Your agent builds the island.

Run one command. Paste to your agent.

One PowerShell command on the Windows box that has UEFN. Source: BizaNator/uefn-mcp. Do not add a second MCP server.

1. Run the installer

   If the client repo is private, the script uses gh or git with your existing GitHub login. The installer writes CONNECT.md and does not dump mcpServers JSON unless you pass -VerbosePaste.

   PowerShellCopy

   irm https://uefnmcp.com/install.ps1 | iex

2. Paste this to your agent

   One line. The installer writes the full brief to CONNECT.md (and UEFN-MCP-CONNECT.md on the island when the project is known). That file tells the agent to ASK THE HUMAN for the folder that contains the .uefnproject if needed, verify already-written .mcp.json, and run setup.ps1 so Content\Python is armed. One server only. A portal key is not required.

   paste to agentCopy

   Read %LOCALAPPDATA%\uefn-mcp\CONNECT.md and configure UEFN-MCP according to those instructions. In every new session, call list_toolsets and enable_toolset(...) for any group the task needs that is not already listed.

3. CONNECT.md

   The brief on disk tells the agent to verify already-written .mcp.json — do not hand-author. HOSTED_MCP_URL defaults to the hosted grounding endpoint. -VerbosePaste still prints the old mcpServers dump.

   uefn-mcpCopy

   {
     "mcpServers": {
       "uefn-mcp": {
         "command": "node",
         "args": [
           "<path printed by the installer>\\index.js",
           "--stdio"
         ],
         "env": {
           "HOSTED_MCP_URL": "https://uefnmcp.com/mcp",
           "UEFN_PROJECT_PATH": "<absolute project folder — contains the .uefnproject>",
           "UEFN_PROJECT_ROOT": "<absolute Content/Verse or Plugins/<Plugin>/Content/Verse>"
         }
       }
     }
   }

4. Toolsets

   Setup lists the verse, scene, session and ui toolsets by default (UEFN_MCP_TOOLSETS=verse,scene,session,ui), and run_editor_python is always in core. call_epic_mcp reaches Epic's built-in UEFN MCP, which setup starts automatically. For anything else (audio, materials, fab, performance and more), the agent calls list_toolsets, then enable_toolset(...) before the task. That repeats in each new session, LAN sessions included. Codex is set to UEFN_MCP_TOOLSETS=all because it may not refresh its tool list after a change.

Driving the editor from another machine? See Remote control over LAN or VPN.

Something not connecting? Tell your agent to call get_skill('uefn-mcp-connectivity') first. It explains the three layers (client tools on the editor PC, uefnmcp.com, and Epic's UEFN MCP) and walks a fix for each, with children for install (uefn-mcp-install), Claude and Codex plus panels (uefn-mcp-clients), LAN or Tailscale (uefn-mcp-network), and a relay game-thread timeout (uefn-editor-dialogs).

Agent playbooks: get_skill('uefn-tool-contracts') maps each job to the exact tool (client, cloud, call_epic_mcp, call_unreal_mcp) and lists what can be created today versus the object types that still cannot. get_skill('verse-change-workflow') runs an intent check, a plan, compile_check and a two-part review before code is called done. get_skill('verse-dependency-audit') maps Verse dependencies with the local graph toolset (enable_toolset('graph')) before a delete, move, or rename. get_skill('uefn-performance-audit') measures Memory Calculation. A cook that fails because GameFeatureSet delmargfs is unavailable is the same skill: explain the error and follow the bug report. get_skill('uefn-memory-reduction') is the child for lowering that bar (instanced static meshes, a zone spawner, a building shell, a lazy device editable). A Lore check-in crash or packstore read error is get_skill('uefn-p4').

Hosted grounding signs in via browser OAuth on first use. Portal keys (uefn_sk_*) are optional — CI and overrides only. CI / override keys. Already installed? Update.