ratatex

Ratatex

TeX-quality display math that scrolls with your Ratatui UI.

Nanocodex demo · Try it · Embed it · Streaming · Selection · Scrolling

https://github.com/user-attachments/assets/9012dcc3-b7d2-44d0-acdf-c94cc73ed5f7

A live Nanocodex low-reasoning run: render TeX, click back to source, and drag-copy the original LaTeX.

Ratatex turns Markdown display math into cell-aligned PNGs on bounded background workers:

Markdown display math
    → RaTeX parse + TeX layout in-process
    → embedded KaTeX fonts + tiny-skia at 3× resolution
    → antialiasing, padding, and cell alignment
    → content-addressed PNG cache
    → Kitty virtual placement + Unicode-placeholder cells

Rendering uses the open-source RaTeX parser, layout engine, embedded fonts, and rasterizer entirely in-process. Ratatex never invokes a system TeX installation, writes DVI, or starts a rendering subprocess. Unsupported expressions return a typed failure so the host application can keep its text representation.

The placeholder cells live in the normal Ratatui buffer. Equations therefore scroll and clip with the surrounding text instead of behaving like cursor-positioned overlays.

Install

cargo add ratatex

Requirements

• A terminal implementing Kitty graphics Unicode placeholders.
• Ratatui 0.29.
• No TeX distribution or external rendering programs.

Ghostty, Kitty, WezTerm, and recent Konsole releases implement the graphics protocol. When running inside tmux, enable graphics passthrough:

set -g allow-passthrough on

Try it

From a compatible terminal:

cargo run --example demo

Press q, Esc, or Ctrl-C to leave the demo.

Embed it

Query the terminal after entering the alternate screen and before starting a competing input reader. Build one renderer for the application, not one per formula:

use std::{io::Write, time::Duration};

use ratatex::{FormulaState, FormulaWidget, Ratatex, TerminalProfile};