Desktop app does not render inline LaTeX math ($...$) #39170

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1. github-actions

   assigned

   Brendonovich

   on Jul 27, 2026
2. github-actions commented on Jul 27, 2026

   

   github-actionsBot

   on Jul 27, 2026 – with GitHub Actions

   Contributor

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   This issue might be a duplicate of existing issues. Please check:

   • Desktop: LaTeX math equations are not rendered after upgrading, Markdown still works。 #38030: Desktop app LaTeX math equations not rendered after upgrading (same environment: Windows, Desktop app)
   • math equations not rendered #37326: Math equations not rendered in Desktop app (Windows)
   • CLI: LaTeX math formulas rendered as raw text instead of being rendered in terminal #34407: LaTeX math formulas rendered as raw text in CLI

   Please search existing issues before submitting to help us keep the tracker tidy. If your issue is distinct (e.g., specifically about inline $...$ vs block $$...$$ rendering asymmetry rather than math not rendering at all), please note what makes it different from the issues above.
3. bisuwuss-netizen commented on Aug 3, 2026

   

   bisuwuss-netizen

   on Aug 3, 2026

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   Confirmed on macOS as well.

   Environment

   • OpenCode Desktop: 1.18.11
   • Bundle ID: ai.opencode.desktop
   • macOS: 26.5.2 (25F84)
   • Architecture: Apple Silicon (arm64)

   Reproduction

   1. Open a Desktop conversation.
   2. Ask the model to include inline LaTeX in normal prose, for example:
      • $v_\pi(s) = \mathbb{E}_\pi[G_t \mid S_t=s]$
      • $R_{t+1} + \gamma V(S_{t+1})$
   3. The expressions are shown as literal LaTeX source instead of rendered math.

   Markdown headings, lists, and other formatting render normally; the problem is specifically noticeable for math delimiters in assistant messages.

   Expected behavior

   Inline $...$ expressions should render as math in the Desktop UI (for example via KaTeX), with consistent support for standard block math as well.

   This is particularly disruptive in math-heavy tutoring and technical explanations because subscripts, Greek symbols, expectations, and longer equations become difficult to read.
4. pradnX commented on Aug 30, 2026

   

   pradnX

   on Aug 30, 2026

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   $ opencode --version
   1.18.25
   

   ~/.config/opencode/AGENTS.md

   $ cat ~/.config/opencode/AGENTS.md
   # Global Engineering Guidelines
   
    # MATH & SYMBOL FORMATTING:
    - DO NOT use LaTeX formatting (e.g., $ ... $ or $$ ... $$) for math, symbols, or equations.
      You must use standard plain text and native Unicode characters (e.g.,
      use ≈ instead of \approx, or x^2 instead of $x^2$).
   

   This fails for me - despite instructions in agent.
5. beihaixingchen commented on Sep 9, 2026

   

   beihaixingchen

   on Sep 9, 2026

   Last edited by beihaixingchen

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   Related reproduction on the Desktop GUI: display math delimited with \[...\] is also rendered as raw LaTeX instead of KaTeX. This happens frequently with OpenAI models, which often emit \[...\] for standalone equations.

   Example assistant output:

   \[
   \text{weight}=\operatorname{softmax}\left(\frac{q_{\text{new}}K_{\text{all}}^\top}{\sqrt{d_k}}\right)
   \]

   Expected: the expression should render as display math in the Desktop UI.
   Actual: the complete \[...\] source is shown as plain text, while some inline expressions using \(...\) render correctly.

   The current GUI parser in packages/ui/src/context/marked-parser.tsx already uses KaTeX. Its inline tokenizer recognizes \(...\), and its block tokenizer recognizes $$ blocks only when the opening and closing delimiters are on separate lines. It does not include a tokenizer for \[...\].

   The GUI path uses this parser through packages/session-ui/src/components/markdown.worker.ts, so this looks like a small Markdown tokenizer coverage gap rather than a missing rendering dependency. Supporting \[...\] as display-math delimiters would make the existing KaTeX integration handle the format produced by these models.
6. Focus786 commented on Sep 24, 2026

   

   Focus786

   on Sep 24, 2026

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   Same symptom on the latest Desktop build — adding a v2.0.14 case with byte-level evidence that the message content is not the cause.

   Environment

   • OpenCode Desktop: 2.0.14 (bundled CLI 2.0.14)
   • OS: Windows 11 (Windows_NT 10.0.26200, win32 x64)
   • Install/channel: release

   Symptom

   Assistant replies render Markdown normally (headings, bold, tables, lists, code blocks), but all math falls back to raw LaTeX source. No error is surfaced; the $...$ / $$...$$ delimiters are shown literally.

   Evidence that the message content is fine

   Reading the raw message back from the local session store (GET /api/session/{sessionID}/message):

   • The text is standard Markdown + LaTeX.
   • No \ escaping and no ``` fence wrapping.
   • $ delimiters are balanced (even count).

   So this is not a producer-side escaping or fencing problem.

   Evidence that the formulas are fine

   Every formula from the failing reply was rendered through KaTeX 0.16.11 with throwOnError: true (the same strictness the Desktop renderer uses):

   Formula	Result
   A^{-1}	ok
   AB=BA=I,\qquad B=A^{-1}	ok
   \det(A)\neq0\iff\operatorname{rank}(A)=n\iff A\ \text{可逆}\iff Ax=0\ \text{只有零解}\iff \text{行（列）向量组线性无关}	ok
   A^{-1}=\dfrac{1}{ad-bc}\begin{pmatrix}d&-b\\-c&a\end{pmatrix}	ok
   (A\mid I)\to(I\mid A^{-1})	ok
   \text{可逆}	ok

   All render without error, including \operatorname and CJK inside \text{}. The failure is therefore in the Desktop chat renderer's math recognition, not in KaTeX parsing.

   Notes

   • app.asar bundles KaTeX (fonts + renderToString) and streamdown, so the capability is present in this build; it is simply not applied to the math in messages.
   • Related: Desktop: LaTeX math equations are not rendered after upgrading, Markdown still works。 #38030 ("Markdown still works", math raw) and the \[...\] report above look like the same root cause.

   Workaround

   Pasting the same message into Obsidian renders $...$ correctly, confirming the source bytes are correct.
7. neriousy commented on Oct 1, 2026

   

   neriousy

   on Oct 1, 2026

   Member

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   Closing as a duplicate of #38030. Same Desktop LaTeX rendering regression (comments show block math is affected too). Tracking in #38030.
8. neriousy

   closed this as a duplicateof Desktop: LaTeX math equations are not rendered after upgrading, Markdown still works。 #38030 on Oct 1, 2026