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kUML

kuml.dev

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Spec score 7.8 #14 of 26 in UML Modeling Software

What it is

kUML is a modeling tool that expresses UML 2.x, SysML 2, C4, BPMN 2.0, and ERM as a type-safe Kotlin DSL. It supports all 14 UML 2.x diagram types, with compile-time validation and IDE support. Built-in transformations generate JPA, OpenAPI 3.0 YAML, Kubernetes manifests, and Dockerfiles. Integrations include CLI, Gradle, IntelliJ, Obsidian, Asciidoctor, and VS Code. For interoperability, it supports Structurizr DSL round-tripping and optional XMI through the kuml-io-emf module. kUML also includes an MCP server for agent introspection and a kuml ai subcommand for AI-assisted modeling. It is free and open source under Apache 2.0, with no paid plans or feature limits stated. It runs on Windows, macOS, Linux, and the web, and can be deployed both self-hosted and through other means. Install options include packages for major desktop systems, Docker, and Maven Central library modules. Rendering Kotlin scripts executes their source code, so use only scripts or workspaces you trust.

Spec sheet

What it does
kUML expresses UML 2.x, SysML 2, C4, BPMN 2.0 and ERM as a type-safe Kotlin DSL.Read 8 Oct 2026 · github.com
Integrations
The project lists CLI, Gradle, IntelliJ, Obsidian, Asciidoctor, and VS Code integrations.Read 8 Oct 2026 · github.com
Security
The MCP authoring server validates scripts with KumlScriptGuard before evaluation, using the same sandboxing applied by the CLI render and validate commands.Read 8 Oct 2026 · docs.kuml.dev
License
The project is licensed under Apache 2.0.Read 8 Oct 2026 · github.com
AI workflows
It includes an MCP server for agent introspection and a kuml ai subcommand for AI-assisted modeling.Read 8 Oct 2026 · github.com
Code generation
Built-in model transformations generate JPA, OpenAPI 3.0 YAML, Kubernetes manifests, and Dockerfiles.Read 8 Oct 2026 · github.com
Desktop app
The project provides a Compose Multiplatform desktop app distributed as a macOS cask.Read 8 Oct 2026 · github.com
Distribution
Install options include Homebrew for macOS and Linux, Chocolatey and MSI for Windows, native DEB/RPM/DMG packages, Docker, and Maven Central library modules.Read 8 Oct 2026 · github.com
Interoperability
kUML supports Structurizr DSL round-trip and optional XMI interoperability through its kuml-io-emf module.Read 8 Oct 2026 · github.com
Modeling
It supports all 14 UML 2.x diagram types alongside SysML 2 and C4.Read 8 Oct 2026 · github.com
Support and documentation
The project links to an online handbook covering installation, usage, and its features.Read 8 Oct 2026 · docs.kuml.dev
Trust limitation
Rendering Kotlin scripts executes their source code, and the handbook advises running only scripts or workspaces the user trusts.Read 8 Oct 2026 · docs.kuml.dev
Validation
Its Kotlin DSL provides compile-time validation and IDE support.Read 8 Oct 2026 · github.com

Plans and prices

Free / open source Free Apache 2.0 licensed software; paid plans and feature limits not stated Read 8 Oct 2026 · github.com

Every kUML plan and price →

Strong points and limits

Strong points

  • All 14 UML 2.x diagram types supported
  • Compile-time validation and IDE support
  • Generates JPA, OpenAPI, Kubernetes, and Docker outputs
  • Structurizr DSL and optional XMI interoperability
  • Free and Apache 2.0 licensed

Limits

  • Rendering scripts executes their source code
  • XMI support is optional via kuml-io-emf

Who it suits

kUML suits developers and modelers who want diagramming and code-generation workflows expressed in Kotlin. It may also fit teams that need integrations, model exchange, or AI-assisted modeling.

Verdict

kUML combines broad modeling coverage with validation, integrations, and code generation in a free, open-source package. Treat Kotlin scripts and workspaces as executable code and use trusted ones only.

Where Specifiction places it

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