codewrench 0.1.3

A multi-language code performance analyser with static analysis and AI-powered fix generation.

🔧 codewrench

Point it at your code. Get back what's slow and how to fix it.

Codewrench is a multi-language performance analyser that combines static analysis with AI-powered explanations. It finds real performance issues in your code — nested loops, inefficient patterns, bad practices — then explains exactly why they're a problem and shows you the fix.

No cloud, no setup hell, no enterprise pricing. Just run it on a file.

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Installation

pip install codewrench

Create a .env file in your project root:

GROQ_API_KEY=your_key_here

Get a free Groq API key at console.groq.com

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Usage

codewrench yourfile.py
codewrench app.js
codewrench main.go
codewrench ./myproject

Codewrench detects the language from the file extension automatically. Point it at a folder and it walks the entire project.

Example output

========================================
         CODEWRENCH REPORT
========================================
Files Scanned  : 1
Languages      : python
Issues Found   : 8 across 1 files
========================================

--- Warnings ---
  Nested loop at line 19 — potential O(n²)
  String concatenation at line 22 — use ''.join() instead
  re.compile() inside loop at line 31 — move it outside, compile once and reuse
  Bare except at line 40 — catches everything, be specific

Top 5 slowest functions BEFORE fix:
  process_data                   cumtime: 2.341s
  build_string                   cumtime: 0.812s

Top 5 slowest functions AFTER fix:
  process_data                   cumtime: 0.421s
  build_string                   cumtime: 0.109s

Want AI analysis? (y/n): y

--- AI Analysis ---

1. Nested loop at line 19
   Problem: Two nested loops over the same data gives you O(n²) complexity.
   For 1000 items that's 1,000,000 iterations instead of 1,000.

Want to apply fixes to files? (y/n): y
  Original saved as yourfile.py.bak
  Fixes applied to yourfile.py

Save report? (y/n): y
  Report saved to codewrench_report.md

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What it catches

High priority

• Nested loops — O(n²) and worse
• Expensive I/O calls inside loops (open, requests, etc.)
• re.compile() inside loops — compile once, reuse
• print() / logging inside loops — I/O on every iteration
• await inside loops — use asyncio.gather() or Promise.all()
• Repeated attribute access that should be cached
• String concatenation with += in loops
• String concatenation in nested loops — quadratic complexity
• Unnecessary object creation in loops (dict(), list(), etc.)

Medium priority

• List concat with + instead of .extend()
• List appends inside nested loops
• Unnecessary list(range(n)) creation
• Bare except: and overly broad except Exception
• try/except inside loops
• Global variable access inside loops
• Mutable default arguments
• Import inside functions
• len() calls inside loops

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Supported languages

Language	Extension
Python	.py
JavaScript	.js
TypeScript	.ts
Go	.go
C	.c
C++	.cpp, .cc

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.wrenchignore

Create a .wrenchignore file in your project root to skip files or folders:

migrations/
tests/
legacy_code.py
*.min.js

Works like .gitignore — supports wildcards and directory patterns.

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How it works

your file
    ↓
Tree-sitter parses it into a syntax tree
    ↓
IR translator converts to language-agnostic representation
    ↓
20 detectors run static analysis on the IR
    ↓
Before/after profiling (Python, Node.js, go)
    ↓
Findings sent to Groq (Llama 3.3 70B)
    ↓
Plain English explanation + fix

The static analysis layer is deterministic — it either finds a nested loop or it doesn't. No hallucination. The AI layer explains what the detectors already confirmed exists.

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Roadmap

• Static analysis (Python, JS, TS, Go, C, C++)
• AI-powered explanations and fixes
• Multi-language IR architecture
• Runtime profiling — before/after benchmark (Python)
• 20 detectors across high and medium priority
• Folder support with recursive analysis
• .wrenchignore support
• Smart API batching — one call per folder, not per file
• pip install codewrench
• Multi-language profiling (Node, Go)
• Language-specific detectors
• Git diff integration — analyse only what changed
• VS Code extension
• Web UI

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Project structure

codewrench/
├── detectors/
│   ├── base.py          ← depth tracking, core visitor
│   ├── high.py          ← high priority detectors
│   └── medium.py        ← medium priority detectors
├── languages/
│   ├── python_rules.py  ← Tree-sitter node mappings per language
│   ├── js_rules.py
│   ├── ts_rules.py
│   ├── go_rules.py
│   ├── c_rules.py
│   └── cpp_rules.py
├── profilers/
│   └── profiler.py      ← cProfile integration
├── ir.py                ← language-agnostic IR node
├── ir_translator.py     ← Tree-sitter → IR translation
├── parser_engine.py     ← language detection + parser setup
├── ai_engine.py         ← Groq integration
├── report.py            ← Layer 5 report and output
├── errors.py            ← error handling
├── wrenchignore.py      ← .wrenchignore support
└── main.py              ← entry point

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Contributing

Pull requests welcome. If you want to add a new language, add a rules file in languages/ mapping Tree-sitter node types to the generic IR types. That's it — the detectors work on all languages automatically.

Open an issue first for anything major.

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Built by Vishad Jain