Diffsmith - Comment on your AI agent's code & collaborate on changes
by•
Diffsmith is a code review studio for local git changes made by Claude Code, Cursor, Codex, Copilot, or any other AI coding agent.
Open a repo, read the uncommitted diff, and click any line to leave a comment anchored to that exact spot. Then hand your notes straight back to the agent.
Supports MCP for viewing you're agent's replies to your comments directly at the line of code it relates to.
Diffsmith is 100% offline and a one time purchase unlocks lifetime access.
Replies
One-time purchase for a tool that sits in the hot loop of agent coding is a refreshing call. The mechanic I want to understand: when the agent answers a comment by rewriting the whole block, where does the anchor go, does the comment follow the moved logic or die with the old lines? That resolution step decides whether review rounds stay readable after round three.
@vollos Great question! In that situation, comments can’t stay with the new lines so they get archived into a “Past” tab in the sidebar (you can click it there to see the original lines it was anchored too).
Agents can add a comment to the newly changed code if they want to (and in my experience they often do because they understand that the original comment will be archived)
@maxchuquimia Archiving beats the pretend option, a comment glued to lines it no longer describes is worse than one that admits it's history. Agents leaving a fresh comment on the new code because they know the old one gets archived surprised me, that's the loop closing itself. Thanks Max.
Would love a side-by-side mode that shows the original file alongside the diff, since right now I'm flipping back to my editor a lot to remember the surrounding context before leaving a comment on a single line.
Finally, a way to review what my AI agent actually wrote without scrolling through terminal output. The line-anchored comments feeding straight back through MCP is genuinely clever.
AI code review is most useful when it is tied to release risk, not just style feedback. I would rather see fewer comments with clear repro, affected behavior, and test evidence than a long list of plausible-sounding notes the team has to triage again.
honestly this looks really useful for my workflow since i use cursor and claude code daily. one thing i'd love is a way to batch similar comments together, like if i want to flag the same issue across multiple files, it gets tedious clicking line by line for repetitive notes. a "apply comment template to selection" or something similar would save a lot of time when reviewing bigger changes
finally something that doesn't nuke my local diffs when I'm reviewing what cursor spit out, the line-anchored comments are kind of genius honestly
This is awesome, much needed visibility upgrade for reviewing what your coding assistant is ACTUALLY doing, love it.
One thing I'd love to see is a way to group related comments into threads so I can have a back and forth on the same block of code without the chat getting messy.
Love how cleanly it anchors comments right to the diff line, makes giving feedback to the agent way less painful. The offline approach is a nice touch too.
The line-anchor model nails what the agent wrote, but reviewing Claude Code and Codex diffs my highest-leverage notes are almost always about what it didn't write: 'you skipped the error path here', 'no test for the empty input'. There's no changed line to click on for those. How do you attach a comment to an omission, or to a file the agent should have touched but left alone? That's where a lot of my review time actually goes.