Node definition¶

A node definition describes a node class: its pins, how the editor presents it, and — for GPU nodes — what it runs. One file may define several node classes.

Definitions live in Nodes/*.nosnode and are discovered automatically. Do not list them in the manifest.

Structure¶

{
  "nodes": [
    {
      "class_name": "PrintFloat",
      "menu_info": { "...": "how the editor presents it" },
      "node":      { "...": "what it is" }
    }
  ],
  "schema_version": "1.4-v1"
}

The split is deliberate: menu_info is editor presentation, node is the class itself.

Complete example¶

Nodes/LLMGenerate.nosnode

{
    "nodes": [
        {
            "class_name": "LLMGenerate",
            "menu_info": {
                "category": "AI",
                "display_name": "LLM Generate"
            },
            "node": {
                "class_name": "LLMGenerate",
                "contents_type": "Job",
                "description": "Loads a GGUF model and generates a completion for the given prompt.",
                "pins": [
                    {
                        "name": "ModelPath",
                        "type_name": "string",
                        "show_as": "PROPERTY",
                        "can_show_as": "INPUT_PIN_OR_PROPERTY",
                        "visualizers": [
                            {
                                "type": "FILE_PICKER",
                                "file_extensions": ["gguf"],
                                "file_picker_type": "OPEN"
                            }
                        ]
                    },
                    {
                        "name": "Temperature",
                        "type_name": "float",
                        "show_as": "PROPERTY",
                        "can_show_as": "INPUT_PIN_OR_PROPERTY",
                        "data": 0.7
                    },
                    {
                        "name": "Output",
                        "type_name": "string",
                        "show_as": "OUTPUT_PIN",
                        "can_show_as": "OUTPUT_PIN_ONLY"
                    }
                ]
            }
        }
    ],
    "schema_version": "1.4-v1"
}

Node entry¶

class_name — string, required

The node class name. If it is not already prefixed with the owning module's name, the module name is prepended when the definition is loaded, so LLMGenerate in nos.llm becomes nos.llm.LLMGenerate.

This is the name that must match NOS_BIND_NODE_CLASS, fully qualified.

menu_info — object

Editor presentation. See below.

node — object, required

The node class itself. See below.

presets — array

Preconfigured variants of the same class, each with its own menu_info and a params list setting pin values. This is how one generic Arithmetic class provides Add, Sub, Mul, Div and Log menu entries.

hide_in_context_menu — bool

Hide from the right-click menu. Useful on a base class that only ships presets.

`menu_info`¶

category — string: Menu category. Nest with |, e.g. "Math|Addition".
display_name — string: Name shown in the editor.
name_aliases — array of strings: Extra search terms. Add carries ["plus", "sum"] so that searching either finds it. Worth filling in — it is the cheapest usability improvement available to a node author.
hide_in_context_menu — bool: Hide from the right-click menu.

`node`¶

contents_type — string, required

"Job" for a node that does work, "Graph" for one containing a subgraph.

class_name — string

Class name, repeated. Conventionally present.

display_name — string

Overrides the display name for this class.

description — string

Description shown in the editor.

always_execute — bool, default false

Execute every frame even when no input is dirty.

Leave it false for pure transformations. Set it true for time-varying sources, per-frame side effects or edge detection, threaded sources, and functions that mutate internal state without writing to a pin. Note that SetPinValue on an input pin dirties the node on its own, so a callable function usually does not need this.

pins — array

Pin definitions. See below.

functions — array

Callable functions — the buttons on a node. Each entry is shaped like a node: class_name, contents_type, optional contents and pins. Bind them from a static GetFunctions on the context struct; see Plugin API.

contents — object

What the node runs, for nodes not implemented in your plugin's C++.

"contents": {
  "type": "nos.sys.vulkan.GPUNode",
  "options": {
    "shader": "../Shaders/ColorCorrect.hlsl",
    "stage": "FRAGMENT"
  }
}

type is nos.sys.vulkan.GPUNode for a shader node or nos.py.PythonNode for a Python node. The shader path is relative to the manifest, not to this file. stage is FRAGMENT or COMPUTE. If the file extension is not .spv, nos.sys.vulkan compiles it with whichever of glslc and dxc succeeds. See Write a shader-only node.

template_parameters — array

Parameters for generic node classes.

status_messages — array

Predeclared status messages.

meta_data_map — object

Free-form key/value metadata.

Pins¶

Required¶

name — string: Pin name. This is the identity used by GetPinValue(NOS_NAME("...")) and, for shader nodes, the shader parameter it binds to.
type_name — string: Data type. A built-in such as float, string, uint, bool; a module type such as nos.sys.vulkan.Texture or nos.audio.AudioPacket; nos.exe for an execution pin; or nos.Generic for a pin whose type resolves on connection. See Built-in data types.
show_as — string: Initial presentation: INPUT_PIN, OUTPUT_PIN or PROPERTY.

Presentation¶

can_show_as — string: What the user may switch it to. One of PROPERTY_ONLY, INPUT_PIN_ONLY, INPUT_PIN_OR_PROPERTY, OUTPUT_PIN_OR_PROPERTY, OUTPUT_PIN_ONLY, INPUT_OUTPUT, INPUT_OUTPUT_PROPERTY.
display_name — string: Label shown in the editor when it should differ from name. Use this rather than putting spaces in name.
description — string: Tooltip text.
pin_category — string: Groups pins into sections on the node.
advanced_property — bool: Hide behind the advanced disclosure.
readonly — bool: Display only; not user-editable.

Values¶

data — any: Current default value, in the pin's own type.
def — any: The value "reset to default" restores.
min, max — number: Range limits for numeric pins. Enforced by the editor widget.
step — number: Increment for drag and spin widgets.

Behaviour¶

live — bool

Marks the pin as live.

connection_conditions — string

Constrains what may connect. For example "!resource" on the generic Arithmetic pins rejects resource types, so an Add node cannot be handed a texture.

visualizers — array

Editor widgets for the pin.

`type`	Purpose	Extra fields
`FILE_PICKER`	File chooser	`file_extensions`, `file_picker_type` (`OPEN` / `SAVE`)
`FOLDER_PICKER`	Directory chooser
`COLOR_PICKER`	Colour swatch
`COMBO_BOX`	Dropdown	`name` of the value set
`NAMED_VALUE`	Named value from a registered set	`name`