ij - Idea Junction

Connect vague ideas and evolve them to fully functional systems

Idea Junction (ij) is a bidirectional diagramming system that enables seamless movement between natural language, visual diagrams, and code. Built on research into modern diagramming tools and best practices, it provides a foundation for transforming ideas into structured, analyzable diagrams.

Features

Phase 1 (Core) ✅

• Text-to-Diagram Conversion: Convert simple text descriptions into diagrams
• Intermediate Representation (IR): AST-like structure for bidirectional conversion
• Graph Analysis: Powered by NetworkX for path finding, cycle detection, and graph manipulation
• Mermaid Support: Full rendering support for GitHub-native diagrams
• CLI & Python API: Use as a command-line tool or integrate into your Python projects
• Type-Safe: Full type hints and validation

Phase 2 (Bidirectional & Multi-Format) ✅

• Mermaid Parser: Parse Mermaid diagrams back to IR (true bidirectional conversion)
• PlantUML Renderer: Export to PlantUML for enterprise UML diagrams
• D2 Renderer: Export to D2 (Terrastruct) for modern, beautiful diagrams
• Graphviz Renderer: Export to DOT format with multiple layout engines
• Enhanced Text Converter: Support for conditionals, parallel flows, and loops
• Format Conversion: Convert between Mermaid, PlantUML, D2, and Graphviz

Phase 3 (AI & Code Analysis) ✅

• AI/LLM Integration: Natural language to diagrams using OpenAI API (10-20x faster)
• Python Code Analysis: Reverse engineer flowcharts from Python functions
• Call Graph Generation: Visualize function dependencies
• Class Diagrams: Generate from Python classes with inheritance
• Iterative Refinement: Conversational diagram improvement with AI
• Hybrid Workflows: Combine code analysis with AI enhancement

Phase 4 (Advanced Features) ✅

• Bidirectional D2: Parse and render D2 diagrams (complete format support)
• Sequence Diagrams: Generate Mermaid sequence diagrams for interactions
• Interaction Analysis: Extract sequence diagrams from code and text
• Diagram Transformations: Simplify, filter, merge, and optimize diagrams
• Cycle Detection: Find circular dependencies and loops
• Subgraph Extraction: Extract relevant portions of large diagrams
• Multi-Format Workflows: Seamlessly convert between all supported formats
• Statistics & Analysis: Comprehensive diagram metrics and insights

Installation

pip install ij

Or install from source:

git clone https://github.com/i2mint/ij
cd ij
pip install -e .

Quick Start

Command Line

# Convert text to Mermaid diagram
ij "Start -> Process data -> Make decision -> End"

# Save to file
ij "Step 1 -> Step 2 -> Step 3" -o diagram.mmd

# Specify direction
ij "A -> B -> C" -d LR -o horizontal.mmd

# Read from file
ij -f process.txt -o output.mmd

Python API

from ij import text_to_mermaid

# Simple conversion
mermaid = text_to_mermaid("Start -> Process -> End")
print(mermaid)

Output:

flowchart TD
    n0([Start])
    n1[Process]
    n2([End])
    n0 --> n1
    n1 --> n2

Manual Diagram Creation

from ij import DiagramIR, Node, Edge, NodeType, MermaidRenderer

# Create diagram programmatically
diagram = DiagramIR(metadata={"title": "My Process"})

diagram.add_node(Node(id="start", label="Start", node_type=NodeType.START))
diagram.add_node(Node(id="process", label="Do work", node_type=NodeType.PROCESS))
diagram.add_node(Node(id="end", label="End", node_type=NodeType.END))

diagram.add_edge(Edge(source="start", target="process"))
diagram.add_edge(Edge(source="process", target="end"))

# Render to Mermaid
renderer = MermaidRenderer(direction="LR")
print(renderer.render(diagram))

Graph Analysis

from ij import DiagramIR, Node, Edge
from ij.graph_ops import GraphOperations

# Create a workflow
diagram = DiagramIR()
diagram.add_node(Node(id="a", label="Start"))
diagram.add_node(Node(id="b", label="Task 1"))
diagram.add_node(Node(id="c", label="Task 2"))
diagram.add_node(Node(id="d", label="End"))

diagram.add_edge(Edge(source="a", target="b"))
diagram.add_edge(Edge(source="b", target="c"))
diagram.add_edge(Edge(source="c", target="d"))
diagram.add_edge(Edge(source="a", target="d"))  # Shortcut path

# Find all paths
paths = GraphOperations.find_paths(diagram, "a", "d")
print(f"Found {len(paths)} paths")  # Output: Found 2 paths

# Get topological order
order = GraphOperations.topological_sort(diagram)
print(order)  # Output: ['a', 'b', 'c', 'd']

# Simplify (remove redundant edges)
simplified = GraphOperations.simplify_diagram(diagram)

Architecture

Based on comprehensive research into bidirectional diagramming systems, ij uses:

• AST-based IR: Core data structure for diagram representation
• Graph Model: NetworkX for analysis and transformation
• Extensible Renderers: Pluggable output formats (Mermaid, PlantUML, D2, etc.)
• Text-based DSL: Git-friendly, version-controllable diagram source

Natural Language → DiagramIR → Mermaid/PlantUML/D2
                      ↓
                  NetworkX Graph
                      ↓
                Analysis & Transformation

Node Types

ij supports several node types with automatic inference:

• START: Beginning of a process (stadium shape in Mermaid)
• END: End of a process (stadium shape)
• PROCESS: Processing step (rectangle)
• DECISION: Decision point (diamond)
• DATA: Data storage (cylinder)
• SUBPROCESS: Sub-process (double rectangle)

Keywords like "Start", "End", "decide", "database" automatically set the correct type.

Examples

See the examples/ directory for comprehensive usage examples:

# Phase 1: Basic features
python examples/basic_usage.py

# Phase 2: Bidirectional conversion and multiple formats
python examples/phase2_features.py

Phase 1 Examples:

• Simple text-to-diagram conversion
• Manual diagram creation
• Graph analysis (path finding, topological sort)
• Different diagram directions
• Natural language processing
• Saving diagrams to files

Phase 2 Examples:

• Bidirectional conversion (Mermaid ↔ IR)
• Multi-format rendering (Mermaid, PlantUML, D2, Graphviz)
• Enhanced text conversion with conditionals
• Parallel flows and loops
• Format conversion workflows
• Complex workflow examples

Phase 3 Examples:

• Python code → flowchart diagrams
• Call graph generation
• Class diagram generation
• AI-powered natural language → diagram
• Iterative refinement with AI
• Hybrid code + AI workflows

See PHASE2.md and PHASE3.md for complete documentation.

Viewing Diagrams

Generated Mermaid diagrams can be viewed in:

1. GitHub/GitLab - Paste in markdown files (native support)
2. Mermaid Live Editor - https://mermaid.live/
3. VS Code - Install Mermaid preview extension
4. Command line - Use mmdc (Mermaid CLI)

Example in markdown:

```mermaid
flowchart TD
    A[Start] --> B{Decision?}
    B -->|Yes| C[Process]
    B -->|No| D[Skip]
    C --> E[End]
    D --> E
```

Development

Running Tests

pip install -e ".[dev]"
pytest tests/ -v

All tests should pass:

71 passed in 1.41s

Test breakdown:

• Phase 1: 26 tests (core, renderers, converters, graph operations)
• Phase 2: 26 tests (parsers, new renderers, enhanced converter)
• Phase 3: 19 tests (AI mocks, Python analyzer, +2 optional real API tests)

Note: AI tests use mocks by default. For real OpenAI API tests:

export OPENAI_API_KEY=your-key
pytest tests/test_llm_converter.py -v  # Includes real API tests

Code Quality

# Run linter
ruff check ij/

# Format code
ruff format ij/

Roadmap

Phase 1 (Core Foundation) ✅

• Core DiagramIR architecture
• Mermaid renderer
• NetworkX integration
• CLI interface
• Basic text-to-diagram conversion
• Comprehensive tests (26 tests)

Phase 2 (Bidirectional & Multi-Format) ✅

• Mermaid parser (Mermaid → IR bidirectional)
• PlantUML renderer
• D2 renderer
• Graphviz/DOT renderer
• Enhanced text converter (conditionals, parallel, loops)
• Comprehensive tests (52 total tests)
• Multi-format examples

Phase 3 (AI & Code Analysis) ✅

• AI/LLM integration with OpenAI API
• Python code-to-diagram reverse engineering
• Function flowchart generation
• Call graph visualization
• Class diagram generation
• Iterative refinement with AI
• Comprehensive tests (71 total tests, including AI mocks)
• Optional real API tests

Phase 4 (Future)

• Visual editor integration
• Real-time collaboration (CRDT-based)
• Java/JavaScript code analysis
• Additional parsers (PlantUML, D2 → IR)
• Web-based interactive editor
• Local LLM support (Ollama, etc.)
• Sequence diagram generation

Research Foundation

This project is built on comprehensive research into:

• Diagram-as-code languages (Mermaid, PlantUML, D2, Graphviz)
• Python libraries (NetworkX, diagrams, graphviz)
• JavaScript frameworks (React Flow, Cytoscape.js)
• Bidirectional editing patterns
• AI-powered generation
• Technical architecture patterns

See misc/REASEARCH.md for the full research report.

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Ensure all tests pass
5. Submit a pull request

License

MIT License - see LICENSE file for details

Links

• Repository: https://github.com/i2mint/ij
• Issues: https://github.com/i2mint/ij/issues
• Mermaid Docs: https://mermaid.js.org
• NetworkX Docs: https://networkx.org

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Idea Junction - From vague ideas to fully functional systems