Editor Automation RPC Gateway — let AI agents build in Unreal Engine

Say what you want. The agent builds it.

You prompt your agent in plain language; it discovers the right RPCs and edits your project. Here is the kind of work it does, and the text it round-trips.

“Add a BeginPlay that prints a message, waits a second, then prints again.”

entry event BeginPlay() {
    call PrintString(InString: "Hello World")
    call Delay(Duration: 1.0)
    call PrintString(InString: "Done")
}

BPIR · authored & read back as text

“Make a material with a flat blue base color.”

entry material `/Game/Materials/M_Test` {
    %base = constant Float3(0.2, 0.4, 1.0) @(0, 0)
    output BaseColor: %base
}

MGIR · authored & read back as text

“Build a HUD widget with a lap-timer text block bound to a variable.”

call("widget.export_xml", { … })
call("widget.add_widget", { … })
call("widget.bind_event", { … })
✓ WBP_HUD · LapTimer bound · saved

Widget tree · inspect → author → verify

“Show me what this VFX system does so I can review the change.”

call("niagara.decompile_nir", { … })
→ NIR text: emitters, modules, script graphs
# diff-friendly review, straight in git

NIR · decompile for review

Screenshots land here as the visuals are captured — the text IRs above are real.

One gateway, the whole editor

~1,200 RPCs across 50+ namespaces. A few of the things agents reach for:

Blueprint authoring

Create classes, variables, functions and events; compile, decompile, and edit graphs as text.

Materials

Author and inspect material graphs, set instance parameters, round-trip whole graphs through MGIR.

Widgets & UMG

Edit the widget tree, styles, event bindings and animations; export and re-import structure.

Niagara & VFX

Inspect and author systems and emitters; decompile to readable text for review.

Animation & rigging

Anim Blueprints, Control Rig, sequences, montages, skeletons, IK and retargeting.

Scene, level & world

Spawn and transform actors, manage levels and World Partition, build lighting and navigation.

Plus assets, AI/behavior trees, GAS, landscape, audio, sequencer, tests, logs, screenshots and project automation.

Graphs as text — that round-trip

The differentiator. Most tools fire off one node-create call at a time. This gateway compiles whole graphs from a compact text IR and reads them back — so an agent can author, review a diff, and re-apply, all in plain text that lives in git.

Round-trip — author & read back

BPIR — Blueprint graphs
MGIR — Material graphs
AGIR — Animation Blueprint graphs
CRIR — Control Rig (RigVM)

Decompile — read for review

BTIR — Behavior Trees
SCIR — Sound Cues
MSIR — MetaSounds
NIR — Niagara systems
PCGIR — PCG graphs

Round-trip is logical equivalence — same nodes, connections and values. Pure layout (comment boxes, colors) is out of scope.

1,200 RPCs, one tool, zero context bloat

A flat list of 1,200 tools would drown an agent's context. Instead the gateway exposes a single call tool with a self-documenting wiki: the agent discovers what it needs, when it needs it.

call()browse the namespace index

call("material")read that namespace's page

call("material.compile_mgir", {…})execute the RPC

The endpoint is a local MCP server at http://127.0.0.1:19880/mcp — loopback-only, editor-only. The agent talks to it through its MCP client; you never wire raw HTTP.

Why this, not raw scripting

Capability	This gateway	UE Python / Remote Control	Typical per-node MCP server
Author Blueprint graphs from text	Yes	No	Node-by-node
Read graphs back as editable text	Yes	No	No
Material / Anim / Control Rig text IRs	Yes	Partial	No
One self-documenting tool, on-demand discovery	Yes	n/a	Flat tool dump
Native C++ handlers (no Python ceiling)	Yes	No	Varies
Breadth (~1,200 ops, 50+ namespaces)	Yes	Partial	Small

Compared against the general approaches, not any one product.

Works with your agent

One-click setup bakes the endpoint into each agent's project config.

Claude Code
Cursor
Codex CLI
Gemini CLI
VS Code · Copilot
Windsurf
Cline

What “Early Access” means here

Actively developed

Shipping regularly with fast bug-fix turnaround. Expect rough edges — and quick responses.

Price locked for you

Buy at $20 now; it goes to $50 at 1.0. Early buyers keep every update for free.

Source-available to buyers

Access to the private repository and issue tracker comes with your purchase.

Local & safe by default

Editor-only, loopback-only. Nothing is sent anywhere; use it with trusted local tools.

Get it at launch

Listing on Fab is on the way. After buying, request access to the private repo with your Fab order number and GitHub username, and we send an invite.

Coming soon to Fab Already purchased? Request access