Show HN: LaTerM: LaTeX renderer for terminal AI tools

2 hours ago 1

Display beautiful mathematical equations directly in your terminal

Zero-config - Just load the addon and LaTeX works
Agent compatible - Made for use with CLI AI tools
Inline & Display Math - Support for both $...$ and $$...$$
Heuristic Detection - Distinguishes between LaTeX and shell variables
Theme Aware - Automatically matches terminal colors

import { Terminal } from '@xterm/xterm' import { LatexAddon } from 'xterm-latex' const terminal = new Terminal() const latexAddon = new LatexAddon() terminal.loadAddon(latexAddon) terminal.open(document.getElementById('terminal')) terminal.write('The equation $E = mc^2$ is not the whole story\n')

Important: Make your AI aware that it can write in LaTeX. We reccomend you include the attached 'recPrompt.txt' in the model context.

terminal.write('Inline equation: $\\sqrt{x^2 + y^2}$\n') terminal.write('Greek letters: $\\alpha, \\beta, \\gamma$\n')

terminal.write('$$\\int_0^\\infty e^{-x^2} dx = \\frac{\\sqrt{\\pi}}{2}$$\n')

Matrices (using @nl macro)

// Use @nl instead of \\ for row separators (PTY-safe) terminal.write('$$\\begin{bmatrix} 1 & 2 @nl 3 & 4 \\end{bmatrix}$$\n')

const latexAddon = new LatexAddon({ macros: { '@nl': '\\\\', // Row separator (necessary) } }) terminal.write('Gradient: $@del f = (@del_x f, @del_y f)$\n')

const latexAddon = new LatexAddon({ // Enable debug logging debugLogging: false, // Custom macros for easier input macros: { '@nl': '\\\\', // Add your own macros here }, // Maximum cached equations (default: 5000) cacheSize: 5000, // Minimum placeholder width in characters (default: 4) minPlaceholderWidth: 4, // Custom logging function onLog: (message) => console.log(message) })

For more control, you can use the components individually:

import { LatexProcessor, OverlayManager } from 'xterm-latex' const processor = new LatexProcessor(terminal, config) const overlayManager = new OverlayManager(terminal, processor.getLatexMap())

Enable/Disable at Runtime

// Disable LaTeX rendering latexAddon.setEnabled(false) // Re-enable it latexAddon.setEnabled(true)

latexAddon.updateConfig({ debugLogging: true, macros: { '@sum': '\\sum' } })

'terminal.write()' is hooked (notably NOT all pty data, just what is forwarded to render) and inline math is filtered out. Detected LaTeX is then removed from the display stream and replaced with a 4 character deterministic base63 hash generated in latex-hashmap.ts. We also pre-render the LaTeX and associate that pre-rendering with the generated hash. Rendering logic in overlay-manager then decides where to place this relative to the terminal and responds to things like zoom, scroll.

Import drawbacks: Because terminals often have uses for the LaTeX operator '\\' and '\\\\', these cannot be directly used, and we replace them with a safe macro @nl, and the AI must be told to write with this constraint. An interface is provided for more custom macros, in case there are user specific LaTeX operands that may not work in their environment.

Xterm MUST use the DOM renderer for this plugin to function

The obsidian-latex-terminal plugin uses this library to bring LaTeX rendering to Obsidian's terminal emulator. It's included as a submodule in the plugins/ directory.

MIT

Contributions welcome! Please feel free to submit a Pull Request. Things that could be expanded upon are the heuristic used to detect LaTeX, better support for writing LaTeX manually in terminal, and that inline math expressions with fractions often render on top of eachother (which is more the AIs fault most of the time).

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