HELICS (Hierarchical Engine for Large-scale Infrastructure Co-Simulation) is a general-purpose, modular co-simulation framework that lets you connect existing simulation tools into a unified federation. Rather than building monolithic simulators, HELICS coordinates data exchange and time synchronization between independent simulation tools — each called a federate — so they collectively model complex systems of systems.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/GMLC-TDC/HELICS/llms.txt
Use this file to discover all available pages before exploring further.
Introduction
Learn what HELICS is, how it works, and when to use it.
Installation
Install HELICS via package managers, pre-compiled binaries, or from source.
Quickstart
Build and run your first two-federate co-simulation in minutes.
Core Concepts
Understand federates, brokers, timing, and data interfaces.
Why HELICS?
HELICS solves the hard problems of co-simulation: keeping heterogeneous simulators synchronized in time, routing data between them efficiently, and scaling from a developer laptop to a national lab supercomputer — without modifying the simulators themselves.Multi-language
C++, C, Python, Java, MATLAB, Julia, Octave, and more.
Massively scalable
Two federates to 100,000+ across distributed computing environments.
Domain-agnostic
Energy, communications, buildings, transportation, and beyond.
Explore the documentation
Simulator integration guide
Step-by-step guidance for connecting your simulation tool to HELICS.
Federation configuration
Configure federates with JSON files, command-line flags, or direct API calls.
HELICS apps
Use the Broker, Player, Recorder, and other built-in helper applications.
C++ API reference
Browse the full public API surface for the C++ application library.
Get started in 3 steps
Install HELICS
Use conda, pip, or a pre-built package for your platform. See Installation.
Define your federation
Create JSON configuration files for each federate, specifying publications, subscriptions, and timing. See Configuration.
Run the co-simulation
Launch a broker and your federates. HELICS handles time synchronization and data routing automatically. See Quickstart.
HELICS is developed by the Grid Modernization Laboratory Consortium (GMLC) with support from the U.S. Department of Energy. It is open source under the BSD-3-Clause license.