A tiny, offline Markdown previewer for the desktop. Point it at a .md file and it opens a native window that renders like GitHub and live-reloads as you edit.

• Renders like GitHub — tables, task lists, alerts, footnotes, syntax highlighting, math (KaTeX) and mermaid diagrams.
• Live reload — save the file and the window updates instantly.
• Fully offline — every asset is baked into the binary. No CDN, no network.
• One small native binary for macOS and Linux. No editor, no config, no fuss.

# macOS / Linux
curl -fsSL https://raw.githubusercontent.com/jondot/picomd/main/install.sh | sh

# or npm
npm install -g @jondot/picomd

# or cargo
cargo install picomd

picomd README.md

Leave the window open while you edit. Every save re-renders. That's the whole tool.

When an agent (Claude Code, Cursor, Codex, …) is writing Markdown — a README, docs, a design note — keep picomd open on the file. You get a live, GitHub-accurate preview that updates on every save the agent makes, so you can watch the document take shape instead of guessing how it'll render.

Any agent that can run a shell command can launch it:

picomd README.md &

It backgrounds, watches the file, and re-renders as the agent edits. Nothing else to wire up.

Drop this in .claude/skills/preview-markdown/SKILL.md so the agent reaches for picomd whenever you ask to preview Markdown:

---
name: preview-markdown
description: Open a live GitHub-style preview of a Markdown file with picomd. Use when the user wants to see how a README or doc renders.
---

Open a live preview window for the Markdown file the user is working on:

    picomd "<file>" &

The window live-reloads on every save, so keep editing — it stays current.
Launch it once per file; don't relaunch on each edit.

Or add .claude/commands/preview.md for an explicit /preview:

Open a live picomd preview of $ARGUMENTS (default: README.md):

    picomd "${ARGUMENTS:-README.md}" &

Then /preview docs/guide.md opens the preview and your following edits show up live.

macOS (Intel and Apple silicon) and Linux x86_64. Building from source on Linux needs the GUI libraries:

sudo apt-get install -y libwebkit2gtk-4.1-dev libgtk-3-dev

MIT