Review Comment Generator for GitHub PRs

This agentic workflow automates the process of generating a code review comment for a GitHub pull request based on predefined guidelines. It retrieves the pull request details, analyzes the code changes, and formats a structured comment that can be posted back to GitHub.

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How it Works / How to Build It

1. CreatePullRequestURL: This node constructs the URL for the specific pull request using the organization name, repository name, and pull request number provided in the inputs.
2. GetPullRequest: This node makes an API call to GitHub to retrieve the details of the specified pull request, including the code diff that needs to be reviewed.
3. GithubReviewerPrompt: This node uses a prompt to instruct an AI model (GPT-4.5) to analyze the code diff and provide feedback based on the guidelines provided in the prompt.
4. FormatPostGitHubComment: This node formats the feedback generated by the AI into a structured comment that can be posted on GitHub.
5. FinalOutput: This node outputs the final formatted comment, ready to be sent to GitHub.

What You Can Use This For

• Automating code reviews for development teams.
• Providing consistent feedback based on established coding guidelines.
• Enhancing collaboration by streamlining the review process on GitHub.

Prerequisites

• Vellum account.
• GitHub repository with pull requests.
• GitHub personal access token with permissions to read pull requests and post comments.

How to Set It Up

1. Clone the workflow template into your Vellum account.
2. Configure the Inputs node with your GitHub organization name, repository name, and the pull request number you want to review.
3. Set up the bearer token in the Vellum secret manager for GitHub API access.
4. Customize the GithubReviewerPrompt node if you want to adjust the feedback guidelines or the AI model's behavior.
5. Run the workflow to generate and post the review comment on the specified pull request.