dsh-composer-prediction
ChatGPT-style composer predictions for DeepSeek Harness.
After each assistant turn, the plugin asks a cheap chat model for the message you
are most likely to send next and paints it as ghost text in the empty
composer. Press Tab to insert it into the draft (nothing is sent), Esc
to dismiss it, or just start typing to discard it. Turn the whole thing off in
Settings → Predictions, a dedicated Settings section this plugin
contributes (settings.section), because the shipped Plugins page is read-only.
Behaviour
| Event | Result |
|---|
Assistant turn ends (running: true → false) | A prediction is requested after the configured delay |
| Composer is not empty, or you are already typing | Nothing is requested or shown |
| Tab while a prediction is visible | The whole suggestion is inserted into the draft; nothing is sent |
| Esc while a prediction is visible | The offer is withdrawn and not repeated for that turn |
| You open a session that already has an assistant answer | One prediction is made for its latest turn, then deduped per session + turn |
| You switch to another session and back | The cached offer is restored immediately; no new request is made (up to 40 sessions are remembered) |
| A switched-to session needs a new prediction | It waits for the chat store to swap (node list change, 400 ms cap) so the request can never carry the previous session's transcript |
| You type or attach a file | The offer is hidden; clearing the draft brings it back for the same turn |
| You switch the feature off and back on | Forgets the session's offer and "already asked" marker, then predicts again immediately |
| You accept, dismiss, start a new turn, or disable the feature | The offer is discarded and any in-flight request is cancelled |
| A response arrives late or for an older turn | Dropped — it can never replace or resurrect a newer offer |
Install
From the npm registry:
dsh plugin --profile <your-profile> add dsh-composer-prediction
Or straight from a checkout:
dsh plugin --profile <your-profile> add ./dsh-composer-prediction --config.auto-install-peers=false
dsh links the package into the profile and appends the bundle to
dsh.profile.bundles because the package declares dsh.bundle. Restart the app
afterwards (a page refresh only reloads the browser half).
Verify the layer composed without booting:
dsh --profile <your-profile> --dump-config
You should see a # == dsh-composer-prediction layer and a composer-predict row.
Remove it with:
dsh plugin --profile <your-profile> remove dsh-composer-prediction
Install from the Discover tab
market/index.json is a ready-to-host plugin-market index
listing this package. Turn on Custom plugin markets, then add this URL under
Plugins → Discover → Add index source:
https://raw.githubusercontent.com/Amir-Bazylkhanov/dsh-composer-prediction/main/market/index.json
Regenerate it after a release with npm run market.
Configuration
Everything lives in $DSH_HOME/composer-predict.json and in the Settings page.
The document is written by the plugin's host half (merge + atomic rename); it is
not a settings.yaml namespace because the 0.2.x ctx.settings service is a form
layer over loader entries and no longer hands a plugin a live namespace scope.
| Key | Default | Meaning |
|---|
enabled | true | Master switch (also the Settings toggle) |
provider | "" | Empty = the deployment default route (ctx.agentDefaultModel) |
model | "" | Empty = the deployment default model |
maxTokens | 64 | Output cap for the prediction |
temperature | 0.8 | Sampling temperature (direct-HTTP transport only) |
delayMs | 0 | Quiet period after a turn before predicting |
maxSuggestionChars | 200 | Hard cap on an offered suggestion |
contextMessages | 10 | Trailing messages fed to the predictor |
maxContextChars | 6000 | Transcript character budget |
baseUrl | https://api.deepseek.com | Fallback only: used when no harness LLM service is composed |
apiKey | "" | Fallback only: DEEPSEEK_API_KEY, then $DSH_HOME/.credentials.yaml |
Model and reasoning
By default the plugin calls the harness's own LLM service (ctx.llm), not a
private endpoint. That means:
- it uses the same provider route and credentials as your sessions — with a
subscription route (
deepseek-account, Kimi, …) you need no API key at all;
- the model is your deployment default (
ctx.agentDefaultModel, e.g.
deepseek-flash) unless you override provider/model in Settings;
- reasoning is pinned to the model's cheapest advertised effort
(
model.reasoning.efforts[0]). A next-message guess should not spend a
thinking budget; if the model advertises no efforts, the provider default is
left alone. Output is capped at maxTokens (64 by default).
The direct OpenAI-compatible HTTP path (baseUrl + apiKey) exists only for
compositions with no ctx.llm; it is not used in a normal DSH install.
If a prediction cannot run, the reason is no longer swallowed: the Settings card
shows it and the browser console logs [composer-predict] ….
Settings page and status
The plugin contributes its own Settings → Predictions section
(settings.section, the same list slot that hosts "Built-in plugins"), with the
enable switch, provider/model overrides and timing.
There is no placeholder state: the ghost text simply appears when it is ready.
When a prediction comes back empty or fails, the composer shows the reason
instead (no prediction: no-model-route, composer-predict: provider HTTP 401, …)
and keeps showing it until you type, dismiss it, switch session, or disable the
feature. The console logs [composer-predict] … in both cases.
How it works
host half (lib/index.js, lib/handler.js)
├─ config document `composer-predict.json` → $DSH_HOME
└─ POST /api/composer-predict/rpc → config.get / config.set / predict / cancel
└─ chat completion → normalizeSuggestion()
browser half (lib/client.js)
├─ slot conversation.input.overlay → ghost text over the empty composer
├─ slot settings.section → "Predictions" Settings page
├─ useChat(legacy.nodes) → transcript tail
├─ useInput(draft) / useSession(running) → eligibility
└─ capture keydown → Tab accepts, Esc dismisses
The overlay measures the real [data-composer-input] element and clones its
font metrics, so padding, wrapping and height follow the composer instead of
guessing at CSS. The native placeholder is hidden (and restored) only while the
ghost is visible.
Bundles are built without a toolchain: scripts/build-client.mjs concatenates
the shared helpers and the component body into the window.__ModuleLoader__
factory the host serves — no bundler, no dependencies, no network.
Development
node scripts/build-client.mjs # regenerate lib/client.js
node scripts/test.mjs # 33 tests across shared/host/client
node --check lib/index.js
Tests cover suggestion normalization, transcript extraction, prompt building,
config sanitization, every RPC endpoint (with a stubbed provider), cancellation,
and a VM smoke test that loads the generated bundle, runs apply() and renders
the overlay.
Manual verification
The client exposes window.__composerPredict so the overlay can be exercised
without waiting for a turn:
__composerPredict.suggest('Add a regression test for the empty-input case.')
__composerPredict.state()
__composerPredict.clear()
__composerPredict.predictNow() // re-run the real prediction path
Limitations
- The prediction triggers on the idle transition; if you are already typing when
the turn ends, no offer is made (deliberately: it should never fight the user).
- The ghost is positioned over the first line of an empty composer; a composer
pre-filled with attachments does not show an offer.
predictNow needs a finished turn to have transcript context.- Verified against DSH
0.2.1-rc.2; the client bundle targets the
conversation.input.overlay slot and the data-composer-input contenteditable
introduced in 0.1.5.
Credits
The Settings navigation glyph is from SVG Repo and is
CC0 1.0 (public domain; no attribution required — the credit is a courtesy).
It has been modified: cropped viewBox, filled with currentColor via an alpha
mask. See NOTICE for details.
License
MIT
