diffscope 0.2.0

A composable code review engine for automated diff analysis
diffscope-0.2.0 is not a library.

DiffScope

A composable code review engine for automated diff analysis.

Features

  • Model Agnostic: Works with OpenAI, Anthropic Claude 4, Ollama, and any OpenAI-compatible API
  • Git Integration: Review uncommitted, staged, or branch changes directly
  • PR Reviews: Analyze and comment on GitHub pull requests
  • Smart Prompting: Advanced prompt engineering with examples, XML structure, and chain-of-thought
  • Commit Messages: AI-powered commit message suggestions following conventional commits
  • Composable Architecture: Modular components that work together
  • Plugin System: Extensible pre-analyzers and post-processors
  • Multiple Outputs: JSON, patch, or markdown formats
  • CI/CD Ready: GitHub Action, GitLab CI, and Docker support

Quick Start

Install via Homebrew (macOS/Linux)

brew tap haasonsaas/diffscope
brew install diffscope

Install from source

cargo install --git https://github.com/Haasonsaas/diffscope

Docker

docker run --rm -v $(pwd):/workspace ghcr.io/haasonsaas/diffscope:latest review --diff /workspace/pr.diff

Usage

Review a diff file

diffscope review --diff changes.diff

Review from stdin

git diff | diffscope review

Git integration

# Review uncommitted changes
diffscope git uncommitted

# Review staged changes
diffscope git staged

# Review changes from a branch
diffscope git branch main

# Suggest commit message for staged changes
diffscope git suggest

Pull Request review

# Review current PR
diffscope pr

# Review specific PR
diffscope pr --number 123

# Post comments directly to PR
diffscope pr --post-comments

Use different models

# OpenAI GPT-4
export OPENAI_API_KEY=your-openai-key
diffscope review --model gpt-4o --diff changes.diff

# Anthropic Claude
export ANTHROPIC_API_KEY=your-anthropic-key
diffscope review --model claude-3-5-sonnet-20241022 --diff changes.diff
diffscope review --model claude-3-haiku-20240307 --diff changes.diff

# Local Ollama
diffscope review --model ollama:codellama --diff changes.diff
diffscope review --model ollama:llama3.2 --diff changes.diff

Supported Models

OpenAI: gpt-4o, gpt-4-turbo, gpt-3.5-turbo

Anthropic:

  • Claude 4: claude-opus-4-20250514, claude-sonnet-4-20250514
  • Claude 3.5: claude-3-5-sonnet-20241022, claude-3-5-haiku-20240307
  • Claude 3: claude-3-opus-20240229, claude-3-haiku-20240307

Ollama: Any locally installed model (codellama, llama3.2, mistral, etc.)

Output formats

# JSON (default)
diffscope review --diff changes.diff --output-format json

# Markdown
diffscope review --diff changes.diff --output-format markdown > review.md

# Patch comments
diffscope review --diff changes.diff --output-format patch

GitHub Action

name: Code Review
on: [pull_request]

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: haasonsaas/diffscope@v1
        with:
          model: gpt-4o
          openai-api-key: ${{ secrets.OPENAI_API_KEY }}

Configuration

Create a .diffscope.yml file in your repository:

model: gpt-4o
temperature: 0.2
max_tokens: 4000
system_prompt: |
  You are an expert code reviewer. Focus on:
  - Security vulnerabilities
  - Performance issues
  - Best practices
  - Code clarity

Plugin Development

Create custom analyzers:

export interface PreAnalyzer {
  id: string
  run(diff: UnifiedDiff, repoPath: string): Promise<LLMContextChunk[]>
}

export interface PostProcessor {
  id: string
  run(comments: Comment[], repoPath: string): Promise<Comment[]>
}

Architecture

graph LR
  A[git diff] --> B(core-engine)
  subgraph core-engine
    B1[Diff Parser]
    B2[Context Fetcher]
    B3[Prompt Builder]
    B4[LLM Adapter]
    B5[Comment Synthesizer]
  end
  B -->|JSON| C(output)

License

Apache-2.0 License. See LICENSE for details.

Example Output

Code Review

Line 32: Security - Logging raw input data may expose sensitive information. 
Risk of data leakage. Remove or sanitize before logging.

Line 14: Bug - TODO indicates missing error handling. Could cause crashes. 
Implement proper error handling.

Commit Message Suggestion

feat(auth): add JWT-based authentication system

Author

Jonathan Haas jonathan@haas.holdings

Contributing

Contributions are welcome! Please open an issue first to discuss what you would like to change.

Support