dsh-prompt-enhance

Prompt enhancement for the DeepSeek Harness web GUI — one click turns a rough composer draft into a well-structured prompt: explicit role and goal, executable steps, output format, acceptance criteria, and edge cases. Your intent is never changed, nothing is fabricated, and the original draft is always preserved.

English | 简体中文

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Why

Good agent prompts state who the model should be, what to deliver, in what format, and how success is judged. Most drafts don't. This plugin adds a WorkBuddy-style "enhance" affordance to the dsh composer: it sends your draft through a low-temperature rewrite pass (via the harness's own LLM service), shows the result next to the original, and lets you apply, copy, or discard it. Undo is one click away, and every failure path leaves your draft exactly as you typed it.

Features

✨ Composer button	A small button in the input box's tool row (next to the send button), always at hand
🔀 Preview panel	Original vs. enhanced side by side, with model name and elapsed time
↩️ One-click undo	After applying, a quiet bar above the composer restores the original draft
⌨️ Shortcut	Default Ctrl+Alt+E, fully configurable, acts on the composer you are working in
💬 /enhance command	Rewrite any text from the slash-command plane; the result never enters model history
🧠 Model routing	Settings pair → current session model → harness default model, in that order
🔑 Zero credential setup	Calls ride the harness LLM service; keys come from the harness credential store
⚙️ Live settings	Every knob (model override, temperature, budgets, system prompt, shortcut) hot-applies from Settings → 插件配置
🛡️ Draft safety	Empty, over-length, images-only, and command-chip inputs are rejected locally; upstream failures are mapped to readable messages; the draft is never mutated on failure

How it works

flowchart LR
    A[Composer draft] --> B{Local guards<br/>empty / length / chips / busy}
    B -- pass --> C["POST /prompt-enhance/enhance<br/>(loopback-fenced host route)"]
    B -- reject --> P[Preview panel:<br/>readable error, draft untouched]
    C --> D["ctx.llm.stream<br/>rewrite with system strategy"]
    D --> E[Normalize:<br/>strip fences, trim, refuse empty]
    E --> F[Preview panel:<br/>original / enhanced]
    F -- Apply --> G["setDraft(enhanced)<br/>original pushed to undo stack"]
    F -- Cancel / Copy --> H[Draft untouched]
    G --> U[Undo bar: one click restores]

The plugin is one npm package with two halves, following the dsh plugin conventions:

• Host half (exports ".", Node): registers the prompt-enhance settings section (schemastery — rendered automatically by the built-in plugin config page), the POST /prompt-enhance/enhance route on the shared webserver (loopback-fenced, body-capped), and the /enhance slash command. The model call goes through ctx.llm.stream with a normalized output pass — the same auxiliary-call discipline the harness applies to session titles: deadline + caller cancellation rechecked during and after the stream, terminal-finish validation, tool-call rejection.
• Browser half (exports "./client"): registers the enhance button into the conversation.input.right slot and the undo bar into conversation.input.dock, binds a live mirror of the settings namespace, and installs the global shortcut. All copy is localized (zh/en) through the harness locale system.

Requirements

• dsh >= 0.1.1-rc.1
• Node ^22.19.0 || >=24.0.0 (for building from source)

Install

From npm (recommended):

dsh plugin --profile web add dsh-prompt-enhance
# restart dsh web

From GitHub (the built lib/ is committed, so no local build happens):

dsh plugin --profile web add github:rongxingda/dsh-prompt-enhance

From a local checkout (for development — changes rebuild + restart take effect):

git clone https://github.com/rongxingda/dsh-prompt-enhance.git
cd dsh-prompt-enhance && npm install && npm run build
dsh plugin --profile web add link:C:\path\to\dsh-prompt-enhance

Uninstall:

dsh plugin --profile web remove dsh-prompt-enhance
# check the profile's package.json `dsh.profile.bundles` array for a leftover
# "dsh-prompt-enhance" row and remove it if present, then restart dsh web

Usage

Composer button / shortcut — type (or leave) a draft, hit ✨ or Ctrl+Alt+E:

1. Local guards run first: empty drafts, over-length drafts (never auto-truncated — that would change your meaning), images-only drafts, and drafts containing command or file-reference chips are refused with a clear message. Chips are rejected because filling back would destroy them.
2. The preview panel opens with a cancellable spinner. Your draft stays untouched — the hint says so.
3. The result phase shows both texts side by side. Apply fills the enhanced text back and raises the undo bar; Copy puts it on the clipboard; Cancel (or Esc, or clicking the overlay) discards everything.
4. The undo bar sits above the composer: one click restores the original. If you keep typing after applying, the bar quietly retires itself so stale text can never overwrite newer edits.

/enhance <text> — rewrite any text from the slash menu. The result renders in the command plane (copyable) and never enters the conversation history or the model's context. To enhance the composer draft itself, use the button or shortcut — the draft lives in the browser.

Language consistency is guaranteed by the rewrite strategy: Chinese in, Chinese out; English in, English out.

Configuration

Everything lives in the prompt-enhance settings namespace, edited from the web GUI's Settings → 插件配置 page. Changes apply to the very next call — no restart.

Field	Default	Description
enabled	true	Master switch; off hides the button and disables every trigger
provider + model	empty	Explicit route override; must be filled as a pair (or both empty to follow the current session model)
temperature	0.3	Low temperature keeps the rewrite faithful to the original
maxOutputTokens	2048	Output token budget of one enhancement call
maxInputChars	12000	Input character cap; over-limit drafts are rejected, never truncated
timeoutMs	60000	End-to-end deadline of one call
systemPrompt	built-in strategy	Replace the whole enhancement strategy if you prefer your own
shortcut	ctrl+alt+e	Global shortcut spec (at least one modifier + one alphanumeric/function key — bare keys are ignored so normal typing can never be swallowed); empty disables it
provider + model values	—	Match the harness settings: each key under llm-pi-ai.providers (e.g. zhipu, muyuu) is a provider and each models[].id under it (e.g. glm-5.3-flash) is a model. Example pair: provider: zhipu + model: glm-5.3-flash

Model routing precedence: explicit settings pair → the route recorded in the current session's request header → the harness-wide default model (agent-default-model). If none of them names a route (e.g. a fresh session with no default model), the plugin fails with an actionable message instead of guessing.

The built-in enhancement strategy

The default system prompt instructs the model to be a prompt-rewriting expert and to apply what the draft actually needs:

1. Role and goal — state who the assistant acts as and what the deliverable is.
2. Context and constraints — add only what the draft implies; never invent facts, data, names, or requirements.
3. Steps — break vague or multi-part requests into numbered, executable steps.
4. Output format — specify structure, language, length, and style where implied.
5. Acceptance criteria — state how to recognize a correct result.
6. Boundary conditions — list edge cases and what to do when information is missing.

Hard rules: preserve intent exactly (never remove, alter, or contradict user information); never fabricate — insert an explicit placeholder like (待补充：…) / (TBD: …) for unknown details; keep the scope unchanged; output only the rewritten body (no explanations, fences, or pleasantries); mirror the input language; stay within roughly 1–3× the original length; lightly polish already-well-formed prompts instead of inflating them.

Set systemPrompt in the settings to replace all of this with your own strategy.

Error handling & edge cases

Case	Behavior
Empty / whitespace / invisible-only draft	Local refusal: "input box is empty"
Draft over maxInputChars	Rejected locally and at the route with exact counts; no auto-truncation
Images attached but no text	Refused: text-only feature
Command or file-reference chips in the draft	Refused: fill-back would destroy the chips
Submitting / busy phase or a request already in flight	Refused with "try again in a moment"
Upstream model failure	Stable codes mapped to readable hints: AUTH → check API key, RATE_LIMIT → retry later, QUOTA_EXCEEDED → check balance, CONTEXT_WINDOW_EXCEEDED → shorten input, NO_ADAPTER/unconfigured → configure a model
Output reaches maxOutputTokens	Refused with a hint to raise the cap or shorten the draft
Model returns empty / fence-wrapped / tool-call output	Normalized (fences stripped) or refused; retryable
Timeout	504-mapped message with the configured seconds; retryable
Browser tab closed mid-flight	The host route detects the disconnect and aborts the model call
Session switch	Panel state, undo stack, and shortcut targeting are per-session; switching closes the panel and clears its undo entries

Every failure surfaces inside the plugin's own panel; the composer draft is never modified by a failed call, so manual input continues undisturbed.

Security model

The enhance route is served by your own dsh host and reachable only from this machine:

• Socket fence — requests from non-loopback addresses are refused (127.0.0.1 / ::1 only). Note this means any local process can call the route; it carries no user authentication.
• Host allowlist — the route also validates the Host header against localhost / 127.0.0.1 / [::1], which defeats DNS-rebinding (a rebound attacker domain keeps the loopback socket address but carries the attacker's hostname and is refused). Responses are cache-control: no-store.
• Proxy rejection — requests carrying X-Forwarded-For / Forwarded headers are refused outright: those headers only exist when a proxy is in the path, which the trust model does not cover.
• Not for reverse-proxy exposure — if you put dsh web behind a proxy that listens on the LAN, external callers appear as loopback to the route and the fence is moot. Do not expose a proxied host without adding your own authentication at the proxy.
• Prompt-injection boundary — the draft is framed between <raw_prompt> tags, literal closing tags inside the draft are neutralized, and the strategy prompt treats the framed text as pure data. Enhancements run with your own credentials and the result is only ever shown back to you.

Architecture

src/
├── index.ts            host apply(): settings section + route + command
├── config.ts           schemastery schema + resolution (paired route validation)
├── prompts.ts          built-in strategy system prompt + <raw_prompt> framing
├── enhancer.ts         the ctx.llm auxiliary call (route resolution, deadline
│                       racing, finish validation, code → message mapping)
├── enhance-routes.ts   POST /prompt-enhance/enhance (loopback fence, body cap)
├── enhance-command.ts  /enhance slash command (host command registry)
├── loopback.ts         127.0.0.1/::1 fence for the route
├── http.ts             bounded JSON body reader / writer
├── shared/             wire protocol types, input checks, output normalization
│                       (imported by both halves)
└── client/             browser half
    ├── index.tsx       slots registration + settings mirror + shortcut listener
    ├── EnhanceButton   conversation.input.right entry: guards + call orchestration
    ├── ResultPanel     overlay panel: compare / apply / copy / cancel / retry
    ├── UndoBar         conversation.input.dock entry: restore affordance
    ├── ui-state.ts     external store shared by components (panel, undo, sessions)
    ├── enhance-client  fetch client with abort + typed errors
    ├── undo-stack.ts   per-session LIFO (depth 3)
    ├── shortcut.ts     pure combo parsing / matching
    ├── settings.ts     client mirror of the settings namespace
    ├── locales.ts      zh + en dictionaries (harness locale namespace)
    └── styles.ts       self-injected stylesheet (dsh-pe- prefixed classes)

Build outputs: lib/index.js (host half, ESM, package imports kept external) and lib/client.js (browser half bundled to CJS inside the window.__ModuleLoader__.load({ id, factory }) envelope the dsh web shell expects). Both are committed so GitHub installs need no build step; CI fails if lib/ drifts from src/.

Development

Daily debug loop (link install + watch): install once via dsh plugin --profile web add link:..., run npm run watch, and restart dsh web after host-half changes — see CONTRIBUTING.md.

npm install
npm run typecheck     # tsc --noEmit
npm test              # unit + real-http + component suites
npm run build         # typecheck + both halves
npm run watch         # esbuild watch for both halves

Test coverage: input validation, output normalization, the enhancer against stubbed ctx.llm streams, a real-node:http route suite (loopback Host fence, disconnect abort, error envelopes), the loopback/Host fence units, prompt framing, config resolution, the undo stack, shortcut parsing, client settings, and React component tests locking the enhance → apply → undo flow (guards, stale marking, diverged-draft undo semantics).

Release process (maintainers):

npm version patch   # or minor / major — bumps package.json and tags
npm run build       # make lib/ match src/
git push --follow-tags
npm publish         # with 2FA OTP, or a granular token with "bypass 2FA" checked

CI runs typecheck + tests + build on every push/PR and rejects merges where lib/ differs from the committed build.

FAQ

Why is my draft rejected when it contains /commands or @references? The fill-back writes plain text via inputActions.setDraft, which would destroy the chips. Remove them, enhance, then re-insert.

Why isn't over-length input auto-truncated? Truncation silently changes your meaning — the plugin refuses and shows the exact counts instead.

Can I pin a specific model? Fill provider and model as a pair in the settings (e.g. your harness-configured provider route). Leave both empty to follow the current session's model.

Where does my draft go? Browser → your own dsh host over a loopback-only route → the harness LLM service → the configured model provider. Nothing is sent anywhere else, and the enhancement never enters the session's model history.

Does it work with the official DeepSeek route? Yes — it rides ctx.llm, so any provider the harness serves (DeepSeek official, OpenAI-compatible gateways) works.

Acknowledgments

Plugin structure, the loopback fence, and the settings-section pattern follow the conventions established by the dsh plugin family — in particular @linxin666/dsh-tool-describe-image.

License

Apache-2.0