Klaiv

VS Code extension for architecture modeling. Models are YAML files stored in your repo. Diff, merge, and PR-review them the same way you review code.

In preview. Expect changes.

Component diagram — checkout architecture

Basics

Open a folder in VS Code. Press Ctrl+Shift+P (Cmd+Shift+P on macOS) to open the command palette, then pick Klaiv: Initialize New Model. This creates an architecture/ directory with a basic YAML scaffolding.

The Model Explorer (activity bar) shows elements and diagrams in a package tree. Right-click to create, rename, delete, or reorganize.

Model Explorer with packages, elements, and diagrams

Opening a diagram from the Explorer shows a canvas. Drag nodes to position them; positions save to .layout.yaml files so they don't end up in semantic diffs. The "Connect" button lets you draw relationships with two clicks. Clicking a node opens its properties (name, stereotype, tags, ports, attributes, operations, depending on type).

Supported diagram types:

Structural, interactive: Component, Class, Package, Deployment, Use Case.
Behavioural, rendered read-only: Sequence (with fragments), State Machine, Activity (with swimlanes).

Class diagram — order domain model

Use case diagram with system boundary

Sequence diagram — checkout flow with fragments

Broken references, unknown types, and stereotype violations show up as squiggles in the YAML and entries in the Problems panel. The same validation is available as a klaiv validate CLI for pre-commit hooks and CI.

Getting started

Install Klaiv from the marketplace.
Open any folder in VS Code.
Press Ctrl+Shift+P (Cmd+Shift+P on macOS) and pick Klaiv: Initialize New Model.
Open the Klaiv view in the activity bar (left sidebar).
Right-click the tree → New Element / New Diagram.

An empty model shows an empty Explorer. That's not a bug.

Requirements

VS Code 1.115 or later. Node 18+ for the CLI.

Feedback

Preview software, so feedback is useful. Two paths:

The "Share feedback" link at the bottom of any diagram panel.
Klaiv: Share Feedback from the command palette.

Both let you choose between filing a public bug on GitHub or sending a short private note to the team.

License

Proprietary. Not open source.