unity-cli

Automates Unity Editor cold starts, headless tests, batch runs, and builds via the Unity CLI.

1.7k|162|Updated Jan 18, 2026
One-click install
npx skills add https://github.com/Besty0728/Unity-Skills --skill unity-cli
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: unity-cli
Source: https://github.com/Besty0728/Unity-Skills/tree/main/SkillsForUnity/unity-skills~/skills/unity-cli
Command: npx skills add https://github.com/Besty0728/Unity-Skills --skill unity-cli

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

When the Unity Editor is closed, REST-based automation cannot reach the project. This Skill guides AI agents in using the experimental Unity CLI to cold-start the bound Unity project, run headless tests, execute one-shot batch methods, and produce builds without opening the editor manually.

Core Features & Use Cases

  • Cold Start & Lifecycle: Launch the bound Unity project with the -unityskills-coldstart marker so the REST server starts automatically, with liveness triage via registry, lockfile, and CLI process checks.
  • Headless Tests & Batch Runs: Run EditMode/PlayMode tests with NUnit XML output and timeouts, or execute one-shot -executeMethod batch automation while the editor is closed.
  • Headless Builds: Build via Unity 6 Build Profiles, built-in desktop targets, or custom C# build methods, with structured JSON/NDJSON output and defined exit codes.
  • Use Case: In a CI pipeline, cold-start a Unity project, run the full EditMode and PlayMode test suites headlessly, then produce a Windows build — all without human interaction with the editor.

Quick Start

Check the project's Library/UnitySkills/cli_config.json to confirm the Unity CLI is enabled, then use the configured cliPath to cold-start the project and wait for the REST health endpoint to respond.

Frequently Asked Questions about unity-cli

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I cold-start a Unity project from the command line?▼

Use the Unity CLI's open command with the project path and pass --args -unityskills-coldstart so the UnitySkills plugin force-starts its REST server. First verify the project's cli_config.json has enabled set to true and the required editor version is installed.

How to run Unity tests headlessly in CI?▼

Run the CLI test command with --mode EditMode or PlayMode, a --filter pattern, --output for the NUnit XML report, and a --timeout. Exit code 0 means all tests passed, while 6 indicates test failures or abnormal editor exit.

Can I run Unity CLI commands while the editor is already open?▼

No. Unity refuses a second instance on the same project due to the Library/UnityLockfile. When the editor is running, use the UnitySkills REST skills instead; the CLI is only for closed-editor lifecycle operations.

Why does the Unity CLI fail to start on older Linux distributions?▼

Starting with beta4, the Unity CLI requires glibc 2.34 or newer, so it fails on Ubuntu 20.04, Debian 11, RHEL/CentOS 8, and Amazon Linux 2. This is a compatibility constraint, not a missing installation, so reinstalling will not fix it.

What are the limitations of Unity CLI headless builds?▼

Builds only work on the bound project with the editor closed, and the build command refuses to run with uncommitted changes unless --allow-dirty-build is passed. Mobile and WebGL targets require a custom static C# build method via --execute-method.