Unity Code MCP Server v0.3-preview Release Notes

Unity Code MCP Server 0.3 Release Changes

✨ What’s New for You?

The 0.3 release expands Unity Code MCP Server from editor automation into guided gameplay automation, while also making day-to-day agent workflows safer and more reliable.

• New Tools: Play and Test Your Game: New tools like enter_play_mode, play_unity_game, and exit_play_mode let agents automate gameplay and testing directly in Play Mode. Agents can now enter the game, simulate Input System actions, capture screenshots and logs, and exit cleanly, making real gameplay validation part of the workflow.
• More reliable tool execution: MCP tools and automated test runs now detect Unity compilation state earlier and avoid common hangs or invalid transitions.
• Safer test workflows: Scene restore and Play Mode handling were strengthened so automated runs are less likely to leave the Editor in an unexpected state.
• Less setup for AI agents: Bundled skills are now installed and updated automatically, so agents can discover the right workflows with less manual configuration.
• Smarter built-in guidance: A new unity-game-player skill teaches agents how to inspect a running game, compute actions, and adapt during gameplay testing.

⚠️ Breaking Changes & Migration

This release has no breaking MCP configuration changes.

• Unity Input System dependency added: Gameplay automation now depends on the Unity Input System package, which is added automatically through the package manifest.
• Skill installation is now automatic: If you previously installed skills manually, review the configured target directory in Tools > UnityCodeMcpServer > Show or Create Settings to confirm it still matches your preferred agent setup.

🚀 Key Improvements

🕹 Play Mode Automation

• New tools: enter_play_mode, play_unity_game, and exit_play_mode
• play_unity_game can temporarily unpause the game, send press and hold input actions, collect gameplay logs, and return a screenshot for fast feedback loops.
• Together, these new tools let agents automate both play and gameplay testing in a closed loop, observing the game, acting on it, and re-checking results without leaving the Editor.

🛡 Reliability and Safety

• Compilation guards: Tooling now fails fast when Unity is compiling instead of waiting on operations that cannot complete safely.
• Improved scene restoration: Automated test execution does a better job restoring Editor scene state after runs.
• Play Mode test coverage: The new gameplay automation path ships with dedicated Edit Mode and Play Mode tests.

🧠 Skills and Setup

• Automatic skill updates: Built-in skills are copied during package install and update, and unchanged files are skipped.
• Clearer skills configuration: Settings now support GitHub, Claude, Agents, or Custom install targets with a clearer inspector workflow.
• New bundled skill: unity-game-player was added alongside updates to the existing script-execution skill.
• Synchronous script execution support: Editor-side script execution now supports tighter coordination with tests and automation flows.