOM.
License
MIT — see LICENSE.
Not affiliated with DeepSeek.
