Syntax
Each line in a sequence diagram consists of two columns (i.e. entities), an arrow (i.e. direction of flow), and a message. The two columns are separated by the >
arrow and the message is prepended with the :
.
Here is an example:
Web App > DB: Start transaction

Here are the types of arrows:
Arrow | Syntax | Description |
---|---|---|
> |
Left-to-right arrow | |
< |
Right-to-left arrow | |
<> |
Bi-directional arrow | |
- |
Line | |
-- |
Dotted line | |
--> |
Dotted arrow |
Each line is parsed in sequential order from top to bottom and rendered in the diagram the same way.
Column names are required to be unique. If a line refers to a column name that hasn't been used in prior lines, a new column will be created.
Properties
Properties are key-value pairs enclosed in [ ]
brackets that can be appended to column names. Properties are optional.
It is possible to set multiple properties like shown below:
Web App [icon: monitor, color: blue] > DB [icon: database, color: green]: Start transaction

Here are the properties that are allowed:
Property | Description | Value |
---|---|---|
Icon | Attached icons | Icon names (e.g. aws-ec2 ). See Icons page for full list. |
Color | Stroke and fill color, when possible | Color name (e.g. blue ) or hex code (e.g. #000000 ) |
Here are the lists of icon names:
Updated 4 months ago