Project Introduction
Project Description
This quantum low-code tool enables users to model quantum algorithms combining classical and quantum logic in a visual, node-based interface.
The main components of the Low-Code Modeler:
Editor: drag-and-drop interface for modeling quantum applications using visual constructs
Validator: checks syntactic and semantic correctness of the created models
Transformer: prepares the validated model for backend processing
Connector: integrates external services into the modeling process
Template Library: provides reusable templates to accelerate development
The system interacts with the following components:
Low-Code Backend: enriches modeling constructs with corresponding OpenQASM 3 implementations, selecting or adapting them based on the required circuit width. Returns the resulting OpenQASM code to the frontend.
NISQ Analyzer: helps select suitable quantum devices and filters out backends that do not support conditional operations.
QProv: continuously collects and stores information about available quantum devices and supports the updated selection logic.
Qunicorn: executes the OpenQASM code once a suitable backend is selected.

System architecture of the quantum low-code tool.
User Interface
The modeler interface consists of several components that facilitate the creation and execution of quantum applications.
At the top of the screen is the toolbar, which provides functions such as:
New Diagram
Open
Save
Save As
Upload
Configuration
Send to Backend
Send to Qunicorn
These options enable users to manage files, configure the modeling tool, and deploy quantum applications. Tooltips and visual feedback confirm actions and enhance usability.
On the left side is the palette, offering a searchable, categorized list of modeling elements. Categories include:
Boundary Nodes
Circuit Nodes
Data Types
Control Structure Nodes
Operators
Custom Operators
Users can drag and drop elements from the palette onto the canvas. Usability features include a responsive search bar, intuitive category labels, and collapsible groups to reduce visual clutter.
The central canvas area serves as the main workspace for diagram construction. It features a grid layout to support alignment and design precision. Users can interact with the canvas using keyboard and mouse controls, including:
Zooming in and out
Resetting the view
Locking the canvas via controls located at the bottom left
Keyboard shortcuts:
Delete to remove nodes
Arrow keys for moving elements
Lasso tool (hold Shift) to select multiple nodes
Undo/Redo functionality to support editing

Modeling Constructs and Blocks
The quantum low-code tool provides modeling constructs for defining quantum applications at different levels of abstraction. In particular, quantum modeling constructs offer both higher-level abstractions and lower-level modeling blocks representing quantum gates, while supporting users across a broad spectrum of quantum computing expertise.
The constructs are organized into six categories: Data Types, Circuit-Level Nodes, Boundary Nodes, Operators, Control Structure Nodes, and Custom Nodes. Each category includes visual elements that enable users to build quantum circuits, workflows, and logic in an intuitive way.
Detailed descriptions and examples for each construct type are provided in the corresponding subsections.