About CodeReview Bot
CodeReview Bot is an open-source GitHub Action that leverages ChatGPT to automatically review code changes in pull requests. It integrates seamlessly into GitHub workflows, providing instant feedback on code diffs when PRs are opened, reopened, or synchronized. The bot supports multiple LLM backends (OpenAI, Azure OpenAI, GitHub Models) and allows customization of review language, prompts, and model parameters. It is designed for teams and individual developers who want to automate code review, catch issues early, and improve code quality without manual effort.
Key Features
Automatically reviews code changes when pull requests are created, reopened, or synchronized
Supports multiple LLM providers: OpenAI, Azure OpenAI, and GitHub Models
Customizable review language, prompt, and model parameters (temperature, top_p, max_tokens)
Easy integration via GitHub Actions workflow file
Open-source and free to use (LLM API costs apply)
Can be deployed on AWS Lambda or self-hosted for better reliability
Pros & Cons
Pros
- Free and open-source – no licensing cost for the bot itself
- Quick and easy setup via GitHub Actions marketplace or direct workflow configuration
- Highly customizable – supports different models, languages, and prompt templates
- Works with public and private repositories
- Active community with translations and contributions
Cons
- Requires an OpenAI or compatible API key, which incurs usage costs
- GPT-based reviews may not catch domain-specific or complex logic errors reliably
- Public deployment on AWS Lambda has rate limits and stability issues (recommends self-hosting)
- Relies on external API availability; no offline capability
Best For
Automated code review for open-source projects on GitHubCatching bugs, security issues, and code style problems early in the development cycleReducing manual review workload for maintainers and teamsProviding consistent, AI-powered feedback across pull requests
FAQ
How does CodeReview Bot work?
When a pull request is opened, reopened, or synchronized, the bot analyzes the code diff using ChatGPT and posts review comments directly in the pull request timeline or file changes section.
What do I need to use this bot?
You need a GitHub repository with pull request access, an OpenAI API key (or equivalent for Azure/GitHub Models), and the necessary GitHub secrets/variables configured.
Is CodeReview Bot free?
The bot itself is free and open-source. However, you must provide your own API key for the LLM, and API usage costs apply based on your chosen model and usage volume.
Can I customize the review prompt?
Yes, you can customize the prompt, language, model parameters (e.g., temperature, top_p, max_tokens), and even switch between different LLM providers via the workflow configuration.