\begin{article}
Understand Any LaTeX Command or Warning — latex-explain
Ask what any LaTeX command does or what a warning means — get a plain-English answer with a minimal example instead of 900 pages of documentation.
The LaTeX manual is 900 pages long. The texdoc database has thousands of package documentation files. Stack Overflow has a decade of LaTeX questions with contradictory answers. And you just want to know what \parskip does, or why LaTeX keeps warning about an overfull hbox, or whether you should use \centering or the center environment. The latex-explain Claude Code skill cuts through all of that. Ask a question in plain English, get a plain-English answer with a minimal working example — not a pointer to chapter 12 of a reference manual you do not have time to read.
The Problem: LaTeX Documentation Is Not Written for Developers
If you write LaTeX occasionally — for academic papers, technical reports, or as part of a PDF generation pipeline built on the FormatEx API — you do not have the luxury of memorizing the LaTeX ecosystem. You hit a warning, you see an unfamiliar command in someone else's code, or you wonder why two packages conflict. The standard workflow is: Google the error, find a Stack Overflow thread from 2011, read four answers, and try to figure out which one applies to your version of TeX Live.
That workflow is slow. It is also error-prone. LaTeX has accumulated 40 years of deprecated commands, obsolete patterns, and "this used to be the right way" advice that is still ranked highly by search engines.
The latex-explain skill is a Claude Code skill that replaces that workflow. It is specifically designed to answer the question "what does this do?" with a direct answer and a minimal example you can copy into your document immediately.
How to Install
The latex-explain skill is part of the latex-skills repository on GitHub. Install it with a single cp command:
# Install just the latex-explain skill
cp -r skills/latex-explain ~/.claude/skills/
# Or install the full latex meta-skill bundle (includes explain + related skills)
cp -r skills/latex ~/.claude/skills/
# Or install the FormatEx meta-skill (latex skills + FormatEx API helpers)
cp -r skills/formatex ~/.claude/skills/
# Or install everything at once
cp -r skills/latex-full ~/.claude/skills/After copying, the skill is immediately available in any Claude Code session. No configuration required. No API keys. No environment variables. It works in any project directory.
What latex-explain Does
The skill intercepts questions about LaTeX commands, warnings, environments, packages, and behaviors. It then:
- Gives a one or two sentence plain-English explanation of what the command or concept does.
- Provides a minimal working example — the smallest document fragment that demonstrates the behavior clearly.
- Compares alternatives when relevant. For example, if you ask about
\bf, it will explain what it does but also tell you that\textbf{}is the correct modern replacement. - Flags deprecated commands explicitly. LaTeX has many commands that still work but should not be used in new documents. The skill marks these clearly rather than letting you copy deprecated patterns into your codebase.
- Explains package requirements. If the command requires a package that is not loaded by default, the skill tells you which
\usepackage{}line you need.
The skill is not a general LaTeX tutor. It does not generate full documents or explain LaTeX history. It answers the specific question you asked, concisely, and moves on. That directness is the point.
Before and After: Looking Up a LaTeX Warning
Before the Skill
You are building a PDF report generator using the FormatEx API. Your template compiles cleanly on your local TeX Live installation but the compilation logs returned by the API include this warning repeatedly:
Underfull \hbox (badness 10000) in paragraph at lines 47--52Your old workflow: open a browser, search "underfull hbox badness 10000 latex", scan three Stack Overflow threads, find answers ranging from "ignore it" to "add \sloppy" to "rewrite the paragraph", try to figure out which applies, test each fix, recompile via the API, check the logs again. Total time: 15 to 25 minutes. Total confidence: low.
After the Skill
In your Claude Code session:
/latex-explain What does "Underfull \hbox (badness 10000)" mean and how do I fix it?The skill responds immediately. It explains that an underfull hbox means LaTeX could not find a good way to fill a line and left too much whitespace. Badness 10000 is the maximum — LaTeX is telling you the line looks bad. It then shows you three options with a minimal example for each: use \sloppy for the whole document, use a sloppypar environment around the specific paragraph, or add \linebreak manually to suggest a break point. It notes that \sloppy is a blunt instrument and the scoped sloppypar approach is usually better.
You pick the right fix for your context in 30 seconds instead of 20 minutes.
Common Use Cases
1. Understanding an Unfamiliar Command in Inherited Code
You are working on a LaTeX template someone else wrote. You see \vspace*{\fill} and you are not sure what the asterisk does or why it is there. Ask the skill. It explains that the asterisk suppresses the normal suppression of vertical space at the top of a page — without it, \vspace at the top of a page does nothing. It gives you a minimal two-page document showing the difference. This is exactly the kind of subtle behavior that is easy to miss even with documentation in front of you.
2. Choosing Between Two Similar Commands
Should you use \includegraphics with a width in cm or in fractions of \textwidth? Should you use tabular or tabularx? Should bibliography management use bibtex or biber? The skill compares both options in concrete terms, tells you when each is appropriate, and recommends the modern default where one exists. This pairs well with the latex-write-markup skill when you are drafting new LaTeX from scratch.
3. Decoding Compilation Errors in a PDF Pipeline
When you compile LaTeX through an API like FormatEx — see the getting started guide — the compilation output comes back as log text. Errors like ! LaTeX Error: \begin{document} ended by \end{figure} or ! Missing $ inserted are cryptic if you do not read LaTeX daily. The skill translates them into plain English and tells you the most likely cause. This works alongside the latex-fix-errors skill, which goes further and applies the fix directly to your source.
4. Identifying Deprecated Commands Before They Cause Problems
Older LaTeX templates and documentation use commands like \rm, \it, \bf, \sc, and \tt for font styling. These work in most environments but are two-argument font commands that do not scope correctly in all contexts. The skill flags these as deprecated and shows you the modern \textrm{}, \textit{}, \textbf{}, \textsc{}, \texttt{} equivalents. If you are building a pipeline that compiles user-submitted LaTeX — exactly the use case the FormatEx API is built for — catching deprecated patterns early reduces compilation edge cases.
5. Understanding Package Interactions
You load hyperref and suddenly your \ref commands produce red boxes around numbers. You load babel and your quotes look wrong. You load listings and code blocks lose their font. Package interaction bugs are some of the hardest LaTeX problems to diagnose because the symptom appears far from the cause. The skill explains common interaction patterns, tells you the correct package load order, and points you to the package option that disables the conflicting behavior.
This is especially relevant if you are building document templates for clients through the FormatEx API — see the Go client guide, PHP/Laravel guide, or Ruby on Rails guide for language-specific integration examples. Templates need to be robust across a range of user inputs, and understanding how packages interact is essential for that.
How latex-explain Fits Into a Larger LaTeX Workflow
The latex-explain skill is one piece of a larger set of Claude Code skills for LaTeX. The typical workflow in a LaTeX-heavy project looks like this:
- Use latex-document-structure to scaffold the initial document layout.
- Use latex-write-markup to write LaTeX from prose or structured content.
- Use latex-explain to understand unfamiliar commands or warnings as you encounter them.
- Use latex-fix-errors to automatically resolve compilation errors.
- Use latex-math-equations for mathematical typesetting.
- Use latex-citations-bibliography for reference management.
- Use latex-convert-content to migrate content from other formats into LaTeX.
Each skill is scoped narrowly on purpose. The latex-explain skill does one thing: it answers "what does this mean?" That focus makes it fast and predictable. You do not have to prompt-engineer around it or worry about it making changes you did not ask for. It explains. You decide what to do with the explanation.
Deploying LaTeX at Scale with FormatEx
If you are using LaTeX not just for occasional documents but as a core part of a PDF generation system — invoices, reports, certificates, technical documentation — you need a reliable compilation backend. Installing and maintaining TeX Live is significant operational overhead. The FormatEx API handles that infrastructure so you can focus on the document layer.
The API compiles LaTeX to PDF via a simple HTTP request, supports pdflatex, xelatex, lualatex, and latexmk, and returns the compiled PDF or detailed compilation logs. The latex-explain skill helps you write better LaTeX templates for that pipeline. The latex-fix-errors skill helps you handle compilation failures automatically. Together they make LaTeX compilation in production significantly less painful.
For teams building serverless document generation, the AWS Lambda integration guide shows how to call the FormatEx API from a Lambda function with no TeX Live dependency in your deployment package.
Get Started
Install the skill:
cp -r skills/latex-explain ~/.claude/skills/Browse all available LaTeX skills and full documentation at the latex-skills GitHub repository.
To compile the LaTeX you write using a production-grade API with no infrastructure to manage, visit formatex.io and start with the free tier — 15 compilations per month, no credit card required.
\end{article}
\related{posts}
