Skip to content


Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
FMI logo horizontal

Functional Mock-up Interface

The Functional Mock-up Interface (FMI) is a free standard that defines an interface to exchange dynamic models using a combination of XML files, binaries and C code. It’s supported by 170+ tools and maintained as a Modelica Association Project.

Releases and the latest development version of the specification are available on the FMI website.

Repository Structure

  • docs — sources of the specification document

  • headers — header files of the C-API

  • schema — XSD schema for the modelDescription.xml

  • CONTRIBUTING.adoc — info on contributing to the project and building the specification document

  • README.adoc — this document


  • main — development of the next release

  • v{2|3}.0.x — maintenance of the 2.0 and 3.0 releases

Layered Standards

The following layered standards are currently under development.

  • XCP — information for calibration and measurement

  • Network Communication — mapping of variables to buses

  • Structure — semantic grouping of variables

Code and documentation copyright © 2008-2011 the MODELISAR consortium and 2012-2023 the Modelica Association Project FMI. Code released under the 2-Clause BSD License. Docs released under Attribution-ShareAlike 4.0 International.