R

Product overview

Ralpha 1.3.1 for Unreal Engine 5.8

Unreal Engine 5.8 ships its own Model Context Protocol server, so any MCP client can already spawn actors, set properties and capture the viewport. Ralpha does not replace that. It plugs into it, as toolsets and skills that sit alongside Epic’s own.

What it adds is the knowledge a general editor API does not have: where a place is, where the sun sits over it at a given minute, how bright the scene should be when it does, and what people who light real scenes for a living set first.

Coming soon to Fab. See the plugin page for platforms and pricing.

Connecting

The recommended path is Unreal’s native MCP. Enable Unreal’s MCP plugins in your project, start the editor with the server on port 30030, and point your client at it:

-ModelContextProtocolStartServer -ModelContextProtocolPort=30030
http://127.0.0.1:30030/mcp

Ralpha registers its toolsets and skills with Unreal at startup, so Claude Code, Epic’s AI Assistant or any other MCP client sees them next to Epic’s own. The plugin also serves HTTP MCP on port 30020 and TCP/JSON on 30010, for clients that do not use Unreal’s server. This is an editor workflow: the toolsets and skills need the editor running.

Toolsets

Geo toolset

Drives Cesium for Unreal 2.x, so an agent works in latitude, longitude and altitude instead of engine centimetres. It sets the georeference, loads a tileset, puts the camera at a real position and reads the ground height beneath it. Cesium is a free plugin you install yourself; without it the geo tools say they are unavailable.

Solver toolset

Calculates rather than guesses: sun position for any place and time, the exposure that suits that sun elevation, a lens’s field of view, the distance to the horizon, the sea state for a given wind and the stars overhead. The answers are deterministic, and one call applies the sun for a place and time to your directional light.

The command layer

Behind the toolsets sits a broader command layer: lighting, sky and atmosphere, fog, clouds, post-process, cameras, materials, characters, animation, physics, PCG, audio and more. Curated typed tools carry full schemas, and a single ralpha_command tool reaches the rest. Agents find what they need through discover_capabilities, discover_domain and discover_command rather than reading the whole list.

3,248 commands register in UE 5.8; 3,176 were verified one by one in a fresh project, each with its effect read back. The other 72 need particular hardware, a platform, or a paid service or device.

Skills

Six domain skills load through Unreal’s own agent-skill system, next to the skills Epic ships. They hold the rules we measured building production scenes: what to set first, which combinations break, and which numbers hold up on camera.

  • Sky and sun
  • Sunset
  • Water and ocean
  • Clouds
  • Exposure
  • Real places

Also in the package

Water and ocean
Ocean and water-body spawning and wave control for Unreal’s Water system, with no modal dialog that stops the editor.
Photoreal MetaHuman support
Character performance controls in Sequencer, with Control Rig channels inspected and keyed exactly; two characters on the same rig stay separately addressable. You supply the MetaHumans.
MuJoCo physics
The MuJoCo 3.3.2 runtime is included: load a model, step it, bind its bodies to actors and read them back.
Local by design
Every endpoint listens on localhost only. Outbound network use is off unless you turn it on, and there is no telemetry. You bring your own MCP client and model.

What you supply: your project, its assets, MetaHumans, animations and audio, and Cesium for Unreal if you want real places. Ralpha includes no characters, maps, meshes or other content.

Known limits

  • Hardware or platform (50) nDisplay is not available on Mac, because UE 5.8 ships nDisplay only for Windows and Linux (on Windows all 46 nDisplay commands passed). Path tracing and VDB volume import need hardware ray tracing (verified on Windows with an RTX 4070). Hand tracking needs an XR device. Vehicle commands need a Chaos wheeled vehicle you supply.
  • Paid services, licences or devices we have not tested with (22) For example Wwise audio, Meshy mesh generation, VR headsets, OSC tally devices and multi-node nDisplay clusters. They stay in the package and are listed in Docs/COMMAND_REFERENCE.md.
  • Some Mac Development builds can fail to launch intermittently; a stock UE 5.8 project shows the same. Docs/TROUBLESHOOTING.md has the measured rates and the -LLM launch option (0 failures in 150 launches with it).
  • Linux builds from the release archive but has not been live-tested by us.
  • Editor workflow. The native toolsets and skills need the editor running.

Docs inside the package

The full documentation ships in the plugin’s Docs folder:

  • Docs/README.md · What Ralpha adds and the two ways to connect
  • Docs/INSTALLATION.md · Engine plugins to enable, per platform
  • Docs/GETTING_STARTED.md · First connection through Unreal’s native MCP
  • Docs/COMMAND_REFERENCE.md · Discovery tools, and every command not verified with what it needs
  • Docs/SAFETY_AND_NETWORK.md · Localhost-only endpoints, outbound network, no telemetry
  • Docs/TROUBLESHOOTING.md · Measured launch rates and fixes

Version history is on the changelog. Questions: support@ralpha.io