Node Reference

Nodes are the fundamental building blocks of Hermes workflows. Each node performs a specific task and can receive inputs from and provide outputs to other nodes.

Node JSON Structure

Every node in a workflow has this basic structure:

{
    "NodeName": {
        "Execution": {
            "input_parameters": {
                "param1": "value1",
                "param2": "value2"
            }
        },
        "type": "category.NodeType",
        "requires": ["OtherNode"]
    }
}

Field	Description
Execution.input_parameters	Parameters that configure the node's behavior
type	Node type identifier (e.g., general.CopyDirectory)
requires	Optional explicit dependencies on other nodes
GUI	Optional FreeCAD GUI configuration

Dependencies

Dependencies between nodes are resolved in two ways:

1. Implicit — via parameter references like {NodeName.output.Field}
2. Explicit — via the requires field

Node Categories

General Nodes

Basic file operations, code execution, and template processing.

Node	Type	Description
CopyDirectory	general.CopyDirectory	Copy entire directory trees
CopyFile	general.CopyFile	Copy individual files
RunOsCommand	general.RunOsCommand	Execute shell commands
RunPythonCode	general.RunPythonCode	Execute Python code
JinjaTransform	general.JinjaTransform	Process Jinja2 templates
FilesWriter	general.FilesWriter	Write files with generated content
Parameters	general.Parameters	Define simulation parameters

OpenFOAM Nodes

Specialized nodes for OpenFOAM CFD simulation setup.

Category	Nodes	Description
Mesh	BlockMesh, SnappyHexMesh, GeometryDefiner, RefineMesh	Mesh generation
System	ControlDict, FvSchemes, FvSolution, ChangeDictionary, CreatePatch, DecomposePar, FvConstraints, MeshQualityDict, SetFields, SurfaceFeatures, TopoSetDict	Solver and case configuration
Constant	TransportProperties, TurbulenceProperties, PhysicalProperties, MomentumTransport, ThermophysicalProperties, Gravity, WindLogProfile, BuildAllrun	Physical properties and execution
Dispersion	KinematicCloudProperties, MakeFlowDispersion, Stable2018Dict, Neutral2018Dict, Convective2018Dict, IndoorDict	Particle and atmospheric dispersion
BC	Boundary Conditions	Field boundary conditions