Sequence Diagram
The highest-value diagram in this list. Time runs down; participants across.
- Format.puml
- Length27 lines
- Includesnone
The source
27 lines of PlantUML, and needs nothing beyond the bundled engine. Copy it, or open the template inside Gnomon and render it as it is.
@startuml
title Sequence Diagram
actor User as U
participant "Web App" as W
participant "API" as A
database "Database" as D
U -> W: Request
activate W
W -> A: API Call
activate A
A -> D: Query
activate D
D --> A: Results
deactivate D
A --> W: Response
deactivate A
W --> U: Display
deactivate W
@endumlRender this offline
This template ships in Gnomon and renders on your machine, with no account and nothing sent to a server. The browser editor is free and needs no install.
Others in UML and standard diagrams
- Activity / Flow DiagramEarns its place when there are real branches and joins.
- Use Case DiagramActor-to-goal. Dated, but still the clearest way to show scope boundaries.
- Class DiagramBest used for a single bounded context, not a codebase.
- State DiagramForces the awkward questions about duplicate and out-of-order events.
- ER DiagramCardinality is the part people get wrong. Write it explicitly.
- Mind MapFor structuring thinking, not for documenting a system.
- Gantt ChartPlans, not architecture, but it renders from text, so it diffs in review.
- JSON VisualizationVisualises a JSON payload: handy in an API design review.
- Work Breakdown StructureWork breakdown. Useful for scoping a piece of delivery.