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OMG UML 2.5.1 compliant  ·  2-3× more concise than PlantUML  ·  In-browser rendering

Sequence Diagrams in Confluence with ZenUML

Write sequence diagrams as code directly inside Confluence using ZenUML DSL — a concise, standards-compliant text syntax. No image uploads, no external tools. The diagram renders in the browser in real time from the moment you type.

Install Free — Lite Plan · See the syntax

✓ OMG UML 2.5.1 compliant ✓ 2-3× more concise than PlantUML ✓ Renders in-browser — zero server upload ✓ Free Lite plan — no credit card

The ZenUML editor in Confluence: DSL source on the left, the rendered UML sequence diagram updating live on the right. Selecting a line of code highlights the corresponding message on the diagram.

What is a ZenUML Sequence Diagram?

A ZenUML sequence diagram is an OMG UML 2.5.1-compliant sequence diagram written in ZenUML DSL — a concise text syntax designed specifically for sequence diagrams. Unlike generic UML tools that require a graphical editor, ZenUML lets you write diagrams the same way you write code: as plain text that you can version, diff, review in pull requests, and store alongside your source code.

Inside Confluence, ZenUML sequence diagrams live in a macro on the page. The source text is stored as Confluence custom content — it is part of your Atlassian instance, not an external service. On every page view the ZenUML engine (running entirely in the reader's browser) parses the DSL and renders the diagram as an SVG. No content is transmitted to ZenUML servers at any point.

ZenUML DSL models sequence diagrams as call expressions — the same mental model developers use when reading or writing code. Participants are inferred automatically from the messages you write, eliminating the boilerplate declarations that PlantUML requires. The result is diagrams that are typically 2-3× shorter than equivalent PlantUML source while remaining fully UML-compliant.

ZenUML DSL — a four-message order flow

Participants are inferred from message sources and targets. No declarations, no boilerplate. The --> arrow denotes an asynchronous or return message. Dashes render as a dashed line on the diagram.

order-flow.zenuml

✓ 5 lines of source — no boilerplate ✓ Participants auto-inferred ✓ UML 2.5.1 compliant output

How ZenUML DSL compares to PlantUML

Both syntaxes produce the same sequence diagram. ZenUML DSL removes the delimiter scaffolding, eliminates participant declarations (they are inferred), and uses a call-expression style that reads more like code. The result is typically 2-3× fewer lines for the same diagram.

ZenUML DSL 5 lines

title Order Flow Client -> OrderService: placeOrder(items) OrderService -> InventoryService: checkStock(items) InventoryService --> OrderService: stockAvailable OrderService --> Client: orderConfirmed

  • ✓ No @startuml / @enduml delimiters
  • ✓ Participants inferred — no declarations needed
  • ✓ Call-expression style mirrors code semantics

PlantUML (equivalent) 12 lines

@startuml title Order Flow participant Client participant OrderService participant InventoryService Client -> OrderService : placeOrder(items) OrderService -> InventoryService : checkStock(items) InventoryService --> OrderService : stockAvailable OrderService --> Client : orderConfirmed @enduml

  • ✗ Requires delimiter boilerplate
  • ✗ Must declare every participant explicitly
  • ✗ Spaces around : required; ordering sensitive

Note: ZenUML for Confluence also includes a PlantUML renderer — teams can use both syntaxes in separate macros on the same page and migrate diagrams incrementally.

When engineering teams reach for sequence diagrams

ZenUML sequence diagrams in Confluence appear wherever teams need to communicate interactions between actors, services, or systems — in design docs, runbooks, and onboarding guides.

API Documentation

Show request-response flows for REST and GraphQL endpoints alongside the OpenAPI spec. Readers see both the formal contract and the runtime interaction sequence on the same Confluence page.

Microservice Interactions

Document how services communicate across event queues, RPC calls, and HTTP APIs. Sequence diagrams make async handoffs and retry logic visible in architecture docs without a whiteboard session.

User Flows

Map user interactions with a frontend through authentication, data loading, and state changes. Product managers and engineers share one artifact that lives in the Confluence design spec.

System Architecture

Capture the dynamic view of a system alongside static architecture diagrams. Sequence diagrams explain the "how" that component diagrams leave implicit, and they age alongside the code as text in version history.

Onboarding Flows

Walk new engineers through service boot sequences, auth handshakes, and dependency initialization. A sequence diagram in a Confluence runbook is faster to read than three paragraphs of prose.

Incident Post-Mortems

Reconstruct a failure timeline as a sequence diagram in the post-mortem page. Show the exact order of calls, timeouts, and retries. The diagram persists in Confluence version history for future reference.

Built for engineers who write diagrams as code

Every feature in the sequence diagram editor is designed to keep the diagram in sync with the code, the doc, and the team — without leaving Confluence.

Live Preview

The rendered sequence diagram updates on every keystroke in the split-pane editor. No save cycle, no reload. Syntax errors are highlighted immediately, so you can correct them before publishing.

PNG & PDF Export

Export any sequence diagram to PNG or PDF from the inline viewer toolbar. Share in Slack, include in slide decks, or attach to a Jira issue — without re-screenshotting. The export is pixel-exact to the on-page rendering.

Version History

Every publish creates a new Confluence custom content version. Browse previous states, restore an earlier diagram, and audit who changed what and when — using Confluence's native version history, with no extra tooling.

Fullscreen Editor

Open any sequence diagram in a fullscreen split-pane modal directly from the Confluence page. Code on the left, rendered diagram on the right. Resize panes to focus on either the source or the output.

Copy Source Code

Copy the ZenUML DSL source to clipboard with one click from the viewer. Store diagrams in a Git repository alongside source code, paste into another Confluence page, or share in a code review.

AI-Assisted Generation

Describe an interaction flow in natural language and let the AI generate valid ZenUML DSL source. Edit the output directly in the editor — AI produces a starting point, not a final artifact.

Privacy-First Rendering

The ZenUML rendering engine runs entirely in the browser. Diagram source text — including confidential service names and API flows — is never transmitted to ZenUML servers. Suitable for air-gapped or strict data residency environments.

Diagram as Code

Source is stored as plain text in Confluence custom content. Store a copy in Git alongside your service code. Diffs are human-readable. Updates take seconds when the architecture changes.

Frequently Asked Questions

Common questions about ZenUML sequence diagrams in Confluence — syntax, comparison with other tools, export, and supported UML constructs.

What is ZenUML sequence diagram syntax?

ZenUML DSL is a text-based syntax for writing OMG UML 2.5.1-compliant sequence diagrams. It uses a call-expression style that mirrors how developers think about code execution: Client -> OrderService: placeOrder(items) OrderService --> Client: orderConfirmed Participants are inferred automatically from messages — no explicit declarations needed. Notes, combined fragments (alt, loop, opt, par), self-calls, and return arrows are all supported. The source is stored as plain text in Confluence custom content and rendered in the browser via the ZenUML engine.

How does ZenUML DSL compare to PlantUML sequence syntax?

ZenUML DSL is 2-3× more concise than PlantUML for sequence diagrams. PlantUML requires @startuml / @enduml delimiters, explicit participant declarations for every actor, and spaces around the colon separator. ZenUML infers participants from the messages you write and eliminates boilerplate. A four-message interaction takes 12 lines in PlantUML and 5 in ZenUML DSL. Both syntaxes are supported by ZenUML for Confluence in separate macro types, so teams can run both on the same page and migrate incrementally.

Can I use Mermaid sequence diagrams in ZenUML for Confluence?

Yes. ZenUML for Confluence includes a full Mermaid.js renderer alongside the ZenUML DSL renderer — both in the same app. To use Mermaid sequence syntax, insert a ZenUML macro, choose the Mermaid diagram type, and write standard sequenceDiagram Mermaid code. The two diagram types coexist on the same page and are managed through the same macro interface. No separate Mermaid app is required.

How do I document API flows in Confluence?

Insert a ZenUML macro on any Confluence page and choose the Sequence type. Write your API interaction in ZenUML DSL — for example: title Order Flow Client -> OrderService: placeOrder(items) OrderService -> InventoryService: checkStock(items) InventoryService --> OrderService: stockAvailable OrderService --> Client: orderConfirmed Publish the page and the diagram renders inline for all readers. For REST or GraphQL API contracts, pair the sequence diagram with the OpenAPI macro in the same app — interactive swagger-ui renders alongside the sequence diagram on the same Confluence page.

Can I export sequence diagrams to PNG?

Yes. Every ZenUML sequence diagram can be exported to PNG or PDF directly from the diagram viewer in Confluence. Click the export button in the viewer toolbar, choose PNG or PDF, and download the file. The export uses the in-browser rendered output — what you export is exactly what viewers see on the page. No external service or upload is involved at any step.

Does ZenUML sequence diagram support actors, notes, and groups?

  • Participants and actors — named automatically from messages, or declared explicitly
  • Synchronous messages — solid arrow (->)
  • Asynchronous / return messages — dashed arrow (-->)
  • Self-calls — a participant sending a message to itself
  • Notes — over, left of, or right of a participant
  • Combined fragments — alt (alternatives), opt (optional), loop, and par (parallel)
  • Nested groups — fragments inside fragments

Start writing sequence diagrams in Confluence — free

Install ZenUML Lite in under two minutes. No server setup, no external accounts, no credit card. The free Lite plan supports all diagram types including ZenUML sequence diagrams.

Install Free — Lite Plan · Install Full — Paid

1 Find on Marketplace Search "ZenUML" on the Atlassian Marketplace and choose Lite or Full.

2 Click "Get it now" Select your Confluence Cloud site. Atlassian handles the install — no download needed.

3 Type /ZenUML on a page Insert the macro, choose Sequence, write your diagram, and publish.

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