Review local git changes
Open a repository and review the uncommitted diff directly in a native macOS app instead of waiting for a pull request.
Diffsmith
Diffsmith is a native macOS app for reviewing uncommitted code changes made by AI coding agents. It lets you leave inline comments on local git diffs and send feedback back to the agent by prompt or through a local MCP server.
Overview
Diffsmith is a native macOS code review studio for local git changes made by AI coding agents. It is designed for reviewing uncommitted work in a repository before that code becomes a pull request, with inline comments that stay anchored to the exact lines they refer to.
The product supports agents such as Claude Code, Cursor, Codex, and Copilot. Review notes can be copied back as a prompt, or handled through Diffsmith’s optional local MCP server so the agent can read comments and reply inside the app.
Everything in Diffsmith
Inline comments tied to code
Click any line in the diff to leave a note anchored to that exact spot, without typing file names or line numbers by hand.
Return feedback to the agent
Send comments back as a formatted prompt, or use the local MCP server so the agent can read and reply to them in the app.
Track a moving codebase
The app re-diffs as files change on disk, letting you review while the agent is still working and comments move to Past Comments if the code changes.
Review tools for dense diffs
Switch between side-by-side and inline diffs, expand context, hide whitespace, browse file stats, and mark hunks or files as read.
Organize review workflow
Use a fully customisable prompt template, open multiple repositories at once, and distinguish agent replies from your own comments in the sidebar.
Common ways to use Diffsmith
Review agent output before a PR
Open the repo your agent is editing, inspect the uncommitted diff, and leave line-level notes before the work is committed.
Close the loop inside the app
Use the built-in MCP server so a connected agent can read your comments and reply without switching to copy-and-paste.
Keep up with an active agent session
Start reviewing while files are still changing on disk, which is useful when the agent produces code in several passes.
Read complex diffs more comfortably
Switch to side-by-side or inline views, hide whitespace, and expand context when you need to inspect larger or noisier diffs.
Pros and Cons
Pros
- Reviews uncommitted git changes directly, so you can work before a pull request exists.
- Inline comments are anchored to exact lines, reducing manual copy and reference work.
- Supports a round-trip workflow through either copyable prompts or a local MCP server.
- Re-diffs as files change, which fits fast-moving agent-generated code.
- Privacy posture is explicit: no account, no cloud, no telemetry, and no outbound network calls from the app.
Cons
- Pricing is only shown as a single Mac App Store purchase; no plan comparison or trial details are provided on the page.
- MCP integration is optional and local-only, but it still requires setup in both Diffsmith and the chosen agent.
- The app is macOS-only based on the source material.
FAQ
Does Diffsmith work with Claude Code, Cursor, and other AI coding agents?
Yes. The product page says Diffsmith reviews uncommitted changes in your local git working tree and works with Claude Code, Cursor, Codex, Copilot, and other AI coding agents. You can either copy comments back as a prompt or connect through the local MCP server.
How do I connect an agent through MCP?
Open Settings → Agent in Diffsmith, turn on the MCP server, then add the provided snippet for your agent. The setup guide includes examples for Claude Code, Cursor, OpenAI Codex CLI, Windsurf, Antigravity, VS Code (GitHub Copilot), and Zed.
Does Diffsmith send my code anywhere?
No. Diffsmith is described as a sandboxed native macOS app with no account, no cloud, no telemetry, and no outbound network calls of its own. Comments, preferences, and other app data stay on your Mac unless you explicitly copy or save them.
Do I need to commit before reviewing changes?
No. Diffsmith reviews uncommitted work in your local repository and can diff against HEAD or HEAD plus staged changes, so you can review while the agent is still working.
How much does Diffsmith cost?
Diffsmith is listed as a one-time purchase of US$5.99 on the Mac App Store for lifetime access, with no subscription.
Quick Facts
- Category
- Developer Tool
- Platform
- macOS
- Primary workflow
- Review local git diffs from AI coding agents
- Integrations
- Claude Code, Cursor, Codex, Copilot, Windsurf, VS Code, Zed, Antigravity
- Price
- US$5.99 one-time purchase on the Mac App Store
- Source domain
- apps.mergeable.io
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