ClaudusBridge 2.0
Work in Unreal Engine from a terminal, an MCP client, or the embedded agent—with the editor window open or closed.
ClaudusBridge 2.0 for Unreal Engine 5.8 introduces a native CLI, project-aware backend discovery, persistent agent sessions, enforced package locks, and a project timeline. The bundled claudus executable and claudus-mcp-proxy are the same program under two names.
Choose the interface that fits your work:
| Interface | Use it for |
|---|---|
| Claudus CLI | Discover tools, make individual calls, inspect sessions and locks, and automate workflows from scripts. |
| External MCP client | Connect your existing coding assistant through the Claudus CLI over stdio. |
| ClaudusCode terminal | Talk to the embedded coding agent inside Unreal. Node.js and your chosen provider account are needed for this interface. |
| ACP drive path | Drive the embedded agent programmatically from editor tooling. |
What runs when the editor is closed?
The CLI can start an invisible real Unreal process, UnrealEditor-Cmd, for the selected project. Supported asset, reflection and toolset operations still use Unreal's serializers and engine APIs. Closing the editor window does not turn engine-backed editing into a standalone .uasset parser.
| Operation | Runtime required |
|---|---|
help, version, status, doctor, policy show, timeline queries | No Unreal backend. |
asset check/type/to-json/from-json/diff/raw | The separate offline asset utility; supported package formats only. |
toolsets, describe, call, reflection and engine asset editing | A running project backend; the CLI can launch the hidden commandlet. |
| Slate widgets, viewport capture, interactive dialogs and editor-only tools | A full editor process and the context required by that tool. |
The available catalog depends on your engine and enabled plugins. Use toolsets and describe to discover it. A listed tool is not a promise that it can run without an interactive editor.
One project, one active backend
The proxy discovers the exact project instead of relying on a fixed port. Multiple clients can share its backend. When the interactive editor takes over, the proxy coordinates the hidden process's shutdown before forwarding to the editor. Lifecycle and limits explains recovery, timeouts and rebuilds.
The MCP client speaks JSON-RPC over stdio to the proxy. The proxy speaks an authenticated native protocol over loopback to Unreal. Version 2.0 does not provide an HTTP MCP listener or /health route. Migration instructions replace the old URL configuration.
Coordinate agents and keep project context
Give each agent a stable identity, inspect who is connected, and lease packages before editing. The backend enforces supported mutation and save ownership rules; it reports unexpected touches as violations. The timeline records activity and lets agents leave notes and checkpoints that remain readable after Unreal exits. See multi-agent orchestration and sessions and timeline.
Local bridge, your chosen assistant
The CLI and Unreal bridge run on your machine. The CLI itself needs neither Node.js nor an AI account. The embedded agent uses Node.js and your provider's login; model requests may leave your machine according to that provider and your settings. ClaudusBridge does not add its own model service.
Start with installation. The separate UE 5.7 legacy documentation describes an older implementation and does not apply to this transport.