dsh-chat-rtl — auto RTL for Persian chat content

By Mehran Ghalambor (mehran.ghalambor@gmail.com) · MIT License.

Real, installable client plugin + profile bundle for DeepSeek Harness. The app stays in its own language (English); only conversation content reflows: paragraphs that start with Persian render right-to-left, English paragraphs stay left-to-right — and when your latest question reads Persian, the whole flow follows it right-to-left.

How

One owned effect injects a <style> into the document (removed on disable/uninstall) and sets dir="auto" on every message block plus the composer, kept up to date by a MutationObserver (also re-applies if the editor framework drops the attribute):

• Each p/li/heading/blockquote under [data-slot="conversation.chat.flow" | "conversation.chat.node"] gets dir="auto" — direction follows its own first strong character (live-verified: Persian → rtl, English → ltr), with text-align: start.
• pre/code are pinned to direction: ltr so code never flips.
• The composer ([data-composer-input]) gets dir="auto" so typing in Persian aligns right while typing.
• Conversation mode: the last [data-chat-flow-kind="user"] turn decides. If it starts with Persian, the flow gets data-dsh-chat-rtl="fa" and every message block — English headings and trajectory step titles included — renders rtl (code still LTR). Otherwise each block keeps its own dir="auto".

Only stable data-* hooks are used — no hashed class names — so it survives app rebuilds. No locale service, no dictionaries, no global <html dir> change. (An earlier CSS-only attempt with unicode-bidi: plaintext was dropped: it does not resolve computed direction in this Chromium; dir="auto" does.)

Install for other developers

Option A — from GitHub (works today):

pnpm add https://github.com/mehran282/dsh-chat-rtl/releases/download/v0.1.3/dsh-chat-rtl-0.1.3.tgz

or in the Harness: Settings → Built-in plugins → install external bundle → pick the .tgz, enable chat-rtl, restart. Any git address or tarball the plugin manager accepts works — see INSTALL.md.

Option B — from npm (once published): pnpm add dsh-chat-rtl, or by registry name straight from the plugin manager.

Status (v0.1.3)

• node --check clean; loader simulation green (__ModuleLoader__.load with id dsh-chat-rtl, inject: []).
• Disposal verified: style removed, observer disconnected.
• Live-verified in 0.2.2-rc.1 via CDP: app stays lang="en" with no <html dir>; real Persian paragraphs compute rtl, English ltr; newly arriving messages get dir="auto" through the observer; composer is dir="auto"; code blocks stay LTR.