dsh-math-render

dsh-math-render

A DeepSeek Harness (dsh) plugin that renders LaTeX in the web GUI:

• Your own message bubble — $...$, $$...$$, \(...\) and \[...\] in a message you sent render as formulas, in place.
• Composer draft preview — while the draft contains a formula, a strip above the input renders it live. With no formula in the draft the strip does not exist at all.

Assistant replies already render through the shell's KaTeX pipeline; this plugin does not touch them.

Install

dsh plugin --profile web add dsh-math-render

Restart the harness afterwards (the profile's bundle list is read at boot), then reload the GUI page.

dsh plugin --profile web add /path/to/dsh-math-render

How it works

The host half is a package anchor plus one read-only diagnostic route. It holds no state and touches nothing at boot.

This plugin used to shadow conversation.chat.node and rebuild the whole user bubble from copied CSS. 0.2.1 removed the projectUserText primitive that approach depended on, so 2.0.0 moved to the user-text extension point instead: the shipped bubble keeps its own DOM, geometry, attachments, copy action, reference chips and secret masking, and only the formula spans are handed to the shell renderer.

Behaviour

• A message without TeX renders exactly as the shipped bubble does. The message is still parsed and rendered by the shipped user-text document and plain-text run; the plugin only adds one node key.
• Backticks are the escape hatch. TeX inside a fenced code block or an inline code span stays literal, and so does \$.
• Currency is not mistaken for math. costs $5 and $10 stays prose: a closing $ glued to a digit is refused, as is space-padded content.
• Bad TeX is not hidden. It goes to the shell renderer, so a syntax error shows KaTeX's error output, exactly as in an assistant reply.
• A failing rule or renderer falls back to raw text. The user-text document keeps the whole original message as plain text when a rule throws, and the slot boundary contains a crashing node renderer, so the worst case is "no effect", not a broken transcript or a missing bubble.
• No preview on the new-session hero composer. The host renders that seat only for a bound session; it appears once the first message puts you inside the conversation.

Limitations

• Requires dsh 0.2.1-rc.1 or newer. The uiConversation.userText rule registry and the conversation.user.text.node seat were introduced there. On an older shell the plugin stays inert.
• The composer preview is a preview, not inline WYSIWYG. The composer is a Lexical editor and the plugin seams expose no inline widget. Typing $x^2$ renders in the strip above the input, not inside the editable area.
• dsh.bundle and a hand-written file:// row are mutually exclusive. Two active Loader sources for one package name is an error; install it one way.

Diagnostics

curl -s http://127.0.0.1:<port>/plugin/math-render/status
# {"plugin":"dsh-math-render","version":"2.0.0","mounted":true,"clientRegistered":true,"clientBundle":"…/client.js"}

Loopback Host only. mounted proves the row resolved; clientRegistered proves the browser half is in the client module graph. In the page console, document.querySelector('style[data-plugin-css="dsh-math-render/styles.css"]') is non-null once the browser half has loaded.

Tests

npm install
npm test

No harness, no browser, no network. 36 assertions over the tokenizer (delimiters, display math across lines, currency and code-span refusals, exact source ranges), the math rule's candidate contract, the shapes both seats are registered with, the components (TeX routes to MarkdownText, ranges and malformed nodes degrade instead of throwing, the preview's zero footprint), and — when the shell's own slot registry is reachable — that the math key occupies one cell without displacing the shipped keys.

Compatibility

Written and verified against dsh 0.2.1-rc.2 (client packages 0.2.1-rc.2, DSH Desktop 2.0.18). The uiConversation.userText rule contract, the keyed conversation.user.text.node seat, the free math key, and the conversation.input.dock render props were read out of that version's sources. Newer shell versions may move any of them.

License

MIT