Installation

FlowGraph runs on Node.js 18 or newer. It has no build step — the editor is served directly by a small Express backend.

Run it instantly (recommended)

The fastest way to try FlowGraph is with npx, which downloads and runs the package without a global install:

npx @kratos-flowgraph/flowgraph

Then open http://localhost:8182 in your browser.

Global install

To install the CLI permanently:

npm install -g @kratos-flowgraph/flowgraph
kratos-flowgraph

The kratos-flowgraph command starts the editor server on port 8182 (see Configuration to change it).

From source

Clone the repository if you want to modify FlowGraph or contribute:

git clone https://github.com/loumalouomega/Flowgraph.git
cd Flowgraph
npm install

Then run:

npm start        # node app.js

or, for development with auto-reload:

npm run devstart # nodemon app.js

Configuration

Configuration is provided by the config package and lives in config/default.json:

{
    "host" : "127.0.0.1",
    "port" : "8182",
    "kratos_root": "/path/to/Kratos/bin/Release",
    "working_dir": "/path/to/working_dir",
    "python_binary": "python3"
}

Key	Purpose
host / port	Address the editor server binds to.
kratos_root	Path to a local Kratos build — only needed to run simulations from the backend.
working_dir	Where the generated ProjectParameters.json is written and the run is launched.
python_binary	Python interpreter used to launch MainKratos.py.

You can switch configuration files with the NODE_ENV environment variable. For example, creating config/debug.json and running:

NODE_ENV=debug npm start

will load config/debug.json instead of config/default.json.

TIP

The editor UI itself needs no Kratos installation. kratos_root, working_dir and python_binary are only used by the optional "run simulation" backend route. You can build and export cases on any machine with Node.js.

Next: the Getting Started walkthrough.