dsh-task-mode-switch

Switch a DeepSeek Harness task's Agent preset (mode) from the composer, including a task that has already started, plus AUTO, which picks one from the task text.

在 DeepSeek Harness 输入框工具栏切换任务的 Agent 模式（预设），包括已经在进行中的旧任务；另有 AUTO 按任务内容自动选择。

Install / 安装

dsh plugin --profile desktop add dsh-task-mode-switch   # DSH Desktop
dsh plugin --profile web add dsh-task-mode-switch       # dsh web

Or straight from the repository (the package sits at its root):

dsh plugin --profile desktop add https://github.com/StephenXiong001/dsh-task-mode-switch   # DSH Desktop
dsh plugin --profile web add https://github.com/StephenXiong001/dsh-task-mode-switch       # dsh web

Restart DSH, then open the + / tool row at the left of the composer: a mode control sits beside the permission and plan controls.

What you get / 功能

选择	preset	说明
标准模式 / Standard	standard	Everyday tasks: files, commands, search, subagents
PTC 模式 / PTC	ptc	Batches tool calls; bulk filtering, dedupe, aggregation
极简模式 / Minimal	minimal	Smallest tool set, for comparisons and baselines
创造模式 / Creator	cordis	Extends DSH: plugins, presets, skills
AUTO	—	Picks one of the above from the composer draft (keyword heuristic, local, no model call)

Clicking a mode switches the task you are looking at, not just the default for new tasks. A separate menu row (「新任务默认模式 ▸」/ "Default for new tasks") writes the default for tasks created later, so the two actions can never be confused. While a turn is running the control refuses with an explanation; it never re-binds a composition mid-step.

New presets need no plugin update. The menu is drawn from the live roster: the four presets above keep their shipped icons and hints, and any additional preset a newer DSH registers is appended automatically, labeled with the name the preset publishes (or its id). Opening the menu re-reads the roster, so a preset added while the page is open shows up on the next click. AUTO still classifies only the four presets above; a preset it does not know is left alone.

The same switch is available as a slash command:

/mode            # report the current preset and what can be switched to
/mode ptc        # switch this task

How it works / 实现要点

1. Composition. The shipped agentPresets.select Remote refuses a started session (agent-preset/locked). This bundle's Host half re-composes one through the registry's own recompose() entry (whose contract says "the caller owns the blank-session check") and therefore takes that responsibility itself: refuse while running, re-bind through the registry (never by touching scope internals, so tools/change is announced), then append agent-preset/selected to the Session log, because a model-visible change must be logged.
2. Request series. Tool declarations are projected from the Session's recorded request series; a tool missing from it is announced as a deferred addition. A preset switch replaces the whole catalog, so every tool would be deferred, and providers reject a request whose tools are all deferred ("at least one tool must have defer_loading=false"). The plugin asks for a request-series restart on the first admitted step after a switch, via the documented agent/pre-step waterfall and PreStepDecision.startsRequestSeries, the same field the shipped goal-round driver sets.
3. UI. One registration into conversation.input.left, using the baseline @deepseek-ai/dsh-client-ui-primitives Menu (ported popup) and theme tokens; no DOM of other plugins is touched, and no model-facing tool is registered (choosing a mode is a user-owned decision).

Caveats / 代价与限制

• Switching mid-task changes the tool catalog and prompt sections of that task; the next request restarts its request series, so that turn's KV cache is rebuilt from scratch. Earlier turns keep the tools they ran with.
• The switch relies on a registry entry whose caller owns the blank-session guard; the composition is only re-bound between turns.
• AUTO is a keyword heuristic over the draft. It never calls a model, and only ever picks a mode when at least one strong keyword matches; otherwise it keeps the current mode.
• Verified on DSH 0.2.2-rc.1 (Windows desktop). A deployment without the Agent-preset registry has nothing to switch, and the control says so.

License

MIT. See LICENSE.