What's new

New

• C4 model diagrams, as a preview release: Person, Software System, Container (with Database and Queue), Component, boundaries, and Deployment and Infrastructure Nodes, in the standard C4 colours. New Diagram offers System Landscape, System Context, Container, Component and Deployment views. More
• C4 zoom-level guidance in the Validation panel: it points out a Component on a System Context view, a container outside its system’s boundary, or a boundary that names no system. More
• Structurizr DSL export and import for C4 packages. Export writes one workspace.dsl with a view per C4 diagram; import brings a workspace.dsl into a package, merging with what is already there, and Undo reverts it. More
• Schema export from a «schema» package or a single type: Cassandra CQL, Apache Avro, JSON Schema 2020-12 (with an OpenAPI 3.1 option) and Protocol Buffers with gRPC services. Export refuses with a clear list of problems rather than writing a broken schema.
• Assign field numbers fills in missing Protobuf field numbers, skipping any number a parent or child class already uses. Avro adds aliases automatically when you rename a field.
• Label background for relationships: transparent, paper or a colour of your choice, per diagram, under Properties → Appearance. C4 diagrams use paper by default so lines break cleanly around their labels.

Improved

• UML XMI export now includes your stereotypes and the profiles they come from, so other UML tools see a «Container» as a Container.
• A tidier Export section in Properties: image formats in one box, then a full-width line for each other export.
• XMI export writes components, nodes and dependencies as their proper UML types.
• AI assistants connected through MCP can draw C4 diagrams, export schemas, and set a relationship’s label background.
• The server stays warm, so the first load after a quiet period is quicker.

Fixed

• Edits made while EOModeller is being updated are no longer at risk of overwriting newer changes; an open model reconnects and picks up where it was.
• Bold text in sketch-mode PDFs now uses the hand-drawn font instead of Times.
• The stereotype picker and other property-panel menus no longer open underneath the Remove and Delete buttons.
• Containers show what kind they are as plain text, instead of an internal setting in a box that looked editable.

New

• Cassandra access patterns: model each query as an operation on the table that answers it, and validation tells you whether the table can answer it.

Improved

• UML classes grow to fit their attributes and operations when you create or edit them, including classes drawn by an AI assistant.
• The older Cassandra forms («udt», «counter» and keyspaces named by package) are replaced by the current profile, migrated automatically.

New

• Attributes can be marked as identifiers and given field numbers, classes can reserve numbers and names, enumeration literals can have values, and parameters and results can be streams. All of it is visible in Properties.
• Built-in, read-only type libraries for UML primitives, Java, TypeScript, C#, Go, Python and Cassandra, ready to type attributes with.

Improved

• A new version of the Cassandra profile, with existing models migrated once, automatically.

New

• Sign in from Claude or another MCP client with your EOModeller account; no tokens to copy.
• AI assistants can create models, and lay out the diagrams they draw automatically.
• In-app instructions for connecting Claude to EOModeller.

New

• An MCP server for AI assistants: they can read your models (packages, diagrams, elements, dependencies and validation results) and change them through atomic change sets.
• Changes made by an assistant appear live in any open editor, with a notice and one-click revert.
• Personal access tokens with read or write scope.

Fixed

• When the server rejects a change, undo now removes the right step.

New

• Number badges on elements and connectors, for walking through a diagram step by step.
• Image elements: drop or paste an image onto a diagram.
• Download a model backup, and restore it as a new model.

Improved

• Undo and redo now reach the server, so collaborators and your other tabs see them.
• Drag packages to reorder them in the Package Browser, or sort them A–Z.
• Change the line style and routing of many connectors at once.
• Confirmations appear inside the app instead of as browser pop-ups.
• Tightened access checks on every workspace request.

Fixed

• Dashboard groups, long names in the model tree, controls on touch screens and note styles.

Fixed

• Connector lines now end at the back of their arrowheads and diamonds instead of running through them.