PatternIO

A Java CLI tool that detects code smells, discovers design patterns, and generates UML class diagrams from your Java codebase, with optional AI-powered validation from 5 providers.

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Features

Feature	Description
Code smell detection	Large Class, Long Method, Feature Envy, Data Clumps, High Coupling, Low Cohesion, Duplicate Code, Long Parameter List, Unused Variables, Hardcoded Values, Cyclomatic Complexity
Design pattern recognition	All 23 GoF patterns (Behavioral, Creational, Structural) via AI analysis
UML class diagrams	Mermaid and Graphviz/DOT output with inheritance, composition & dependency relations
AI validation	Filter false positives with DeepSeek, Claude, Gemini, GPT, or Groq
Multiple output formats	Console, JSON, TXT, HTML, Mermaid, DOT
Web dashboard	Push results to patternio.dev and track project health over time
Configurable thresholds	YAML/JSON config with built-in profiles (`mvp`, `strict`, `legacy`)

Installation

Quick Install (Recommended)

One-click installers that automatically download and install PatternIO to your system PATH, just download it from the home page.

Manual Installation

Download the binary for your platform:

Platform	Download
Linux (x64)	patternio-1.0.0-linux-amd64
Linux (ARM)	patternio-1.0.0-linux-arm64
macOS (Intel)	patternio-1.0.0-darwin-amd64
macOS (Apple Silicon)	patternio-1.0.0-darwin-arm64
Windows (x64)	patternio-1.0.0-windows-amd64.exe

Then install manually:

# Linux / macOS
chmod +x patternio-*
sudo mv patternio-* /usr/local/bin/patternio

# Windows (PowerShell as Administrator)
Move-Item patternio-*.exe C:\Windows\System32\patternio.exe

# Verify
patternio --help

Usage

Analyze a project

patternio analyze --dir ./java-project

Output formats

# HTML report
patternio analyze --dir ./src --format html

# JSON for CI pipelines
patternio analyze --dir ./src --format json

# Multiple formats at once
patternio analyze --dir ./src --format html,json,txt

# Mermaid class diagram
patternio analyze --dir ./src --format mermaid

AI-powered validation

Use any of the 5 supported AI providers to filter false-positive code smells:

# DeepSeek
patternio analyze --dir ./src --ai-provider deepseek --ai-key sk-***

# Claude
patternio analyze --dir ./src --ai-provider claude --ai-key sk-ant-***

# Gemini
patternio analyze --dir ./src --ai-provider gemini --ai-key AIza***

# GPT
patternio analyze --dir ./src --ai-provider gpt --ai-key sk-***

# Groq (Llama)
patternio analyze --dir ./src --ai-provider groq --ai-key gsk_***

Or set the key as an environment variable:

export AI_API_KEY=sk-***
patternio analyze --dir ./src --ai-provider deepseek

Push results to the dashboard

patternio analyze --dir ./src \
  --api-token pio_sk_*** \
  --format html \
  --ai-provider deepseek --ai-key sk-***

Results appear on your PatternIO dashboard.

Generate UML diagrams

# Mermaid format
patternio diagram --dir ./src --diagram-format mermaid

# Graphviz DOT format
patternio diagram --dir ./src --diagram-format dot

# Split by package
patternio diagram --dir ./src --split-packages

Validate parsing

patternio validate --dir ./src

Browse the GoF pattern catalog

patternio catalog

Prints all 23 Gang of Four design patterns with descriptions, use cases, GRASP mappings, and links.

Commands

Command	Description
analyze	Run full static analysis (smells, patterns, metrics)
diagram	Generate UML class diagrams (Mermaid or DOT)
validate	Check that all Java files parse correctly
catalog	Display the 23 GoF design patterns catalog

Global flags

Flag	Default	Description
--dir	—	Root directory of Java project
--files	—	Specific `.java` files to analyze
--config	—	Config file path (YAML or JSON)
--profile	—	Analysis profile: `mvp`, `strict`, `legacy`
--format	console	Output format(s): `console`, `json`, `txt`, `html`, `mermaid`, `dot`
--output-dir	out	Output directory for reports
--filter	—	Filter by package (e.g. `pkg:com.example`)
--include	—	Include filename pattern
--exclude	—	Exclude filename pattern
--ai-provider	—	AI provider: `deepseek`, `claude`, `gemini`, `gpt`, `groq`
--ai-model	—	Override default AI model name
--ai-key	—	API key (or use env vars)

Built-in profiles

patternio analyze --dir ./src --profile strict   # tighter thresholds
patternio analyze --dir ./src --profile mvp       # relaxed for prototypes
patternio analyze --dir ./src --profile legacy    # tolerant for old codebases

Code smells detected

Smell	GRASP Principle	Metric
Long Parameter List	Information Expert	params > threshold
High Coupling (CBO)	Low Coupling	CBO > threshold
Low Cohesion (LCOM)	High Cohesion	LCOM > threshold
Large Class	Controller	methods + fields too large
Long Method	Controller	lines > threshold
Cyclomatic Complexity	Polymorphism	branches > threshold
Hardcoded Values	Protected Variations	magic numbers/strings
Duplicate Code	Pure Fabrication	repeated blocks
Unused Variables	Information Expert	declared but never read

Web dashboard

Create a free account at patternio.dev, generate an API token, then push results:

patternio analyze --dir ./src --api-token pio_sk_***

The dashboard gives you:

Analysis history — track smells and health score over time
Per-class metrics — CBO, LCOM, line counts, violation breakdowns
UML diagrams — interactive Mermaid class diagrams
AI suggestions — GoF pattern recommendations with confidence scores
Team sharing — share analysis results across your team