OHM-MCP

AI-Powered Python Refactoring & Code Quality Assistant

Works with GitHub Copilot, Cursor IDE, Cline, and any MCP-compatible AI assistant.

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✨ Core Capabilities

🏗️ Architecture

• God Object Detection
• SOLID Violation Analysis
• Design Pattern Suggestions
• Dependency Injection Refactoring

🔧 Code Quality

• AST Extract Method (100% accurate)
• Dead Code Elimination
• Import Refactoring
• Symbol Renaming (project-wide)
• Duplication Detection

📊 Type Safety

• Type Coverage Analysis
• Type Stub Generation
• Auto Test Generation

⚡ Performance

• O(n²) Pattern Detection
• Hotspot Analysis
• Coverage-Driven Prioritization

🤖 Automation

• Auto-Apply with Rollback
• Operation History
• Quality Dashboard

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🚀 Quick Start

Installation

📦 Recommended: NPM Method (Auto-installs dependencies)

No installation required! Use NPX to run the latest version automatically:

npx -y ohm-mcp@latest

This is the easiest way to get started. Just add the configuration to your AI assistant (see IDE Configuration below).

MCP Registry: mcp-name: io.github.Murugarajr/ohm-mcp

🐍 Alternative: PyPI Method (For local development)

Use this method when you need to:

• Develop locally with the Python package
• Use a specific Python virtual environment
• Install from source for customization

Install from PyPI:

pip install ohm-mcp

Install from source (for development):

pip install -e .

IDE Configuration

📦 Option 1: NPX (Recommended - Auto-installs dependencies)

After publishing to npm:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["ohm-mcp@latest"]
    }
  }
}

For local development:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["--package", "/path/to/ohm-mcp-npm", "ohm-mcp"]
    }
  }
}

Usage:

• Open Copilot Chat
• Type # and select ohm-mcp tools
• Ask: "Analyze this file and suggest refactorings"

Global (After publishing to npm):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["-y", "ohm-mcp@latest"]
    }
  }
}

For local development:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["--package", "/path/to/ohm-mcp-npm", "ohm-mcp"]
    }
  }
}

Usage:

• Open Cursor Chat (Cmd+L / Ctrl+L)
• Tools are automatically available
• Ask: "Use ohm-mcp to detect dead code"

Global (After publishing to npm):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["-y", "ohm-mcp@latest"]
    }
  }
}

For local development:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["--package", "/path/to/ohm-mcp-npm", "ohm-mcp"]
    }
  }
}

Usage:

• Open Cline panel
• Tools are available in agent context
• Ask: "Analyze type coverage and suggest improvements"

Global (After publishing to npm):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["-y", "ohm-mcp@latest"],
      "env": {
        "PYTHONUNBUFFERED": "1"
      }
    }
  }
}

Usage:

• Tools are automatically available in Antigravity
• Ask: "Use ohm-mcp to analyze architecture"

Global (After publishing to npm):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["-y", "ohm-mcp@latest"]
    }
  }
}

Usage:

• Open Roo Code panel
• Tools are available in agent context
• Ask: "Use ohm-mcp to detect duplicates"

Configuration (config.toml):

[mcp_servers.ohm-mcp]
args = ["-y", "ohm-mcp@latest"]
command = "npx"

Usage:

• Open Codex panel
• Tools are automatically available
• Ask: "Use ohm-mcp to suggest design patterns"

Local (For local development with virtual environment):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "/Users/username/project/venv/bin/python",
      "args": ["-m", "ohm_mcp.server"],
      "disabled": false,
      "alwaysAllow": []
    }
  }
}

Global (After publishing to npm):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "npx",
      "args": ["-y", "ohm-mcp@latest"]
    }
  }
}

Usage:

• Open Kilo Code panel
• Tools are available in agent context
• Ask: "Use ohm-mcp for refactoring"

🐍 Option 2: Direct Python (Manual setup)

First install: pip install ohm-mcp

Then add to .vscode/mcp.json:

{
  "servers": {
    "ohm-mcp": {
      "command": "python",
      "args": ["-m", "ohm_mcp.server"]
    }
  },
  "inputs": []
}

Usage:

• Open Copilot Chat
• Type # and select ohm-mcp tools
• Ask: "Analyze this file and suggest refactorings"

First install: pip install ohm-mcp

Then add to Cursor's MCP settings file (.cursorrules or MCP config):

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "python",
      "args": ["-m", "ohm_mcp.server"]
    }
  },
  "inputs": []
}

Example with virtual environment:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "/Users/username/projects/venv/bin/python",
      "args": ["-m", "ohm_mcp.server"]
    }
  }
}

Usage:

• Open Cursor Chat (Cmd+L / Ctrl+L)
• Tools are automatically available
• Ask: "Use ohm-mcp to detect dead code"

First install: pip install ohm-mcp

Then add to Cline's MCP settings:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "python",
      "args": ["-m", "ohm_mcp.server"]
    }
  }
}

Example with virtual environment:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "/Users/username/projects/venv/bin/python",
      "args": ["-m", "ohm_mcp.server"]
    }
  }
}

Note: Cline requires absolute paths for both command and cwd.

Usage:

• Open Cline panel
• Tools are available in agent context
• Ask: "Analyze type coverage and suggest improvements"

Any MCP-compatible client can use this server. General configuration:

{
  "mcpServers": {
    "ohm-mcp": {
      "command": "<python-interpreter-path>",
      "args": ["<path-to-mcp_server.py>"],
      "cwd": "<project-directory>"
    }
  }
}

Finding your Python path:

# Unix/Mac
which python
# or
which python3

# Windows
where python

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💡 Quick Usage Examples

Once configured, simply reference tools in your AI assistant chat using the format: use #ohm-mcp.tool_name on the current file or @file_name.py

🗑️ Find Dead Code

Use #ohm-mcp.detect_dead_code on @utils.py

This will detect:

• ✅ Unused imports (import statements never referenced)
• ✅ Unused variables (assigned but never read)
• ✅ Unreachable code (after return/raise/break/continue)
• ✅ Unused functions (defined but never called)
• ✅ Shadowed variables (inner scope hides outer scope variable)

📋 Code Duplication Detection

Use #ohm-mcp.detect_code_duplicates to find duplicates in /path/to/project

Finds:

• ✅ Exact duplicates (100% identical code blocks)
• ✅ Near duplicates (90%+ similarity)
• ✅ Duplicate functions (same structure, different names)
• ✅ Provides refactoring suggestions to eliminate duplication

🏗️ Architecture Analysis

Analyze architecture of @my_module.py using #ohm-mcp.analyze_architecture

Detects:

• ✅ God Objects (classes doing too much)
• ✅ SOLID principle violations
• ✅ Circular dependencies
• ✅ High coupling issues

✂️ Extract Method Refactoring

Use #ohm-mcp.extract_method_ast to extract lines 45-60 from @handler.py into a new function called "process_request"

Automatically:

• ✅ Detects required parameters
• ✅ Identifies return values
• ✅ Generates refactored code
• ✅ Creates unified diff patch

🔄 Safe Symbol Renaming

Use #ohm-mcp.rename_symbol to rename "old_function_name" to "new_function_name" in /path/to/project

Features:

• ✅ AST-based (100% accurate)
• ✅ Detects naming conflicts
• ✅ Shows all occurrences before applying
• ✅ Updates docstrings and comments

📊 Type Coverage Analysis

Analyze type hints in @module.py using #ohm-mcp.analyze_type_hints

Provides:

• ✅ Coverage percentage and grade
• ✅ Functions missing type hints
• ✅ Suggested type annotations
• ✅ Migration plan with priorities

⚡ Performance Optimization

Use #ohm-mcp.analyze_performance on @slow_module.py

Detects:

• ✅ Nested loops (O(n²) complexity)
• ✅ Quadratic list operations
• ✅ Repeated function calls (missing caching)
• ✅ Mutable default arguments
• ✅ Inefficient string concatenation

🧪 Auto-Generate Tests

Generate tests for @calculator.py using #ohm-mcp.generate_characterization_tests

Creates:

• ✅ Happy path test cases
• ✅ Edge cases (None, zero, negative, empty)
• ✅ Ready-to-run pytest code
• ✅ Preserves current behavior before refactoring

🎨 Design Pattern Suggestions

Suggest design patterns for @legacy_code.py using #ohm-mcp.suggest_design_patterns

Recommends:

• ✅ Strategy pattern for long if/elif chains
• ✅ Factory pattern for repetitive object creation
• ✅ Observer pattern for callback hell
• ✅ Decorator pattern for cross-cutting concerns

🔧 Import Refactoring

Use #ohm-mcp.refactor_imports to update all files in /path/to/project from "old.module" to "new.module"

Handles:

• ✅ Direct imports (import old.module)
• ✅ From imports (from old.module import X)
• ✅ Submodule imports
• ✅ Import aliases

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🎯 Key Tools (30 Total)

Tool	Purpose	Output
analyze_codebase	Comprehensive code analysis	Issues + refactoring plan
propose_function_refactor	Function-level refactor planning	Detailed refactor proposal
explain_refactoring	Explain refactoring patterns	Educational guidance
create_refactor_patch	Generate unified diff patches	Patch file

Tool	Purpose	Output
analyze_architecture	Detect God Objects, SOLID violations	Detailed issue report
suggest_design_patterns	Recommend patterns (Strategy, Factory, Observer)	Pattern suggestions + examples
analyze_tight_coupling	Find coupling issues	DI recommendations
suggest_di_refactor	Generate DI code	Before/after refactor

Tool	Purpose	Key Feature
extract_method_ast	Extract code into function	100% AST-based accuracy
suggest_extractable_methods	Find extractable blocks	Cohesion scoring
detect_dead_code	Find unused code	5 types of dead code
refactor_imports	Update imports project-wide	Safe module renaming
refactor_single_file_imports	Refactor imports in one file	Single file focus
analyze_wildcard_imports	Find wildcard imports	Explicit replacements
rename_symbol	Rename across codebase	Conflict detection
detect_code_duplicates	Find DRY violations	Exact + near duplicates
extract_function_code	Extract single function code	Code extraction utility
apply_function_refactor	Apply function-level refactor	Direct code modification

Example - Extract Method:

# Input: Lines 45-60
result = extract_method_ast(code, 45, 60, "calculate_total")

# Output: Refactored code + patch + auto-detected params/returns

Tool	Purpose	Benefit
analyze_type_hints	Check type coverage	Migration plan
generate_type_stub	Create .pyi files	Gradual typing
generate_characterization_tests	Auto-generate tests	Safe refactoring
generate_test_for_function	Single function tests	Targeted testing
suggest_tests	Suggest test strategies	Test planning

Tool	Purpose	Detects
analyze_performance	Find bottlenecks	Nested loops, mutable defaults, O(n²)
prioritize_by_coverage	Risk-based prioritization	High-risk uncovered code

graph LR
    A[apply_refactoring] --> B{Dry Run?}
    B -->|Yes| C[Show Preview]
    B -->|No| D[Create Backup]
    D --> E[Apply Changes]
    E --> F{Run Tests}
    F -->|Pass| G[Success]
    F -->|Fail| H[Auto Rollback]
    H --> I[rollback_refactoring]

Tool	Purpose
apply_refactoring	Auto-apply refactoring with safety checks
rollback_refactoring	Rollback previous refactoring
show_refactoring_history	View refactoring audit trail
cleanup_old_backups	Clean up old backup files

Features:

• ✅ Automatic backup before changes
• ✅ Test execution validation
• ✅ Auto-rollback on failure
• ✅ Full audit trail with history
• ✅ Automatic backup cleanup

generate_quality_report - Comprehensive dashboard in HTML/Markdown/JSON

Output Preview:

📊 Health Score: 85/100 (Good)
📁 Files: 47 | Lines: 12,450 | Tech Debt: 23 pts

📊 Type Coverage: 67%
🗑️ Dead Code: 8 imports, 12 variables, 3 functions
⚡ Performance: 4 nested loops, 2 mutable defaults
📋 Duplication: 3 exact, 5 near-duplicates

Visual Dashboard:

• 🎨 Circular health gauge
• 📊 Color-coded metrics (🟢🟡🔴)
• 📈 Trend tracking ready
• 🔗 CI/CD integration (JSON export)

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💡 Common Workflows

1️⃣ Safe Refactoring

generate_characterization_tests → pytest → extract_method_ast → pytest

2️⃣ Eliminate Duplication

detect_code_duplicates → review suggestions → extract_method_ast

3️⃣ Type Migration

analyze_type_hints → follow migration plan → generate_type_stub

4️⃣ Performance Optimization

analyze_performance → prioritize_by_coverage → apply fixes

5️⃣ Module Refactoring

refactor_imports(old="myapp.old", new="myapp.new") → review patches

6️⃣ Symbol Renaming

rename_symbol(old="calc", new="calculate", preview_only=True) → apply

7️⃣ Quality Tracking

generate_quality_report(format="html") → open dashboard → track trends

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🎨 Visual Examples

Quality Dashboard Preview

┌─────────────────────────────────────────────┐
│  🔍 Code Quality Dashboard                  │
├─────────────────────────────────────────────┤
│                                             │
│       ╭─────────╮     📁 Overview           │
│       │   85    │     Files: 47             │
│       │  /100   │     Lines: 12,450         │
│       ╰─────────╯     Tech Debt: 23         │
│     Health Score                            │
│                                             │
├─────────────────────────────────────────────┤
│  📊 Type Coverage       ⚡ Performance       │
│  ████████░░ 67%         🔴 4 nested loops   │
│  120/180 typed          🟡 2 mutable args   │
├─────────────────────────────────────────────┤
│  🗑️ Dead Code           📋 Duplication      │
│  8 imports              3 exact             │
│  12 variables           5 near              │
│  3 functions                                │
└─────────────────────────────────────────────┘

Symbol Rename Preview

# Before
- def calc(x, y):
-     return x + y
- result = calc(5, 3)

# After
+ def calculate_sum(x, y):
+     return x + y
+ result = calculate_sum(5, 3)

✅ 1 function renamed
✅ 3 call sites updated
✅ 0 conflicts detected

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🧠 Design Principles

Principle	Implementation
🧪 Test-First	Auto-generate characterization tests before refactoring
↩️ Reversible	Every change = backup + rollback capability
🎯 AST-Driven	100% accurate (no regex)
📊 Risk-Aware	Coverage + complexity = prioritization
🏛️ SOLID	Detect violations + concrete fixes
🚫 No Blindness	Analyze → Plan → Validate

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🔌 IDE Compatibility

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📊 Comparison

Feature	OHM MCP	Traditional Tools
Accuracy	100% AST	~70% Regex
Safety	Auto backup/rollback	Manual
Testing	Auto-generates	Manual
Automation	Full	Suggestions only
Dashboard	HTML/JSON/MD	Text logs
IDE Support	Copilot/Cursor/Cline	Limited

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🎯 Use Cases

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📈 Metrics

✅ 30 MCP Tools
✅ 40+ Static Checks
✅ 100% AST Accuracy
✅ Zero Regex Patterns
✅ Automated Execution with Rollback
✅ Beautiful Dashboards (HTML/JSON/MD)
✅ Universal MCP Compatibility
✅ Safe Refactoring with Auto-Backup

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🛠️ Troubleshooting

1. Verify Python path:

   which python  # Unix/Mac
   where python  # Windows
   

2. Test MCP server directly:

   python -m ohm_mcp.server
   

3. Check logs:

   • VS Code: Check Output panel
   • Cursor: Check Cursor logs
   • Cline: Check Cline settings panel

4. Common issues:

   • ❌ Relative paths in command → Use absolute paths
   • ❌ Missing virtual environment → Activate venv first
   • ❌ Wrong cwd for Cline → Must be absolute path

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🤝 Contributing

Run before submitting:

./static_analyser.sh  # Runs ruff, mypy, pylint, flake8
pytest                 # All tests must pass

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🙏 Credits

Built with Model Context Protocol • Python AST • Compatible with GitHub Copilot, Cursor IDE, Cline

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Made with ❤️ for better code quality

⭐ Star this repo if it helps you write cleaner code!

Documentation