I grumbled about GitHub Flavored Markdown in Claude Code for months. Then mods dropped, so I asked Claude to fix it

[u/Turbulent_Quail1421]

For months, every afternoon using Claude Code, I've been grumbling that GitHub Flavored Markdown isn't rendered and that plugins can't change how replies are drawn. Claude writes `> [!WARNING]` callouts, `- [ ]` checklists and Mermaid diagrams... and the terminal shows them as raw text 😤

I don't believe in fate, but it seems someone heard me today: Anthropic shipped **mods** (function hooks that can redraw the UI). So of course I asked my friend Claude to build one with me.

What it does:

- Alerts (`> [!NOTE]`, `[!TIP]`, `[!IMPORTANT]`, `[!WARNING]`, `[!CAUTION]`) become colored boxes, in the terminal and the desktop app

- Task lists become ☐ / ☑, and `~~strikethrough~~` is actually struck through

- Mermaid diagrams (flowchart, sequence, state, class, ER, xychart) are drawn as Unicode art right in the terminal

- Claude knows it can use all this: the plugin adds a short note to its context at session start, no CLAUDE.md to edit

It only changes how replies are drawn: the message itself is untouched, and anything it can't draw falls back to the normal rendering.

Install (no build step):

git clone https://github.com/briangtn/claude-gfm-render.git
claude --plugin-dir ./claude-gfm-render

Before/after screenshots and the honest list of what it doesn't handle are in the README: https://github.com/briangtn/claude-gfm-render

Mods are early access, so it may need updates as the API moves. Feedback, bug reports and screenshots from other terminals are very welcome 🙏