Unity Version Control agent plugin

Teach your AI coding agent to use Unity Version Control (UVCS, formerly Plastic SCM).

The plugin is a set of Agent Skills packaged as an Agent Plugin. It gives the agent working knowledge of the cm command line and of common UVCS workflows: reading history, reviewing a branch, finding the changeset that broke something, merging, and switching branches. There is nothing to build and no service to run. The agent reads the skills and drives the cm CLI you already have.

It works with Claude Code, Codex, Cursor, Copilot, and any other agent that supports Agent Skills.

What you can ask

Once installed, just describe the task. The agent picks the right skill.

• "Review branch /main/scm-12345 and tell me what looks risky."
• "This test started failing last week. Find the changeset that broke it."
• "Which changesets on /main touched Editor/Inspector/ in the last month?"
• "Merge /main into my branch and resolve the conflicts."
• "Switch to a new branch for this task. Keep my pending changes."
• "Give me a link to changeset 41827 so I can paste it in the ticket."
• "That command you gave me was wrong. Report it as a plugin bug."

Read-only work such as searching, diffing and reviewing runs without asking. The skills are written to ask before changing a repository, such as check-in, merge, undo or deleting a branch. Whether your agent asks depends on the agent and its settings, so review what it proposes.

Results include clickable links: unityhub:// when the workspace is a Unity project, and plastic:// (the UVCS desktop client) otherwise.

Before you install

• The cm command line must be on your PATH. It ships with Unity Version Control. Check with cm version.
• cm must already be signed in to your server. Check with cm whoami.
• Tasks that touch local files need a UVCS workspace. Server-side questions about history and branches work without one.

Install

Claude Code

/plugin marketplace add Unity-Technologies/uvcs-agent-plugin
/plugin install unity-version-control@unity

Or from a terminal:

claude plugin marketplace add Unity-Technologies/uvcs-agent-plugin
claude plugin install unity-version-control@unity

Codex, Cursor, Copilot, Gemini CLI, OpenCode, Zed and others

npx skills add Unity-Technologies/uvcs-agent-plugin --skill '*'

Keep --skill '*'. Every skill depends on uvcs-core, so installing one skill alone does not work. Add -g to install for all projects, or -a <agent> to choose one agent when several are installed.

Clients that implement Agent Plugins 1.0

Install the plugin from the repository URL. In VS Code, run Chat: Install Plugin From Source. Other clients have an equivalent "install plugin from Git URL" command.

https://github.com/Unity-Technologies/uvcs-agent-plugin

Manual

Clone the repository, or download the zip from the Releases page. Then copy the skills/* directories to wherever your agent looks for skills.

We have tested the Claude Code and npx skills routes ourselves. The other routes follow each client's documentation. If you verify one, please tell us.

Update

Installed with	You get	Update with
/plugin install	the latest release	auto-update, or claude plugin update unity-version-control@unity (see below)
npx skills add	the main branch	npx skills update

Turn on auto-update (Claude Code)

Claude Code auto-updates only its official marketplaces by default, so turn it on for this one once:

1. Run /plugin and open the Marketplaces tab.
2. Select the unity marketplace. That is the name this repository's marketplace registers (the @unity in unity-version-control@unity), not a separate product.
3. Choose Enable auto-update.

To turn it on for everyone working in a repository, add autoUpdate to the marketplace entry in the project's checked-in .claude/settings.json. Claude Code then offers the plugin to anyone who opens and trusts the folder:

{
  "extraKnownMarketplaces": {
    "unity": {
      "source": { "source": "github", "repo": "Unity-Technologies/uvcs-agent-plugin" },
      "autoUpdate": true
    }
  },
  "enabledPlugins": {
    "unity-version-control@unity": true
  }
}

With auto-update on, Claude Code checks for a new release in the background after the first message of a session. The session keeps the version it started with; the new one loads on the next launch, or right away with /reload-plugins. Updates arrive with each release, not with every change to main.

Update by hand

Claude Code reads the available versions from its cached copy of the marketplace, so refresh that first or the update finds nothing new. Both commands run from a terminal, and Claude Code has to be restarted for the new version to load.

claude plugin marketplace update unity
claude plugin update unity-version-control@unity

main is kept release-quality. Every change passes skill validation and a behavioral test suite before merge.

Skills

Skill	What it does
uvcs-core	The hub. UVCS concepts and how they differ from git, object specs, the cm command reference, and how to report results with deep links. Every other skill builds on it.
uvcs-code-review	Review a branch, changeset, shelve or pending changes, and publish the findings as merge request or code review comments.
uvcs-address-review	The author side of a review: apply the requested changes, answer questions, and re-request the review.
uvcs-root-cause	Trace a bug, crash or failing test back to the changeset that introduced it. Read-only.
uvcs-merge	Merge a branch, changeset, label or shelve and resolve conflicts without opening a merge tool.
uvcs-switch	Switch the workspace to another branch, creating it if needed, and keep or shelve pending changes.
uvcs-report-issue	Report a defect or a gap in this plugin as a GitHub issue: a rejected command, a missing recipe, a skill that misbehaved. Redacts, shows you the text, then files it.

Project-specific review rules

uvcs-code-review reviews with a general-purpose rule set (the reviewer prompt in skills/uvcs-code-review/assets/review-prompt.md): confidence-gated findings, four severities, a concrete fix on every blocker. Your project probably has rules of its own: what is always a blocker here, what to check that the diff will not show, conventions no linter enforces, what not to comment on. Give the reviewer those by adding one skill to your project, named code-review-rules. The review skill finds it by name, merges it with its general rules, and lets your rules win wherever the two conflict. No configuration, no registration.

1. Copy the template to your project's skills directory, as code-review-rules/SKILL.md:

   Agent	Directory
   Codex, Cursor, Copilot	.agents/skills/code-review-rules/SKILL.md
   Claude Code	.claude/skills/code-review-rules/SKILL.md

   Template: skills/uvcs-code-review/assets/code-review-rules-template.md. Or ask the agent: "Set up code review rules for this project" — it creates the file from the same template for you to fill in.

2. Fill in the sections you need and delete the rest. Keep the frontmatter: the description is how the skill is recognised, and the file is only ever read by the review skill, never run as a workflow on its own.

3. Check it in. Everyone on the project, on every agent, now reviews with the same rules.

A large repository can keep rules for one area in files of their own and list them in the template's Area rules section, each with the paths it applies to. A review pastes only the files its diff reaches, so a server change is not reviewed with the UI checklist.

A checklist the user pastes into the request works the same way, and a project can also replace the default severity names with its own in the template's last section.

Contributing

Contributions are welcome, especially real cm recipes and workflows. Read CONTRIBUTING.md first. One rule matters above all: every cm command must be verified against a real CLI, never remembered.

• Bugs and feature requests: GitHub issues. Or tell the agent: "Report this as a plugin bug". The uvcs-report-issue skill drafts the report, replacing server, repository and user names with placeholders where it can, and shows you the full text before it files it with the gh CLI or gives you the text to paste. Issues are public, so check the text before you approve it. When a command from the plugin is rejected by cm, the agent may offer to do this.
• Security reports: SECURITY.md

Maintenance

The Unity Version Control team at Unity Technologies maintains this repository. Contributions are welcome under the Unity Contribution Agreement.

License

Copyright © 2026 Unity Technologies. Made available under the Unity Terms of Service: see LICENSE.md.

Use of this plugin, as published by Unity, by an AI agent you direct (and the model it uses), through your installed cm client and with your own credentials, is Authorized Agentic Access under those Terms. Unity designates that cm client for this purpose.

"Unity", "Unity Version Control" and "Plastic SCM" are trademarks of Unity Technologies. The license grants no rights to them.