Guide · Agent skill
How to use the Diff Review agent skill (diff-review)
Updated · written with AI from the project's own documentation and checked against our catalogue data
The diff-review skill is an agent skill from the open-design project that handles the review step after an agent has edited code during a larger migration or patch run. It gathers those edits into a standard diff, writes a plain-language summary per file, and asks you to accept all, reject all, or accept some. This guide is for readers who have not used agent skills before. By the end you will know what the skill does, how to install it, how to trigger it, and what to check before you use it on real code.
Diff Reviewnexu-io/open-design · Apache-2.0 Download the skill Quick start
- 1Download the ZIP. Get the diff-review ZIP from this page. It contains open-design.json and SKILL.md.
- 2Unzip the skill. Extract it into ~/.claude/skills/ for personal use, or into the project's .claude/skills/ folder for one project.
- 3Or upload in Claude apps. In the Claude apps, go to Settings → Capabilities → Skills and upload the skill.
- 4Check requirements. Confirm the repository uses git and that the open-design daemon and plugin runner are available.
- 5Ask for a review. After an agent migration or patch run, ask in plain language to review the changes before keeping them.
- 6Choose accept, reject or partial. Read summary.md and diff.patch, then pick a decision on the choice surface. For partial, decide each file.
- 7Confirm the saved decision. Check that review/decision.json contains your decision and the accepted and rejected file lists.
What is an agent skill and what does diff-review do?
An agent skill is a folder with a SKILL.md file that tells an AI agent how to carry out a specific task. When the task matches the skill's description, the agent follows its instructions. The diff-review skill covers one stage: presenting changes for human sign-off.
When an agent has edited code as part of a migration or patch run, diff-review collects those accumulated edits since the run started (or since the previous review pass). It uses the plan in plan/steps.json for context on each file. It then writes review files into a review/ folder in your project.
- review/diff.patch: a unified diff in git apply format
- review/summary.md: a human-friendly walkthrough of each file
- review/decision.json: your decision, plus the accepted and rejected file lists
- review/meta.json: generation time, atom digest and plan revision
Install the diff-review skill
Download the ZIP for the diff-review skill from this page. The package contains open-design.json and SKILL.md. Unzip it into one of these locations, depending on how you want to use it:
- Personal use across projects: unzip into ~/.claude/skills/
- One project only: unzip into the project's .claude/skills/ folder
- Claude apps: upload the skill under Settings → Capabilities → Skills
Trigger the skill with a natural request
You do not need a special command. Ask the agent in plain language to review its changes before they are kept. The skill's description covers rendering accumulated changes as a reviewable diff and recording an accept or reject decision, so requests about those ideas should match it. Check the agent's output to confirm it started the review step.
- "Show me the diff of what you changed in this migration and let me accept or reject it."
- "Review the patch from this run before we keep it."
- "Make a reviewable diff of the edits you made and ask me to accept, reject or partially accept."
What the review looks like
The skill raises a choice surface with three top-level options: accept, reject, or partial. The choice surface is a GenUI element that your host environment provides. If you choose partial, you then decide file by file through follow-up surfaces.
The review finishes only when decision.json has a decision recorded. If you accept, the skill records a handoff kind of patch, or deployable-app when a successful build-test is on file. If you reject, the skill rolls the patch back using git restore or an equivalent command in the repository.
Requirements and what the skill can change
The skill needs git in the repository, because rejection uses git restore or an equivalent. It also needs the open-design daemon and its plugin runner, which implement the referenced TypeScript modules, and a GenUI choice surface from the host. The skill runs scripts. It does not use the network.
- Rejection only touches files within the union of files[] listed in plan/steps.json. The patch boundary is a contract.
- Do not use this skill in a repository where you do not want the agent running git restore. If the patch boundary is wrong, rejection can discard work.
Tips for a safe and useful review
Read summary.md before you open diff.patch. It explains intent per file, which makes the raw diff easier to check.
Commit or stash your own unrelated work before the agent starts a run, so a rejection cannot touch it.
Check that plan/steps.json lists the files you expect. If files are missing or unexpected, choose reject or partial rather than accept.
What people use it for
- Reviewing an agent-driven code migration before merging it into a main branch.
- Giving a human sign-off step to automated patches in a team workflow.
- Accepting most files from a patch run while rejecting a few that changed unexpectedly.
- Running the open-design project's code-migration workflow with a recorded decision.
Frequently asked questions
How do I install the diff-review agent skill?
Download the ZIP from this page and unzip it into ~/.claude/skills/ for personal use or into a project's .claude/skills/ folder. In the Claude apps, you can instead upload it under Settings → Capabilities → Skills.
What does the diff-review skill require?
It requires git in the repository, the open-design daemon and its plugin runner, and a GenUI choice surface from the host environment. It runs scripts but does not use the network.
Is diff-review free to use?
The source describes the skill as licensed under Apache-2.0. Check the licence file in the project for full terms; this page does not state pricing.
Can I use diff-review for a small edit?
It is not designed for that. For solo quick edits, a normal git diff and commit review is usually enough, since this skill adds a multi-file workflow.
What happens if I reject the changes?
The skill rolls back the patch using git restore or an equivalent command in the repository. It only touches files in the patch boundary defined by plan/steps.json, but a wrong boundary can still discard work.
Why won't the review finish?
The review completes only when review/decision.json has a non-empty decision. If the choice surface was skipped, the skill is not finished. Make sure your host supports the GenUI choice surface and that you respond to it.
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Our verdict
Use diff-review if you are a developer, or a team, that wants a human sign-off before agent-made migrations or patches are kept, and you run the open-design code-migration workflow in a git repository. Skip it for small solo edits, or in repositories where you do not want the agent running git restore.
Download the skill