UML Diagram Generator
Quick Start: Choose diagram type → Write PlantUML text → Define elements and relationships → Wrap in ```plantuml fence.
⚠️ IMPORTANT: Always use
```plantumlor```pumlcode fence. NEVER use```text— it will NOT render as a diagram.
Critical Rules
- Every diagram starts with
@startumland ends with@enduml - Use standard PlantUML keywords:
class,interface,abstract,enum,actor,participant,component,node,database,package - Relationships use arrow syntax:
-->,<|--,*--,o--,..>,..|> - Use
skinparamfor global styling and colors - Use
#coloron individual elements for specific colors - Notes use
note left of,note right of,note over, or standalonenote "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 or 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
plantuml@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
plantuml@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
plantuml@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
