Alpha · not yet generally available

SysML v2 authoring in your browser

Write SysML v2 as text or draw it as a diagram — both stay in sync. The OMG standard library is built in, with autocomplete and hover documentation. Nothing to install.

Open the editor Join the alpha programme

What it is

A focused environment for SysML v2. If you need other notations alongside it, that is UMStudio.io — see below.

Text and diagram, in sync

Edit either representation. Changes flow both ways without reformatting what you wrote.

The OMG standard library

KerML foundations, SI units, ISQ quantities and the domain libraries, with autocomplete and hover docs.

Validation you can act on

Semantic checks and JSON Schema validation, reported where the problem is rather than as a wall of output.

Open formats

Export to JSON and OMG JSON-LD. Your models are not locked inside the tool.

How it works

Everything runs in the browser tab. There is no modelling server to install, and no round trip to a backend before you see a diagram.

Editor Monaco for text, a diagram canvas for structure — the same model behind both.

Parser Reads SysML v2 into a model and writes it back, preserving how you spelled it.

Std library The OMG libraries — KerML foundations, SI units, ISQ quantities — resolved for autocomplete and hover docs.

Validation Semantic checks and JSON Schema, reported against the line that caused them.

Export JSON, OMG JSON-LD and diagram images. Nothing is trapped in a proprietary file.

Examples

Each of these opens the editor with a model already loaded. Nothing to sign up for.

Beginner

Thermostat

Parts, attributes, ports and requirements on a system small enough to read in full.

Parametrics

Vehicle

ECU communication with mass and power budgets expressed as parametric constraints.

IoT

Smart home

Security, climate, lighting and energy management across one larger model.

Requirements

Requirements blueprint

Requirements traced onto the structure that satisfies them.

Behaviour

State machines

Behavioural modelling — states, transitions and their triggers.

Multi-file

Lab cluster

A model split across files, with imports resolved across them.

Learning SysML v2

SysML v2 has a lot of vocabulary, so the learning material lives inside the app rather than in a separate manual. It has a guided tour, a hands-on tutorial and a reference guide, all one click from the workbench.

12 steps

Take the tour first

A guided walk through the workbench itself — the project tree, the file tabs, the palette, the property panel and the view switcher — so you know where things are before you start modelling.

8 lessons

Then learn by doing

An interactive tutorial that takes you from packages and part definitions through attributes, composition, ports, connections and requirements. Seven of the lessons give you an editor inside the lesson, seeded with a starting point, and check what you wrote; the eighth is a wrap-up.

Reference

Look things up later

A reference guide covering definitions and usages, packages, parts, ports, connections and requirements, with common patterns and keyboard shortcuts. It also has a step-by-step walkthrough of running a simulation.

Roadmap

Three facts about how this got built, then what's ahead — not a commitment, the order and scope change. Items marked shared are engine work that lands in both SysML Online and UMStudio.io.

What's ahead — not committed Current plan — being built or being considered.

Oct 2025 Thesis began Build a working editor, not a paper about one

May 2026 Thesis Defence Submitted on v0.1.x — diagram, text, and a round-trip between them

So a diagram layout cannot silently drift across a release.

The roadmap above is kept current as work lands, and alpha participants can see what is in flight from inside the product.

Need more than SysML?

UMStudio.io is the same engine with the other fifteen notations switched on — UML, BPMN, ArchiMate 4, C4, DCR, OLOG, Mermaid, D2, Graphviz, statecharts, database schemas, threat models and timing diagrams among them — plus the cross-notation linking that connects them. SysML Online is the focused option; UMStudio.io is the workbench.

Everything marked shared above lands in both, because it is the same codebase underneath.

See UMStudio.io

Alpha adoption programme

The product is in alpha. It is not being sold yet, and there is nothing to pay for.

What joining means

You use it for real work, and tell us where it breaks. In exchange you get direct influence over what gets built, and early access as features land.

No cost, and no payment details taken
Expect rough edges — this is alpha, not a soft launch
Your feedback goes straight to the people building it
No commitment on either side; leave whenever it stops being useful

To take part, open the app and use Send feedback — it is in the toolbar, next to Help. Tell us what you are trying to model and what is getting in your way.

Open the app and tell us

Pricing

Not yet available. Nothing here can be purchased, and no payment details are collected anywhere on this site.

Free / Community

For learning and evaluation

A couple of active projects, in your browser
A cap on the size of each model
Community support

Pro

Early-adopter pricing

For individual practitioners. Early-adopter pricing applies during the alpha.

All modelling features
Work from your own files and folders
Hosted storage and version history
Email support
Save two months with yearly billing

Team / Enterprise

For organisations

Organisations with shared projects
SSO into your identity provider
Real-time collaboration
Priority support
Save two months with yearly billing

Contact sales

Sovereign

Self-hosted, for larger organisations. A minimum seat count applies.

Run it on your own infrastructure
SSO
Your data never leaves your network

Contact sales

One subscription covers both SysML Online and UMstudio. Tiers and limits will change before anything goes on sale. Alpha participants will be told well before that happens.