Docs/Unreal Overview

Unreal Overview

What the Mistscale Unreal plugin gives you and how the pieces fit together.

The Mistscale Unreal plugin connects characters in your project to the NPCs you build in the dashboard. Configure one subsystem, open a connection to an NPC, and the character can hold a conversation: text, voice, or both. Full C++ and Blueprint support. Memory, mood, relationships, and fact grounding all run on Mistscale's side of the connection, so there is nothing to host and no model to manage.

Streaming text chat

Send a player message with one function call. Blueprint-assignable delegates carry every event: streamed tokens, corrections, and the settled reply.

Realtime WebSocket

One connection per NPC, built on the engine's own WebSockets module, with automatic reconnect on an unexpected drop.

Spatial context

Tell the NPC where it is, what time it is, and what the weather is doing. Replies follow.

How it works

The plugin ships a UMistscaleSubsystem, a standard GameInstanceSubsystem — automatically instantiated once per game instance, reachable via GetSubsystem<UMistscaleSubsystem>() in C++ or the "Get Game Instance Subsystem" node in Blueprint. Each NPC connection it opens is its own object, authenticated with your project's API key. Everything stateful, including what the NPC remembers about each player and how its mood shifts over time, happens server-side and persists between sessions automatically.

What you need before starting

  • A Mistscale account with a project. The free tier is enough.
  • At least one NPC created in the dashboard. See Creating an NPC.
  • An API key for the project, generated from Project Settings.
  • Unreal Engine 5. The plugin depends only on built-in HTTP, WebSockets, and Json modules — no extra dependencies to install.

The guides in this section

Same protocol as every other SDK
The Unreal plugin, the Web SDK, the Unity SDK, and the Godot addon all speak the exact same REST + WebSocket protocol — see REST & WebSocket API if you ever need to go around the plugin directly.