uefn-mcp

Lets Claude build Fortnite maps for you inside UEFN (Unreal Editor for Fortnite) — placing props, moving things around, browsing your content — instead of you clicking through the editor UI by hand.

What you need first

• UEFN installed, with a project created.
• Claude Code.

That's it — Claude can install everything else itself.

Setup

Open a terminal in this folder, start Claude Code, and paste this:

Install and register the uefn-mcp server with Claude Code: check whether uv is installed and install it if it's missing, run uv sync in this folder, then run claude mcp add uefn --scope user -- uv --directory "$(pwd)" run uefn-mcp.

--scope user registers the server globally instead of tying it to this one folder, so it's also available from other working directories — e.g. a fortnite-maps notes workspace set up via the fortnite-map-setup skill (see docs/).

Once that's done, start a new Claude Code session in this folder (MCP servers only connect when a session starts). Then open UEFN with your project loaded and paste this:

Set up my UEFN project for remote execution.

Claude will find your project on disk and turn on the setting UEFN needs (it's off by default). If UEFN was already open, Claude will tell you to restart it — this setting only takes effect on startup.

Once UEFN is back up with your project loaded, you're ready to build.

What to ask Claude to do

Once it's set up, just describe what you want in your own words. For example:

Show me everything currently placed in my level

Spawn a chest at the center of the map

Move the actor called "SpawnPoint_1" up by 200 units

Duplicate "Tree_03" and offset the copy to the side

What props/devices are available in my content browser?

Save the level

If Claude gets stuck because it doesn't know the exact name of a Fortnite device or prop, it can look through your content browser itself to find it — you don't need to know Unreal or Python to use any of this.

Limitations

• Only one UEFN instance can be connected at a time — if you have more than one open, Claude connects to whichever one it finds first.
• Claude finds things you've placed by their name in the World Outliner, so giving actors clear, unique names helps it find the right one.

How it works

See docs/ for a deeper look at the architecture, the wire protocol this talks to UEFN, and a traced example of a tool call end to end.