Groups and Subdomains

Organise entities into logical groups representing subdomains, bounded contexts, or categories, with convex hull rendering and group-aware physics.

February 15, 2026

Groups organise entities into logical clusters that represent subdomains, bounded contexts, or architectural categories. They provide both visual organisation (coloured hull backgrounds on the canvas) and physical organisation (group-aware force simulation that keeps related entities together). Groups are stored in the model's groups array and propagate to derived views.

Group Structure

Each group in the model is a GraphGroup with the following fields.

Field	Type	Description
id	string	Unique identifier (UUID) for the group
name	string	Display name for the group (e.g., "Order Management", "Identity")
nodeIds	string[]	Array of entity node IDs belonging to this group
color	string	Display colour as a CSS colour value (e.g., "#3b82f6")
description	string	Optional description of the group's purpose or scope

Group Features

Convex Hull Rendering

Groups are rendered as coloured convex hull backgrounds behind their member nodes. The hull shape adapts as nodes move, always enclosing all group members.

Zoom-aware Opacity

Hull backgrounds adjust their opacity based on the current zoom level. At wider zoom levels the hulls are more prominent, at closer zoom they fade to avoid obscuring detail.

Counter-scaled Labels

Group name labels maintain a consistent screen-space size regardless of zoom. The label text is counter-scaled against the current transform so it remains readable at any zoom level.

Group Clustering Force

The force simulation applies a custom forceGroupClustering function that pulls members of the same group together and pushes different groups apart, creating natural spatial separation.

Focus on Group

Click a group in the groups panel to focus the camera on that group's entities. The viewport animates to fit all member nodes, providing a quick way to navigate large models.

Batch Operations

Assign or remove multiple entities from a group in a single operation. Multi-select entities on the canvas, then use the groups panel to batch-assign them to the target group.

Working with Groups

Group-aware Physics

The force simulation uses a custom forceGroupClustering function that modifies node velocities each tick. For every node that belongs to a group, the function calculates the group centroid (the average position of all member nodes) and applies a gentle pull toward it. Nodes in different groups experience a repulsive force, encouraging spatial separation between domains.

// Simplified view of group clustering force registration
if (groups && groups.length > 0) {
  simulation.force('groupCluster', forceGroupClustering(groups));
}

// Per-node centre strength is reduced for grouped nodes,
// since the group clustering force handles their positioning.

Groups in Derived Views

Groups propagate from the model to derived views. Each view type handles groups differently.

Modelling Patterns

Groups map naturally to several architectural patterns.

Pattern	Group Usage	Example
Domain-driven design	One group per bounded context	Order Management, Customer Identity, Inventory
Microservice boundaries	One group per service	Payment Service, Notification Service, Catalogue Service
Data domains	One group per data domain	Transactional Data, Reference Data, Analytical Data
Security zones	One group per trust boundary	Public API, Internal Services, Data Lake
Deployment regions	One group per deployment unit	EU Region, US Region, APAC Region