Installation

mermaidx is published on PyPI as prebuilt wheels. The base install has no system dependencies: no Node.js, no npm, no Chrome and no compiler.

pip install mermaidx

SVG, PNG, JPEG, PDF and ASCII output all work with the base install. Python 3.9 or newer is required.

Optional extras

Command	Adds
pip install mermaidx[v8engine]	The V8 engine (mini-racer) as backend="v8"
pip install mermaidx[rust]	The Rust backends merman and mermaid-rs-renderer, through mmdr
pip install numpy	Diagram.numpy()
pip install mermaidx[all]	v8engine, rust and numpy together

Check what is available at runtime:

import mermaidx

print(mermaidx.backends())
# ['quickjs']                                      base install
# ['quickjs', 'v8']                                with mermaidx[v8engine]
# ['quickjs', 'merman', 'mermaid-rs-renderer']     with mermaidx[rust]

Coming from mmdc

mermaidx was called mmdc until version 0.7.0. The old package is no longer updated. Uninstall it and install mermaidx instead; the module name changed from mmdc to mermaidx too.

[!note] The upgrade to 0.10.0 has breaking changes: font embedding was removed, and raster="resvg" now raises a ValueError. See the changelog.