Capability status

This is an implementation assessment, not a promise of complete parity with another editor. Features marked partial have useful foundations but should not be treated as finished application contracts.

Capability	Current position
Custom shapes	Available through registry definitions composing shared geometry, text, layers, ports and capabilities.
Editing and history	Canonical commands, selection, transform previews, undo/redo and shared rich-text editing are implemented. Browser input and complex ownership scenarios still need broader conformance coverage.
Standalone text	Distinct TextElement record with shared framed transforms, paragraph editing, and a dedicated registry definition. No shape decoration or port fields.
Custom tools	Open tool IDs and a registry support defaults and host tools through shared command/preview contracts.
Ports and connectors	Shared port geometry, bindings, connection policy and straight/elbow/quadratic/cubic routes are implemented. Elbow routing avoids its disjoint bound owners in covered cases; this is not a general scene-obstacle router.
Connector labels	Canonical labels resolve and render shared rich text at a path fraction. Individual label selection, dragging, corner/side resizing, deletion and undo/redo work. Double-click creation and shared text editing are implemented. Broader composition, clipping and interaction conformance remain under verification.
Port labels	Placement, visibility and editing contract is not implemented.
Embedded Flutter widgets	Region interactions and overlay hooks exist. Arbitrary widgets inside shapes do not yet have a complete focus, gesture, transform, clipping, accessibility and export contract.
Lock/unlock	Definition-level movement/editing capabilities exist. A complete per-instance lock/unlock feature is still missing.
Viewport animation	Public animated navigation to points, bounds, elements, regions and selection is implemented, with duration, curve and cancellation controls.
Canvas grids	Dots, lines and layered grids share validated, immutable pattern declarations. Hosts can compose dot, line and cross layers; visibility and grid snapping are independently configurable.
Path effects	Registry-based effects, particles and pulse, particle appearances, speed and base-path presentation controls exist for connectors. Attaching effects to every kind of authored path remains incomplete.
Persistence	Versioned JSON preserves canonical diagram content. Runtime path effects are not part of saved document content. General migration and output contracts need further work.
PNG output	Snapshot PNG export uses captured scene geometry and awaited images. Basic pixels, resource failures and snapshot lifetime are tested; exhaustive fidelity and browser download proof remain open. See PNG output.
High refresh rate rendering	Incremental and timing checks provide useful evidence. Consistent end-to-end 120 Hz release-browser performance across representative scenes is not yet established.