dsh-compact-after-task

A DSH (Cordis) plugin that auto-compacts a conversation after the current task finishes, whenever context pressure crosses a threshold you set (default 50% of the routed model's context window). Install it and stop manually clicking "compress" — and stop letting the context (and the bill) grow unchecked.

The switch and the threshold are adjustable directly in Settings → Plugins (toggle + slider); changes apply immediately, no restart needed.

The problem it solves

In a long conversation the model re-receives the entire history on every turn. As the conversation grows, this bites harder and harder:

No compaction → exploding cost. The bigger the context, the more tokens each turn re-sends. Even with a provider KV cache (cheaper than fresh input, still not free), the history is re-transmitted and re-billed every single turn. Rolling from tens of thousands to hundreds of thousands of tokens quietly multiplies per-turn cost — the longer you talk, the more each reply costs, without you noticing.
Manual compaction is tedious and easy to forget. /compact or the UI compress button works, but you have to remember to use it — and people only remember once things are already slow and expensive, after several huge turns have been paid for.
The built-in auto-compaction is a late, mid-task safety net. dsh-compaction-basic only fires at 80% of the context window, and only at a step boundary while a task is running — by then you've already paid for several enormous requests, and the compaction interrupts work in progress.
Slower responses. Longer prefixes mean more processing per request and a noticeably sluggish feel.

This plugin automates the "remember to compress" chore: after each task finishes (the agent returns to idle) it checks the pressure and compacts at your chosen threshold — dealing with cost before it hurts, not after.

How it relates to the built-in compaction (complementary, not a replacement)

	Built-in `dsh-compaction-basic`	This plugin
When	At each step boundary (`agent/pre-step`), mid-task	After the task fully finishes (agent returns to idle)
Threshold	`thresholdRatio` 0.8 (fixed)	`thresholdRatio` user-set, default 0.5
Role	Last-resort mid-task safety net	Routine "slim down between tasks"

The compaction itself is identical to /compact: it calls ctx.compaction.compactNow(), produces one <compacted-summary> checkpoint, and the conversation UI shows the usual "compacted N history items" card.

Requirements

DSH Desktop / DSH profile with the base bundle (dsh-base), which provides dsh-compaction-basic, dsh-token-meter, dsh-agent and dsh-llm.
Core auto-compaction works on any version. The settings-page card (toggle + slider) needs DSH ≥ 0.1.0-rc.7 (released 2026-08-17): since rc.7 the Host serves every registered settings namespace to the browser automatically, so a third-party plugin's settings card works out of the box — this is the official mechanism. On rc.6 and earlier the namespace list was hardcoded and a third-party namespace was refused (settings-not-exposed) — upgrade, or apply the two-line patch below only if you cannot upgrade.
On rc.7+ this plugin reaches the compaction service via agentPresets.serviceFor(), not inject: ["compaction"]. Since rc.7 introduced agent presets, the compaction service is no longer provided on the host plane — each session's preset (standard/cordis/…) mounts it inside an isolate realm, so a host-plane plugin that injects compaction pends forever (waiting for service: compaction). This plugin instead calls the official read API ctx.agentPresets.serviceFor(agent, "compaction") when the agent goes idle (that API exists precisely for callers whose request is about a session but arrives from outside it); on rc.6 and earlier it falls back to ctx.get("compaction").
For the settings card to appear, the package exports must expose "./package.json": "./package.json". dsh-client-modules discovers client bundles by resolving <package>/package.json to read the dsh.client metadata; if a package declares exports without that key, the lookup throws ERR_PACKAGE_PATH_NOT_EXPORTED and the package is silently cached as "not a client package" — the host half runs fine but the settings card never shows. All official packages ship this line in exports.

Install

Two ways — pick one (do not mix them: the loader rejects a duplicate entry id).

A. Standard: plugin market / `dsh plugin add` (recommended)

The package ships a dsh.bundle.patch pointing at its own cordis.patch.yml, so it is a first-class bundle: installing it via the market or the CLI adds it to the profile's dsh.profile.bundles, and on the next boot the loader applies the package's own patch layer automatically — no manual editing needed.

# from npm (after publishing) — or from GitHub directly:
dsh plugin --profile desktop add @xiaobanli/dsh-compact-after-task
dsh plugin --profile desktop add github:xiaoliang2/dsh-compact-after-task

Or, in the desktop app, open Settings → Plugin Market and one-click install. Restart DSH Desktop, done.

B. Manual, profile-local (no market, no publishing)

Copy this package into the profile and make it resolvable from the profile's node_modules (same way dshmarket is installed):

# from the DSH home, e.g. C:\Users\you\.dsh\profiles\desktop
Copy-Item -Recurse <path-to>\dsh-compact-after-task .\plugins\dsh-compact-after-task
New-Item -ItemType Junction -Path .\node_modules\@xiaobanli\dsh-compact-after-task -Target .\plugins\dsh-compact-after-task

Add the plugin row to the profile's cordis.patch.yml (your user patch layer, applied after every bundle layer):

- insert:
    - id: compact-after-task
      name: '@xiaobanli/dsh-compact-after-task'
      config:
        enabled: true
        thresholdRatio: 0.5

Declare the dependency in the profile's package.json so a later pnpm install does not prune it:

"dependencies": {
  "@xiaobanli/dsh-compact-after-task": "file:plugins/dsh-compact-after-task"
}

Restart DSH Desktop for the profile change to take effect.

If you already installed it manually (method B), uninstall/remove it before installing via the market, otherwise the same entry id compact-after-task is inserted twice and the loader refuses to boot.

Only on DSH ≤ 0.1.0-rc.6 (if you cannot upgrade)

Before rc.7 the Host exposed only a hardcoded namespace whitelist, so the settings card cannot read/write until you add this plugin's namespace to it (two files in the app install, under resources\app.asar.unpacked\node_modules\@deepseek-ai\dsh-host-apiproxy):

lib/index.js — in const WEB_SETTINGS_NAMESPACES = [ ... ] (~line 888) add "compact-after-task",
lib/types/api-proxy.js — in the single-line const WEB_SETTINGS_NAMESPACES = [...] (~line 50) add "compact-after-task"

Then restart. Note DSH updates overwrite these files, so re-apply after each update. On rc.7+ this patch is unnecessary and these files no longer exist.

Configuration

Key	Type	Default	Meaning
`enabled`	boolean	`true`	Master switch.
`thresholdRatio`	number (0.05–1)	`0.5`	Compress when pressure reaches this fraction of the routed model's context window (`0.5` = 50%).
`onlyRoots`	boolean	`false`	Only compress top-level conversation agents (skip background subagents).

Adjust from the settings page (toggle + slider)

After install, an Auto-compact card appears under Settings → Plugins → Configurable plugins:

Toggle: auto-compact after each task finishes;
Slider: auto-compact threshold (5%–100%, 5% steps).

Releasing the slider saves immediately; the settings/updated event applies it live, no restart needed. The value persists in the settings document and takes precedence over the loader config in cordis.patch.yml (which acts as the default/base layer).

Picking a threshold

Set it from "the max per-turn re-send you can tolerate ÷ the model's context window":

DeepSeek's default 1M window: 0.3–0.6 is the sweet spot; 0.5 is a conservative default.
Want each turn to re-send ≤ 400K tokens → 0.4; ≤ 250K → 0.25.
Don't go ≥ 0.8: the built-in compaction already fires at 0.8 at a step boundary, so a higher threshold here is meaningless.
Small-window models (128K/64K): raise to 0.6–0.8, or you'll squeeze out useful working context.
Too low (below ~0.1) means compressing after every small task, and the summary swallows details that were still useful.

Tune by feel after a couple of long tasks: compressing after every little task / summaries getting coarse → raise it; still re-sending hundreds of thousands of tokens per turn → lower it. Edit thresholdRatio in cordis.patch.yml and restart.

Behavior details

Listens to the agent/status event and acts only on the idle transition — i.e. the current task's drive has fully drained. This is the "compress after finishing the current task" moment; it never interrupts a running task.
Uses the same pressure measurement as the built-in engine: tokenMeter.measure(session).totalTokens vs contextWindow × thresholdRatio (context window resolved via llm.resolveModelInfo).
Compaction is a single ctx.compaction.compactNow(agent, signal) call — the same operation /compact runs; compactNow reserves next-turn admission, so queued messages are correctly deferred until the compaction finishes. On rc.7+ ctx.compaction is the instance returned by agentPresets.serviceFor(agent, "compaction"); the operation is unchanged.
Expected failures are silent: busy (agent busy / a compaction already running) and cancelled are skipped; anything else is logged as a warning without disturbing agent lifecycle events.
If the agent's preset mounts no compaction group (e.g. minimal), serviceFor returns undefined and that agent is skipped.

Test

npm install
node test-compact-after-task.mjs

The unit test stubs the services and covers: idle + above threshold compacts, below threshold does not, running does not, busy is silent, disabled does nothing, onlyRoots filters subagents.

License

MIT

dsh-compact-after-task

Install

README