Preview & export

Render generated artifacts as HTML or PDF and open them in your browser or PDF viewer.

The preview tool renders Feynman’s generated artifacts — research briefs, paper drafts, and any document with LaTeX math, tables, or complex formatting — as polished HTML or PDF. This is particularly useful for artifacts that do not render well in a terminal.

Setup

Preview requires pandoc for Markdown-to-HTML and Markdown-to-PDF rendering. Install preview dependencies with:

feynman --setup-preview

Or as part of initial setup:

feynman setup

The setup command attempts to install pandoc automatically using your platform’s package manager:

• macOS with Homebrew — installs pandoc via brew install pandoc
• Windows — installs pandoc via winget install JohnMacFarlane.Pandoc
• Linux — installs pandoc via apt-get install pandoc

If the automatic install does not work, install pandoc manually from pandoc.org/installing.html and rerun feynman --setup-preview to verify the installation.

Usage

Inside the Feynman REPL, preview the most recent artifact:

/preview

Preview a specific file:

/preview outputs/scaling-laws-brief.md

Additional preview commands:

Command	Description
/preview	Preview the most recent artifact in the browser
/preview --file <path>	Preview a specific file
/preview-browser	Force browser preview
/preview-pdf	Export to PDF via pandoc
/preview-clear-cache	Clear the rendered preview cache

If preview commands are not available, you can open files directly:

open <file.md>   # macOS — opens in default app
open <file.pdf>  # macOS — opens in Preview

Supported formats

The preview tool handles three output formats:

Markdown

Converted to HTML with full LaTeX math support via KaTeX, syntax-highlighted code blocks, and clean typography. Opens in your default browser as a local file.

HTML

Opened directly in your default browser with no conversion step.

PDF

Generated via pandoc with LaTeX rendering. Suitable for sharing or printing. Requires pandoc to be installed.

LaTeX math support

For documents with heavy math notation — common in research drafts — the preview ensures all LaTeX expressions render correctly:

• Inline math: $E = mc^2$
• Display math: $$\nabla \cdot \mathbf{E} = \frac{\rho}{\varepsilon_0}$$

Tables, citation lists, and nested blockquotes all render with proper formatting.

HTML and PDF preview outputs are temporary render artifacts. The canonical saved result is always the Markdown file. Do not treat the rendered output as the primary deliverable — it is a view, not the source.

How it works

The pi-markdown-preview package handles the rendering pipeline. For Markdown files, it converts to HTML with a clean stylesheet, proper code highlighting, and rendered math equations. The preview opens in your default browser as a local file.

The preview stylesheet is designed for research documents and includes styles for heading hierarchy, syntax-highlighted code blocks, tables, inline and display math equations, citation formatting, and blockquotes.