สร้างเอกสารด้วย LaTeX ผ่าน Claude AI

Writing LaTeX Documents with Claude AI

Bottom Line Up Front: XeLaTeX is required to render Thai fonts (like TH Sarabun New) properly. By combining a custom document class with Claude AI and a clear CLAUDE.md instruction file, you can easily generate professional, reusable Thai enterprise reports.

LaTeX is still my go-to for any serious document — especially when it needs to look professional, handle Thai text correctly, and be reusable across projects. In this post I walk through how I built template-doc, a custom LaTeX template for Thai-language enterprise reports, and how Claude became an essential part of that workflow.

The Problem with Thai in LaTeX

Standard LaTeX (pdflatex) cannot render Thai script. You need XeLaTeX, which supports Unicode and OpenType fonts natively. The template is built around the TH Sarabun New font — a clean, readable Thai typeface — loaded via fontspec. Getting Thai hyphenation, line-breaking, and mixed Thai-English spacing right took real iteration, and that is where having Claude as a pair was invaluable.

Project Structure

The repository follows a modular layout to keep large documents manageable:

template-doc/
├── main.tex              # Entry point — includes all sections
├── easreport.cls         # Custom document class (Thai fonts, headers, layout)
├── conf/
│   └── latexmkrc         # Build config: XeLaTeX engine, out/ output dir
├── sections/             # One .tex file per section
│   ├── title.tex
│   ├── togaf.tex
│   ├── a_vision.tex
│   ├── b_business.tex
│   ├── c_system.tex
│   ├── d_technology.tex
│   ├── e_opportunities.tex
│   ├── f_migration.tex
│   ├── g_security_er.tex
│   ├── overview.tex
│   ├── security.tex
│   └── install.tex
├── figures/              # Images referenced in sections
└── assets/               # Watermark and other assets

Each section is an independent .tex file included via \input{} in main.tex. This makes it easy to draft one section at a time with Claude without touching the whole document.

The Custom Class: easreport.cls

The heart of the template is easreport.cls — a custom document class that extends the standard article class. It bundles everything needed for professional Thai-language technical reports:

• fontspec + xunicode — Unicode font management for Thai script
• TH Sarabun New — primary font configured for Thai and Latin text
• microtype — advanced typographic enhancements
• geometry — A4 page with 1" top/bottom and 0.7" side margins
• fancyhdr — header and footer with organization name, document title, and page numbers
• tabularx, booktabs, longtable — professional table formatting
• hyperref — clickable links with hidden borders
• hyphenat + ragged2e — hyphenation control for mixed Thai-English content

The class also defines custom metadata commands — \docversion, \docdate, \authorname — so every document carries consistent version tracking without manual header edits.

Building the PDF

The build uses latexmk with a project-local config file:

# Build PDF
latexmk -r conf/latexmkrc main.tex

# Clean build artifacts
latexmk -r conf/latexmkrc -C main.tex

conf/latexmkrc sets XeLaTeX as the engine and routes all output to the out/ directory. The compiled PDF appears at out/main.pdf. Build artifacts (.aux, .log, .toc) are gitignored so the repository stays clean.

How I Work with Claude on LaTeX

The repository includes a CLAUDE.md file that gives Claude the context it needs to produce correct, compilable LaTeX every time. Without this, AI-generated LaTeX often uses the wrong engine, missing packages, or incompatible commands.

Key rules in CLAUDE.md:

• Always target XeLaTeX — pdflatex will fail because fontspec is required for Thai
• Use \[ ... \] or align environments for display math, not $$
• Escape special LaTeX characters when they appear as literal text
• Prefer semantic markup: \emph{} over \textit{}
• Place \microtypecontext{spacing=nonadjacent} in the preamble when using microtype with Thai fonts
• Use \sloppy / \fussy in sections to control Thai text line-breaking

Practical Workflow

My day-to-day flow when writing a section with Claude:

1. Open a section file — e.g., sections/d_technology.tex
2. Describe the content to Claude in plain language — what the section covers, what diagrams exist in figures/
3. Claude drafts the LaTeX — using the class's custom commands, correct Thai font handling, and proper table/figure environments
4. Build and review — latexmk -r conf/latexmkrc main.tex and open out/main.pdf
5. Iterate — paste compilation errors back to Claude for targeted fixes

The modular section structure is key here. Claude only needs to see one .tex file at a time, which keeps the context focused and the output accurate.

Gotchas Worth Knowing

• XeLaTeX is mandatory. Running pdflatex will immediately fail on \usepackage{fontspec}. Always confirm the engine in your build config.
• TH Sarabun New must be installed. On macOS/Linux, install it as a system font before building. CI environments often need an explicit font installation step.
• microtype + Thai needs a config line. Add \microtypecontext{spacing=nonadjacent} to suppress warnings and prevent spacing conflicts with Thai characters.
• Line-breaking Thai text is tricky. Use \sloppy generously in sections with dense Thai prose to avoid overfull hbox warnings.

Why This Approach Works

Pairing LaTeX's precision with Claude's natural language interface removes the friction of remembering every command and environment. I describe what I need in Thai or English, Claude generates correct LaTeX against a well-defined template, and I compile immediately to verify. The CLAUDE.md file acts as a standing contract between me and the AI — no repeated explanations, no wrong engine, no missing packages.

The template is open on GitHub at nuboat/template-doc. Clone it, add your own sections, and point Claude at your CLAUDE.md — you will be producing professional Thai-language PDFs in minutes.

Note: This blog post was written with Claude Code using the template-doc repository as source material.

template-doc/
├── main.tex              # Entry point — includes all sections
├── easreport.cls         # Custom document class (Thai fonts, headers, layout)
├── conf/
│   └── latexmkrc         # Build config: XeLaTeX engine, out/ output dir
├── sections/             # One .tex file per section
│   ├── title.tex
│   ├── togaf.tex
│   ├── a_vision.tex
│   ├── b_business.tex
│   ├── c_system.tex
│   ├── d_technology.tex
│   ├── e_opportunities.tex
│   ├── f_migration.tex
│   ├── g_security_er.tex
│   ├── overview.tex
│   ├── security.tex
│   └── install.tex
├── figures/              # Images referenced in sections
└── assets/               # Watermark and other assets

# Build PDF
latexmk -r conf/latexmkrc main.tex

# Clean build artifacts
latexmk -r conf/latexmkrc -C main.tex

template-doc/
├── main.tex              # Entry point — includes all sections
├── easreport.cls         # Custom document class (Thai fonts, headers, layout)
├── conf/
│   └── latexmkrc         # Build config: XeLaTeX engine, out/ output dir
├── sections/             # One .tex file per section
│   ├── title.tex
│   ├── togaf.tex
│   ├── a_vision.tex
│   ├── b_business.tex
│   ├── c_system.tex
│   ├── d_technology.tex
│   ├── e_opportunities.tex
│   ├── f_migration.tex
│   ├── g_security_er.tex
│   ├── overview.tex
│   ├── security.tex
│   └── install.tex
├── figures/              # Images referenced in sections
└── assets/               # Watermark and other assets

# Build PDF
latexmk -r conf/latexmkrc main.tex

# Clean build artifacts
latexmk -r conf/latexmkrc -C main.tex

template-doc/
├── main.tex              # Entry point — includes all sections
├── easreport.cls         # Custom document class (Thai fonts, headers, layout)
├── conf/
│   └── latexmkrc         # Build config: XeLaTeX engine, out/ output dir
├── sections/             # One .tex file per section
│   ├── title.tex
│   ├── togaf.tex
│   ├── a_vision.tex
│   ├── b_business.tex
│   ├── c_system.tex
│   ├── d_technology.tex
│   ├── e_opportunities.tex
│   ├── f_migration.tex
│   ├── g_security_er.tex
│   ├── overview.tex
│   ├── security.tex
│   └── install.tex
├── figures/              # Images referenced in sections
└── assets/               # Watermark and other assets

# Build PDF
latexmk -r conf/latexmkrc main.tex

# Clean build artifacts
latexmk -r conf/latexmkrc -C main.tex

template-doc/
├── main.tex              # Entry point — includes all sections
├── easreport.cls         # Custom document class (Thai fonts, headers, layout)
├── conf/
│   └── latexmkrc         # Build config: XeLaTeX engine, out/ output dir
├── sections/             # One .tex file per section
│   ├── title.tex
│   ├── togaf.tex
│   ├── a_vision.tex
│   ├── b_business.tex
│   ├── c_system.tex
│   ├── d_technology.tex
│   ├── e_opportunities.tex
│   ├── f_migration.tex
│   ├── g_security_er.tex
│   ├── overview.tex
│   ├── security.tex
│   └── install.tex
├── figures/              # Images referenced in sections
└── assets/               # Watermark and other assets

# Build PDF
latexmk -r conf/latexmkrc main.tex

# Clean build artifacts
latexmk -r conf/latexmkrc -C main.tex