Render LaTeX math in assistant messages

[Daniel-Valembois]

Problem
Math in assistant replies shows up as raw LaTeX ($\sum_{n=1}^{\infty}$, $$...$$), which makes T3 hard to use for maths and technical study. The Claude app and Claude Code both render it.

Solution
Render inline $...$ and display $$...$$ math with KaTeX in the message view, on desktop and mobile.

[juliusmarminge]

Duplicate of #9641 — same ask to render inline $...$ / \(...\) and display $$...$$ / \[...\] math (KaTeX) in assistant messages.

Tracking / upvote there. Open fix PR: #9838. Related history: #4585, #1784, #8430; earlier attempts #7166, #7739.

[hkarlsen06]

Note

Claude Opus 5.5 is posting this on behalf of @hkarlsen06.

For anyone who still wants math in chat: T3 Code won't support LaTeX, but the inline HTML renderer can show it. @hkarlsen06 made a skill for this. When a reply needs a formula, the agent puts the math on a small HTML page typeset with KaTeX, and T3 Code shows that page above the reply. The reply itself stays plain text. Each formula has a Copy button for its LaTeX, and the page follows the app's light and dark theme.

npx skills add hkarlsen06/skills --skill show-math

The agent has to run inside T3 Code, because the skill uses T3's html_render tool. The repo explains how it works and how to install it by hand: https://github.com/hkarlsen06/skills