mermaido 0.1.0

Render Mermaid diagrams from Python — no Node.js required

mermaido

Render Mermaid diagrams from Python — no Node.js required.

mermaido bundles Node.js via nodejs-bin and wraps mermaid-cli so you can generate diagrams without managing any JavaScript tooling yourself.

Install

pip install mermaido
mermaido install

or with uv:

uv add mermaido
uv run mermaido install

The mermaido install step downloads mermaid-cli and Chromium (~200 MB) into a local cache. You only need to run it once.

Python API

import mermaido

# Render to a file
mermaido.render("graph TD; A-->B;", "output.png")
mermaido.render("graph TD; A-->B;", "output.svg", fmt="svg")

# Render to a string
svg = mermaido.render_to_string("graph TD; A-->B;")

CLI

mermaido is a drop-in replacement for mmdc:

mermaido -i diagram.mmd -o output.svg
mermaido -i diagram.mmd -o output.png -t dark
mermaido --help

Configuration

Environment variable	Default	Description
MERMAIDO_MMDC_VERSION	11.4.2	mermaid-cli version to install

How it works

1. pip install mermaido installs the Python package and a bundled Node.js binary (via nodejs-bin).
2. mermaido install uses that bundled Node.js to npm install mermaid-cli and Chromium into a cache directory (~/.cache/mermaido on Linux, platform-appropriate elsewhere).
3. mermaido.render() or the mermaido CLI invokes mmdc from that cache.

No system-wide Node.js or npm installation is needed.

License

MIT