dsh-thinking-language

English | 中文

A one-section DeepSeek Harness bundle that pins the language an agent thinks, reasons, and replies in. The shipped default is Chinese mode: once installed, every agent composed by the deployment gets an ordered system-prompt section right after its persona telling the model to think and answer in Chinese.

It works on any DeepSeek Harness deployment (Web UI, headless, ACP) because it only contributes a system-prompt section — no tools, no shell access, no model changes. <img width="2202" height="969" alt="image" src="https://github.com/user-attachments/assets/1bb77dfb-4373-423d-8749-0ce83bfaa929" />

Install

dsh plugin --profile <name> add dsh-thinking-language

That installs the package into the profile and appends the bundle layer (the package declares dsh.bundle, so dsh plugin activates it automatically). Then:

dsh --profile <name>

The layer registers the thinking-language row, whose default config is the Chinese instruction. No further setup is needed. Verify the layer first without starting:

dsh --profile <name> --dump-config   # shows a "# == dsh-thinking-language" layer

Config

One row, three fields:

The default text is:

> 请始终使用中文进行思考、推理与回复：你的思考过程（reasoning）与所有输出一律使用中文，包括对工具调用结果的解读与最终回答。

Change the language or wording

Patch layers replace the targeted row's whole config, so an override restates every key it wants. Put this in your profile's cordis.patch.yml (or a --patch overlay) to switch to English:

- id: thinking-language
  config:
    text: >-
      Always think, reason, and reply in English.

How it works

The plugin exports the standard plugin contract (name, inject: ['systemPrompt'], Config type and Schemastery schema, apply) and registers one section:

• Name: thinking:language (exported as THINKING_LANGUAGE_SECTION).
• Order: 1 — immediately after the deployment persona (0), before the tool-guidance band (100–199), so the model reads the language instruction at the start of the prompt body.
• It never shadows the persona: persona presets (@deepseek-ai/dsh-persona) and this plugin coexist in the same composition.
• Registration rides the calling fiber, so hot-reloading a config edit removes the old section before the new one registers.

Model experience

• What the model sees: one extra prompt section between the persona and tool guidance, e.g. 请始终使用中文进行思考、推理与回复：你的思考过程（reasoning）与所有输出一律使用中文，包括对工具调用结果的解读与最终回答。 — every request, for every agent on the deployment.
• Token effect: a fixed cost per request, equal to the rendered instruction text (about 60 tokens for the default).
• KV-cache effect: the section is stable for a given config, so prompt-prefix caching stays intact. Editing the text changes the prefix from the first changed token.

Develop

pnpm install
pnpm test        # vitest
pnpm typecheck   # tsc --noEmit
pnpm build       # tsdown -> lib/
pnpm smoke       # mounts lib/ against the real peers and asserts the rendered prompt

The prepare script runs tsdown with a self-contained config, so installing from git (dsh plugin add github:you/dsh-thinking-language) also produces the published entry. @deepseek-ai/dsh-system-prompt and @deepseek-ai/cordis are peer dependencies resolved from the dsh installation the profile runs on.

Publish

• npm: pnpm publish (the files list ships lib/, cordis.patch.yml, and both READMEs; dsh.bundle points at the patch layer).
• Tarball: pnpm pack, then dsh plugin add ./dsh-thinking-language-0.1.0.tgz.
• Git: push the repo and let users dsh plugin add github:you/dsh-thinking-language — pnpm runs prepare after install, which builds lib/ from source (users must allow the build for git dependencies).

Known limitations

• Thinking text is the model's own reasoning output, steered by the system prompt rather than a wire-level switch: the section is a strong instruction, not a hard guarantee, and occasional non-Chinese fragments may still appear.
• If a deployed preset registers its own complete persona (complete: true on a persona row), it suppresses this section along with every other section.
• Peer range ^0.1.0-rc.2 targets the current rc series of @deepseek-ai/dsh-system-prompt; a future major may rename exports, which a peer bump would address.

License

[MIT](LICENSE)