gptdiff 0.1.3

A tool to generate and apply git diffs using LLMs

GPTDiff

🚀 AI-Powered Code Evolution - Transform your codebase with natural language instructions

cd myproject
gptdiff 'add hover effects to the buttons'

Generates a prompt.txt file that you can copy and paste into a large context gpt to have a conversation with suggested changes. You can also invoke the API and try to directly apply the patch using a smartapply if the git apply fails.

Value Proposition

gptdiff "Update the readme with an api section" --apply

Patch applied successfully.

Why GPTDiff?

• Understands Your Code - Describe changes in plain English
• Safe Modifications - Keeps existing code working
• Auto-Fix - --apply fixes mistakes in generated changes
• Works Instantly - No complex setup needed
• Whole Project View - Handles multiple files together

Core Capabilities

⚡ CLI Excellence

• Target Specific Files - Change just what you need
• Live Updates - See changes as they're made
• Try Before Applying - Test changes safely first
• Clear Pricing - Know costs upfront
• Preview Changes - See what will change with --call
• Fix Mistakes - Automatic error correction

✨ Magic Diff Generation

gptdiff "Convert class components to React hooks" --model deepseek-reasoner

• Full project context awareness
• Cross-file refactoring support
• Automatic conflict prevention

🧠 Smart Apply System

Git-native Workflow:

# 1. Apply AI-generated changes
gptdiff "Improve error handling" --apply

# 2. Review each change interactively
git add -p

# 3. Commit or discard
git commit -m "Enhanced error handling"
git reset --hard  # To undo all changes

gptdiff "Refactor authentication to use OAuth 2.0" --apply

✅ Successfully applied complex changes across 5 files

Get Started

Installation

Requires Python 3.8+. Install from PyPI:

pip install gptdiff
pip install tiktoken  # For token counting

Development install (no pip package yet)

python setup.py install

Configuration

First sign up for an API key at https://nano-gpt.com/api and generate your key. Then configure your environment:

Linux/MacOS

export GPTDIFF_LLM_API_KEY='your-api-key'
# Optional: For switching API providers
export GPTDIFF_MODEL='deepseek-reasoner'  # Set default model for all commands
export GPTDIFF_LLM_BASE_URL='https://nano-gpt.com/api/v1/

Windows

set GPTDIFF_LLM_API_KEY=your-api-key
rem Optional: For switching API providers 
set GPTDIFF_MODEL=deepseek-reasoner
set GPTDIFF_LLM_BASE_URL=https://nano-gpt.com/api/v1/

The default base URL points to nano-gpt.com's API. Supported models can be specified with:

gptdiff 'your prompt' --model deepseek-reasoner
# Default model can be set via GPTDIFF_MODEL environment variable

OpenAI will not be called unless you specify --call or --apply

Prevent files being appended to the prompt by adding them to .gitignore or .gptignore

Command Line Usage

After installing the package, you can use the gptdiff command in your terminal. cd into your codebase and run:

gptdiff '<user_prompt>'

any files that are included in .gitignore are ignored when generating prompt.txt.

Specifying Additional Files

You can specify additional files or directories to include in the prompt by adding them as arguments to the gptdiff command. If no additional files or directories are specified, the tool will default to using the current working directory.

Example usage:

gptdiff 'make this change' src test

Autopatch Changes

You can also call openai and automatically apply the generated git diff with the --apply flag:

gptdiff '<user_prompt>' --apply

Dry-Run Validation

Preview changes without applying them by omitting the --apply flag when using --call:

gptdiff "Modernize database queries" --call

ℹ️ Diff preview generated - review changes before applying

This often generates incorrect diffs that need to be manually merged.

Smart Apply

For more reliable patching of complex changes, use smartapply which processes each file's diff individually with the LLM:

gptdiff 'refactor authentication system' --apply

Completion Notification

Use the --nobeep option to disable the default completion beep:

gptdiff '<user_prompt>' --beep

Local API Documentation

Preview API docs locally using MkDocs:

pip install .[docs]
mkdocs serve

Open http://localhost:8000 to view the documentation

Python API

Integrate GPTDiff directly into your Python workflows:

from gptdiff import generate_diff, smartapply
import os

os.environ['GPTDIFF_LLM_API_KEY'] = 'your-api-key'

# Create environment representation
environment = '''
File: main.py
Content:
def old_name():
    print("Need renaming")
'''

# Generate transformation diff
diff = generate_diff(
    environment=environment,
    goal='Rename function to new_name()',
    model='deepseek-reasoner'
)

# Apply changes safely
updated_environment = smartapply(
    diff_text=diff,
    environment_str=environment
)

print("Transformed codebase:")
print(updated_environment)

Batch Processing Example:

from gptdiff import generate_diff, smartapply

files = load_your_codebase()  # Dict of {path: content}

transformations = [
    "Add python type annotations",
    "Convert string formatting to f-strings",
    "Update deprecated API calls"
]

for task in transformations:
    files = smartapply(generate_diff(build_environment(files), task), files)

Integration Note: GPTDiff leverages the AI Agent Toolbox for seamless tool usage across AI models and frameworks, making it ideal for both single responses and complex agent workflows.

Core Functions

• generate_diff(environment: str, goal: str, model: str) -> str
  Generates a git diff implementing the requested changes

  model parameter defaults to GPTDIFF_MODEL environment variable

• smartapply(diff_text: str, environment_str: str, model: str) -> str
  Applies complex diffs while preserving file context

Testing

To run the test suite:

pip install -e .[test]
pytest tests/

This will execute all unit tests verifying core diff generation and application logic.