mermaid-cli


This is a command-line interface (CLI) for mermaid. It takes a mermaid definition file as input and generates an SVG/PNG/PDF file as output.

Installation

``sh
npm install -g @mermaid-js/mermaid-cli
`

Usage

Convert Mermaid mmd Diagram File To SVG

`sh
mmdc -i input.mmd -o output.svg
`

> Note
>
> See Alternative installations if you don't want to install the package globally.
>
> Locate how to call the mmdc executable for your preferred method
> i.e. Docker, Yarn, NPM, local install, etc.

Examples

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`sh
mmdc -i input.mmd -o output.png -t dark -b transparent
`

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The --cssFile option can be used to inline some custom CSS.

Please see ./test-positive/flowchart1.css for an example of a CSS file that has animations.

Warning: If you want to override mermaid's themeCSS, we recommend instead adding {"themeCSS": "..."}) to your mermaid --configFile. You may also need to use !important to override mermaid's themeCSS.

Warning: Inline CSS files may be blocked by your browser, depending on the HTTP Content-Security-Policy header of the website that hosts your SVG.

`sh
mmdc --input test-positive/flowchart1.mmd --cssFile test-positive/flowchart1.css -o docs/animated-flowchart.svg
`

Example output: docs/animated-flowchart.svg

!docs/animated-flowchart.svg

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`sh
mmdc -i readme.template.md -o readme.md
`

This command transforms a markdown file itself. The mermaid-cli will find the mermaid diagrams, create SVG files from them and refer to those in the markdown output.

This:

~~~md


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`mermaid
graph
[....]
`

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`mermaid
sequenceDiagram
[....]
`

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`mermaid
graph
accTitle: My title here
accDescr: My description here
A-->B
`
~~~

Becomes:

`md


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!diagram

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!diagram

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!My description here
`

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You can easily pipe input from stdin. This example shows how to use a heredoc to
send a diagram as stdin to mermaid-cli (mmdc).

`sh
cat << EOF | mmdc --input -
graph TD
A[Client] --> B[Load Balancer]
EOF
`

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`sh
mmdc -h
`

Alternative installations

Use Docker/Podman:

`sh
docker pull minlag/mermaid-cli
`

or pull from Github Container Registry

`sh
docker pull ghcr.io/mermaid-js/mermaid-cli/mermaid-cli
`

or e.g. version 8.8.0

`sh
docker pull minlag/mermaid-cli:8.8.0
`

The container looks for input files in /data. So for example, if you have a
diagram defined on your system in /path/to/diagrams/diagram.mmd, you can use
the container to generate an SVG file as follows:

`sh
docker run --rm -u id -u:id -g -v /path/to/diagrams:/data minlag/mermaid-cli -i diagram.mmd
`

Or, if using Podman, instead do:

`sh
podman run --userns keep-id --user ${UID} --rm -v /path/to/diagrams:/data:z ghcr.io/mermaid-js/mermaid-cli/mermaid-cli -i diagram.mmd
`

The key differences in the podman command versus the docker command are:

- The addition of the --userns keep-id argument. This allows the container to keep the same UID as the current user's UID in the container namespace instead of mapping to a subuid. To learn more, see the userns=mode documentation.
- The addition of :z to the end of the volume mapping. This instructs podman to relabel the files in the volume with the SELinux label container_file_t, which allows processes in the container to access the files. See the "Labeling Volume Mounts" section of podman-run (1) for more info.

In previous version, the input files were mounted in /home/mermaidcli. You can
restore this behaviour with the --workdir option:

`sh
docker run [...] --workdir=/home/mermaidcli minlag/mermaid-cli [...]
`




Use Node.JS API

It's possible to call mermaid-cli via a Node.JS API.
Please be aware that the NodeJS API is not covered by semver, as mermaid-cli follows
mermaid's versioning.

`js
import { run } from "@mermaid-js/mermaid-cli"

await run(
"input.mmd", "output.svg", // {optional options},
)
`

Install locally

Some people are having issues
installing this tool globally. Installing it locally is an alternative solution:

`
npm install @mermaid-js/mermaid-cli
./node_modules/.bin/mmdc -h
`

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npx is installed by default with NPM. It
downloads and runs commands at the same time. To use Mermaid CLI with npx, you
need to use the -p flag because the package name is different than the command
it installs (mmdc). npx -p @mermaid-js/mermaid-cli mmdc -h




Install with brew

> Warning
>
> This method of installation is no longer supported.
> For more details, see the discussion.
> An old version of mermaid-cli can be installed with brew.
> `sh
> brew install mermaid-cli
> ``

Known issues

1. Linux sandbox issue
2. Docker permission denied issue
3. How to setup up mermaid to use already installed chromium?

For contributors

Contributions are welcome. See the contribution guide.