nf-metro

nf-metro generates transit-style SVG diagrams from Mermaid definitions using %%metro directives. Like a real metro map, the layout isn't necessarily geographic, nor a verbatim trace of every step. Use it to convey what a workflow means scientifically, not just what it runs, with every line, colour, and position a deliberate choice. A natural fit for nf-core and other Nextflow pipelines.

See the gallery →View on GitHub

Install

nf-metro is a Python package. Pick your channel - it requires Python 3.10+.

pipcondaDocker

Install the latest release from PyPI.

pip install nf-metro

Quick start

Render, validate, and inspect a .mmd file. The CLI reference documents every flag.

# Render a .mmd definition into a standalone SVG metro map
nf-metro render examples/simple_pipeline.mmd -o pipeline.svg

# Check a file for errors without producing any output
nf-metro validate examples/simple_pipeline.mmd

# Print the parsed structure: sections, lines, stations, edges
nf-metro info examples/simple_pipeline.mmd

# Or emit a self-contained interactive HTML page (pan, zoom, line isolation)
nf-metro render examples/simple_pipeline.mmd --format html -o pipeline.html

Go further

Write metro maps →

From a minimal example to multi-section pipelines with custom grid layouts.

Embed maps →

Drop a rendered map into a docs site, dashboard, or app - with responsive sizing and live progress.

Browse the gallery →

Rendered examples covering fan-outs, folds, diamonds, and realistic bioinformatics workflows.

nf-core pipelines →

Real-world pipelines rendered with nf-metro, maintained alongside their source.