Skills uml

Create UML diagrams using PlantUML syntax. Best for software modeling — Class, Sequence, Activity, State Machine, Component, Use Case, and Deployment diagrams with concise text-based notation and auto-layout.

install

source · Clone the upstream repo

git clone https://github.com/markdown-viewer/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/markdown-viewer/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/uml" ~/.claude/skills/markdown-viewer-skills-uml && rm -rf "$T"

manifest: uml/SKILL.md

source content

UML Diagram Generator

Quick Start: Choose diagram type → Write PlantUML text → Define elements and relationships → Wrap in

```plantuml

fence.

⚠️ IMPORTANT: Always use
```plantuml
or
```puml
code fence. NEVER use
```text
— it will NOT render as a diagram.

Critical Rules

Every diagram starts with
```
@startuml
```
and ends with
```
@enduml
```

Use standard PlantUML keywords:

class

interface

abstract

enum

actor

participant

component

node

database

package

Relationships use arrow syntax:
```
-->
```
,
```
<|--
```
,
```
*--
```
,
```
o--
```
,
```
..>
```
,
```
..|>
```
Use
```
skinparam
```
for global styling and colors
Use
```
#color
```
on individual elements for specific colors

Notes use

note left of

note right of

note over

, or standalone

note "text" as N

UML Diagram Types

Type	Purpose	Key Syntax	Example
Class	Class structure and relationships	`class` , `interface` , `<\|--`	class-diagram.md
Sequence	Message interactions over time	`participant` , `->` , `-->`	sequence-diagram.md
Activity	Workflow and process flow	`start` , `:action;` , `if/else`	activity-diagram.md
Swimlane Activity	Multi-role activity with swimlanes	`\|Lane\|` , `:action;`	swimlane-activity-diagram.md
State Machine	Object lifecycle states	`state` , `[*] -->`	state-machine-diagram.md
Component	System component organization	`component` , `[name]` , `interface`	component-diagram.md
Use Case	User-system interactions	`actor` , `usecase` , `(name)`	use-case-diagram.md
Deployment	Physical deployment architecture	`node` , `artifact` , `database`	deployment-diagram.md
Object	Runtime object snapshot	`object "name" as id`	object-diagram.md
Package	Module organization	`package "name"`	package-diagram.md
Communication	Object collaboration	Numbered messages with sequence syntax	communication-diagram.md
Composite Structure	Internal class structure	`component` with nested `port`	composite-structure-diagram.md
Interaction Overview	Activity + sequence combination	`group` , `ref over`	interaction-overview-diagram.md
Profile	UML extension mechanisms	`<<stereotype>>` labels	profile-diagram.md

Mxgraph Stencil Icons

draw-uml supports 9500+ mxgraph stencil icons (AWS, Azure, Cisco, Kubernetes, etc.) via the

mxgraph.*

syntax. Default colors are applied automatically — you do NOT need to specify

fillColor

strokeColor

Full stencil reference: See stencils/README.md.

Syntax

mxgraph.<namespace>.<icon> "Label" as <alias>
mxgraph.<namespace>.<icon> "Label" as <alias> #color
mxgraph.<namespace>.<icon> <alias>

mxgraph.<namespace>.<icon>

— the stencil shape key (e.g.

mxgraph.aws4.lambda

mxgraph.kubernetes.pod

)

```
"Label"
```
— display text (quoted if contains spaces, unquoted for single word)
```
as <alias>
```
— identifier for use in relationships
```
#color
```
— optional override color (e.g.
```
#FF6600
```
,
```
#LightBlue
```
)

Examples

@startuml
' Simple icon declaration
mxgraph.aws4.lambda "Lambda\nFunction" as fn
mxgraph.aws4.api_gateway "API GW" as gw
mxgraph.aws4.dynamodb "DynamoDB" as db

gw --> fn
fn --> db
@enduml

@startuml
' Kubernetes architecture with icons
mxgraph.kubernetes.ing "Ingress" as ing
mxgraph.kubernetes.svc "Service" as svc
mxgraph.kubernetes.pod "Pod" as pod
mxgraph.kubernetes.deploy "Deployment" as deploy

ing --> svc
svc --> pod
deploy --> pod
@enduml

@startuml
' Mixing standard UML with stencil icons
node "Cloud" {
  mxgraph.aws4.ec2 "EC2" as ec2
  mxgraph.aws4.rds "RDS" as rds
}
database "Legacy DB" as legacy

ec2 --> rds
rds --> legacy
@enduml