UML Designer

UML Designer is a local-first, anonymous web app for creating UML and workflow diagrams with no backend dependency.

Highlights

• Anonymous usage with no authentication required.
• Unlimited diagram creation on a single device.
• Local persistence using IndexedDB (auto-save).
• Import and export diagram JSON files with semantic metadata.
• Export canvas as PNG.
• First-load guided tutorial with dismiss option.
• Context-aware element palettes by diagram family.
• Connector type toolbar and edge label editing.
• Non-blocking diagnostics panel with guided UML warnings.
• Dashboard create flow respects the selected diagram family for both blank and template-based creation.
• Sequence diagram visuals include improved Actor, Lifeline, and Activation connector handle alignment.
• Auth-ready architecture for future cloud identity integration.

UML Families Supported

• Class
• Sequence
• Activity
• State
• Use Case
• Component
• Deployment
• Workflow

Architecture

• Domain: diagram models, UML semantics, templates, validation rules.
• Application: use cases, validation service, repository contracts.
• Infrastructure: IndexedDB repository implementation.
• Presentation: React UI, dashboard, editor toolbars, diagnostics.

Static Hosting

This app is backend-free and can be hosted as static assets on:

• GitHub Pages
• Netlify
• Vercel
• Cloudflare Pages

Documents

• QUICK_START.md
• TUTORIAL.md
• CHANGELOG.md

Current Scope Notes

• Diagnostics are warning-based (non-blocking) and intended to assist modeling, not fully enforce every notation rule.
• Some element types share generic rendering while core families and common elements have dedicated visuals.