claude-code - 💡(How to fix) Fix [BUG] Inline KaTeX math (`$...$`) no longer renders in chat output — only block `$$...$$` works (regression)

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

When Claude's reply contains inline math wrapped in single dollar signs ($...$), it doesn't render — the raw source is shown instead, dollar signs included. For example, $q_0$ appears as the literal text "$q_0$" rather than a typeset q-zero.

Block math wrapped in double dollar signs ($$...$$) on its own line still renders correctly as typeset KaTeX. So only inline math is broken; block math is fine.

What Should Happen?

Inline math wrapped in single dollar signs ($...$) should render as typeset KaTeX, the same way block math ($$...$$) does, with the dollar delimiters hidden. For example, the start state is $q_0$ should display a typeset q-zero, not the literal text $q_0$. Inline math should render the way it did in earlier versions and the way block math still does today.

Error Messages/Logs

Steps to Reproduce

1. Ask Claude anything whose answer naturally contains inline math, e.g. "explain a Turing machine's transition function".
2. Claude replies with a sentence containing inline $...$, such as: the start state is $q_0$ and the alphabet is $\Sigma = {0,1}$.
3. Observe that each inline $...$ segment shows as raw text with visible dollar signs, not typeset math.
4. For contrast, note that block math on its own line renders correctly:

$$\delta: Q \times \Gamma \to Q \times \Gamma \times {L,R}$$

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

2.1.156 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

Surface: Claude Code desktop app (macOS). The Terminal/Shell dropdown has no desktop-app option, so it may not reflect the actual surface.

Reproducible 100% of the time this session: every inline $...$ expression shows raw dollar signs, while every $$...$$ block renders correctly. Inline single-$ math rendered fine in earlier versions, so this looks like a regression.