GitHub PR Diff

The GitHub MCP server provides functionality to extract diffs from Pull Requests.

Available Tools

get_diff_pr

Retrieves the diff content from a GitHub Pull Request.

Parameters:

• owner: Repository owner/organization name
• repo: Repository name
• pr_number: Pull Request number

Returns: Object containing:

• content: String containing the PR diff

Authentication

Required: Set the GitHub Personal Access Token as an environment variable:

export GITHUB_TOKEN=<your-github-token>

The token needs at least repo scope permissions to access private repositories. For public repositories, a token with public_repo scope is sufficient.

Error Handling

The server implements standard error handling:

• Missing/invalid token returns ErrorCode.AuthenticationError
• Invalid repository details return ErrorCode.InvalidParams
• Non-existent PR returns ErrorCode.NotFound
• Failed diff fetches return formatted error messages
• Graceful shutdown on SIGINT

Technical Details

• Built using the Highlight AI MCP SDK
• Uses GitHub REST API v3
• Input validation via Zod
• Runs as a stdio-based MCP server
• Supports Node.js >=18.0.0

Limitations

• Rate limits apply based on GitHub API restrictions
• Large diffs may be truncated according to GitHub API limits
• Token requires appropriate repository access permissions