Manifest Reference

Every mold is described by a moldo.json file. This document is a complete field-by-field reference.

---

Top-level fields

{
  "name": "webscraper",
  "displayName": "Web Scraper",
  "version": "1.0.0",
  "description": "Fetch and extract content from web pages",
  "author": "Your Name",
  "moldoMinVersion": "0.5.0",
  "isCore": false,
  "blocks": [ ... ]
}

Field	Type	Required	Description
name	string	yes	Machine identifier - lowercase, no spaces, no hyphens. Used as the import name for your Python package.
displayName	string	yes	Human-readable name shown in the sidebar group header.
version	string	yes	SemVer string - "1.0.0".
description	string	yes	One-line description shown on hover.
author	string	yes	Your name or organisation.
moldoMinVersion	string	yes	The minimum Moldo version your mold requires. Use "0.5.0" for now.
isCore	boolean	yes	false for all community molds.
blocks	array	yes	One entry per block type.

---

Block fields

{
  "id": "fetch",
  "name": "Fetch Page",
  "description": "Download text from a URL",
  "nodeType": "process",
  "nodeShape": "rect",
  "color": "#f97316",
  "icon": "globe",
  "hasBranches": false,
  "hasBody": false,
  "inputs": [ ... ],
  "outputs": [ ... ],
  "pythonCall": "webscraper.fetch_page"
}

Field	Type	Required	Description
id	string	yes	Block identifier within this mold - unique per mold.
name	string	yes	Block label shown in the sidebar and on the node.
description	string	yes	Tooltip shown when hovering in the sidebar.
nodeType	string	yes	Semantic type - see below.
nodeShape	string	yes	Visual shape - see below.
color	string	yes	Hex colour for the node accent bar ("#f97316").
icon	string	no	Icon identifier (Bootstrap Icons name or short alias).
hasBranches	boolean	no	true for decision/if nodes - canvas draws true/false ports.
hasBody	boolean	no	true for loop and function-definition nodes - canvas draws a body port.
inputs	array	yes	Form fields shown in the settings panel.
outputs	array	no	Output variable slots.
pythonCall	string	community molds only	Dotted path to your Python callable: "package.function".

nodeType values

Value	Meaning
process	Transforms data - one input port, one output port
decision	Branches on a condition - needs hasBranches: true
output	Produces visible output (print, draw, etc.)
loop	Repeats a body - needs hasBody: true
input	Reads from the user

nodeShape values

Value	Visual
rect	Rectangle with left accent bar (default)
diamond	Rotated square - use for decision nodes
circle	Round pill - use for return / terminal nodes

---

Input field schema

{
  "id": "url",
  "label": "URL",
  "type": "variable",
  "placeholder": "@myUrl",
  "options": []
}

Field	Type	Required	Description
id	string	yes	Parameter key - passed to your Python function by name.
label	string	yes	Label shown above the field in the settings panel.
type	string	yes	Field type - see below.
placeholder	string	no	Placeholder text.
options	array	only for select	List of string options for the dropdown.

Input types

type	Renders as	Value sent to Python
text	Text input	String as typed
variable	Text input	@varName → bare identifier in compiled code
number	Number input	String (cast inside your function)
select	Dropdown	One of the options strings
checkbox	Checkbox	"true" or "false"

---

Output field schema

{
  "id": "result",
  "label": "Save result to",
  "type": "variable"
}

Outputs always have type: "variable". The user types a variable name. The compiler generates variable_name = pythonCall(...) using the return value of your function.

---

Complete example

{
  "name": "imgtools",
  "displayName": "Image Tools",
  "version": "1.0.0",
  "description": "Basic image operations using Pillow",
  "author": "Grace Peter",
  "moldoMinVersion": "0.5.0",
  "isCore": false,
  "blocks": [
    {
      "id": "resize",
      "name": "Resize Image",
      "description": "Scale an image to a new width and height",
      "nodeType": "process",
      "nodeShape": "rect",
      "color": "#8b5cf6",
      "inputs": [
        { "id": "path", "label": "Image path", "type": "variable" },
        { "id": "width", "label": "Width (px)", "type": "number" },
        { "id": "height", "label": "Height (px)", "type": "number" }
      ],
      "outputs": [
        { "id": "result", "label": "Save path to", "type": "variable" }
      ],
      "pythonCall": "imgtools.resize"
    },
    {
      "id": "grayscale",
      "name": "Grayscale",
      "description": "Convert an image to grayscale",
      "nodeType": "process",
      "nodeShape": "rect",
      "color": "#8b5cf6",
      "inputs": [{ "id": "path", "label": "Image path", "type": "variable" }],
      "outputs": [
        { "id": "result", "label": "Save path to", "type": "variable" }
      ],
      "pythonCall": "imgtools.grayscale"
    }
  ]
}