Unified Diff MCP Server

What is Unified Diff MCP Server?

A server for Claude Desktop that transforms code diffs into beautiful HTML visual comparisons using diff2html. It supports GitHub Gist integration for instant sharing and local file output (PNG/HTML). Designed for developers doing code reviews or documentation.

How to use Unified Diff MCP Server?

Install via Smitherly (bunx @smithery/cli install @gorosun/unified-diff-mcp) or manually: clone repo, install Bun, run bun install, then configure Claude Desktop with the unified-diff-mcp MCP server, setting environment variables such as GITHUB_TOKEN. Use the tools visualize_diff_html_content (browser display & sharing) or visualize_diff_output_file (local file storage).

Key features of Unified Diff MCP Server

• Beautiful HTML diff visualization using diff2html
• GitHub Gist integration for instant sharing
• Local file output in PNG or HTML format
• Auto-delete functionality for temporary diffs (1–1440 minutes)
• Multi-level security (Low/Medium/High) for shared diffs
• Cross-platform support (Windows, macOS, Linux)

Use cases of Unified Diff MCP Server

• Quick preview and share a diff via browser-ready URLs
• Save a diff as an HTML or PNG file for documentation
• Securely share sensitive diffs with password protection and auto-delete
• Side-by-side code review inside Claude Desktop
• Image export of diffs for presentations or reports

FAQ from Unified Diff MCP Server

What tools are available and what do they do?

Two tools: visualize_diff_html_content creates a GitHub Gist with an HTML preview URL; visualize_diff_output_file saves a local HTML or PNG file.

What runtimes and dependencies are required?

Requires Bun runtime and clone of the Git repository. Key dependencies include diff2html (HTML diff), playwright-core (browser automation), and @modelcontextprotocol/sdk.

Where are diffs stored, and how long do they persist?

Diffs can be stored as local files (PNG/HTML) or as temporary GitHub Gists. Gists auto-delete after a configurable period (default 30 minutes, max 1440 minutes).

How does authentication work for GitHub Gist integration?

A GitHub Personal Access Token with gist scope is required. Set it as the GITHUB_TOKEN environment variable. If the token is unavailable, the server falls back to local file output.

What transport/protocol is used?

The server uses the Model Context Protocol (MCP) and is configured in Claude Desktop’s claude_desktop_config.json. It connects via bun commands and supports standard MCP clients.