uefn-ai-toolkit

Build Fortnite maps by describing them to Claude, instead of clicking through the UEFN editor by hand.

It is a Claude Code plugin with three parts: an MCP server that drives a running UEFN editor over Epic's Python remote execution protocol, a set of skills, and a knowledge base of what actually works in Fortnite Creative — which assets are publish-safe, which device settings are scriptable, and which routes are dead ends that look promising.

What you need

• UEFN installed, with a project created.

• Claude Code.

• uv on your PATH (the server is Python).

Related MCP server: Unreal-MCP-Ghost

Install

/plugin marketplace add dylannalex/uefn-ai-toolkit
/plugin install uefn-ai-toolkit@dylannalex-uefn

Then start a new Claude Code session — MCP servers only connect at session start. Open UEFN with your project loaded and ask:

Set up my UEFN project for remote execution.

Claude finds the project on disk and turns on the two settings UEFN needs — Python Scripting, and remote execution for it — both off by default. If UEFN was already open you will be told to restart it; those settings are only read at startup.

Use it

Describe what you want:

Show me everything currently placed in my level

Spawn a chest at the centre of the map and put an assault rifle in it

Move "SpawnPoint_1" up by 200 units

Take a screenshot of the map from above so you can see it

Check whether anything in my level will fail to publish

You don't need to know Unreal or Python. If Claude doesn't know a device or prop's name, it can search your content browser for it.

Keeping notes between sessions

Claude has no memory of the editor between conversations, and a .uefnproject is binary — it can't be diffed or reviewed. Ask for a map project and the plugin scaffolds a plain git repository of markdown alongside your map: the design, what is currently built, what is still pending, and a build log.

Set up a project folder for my new map

That repository is yours and holds no plugin files, so updating the plugin never touches your notes.

Limits worth knowing

• One editor at a time. Discovery connects to whichever UEFN instance it finds first, so keep one open. Several Claude Code sessions can now run against it — each gets its own command port.

• Compiling Verse is a manual click. There is no scriptable trigger for Verse > Build Verse Code; everything downstream of a compile is automated, the compile itself isn't.

• Item content is only scriptable on Item Spawner V3. Item Granter and Class Designer hold theirs behind a platform wall. This is documented rather than worked around, so nobody spends a session rediscovering it.

• Claude finds placed things by their World Outliner name, so clear, unique labels help.

How it works

See skills/uefn-knowledge/SKILL.md for the knowledge base's routing table, and docs/internals/INDEX.md for the architecture, the wire protocol, and a tool call traced end to end.