Unreal Engine 5 project skill

A reusable skill for AI assistants working on Unreal Engine 5 projects. It helps establish project rules, develop C++ and Blueprint features, and work in a running Unreal Editor through MCP when connected. The skill ID remains unreal-cpp-developer.

Install the skill in your assistant and open the Unreal project. Use your own words to ask it to set up your team's workflow. Here are three ways to ask.

• “Let's get you set up to work in this project.”
• «Давай договоримся, как ты будешь работать с этим проектом».
• 「このプロジェクトで今後どう作業するか、一緒に決めておこう。」

These are examples. The assistant recognizes the intent across languages and responds in the language you use. To explore the options first, just ask for an explanation. To revise one choice later, say what changed, for example “We've moved our tasks to Linear.”

In Codex projects, AGENTS.md normally holds the core working agreements on Editor access, project management, documentation and task tracking. During setup, the assistant also asks “Would you like to set up custom project rules now or later?” in your language. These can cover folder structure, C++ conventions, asset naming or anything else you want the assistant to follow. How Codex reads project instructions

Choose now to describe your conventions or point to an existing team guide. The assistant records agreed additions in a project-owned custom_rules.md by default, reuses existing rules in their original scope, and links to them from the active project instructions. Choose later to finish setup without creating an empty file. You can add rules in a future session by asking in your own words. Project documents can have a different language from the conversation.

Setup also asks how to maintain the architecture overview. By default, the agent updates it in the same change when responsibility moves between systems, module dependencies change, or data flows through a new interface. It uses the team's existing document or README section, or starts docs/ARCHITECTURE.md once there is an implemented design to describe. You can choose updates only on request, defer the decision, or turn maintenance off. This applies independently of your project-management choice.

These choices are independent of the tracker. For example, a team can choose its own PM skill with a local task list, or turn PM off and still ask for a GitHub issue update. You can switch the PM choice later without redoing setup.

For live work, connect your assistant to the target Unreal Editor. The assistant discovers the operations available in that session, including tools added by enabled extensions. In UE 5.8, VibeUE adds tools to Unreal's native MCP connection. Source-only projects can use all project setup and C++ workflows. Editor connection guide

• Ownership and loading: reflected strong references, weak observation, soft loading, and legitimate hard references; pointer types follow lifetime and loading needs.
• Reflection and authoring: Details, Blueprint, and Sequencer access; correct Interp placement; handling direct property writes without assuming setters run.
• Lifecycle and callbacks: timers, delegates, async proxies, cancellation, reentrant handlers, and stale-operation protection.
• Tick and optimization: capability versus activation, appropriate update frequency, cache invalidation, and source-supported improvements without unsupported performance claims.
• Architecture: runtime/editor separation, plugin independence, interfaces, Data Assets, Gameplay Tags, and Subsystems when the task calls for them.
• Blueprint integration: callable/pure functions, implementable/native events, World Context, public compatibility, and useful tooltips.
• Everyday C++ work: IWYU, Unreal naming and types, strings/localization, logging, input integration, runtime guards, and threading constraints.

Final generated C++ contains only /** ... */ comments used as Editor tooltips for UPROPERTY and UFUNCTION declarations. It contains no explanatory inline, function-body, or internal-variable comments. Clear names and structure express intent; longer explanations belong in external documentation.

Template files intentionally retain instructional comments for the agent. Those comments explain what to replace and where code belongs. They must not be carried into generated implementations. Existing genuine legal notices must be preserved; the templates do not invent an Epic Games copyright attribution.

The supplied formatter disables automatic namespace comments. Formatting alone does not enforce the full comment policy.

• SKILL.md contains workflow selection, documentation, delivery and Unreal C++ guidance.
• Project setup covers first use, legacy project rules and subsequent revisions.
• Editor and MCP covers capabilities, asset edits and verification.
• Build and plugin diagnostics covers build targets, failure stages and checks for dependent assets.
• custom_rules.md remains available for installations with existing overrides.
• templates/ contains adaptable UObject header and source examples.
• .clang-format provides a starting formatting configuration.

Copy the entire unreal-cpp-developer folder into one of the parent directories below. Project paths are relative to your Unreal repository. User paths apply to projects on that machine. Inside unreal-cpp-developer/, keep SKILL.md next to references/ and templates/.

For other clients, use their documented skill location. The source folder here retains its original .agent/skills/ layout for clients configured to read it. The optional .clang-format is independent of skill installation.

Open a fresh session from the Unreal repository and check that the client's skill list includes unreal-cpp-developer. Then ask in your own language to set up how you will work together, without giving a skill name or path. The expected first step is to inspect project conventions and ask about unresolved choices. You can also start with a development task.

Codex CLI 0.167.0-alpha.4 discovered the skill in fresh sessions from both documented locations in an isolated test. That check queried the skill list. Selection for a natural-language request is a separate check. The Claude Code paths above follow Anthropic's documentation.

To move between computers, keep project-scoped skills and project-owned rules in version control, or install the user-scoped copy on each machine. For live Editor work, connect the local client to the correct Unreal instance on that machine and run the Editor smoke test.

For a new class, the assistant reads the templates, chooses the actual Actor/Component/Subsystem/UObject base, fills in the requested behavior, and removes instructional comments from the output. For existing code, it preserves public APIs and avoids unrelated rewrites.

Keep your existing custom_rules.md and project/plugin-specific instructions when updating the installed package. Bring in the updated SKILL.md, templates and references/ together. Ask the assistant to bring the project's working rules up to date. It can link to existing authoritative files or migrate agreed rules from a replaceable installation into the project. Keep the original until you have reviewed the migration.

Validation must follow the user's authorization. A source review or skill-format check does not establish that generated C++ compiles or works in Unreal.

Keep guidance concise, technically grounded, and consistent with the templates and README. Explain when a recommendation applies rather than adding universal restrictions for isolated problems. Preserve the tooltip-only policy in generated code and the instructional comments in templates.

MIT License. Free to use, modify, and distribute under its terms.