Building a MCP Server for the SysML v2 API
Author: Stephan Roth | Category: AI, MBSE | Published on: September 18, 2025
In a previous blog post, I introduced you to the Model Context Protocol, MCP for short. In the last paragraph of the article, I mentioned that this protocol and the new SysML v2 API & Services are a good combination for providing a SysML v2 model as context to AI agents. So now it's time to explore this idea in more depth and to realize it.
The SysML v2 API: A Game Changer
The complete revision of the Systems Modeling Language (SysML) to a new version 2 (SysML v2) by the Object Management Group® (OMG®) was driven, among other things, by the fact that SysML 1.x can no longer easily meet the future needs of modern systems engineering. These include the trend toward the so-called digital twin—a digital representation of a physical asset or process—as well as the digital thread, which describes a coherent chain of product information that can be tracked throughout the entire product lifecycle. Other challenges facing SE today include model integration with other tools (e.g., design tools/CAD), simulations for early verification, Product Line Engineering (PLE), and, of course, the use of artificial intelligence (AI) in Model-Based Systems Engineering (MBSE).
A special feature of the new SysML v2 is that OMG® has not only specified a formal modeling language for complex systems with syntax and precise semantics. They have also provided a normative interface specification with the new Systems Modeling Application Programming Interface (API) and Services (SysML v2 API & Services). This new standard defines and specifies a programming interface for accessing the data of a SysML v2 model.
OMG's SysML v2 API & Services specification defines basically two API models:
- A Platform-Independent Model (PIM), providing a service specification independent of any platform, programming language or technology.
- Two Platform-Specific Models (PSM) which are so-called bindings of the PIM using a particular technology. One PSM is HTTP/REST, the architectural style of the modern World Wide Web (WWW).
The huge advantage of having a standardized API is depicted in Figure 1. It means that the model's data can now be easily queried, visualized, and modified not only with professional SysML modeling tools, but also with any conceivable software tool, such as spreadsheet programs, CAD tools, and, of course, large language models (LLMs) like ChatGPT, Claude or Google Gemini. For many MBSE practitioners, this standardized API represents a significant innovation that opens up brand new possibilities and is considered a game changer. It is a significant step towards the MBSE-Vision of the system model as the so-called single source of truth.
The Project
The project idea was to develop a piece of software (server) that could serve as a client for a MCP Host (e.g., Visual Studio Code with Copilot) on the one hand, and on the other hand accesses a SysML v2 model repository via its standardized API to retrieve or manipulate model data.
You can find the project named SysML v2 API MCP-Server on GitHub. Please note that the project is currently still in a very early stage of development and is a work in progress! You can of course submit issues, but keep in mind that this is a leisure project of mine and is not subject to any strict development process or schedule—it will be worked on when I have the time and the energy.
SysML v2 API MCP-Server is an application written in modern C++ (C++23) and uses a few libraries hosted on GitHub too. On the project's GitHub homepage, you will also find some documentation, which is also constantly maintained and expanded. A good introduction to the fundamental architecture of MCP client/server applications can also be found on Anthropic's MCP website.
I will continue to report on the project here in the future and also present examples of its application. Stay tuned!