String Diagram Generator MCP Server

Category-theoretic visualization of Lushy brick compositions

Overview

The String Diagram Generator is a meta-brick MCP server that generates formal string diagram visualizations of Lushy workflow compositions. It demonstrates category theory foundations through recursive self-documentation capability.

Key Features

• 🎨 Zero-cost diagram generation (0 tokens in deterministic mode)

• 🔄 Recursive capability (can diagram itself!)

• 📊 Cost analysis (visualize token usage across layers)

• ✅ Validation (catch composition errors before generation)

• 🎯 Production-ready (full test suite, comprehensive docs)

Category Theory Foundation

Graded Traced Symmetric Monoidal Category over Kleisli(LLM)

• Traced: Feedback loops for versioning and validation

• Graded: Cost tracking (Grade 0 = free, Grade 1 = LLM, Grade 2 = human)

• Symmetric Monoidal: Sequential (∘) and parallel (⊗) composition

• Over Kleisli(LLM): Probabilistic composition with reproducibility bounds

Related MCP server: Draw.io MCP Server

Quick Start

Installation

# Clone repository
git clone https://github.com/lushy/string-diagram-mcp.git
cd string-diagram-mcp

# Install with dev dependencies
pip install -e ".[dev]"

# Run tests
./tests/run_tests.sh

Usage as MCP Server

# Run locally
python src/string_diagram_mcp/server.py

# Or configure in Claude Desktop
# Add to claude_desktop_config.json:
{
  "mcpServers": {
    "string-diagram-generator": {
      "command": "python",
      "args": ["/path/to/string-diagram-mcp/src/string_diagram_mcp/server.py"]
    }
  }
}

MCP Tools

1. generate_string_diagram

Generate a string diagram from brick composition (0 tokens)

2. generate_meta_diagram

Generate diagram of the generator itself (0 tokens)

3. get_brick_layer_info

Get four-layer architecture details (0 tokens)

4. create_sample_diagram

Generate sample diagrams for demos (0 tokens)

5. validate_composition

Validate brick compositions (0 tokens)

6. get_server_info

Get server metadata (0 tokens)

Architecture

Four-Layer Structure

┌─────────────────────────────────┐
│ Layer 4: Contextual (Grade 0/1)│  SVG rendering + cost analysis
├─────────────────────────────────┤
│ Layer 3: Relational (Grade 0)  │  Wire routing & crossing detection
├─────────────────────────────────┤
│ Layer 2: Structure (Grade 0)   │  Topological layout computation
├─────────────────────────────────┤
│ Layer 1: Foundation (Grade 0)  │  Primitives & validation
└─────────────────────────────────┘

Documentation

• User Guide - Complete usage documentation

• API Reference - Tool specifications

• Architecture - Technical deep-dive

• Examples - Sample workflows and outputs

Development

# Run tests with coverage
pytest --cov=string_diagram_mcp

# Format code
black src/ tests/

# Lint
ruff check src/ tests/

# Type check (if you add type hints)
mypy src/

Cost Analysis

Typical Workflow Savings:

• 3-brick workflow: 75% savings (450 vs 1800 tokens)

• 5-brick workflow: 80% savings (800 vs 4000 tokens)

String Diagram Generator itself:

• Deterministic mode: 0 tokens

• With LLM annotations: ~200 tokens

License

MIT License - see LICENSE file

Contributing

Contributions welcome! Please see CONTRIBUTING.md

Support

• Issues: GitHub Issues

• Discussions: GitHub Discussions

• Email: support@lushy.ai