Mermaid was nominated and won the JS Open Source Awards (2019) in the category "The most exciting use of technology"!!! Thanks to all involved, people committing pull requests, people answering questions and special thanks to Tyler Long who is helping me maintain the project.

Mermaid is a tool that generates diagrams and charts, from markdown-inspired text definitions

This allows for simplified generation and updating of even the most complex diagrams and charts, while avoiding time-damanding and heavy tools like visio.

mermaid, is a simple markdown-inspired script language for generating charts from text-definitions, via javascript. As such, using it cuts the times it takes to create, modify and render diagrams.

Even non-programmers can create diagrams through the mermaid live editor.

For a more detailed introduction to mermaid, look to the Beginner's Guide section.

You should also Check out the list of Integrations and Usages of Mermaid

You can also watch some popular mermaid tutorials on the mermaid Overview

CDN

Documentation

Contribution

New in Version 8.6.0

New Mermaid Live-Editor Beta

New Configuration Protocols in version 8.6.0

New diagrams in 8.5

With version 8.5 there are some bug fixes and enhancements, plus a new diagram type, entity relationship diagrams.

Special note regarding version 8.2

In version 8.2 a security improvement was introduced. A securityLevel configuration was introduced which sets the level of trust to be used on the parsed diagrams.

securityLevel

Parameter	Description	Type	Required	Values
securitylevel	Level of trust for parsed diagram	String	Required	Strict, Loose

**Notes:

strict: (default) tags in text are encoded, click functionality is disabeled
loose: tags in text are allowed, click functionality is enabled

Closed issues:

⚠️ Note : This changes the default behaviour of mermaid so that after upgrade to 8.2, if the securityLevel is not configured, tags in flowcharts are encoded as tags and clicking is prohibited.

If your application is taking responsibility for the diagram source security you can set the securityLevel accordingly. By doing this clicks and tags are again allowed.

mermaidAPI.initialize({
    securityLevel: 'loose'
});

🖖 Keep a steady pulse: mermaid needs more Collaborators #866

Diagrams that mermaid can render:

Flowchart

graph TD;
    A-->B;
    A-->C;
    B-->D;
    C-->D;

Sequence diagram

sequenceDiagram
    participant Alice
    participant Bob
    Alice->>John: Hello John, how are you?
    loop Healthcheck
        John->>John: Fight against hypochondria
    end
    Note right of John: Rational thoughts <br/>prevail!
    John-->>Alice: Great!
    John->>Bob: How about you?
    Bob-->>John: Jolly good!

Gantt diagram

gantt
dateFormat  YYYY-MM-DD
title Adding GANTT diagram to mermaid
excludes weekdays 2014-01-10

section A section
Completed task            :done,    des1, 2014-01-06,2014-01-08
Active task               :active,  des2, 2014-01-09, 3d
Future task               :         des3, after des2, 5d
Future task2               :         des4, after des3, 5d

Class diagram - ❗ experimental

classDiagram
Class01 <|-- AveryLongClass : Cool
Class03 *-- Class04
Class05 o-- Class06
Class07 .. Class08
Class09 --> C2 : Where am i?
Class09 --* C3
Class09 --|> Class07
Class07 : equals()
Class07 : Object[] elementData
Class01 : size()
Class01 : int chimp
Class01 : int gorilla
Class08 <--> C2: Cool label

Git graph - ❗ experimental

gitGraph:
options
{
    "nodeSpacing": 150,
    "nodeRadius": 10
}
end
commit
branch newbranch
checkout newbranch
commit
commit
checkout master
commit
commit
merge newbranch

Entity Relationship Diagram - ❗ experimental

erDiagram
    CUSTOMER ||--o{ ORDER : places
    ORDER ||--|{ LINE-ITEM : contains
    CUSTOMER }|..|{ DELIVERY-ADDRESS : uses

User Journey Diagram

journey
    title My working day
    section Go to work
      Make tea: 5: Me
      Go upstairs: 3: Me
      Do work: 1: Me, Cat
    section Go home
      Go downstairs: 5: Me
      Sit down: 5: Me

Installation

CDN

https://unpkg.com/mermaid@<version>/dist/

To select a version:

Replace <version> with the desired version number.

Alternatively, you can also adjust the version number in the page itself.

Latest Version: https://unpkg.com/browse/mermaid@8.6.0/

Incorporating mermaid to a website

to support mermaid on your website, all you have to do is add Mermaid’s JavaScript package

1.You will need to isntall node v10 or 12, which would have npm

2. download yarn using npm.

2. enter the following command:
    yarn add mermaid

3. You can then add mermaid as a dev dependency using this command: 
    yarn add --dev mermaid

To install mermaid without a bundler, one can use the script tag like so:

it can then be followed by the diagram definitions as could be found in the examples in the documentation.

On your page mermaid will look for tags with class="mermaid". From these tags mermaid will try to read the chart definiton and replace it with an svg chart.

Sibling projects

Request for assistance

Things are piling up and I have a hard time keeping up. To remedy this it would be great if we could form a core team of developers to cooperate with the future development of mermaid.

As part of this team you would get write access to the repository and would represent the project when answering questions and issues.

Together we could continue the work with things like:

Adding more types of diagrams like mindmaps, ert diagrams, etc.
Improving existing diagrams

Don't hesitate to contact me if you want to get involved.

For contributors

Setup

yarn install

Build

yarn build:watch

Lint

yarn lint

We use eslint. We recommend you installing editor plugins so you can get real time lint result.

Test

yarn test

Manual test in browser: open dist/index.html

Release

For those who have the permission to do so:

Update version number in package.json.

npm publish

Command above generates files into the dist folder and publishes them to npmjs.org.

Credits

Many thanks to the d3 and dagre-d3 projects for providing the graphical layout and drawing libraries!

Thanks also to the js-sequence-diagram project for usage of the grammar for the sequence diagrams. Thanks to Jessica Peter for inspiration and starting point for gantt rendering.

Mermaid was created by Knut Sveidqvist for easier documentation.

Tyler Long has became a collaborator since April 2017.

Here is the full list of the projects contributors.

README.md Unescape Escape

Mermaid