PyCFAST

PyCFAST is a Python interface for the Consolidated Fire and Smoke Transport (CFAST) fire simulation software. Its primary goal is to automate CFAST calculations at scale, run parametric studies, sensitivity analyses, data generation, or optimization loops that would be impractical through the graphical interface. It also provides a convenient way to create CFAST input files, execute simulations, and analyze results using the versatility and extensive ecosystem of Python.

From CEdit GUI to Python

PyCFAST can be seen as an alternative to the CEdit graphical interface. It exposes Python objects with rich interactive representations that integrate naturally into your Python workflow. Instead of relying on static input files, you define and manipulate CFAST models programmatically.

CEdit (GUI)	PyCFAST (Python)
	from pycfast import Compartments room = Compartments( id="Comp 1", width=10.0, depth=10.0, height=10.0, ceiling_mat_id="Gypboard", wall_mat_id="Gypboard", floor_mat_id="Gypboard", ) room # displays interactive HTML card

Every PyCFAST object such as compartments, fires, vents, devices, materials can render as an interactive HTML card when displayed in Jupyter notebooks or VS Code notebooks. These cards provide a visual summary of the component's properties and can be expanded to show more details.:

The complete model overview displays all components at a glance with expandable details:

Example Usage

You can define your own CFAST model directly in python by importing the required classes.

from pycfast import (
    CeilingFloorVents,
    CFASTModel,
    Compartments,
    Fires,
    MaterialProperties,
    MechanicalVents,
    SimulationEnvironment,
    WallVents,
)

simulation_environment = SimulationEnvironment(...)
material_properties = [MaterialProperties(...)]
compartments = [Compartments(...)]
wall_vents = [WallVents(...)]
ceiling_floor_vents = [CeilingFloorVents(...)]
mechanical_vents = [MechanicalVents(...)]
fires = [Fires(...)]

model = CFASTModel(
    simulation_environment=simulation_environment,
    material_properties=material_properties,
    compartments=compartments,
    wall_vents=wall_vents,
    ceiling_floor_vents=ceiling_floor_vents,
    mechanical_vents=mechanical_vents,
    fires=fires,
    file_name="test_simulation.in",
    cfast_exe="/path/to/cfast_executable",
    extra_arguments=["-f"],
)

results = model.run()
# results is a dict of pandas DataFrames for each output CSV file

Or you can import your existing model from a CFAST input file:

from pycfast.parsers import parse_cfast_file

model = parse_cfast_file("existing_model.in")

Note: When importing an existing model, ensure that all component names (such as TITLE, MATERIAL, ID, etc.) use only alphanumeric characters. Avoid special characters like quotes and slashes, as these may cause parsing issues and will be automatically sanitized where possible.

You can inspect any model interactively (displays the HTML card shown above), or use text-based methods:

model             # interactive HTML card in Jupyter/VS Code
model.summary()   # text summary to stdout
model.save()      # writes the CFAST input file to disk
model.view_cfast_input_file()  # view the generated input file

With this library you can easily obtain a similar data generation workflow as below:

pycfast-demo.mp4

Check out the examples for more usage scenarios.

Installation

PyCFAST requires Python 3.10 or later. It is fully tested on verification input file with CFAST 7.7.5 and is expected to be compatible with all CFAST 7.7.x versions.

Pip or Conda

PyCFAST can be installed from PyPI or conda-forge:

pip install pycfast

conda install -c conda-forge pycfast

Source

To install PyCFAST from source, clone the repository and install the required dependencies:

git clone https://github.com/bewygs/pycfast.git
cd pycfast
python -m pip install .

CFAST Installation

Download and install CFAST from the NIST CFAST website or the CFAST GitHub repository. Follow the installation instructions for your operating system and ensure cfast is available in your PATH. If CFAST is installed in a non-standard location, you can manually specify the path with these methods :

• From an environment variable CFAST:

  export CFAST="/path/to/your/cfast/executable"  # Linux/MacOS
  set CFAST="C:\path\to\your\cfast\executable"  # Windows (cmd)
  $env:CFAST="C:\path\to\your\cfast\executable"  # Windows (PowerShell)

• From Python code when defining the CFASTModel:

  import pycfast
  
  # set custom CFAST executable path via environment variable
  import os
  os.environ['CFAST'] = "/path/to/your/cfast/executable"
  
  # Or directly when defining CFASTModel
  model = pycfast.CFASTModel(cfast_path="/path/to/your/cfast/executable")

Documentation

Full documentation, including the API reference and examples, is available online: PyCFAST Documentation

Examples

Some examples on how to use PyCFAST with various python libraries (Numpy, SciPy, SAlib, etc.) can be found in the examples.

Contributing

We welcome contributions! Please see our Contributing Guide for more information.

References

If you use PyCFAST in your projects, please consider citing the following:

@software{wygas_2026_pycfast,
  author    = {Wygas, Benoît},
  title     = {PyCFAST},
  year      = {2026},
  publisher = {Zenodo},
  version   = {v0.1.1},
  doi       = {10.5281/zenodo.18703352},
  url       = {https://doi.org/10.5281/zenodo.18703352}
}

Acknowledgments

This Python package was developed with the support of Orano.

PyCFAST is built on top of the work of the CFAST development team at the National Institute of Standards and Technology (NIST). We acknowledge their ongoing efforts in maintaining and improving the CFAST fire modeling software.