Monolith

One plugin. Every Unreal domain. Zero dependencies.

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What is Monolith?

Monolith is an Unreal Engine editor plugin that gives your AI full read/write access to your project through the Model Context Protocol (MCP). Install one plugin, point your AI client at one endpoint, and it can work with Blueprints, Materials, Animation, Niagara, AI (Behavior Trees, State Trees, EQS, Smart Objects), Gameplay Ability System, Logic Driver state machines, project configuration, and more.

It works with Claude Code, Cursor, or any MCP-compatible client. If your AI tool speaks MCP, it speaks Monolith.

Platform: Windows only. Mac and Linux support is coming soon.

Why Monolith?

Most MCP integrations register every action as a separate tool, which floods the AI's context window and buries the actually useful stuff. Monolith uses a namespace dispatch pattern instead: each domain exposes a single {namespace}_query(action, params) tool, and a central monolith_discover() call lists everything available. Small tool list (18 tools), massive capability (1125 actions across 15 modules). The AI gets oriented fast and spends its context on your actual problem.

What Can It Actually Do?

Blueprint (88 actions) — Full programmatic control of every Blueprint in your project. Create from any parent class, build entire node graphs from a JSON spec, add/remove/connect/disconnect nodes in bulk, manage variables, components, functions, macros, and event dispatchers. Implement interfaces, reparent hierarchies, edit construction scripts, read/write CDO properties on any Blueprint or DataAsset. The auto-layout engine uses a modified Sugiyama algorithm so AI-generated graphs actually look clean. Compare two Blueprints side-by-side, scaffold from templates, manage data tables, user defined structs and enums. Hand the AI a description and it builds the whole thing — or point it at an existing Blueprint and it'll surgically rewire what you need.

Material (57 actions) — Create materials, material instances, and material functions from scratch. Build entire PBR graphs programmatically — add expressions, connect pins, auto-layout, recompile. Drop in custom HLSL nodes. Import textures from disk and wire them directly into material slots. Batch-set properties across dozens of instances at once. Render material previews and thumbnails without leaving the AI session. Full material function support: create, build internal graphs, export/import between projects. Get compilation stats, validate for errors, inspect shader complexity. Covers the full material workflow from creation to validation.

Animation (115 actions) — The entire animation pipeline, end to end. Create and edit sequences with bone tracks, curves, notifies, and sync markers. Build montages with sections, slots, blending config, and anim segments. Set up 1D/2D Blend Spaces and Aim Offsets with sample points. Animation Blueprint graph writing — add states to state machines, create transitions, set transition rules, add and connect anim graph nodes, set state animations. AI can build ABP locomotion setups programmatically, not just read them. PoseSearch integration: create schemas and databases, configure channels, rebuild the search index. Control Rig graph manipulation with node wiring and variable management. Physics Asset editing for body and constraint properties. IK Rig and Retargeter support — chain mapping, solver configuration, the works. Skeleton management with sockets, virtual bones, and curves. 115 actions covering the full animation pipeline.

Niagara (96 actions) — Full system and emitter lifecycle — create, duplicate, configure, compile. Module CRUD with override-preserving reorder so you don't blow away artist tweaks. Complete dynamic input lifecycle: attach inputs, inspect the tree, read values, remove them. Event handler and simulation stage CRUD. Niagara Parameter Collections with full param management. Effect Type creation with scalability and culling configuration. Renderer helpers for every type — mesh assignment, ribbon presets (trail, beam, lightning, tube), SubUV and flipbook setup. Data interface configuration handles JSON arrays and structs natively. Diff two systems to see exactly what changed. Clone overrides between modules, discover parameter bindings, inspect module outputs. Batch execute with read-only optimization so queries don't trigger unnecessary recompiles. Full export_system_spec dumps everything — event handlers, sim stages, static switches, dynamic inputs. Covers the full Niagara workflow from system creation to final polish.

UI (42 actions) — Widget Blueprint CRUD with full widget tree manipulation. Pre-built templates for common game UI: HUD elements, menus, settings panels, confirmation dialogs, loading screens, inventory grids, save slot lists, notification toasts. Style everything — brushes, fonts, color schemes, batch style operations. Create keyframed widget animations. Full game scaffolding: settings systems, save/load, audio config, input remapping, accessibility features. Run accessibility audits, set up colorblind modes, configure text scaling. Covers the full UI workflow from widget creation to accessibility.

Editor (19 actions) — Trigger full UBT builds or Live Coding compiles, read build errors and compiler output, search and tail editor logs, get crash context after failures. Capture preview screenshots of any asset — materials, Niagara systems, meshes. Import textures, stitch flipbooks, delete assets. The AI can compile your code, read the errors, fix the C++, recompile, and verify the fix — all without you touching the editor.

Config (6 actions) — Full INI resolution chain awareness: Base, Platform, Project, User. Ask what any setting does, where it's overridden, what the effective value is, and how it differs from the engine default. Search across all config files at once. Perfect for performance tuning sessions where you want the AI to just sort out your INIs.

Source (11 actions) — Search over 1M+ Unreal Engine C++ symbols instantly. Read function implementations, get full class hierarchies, trace call graphs (callers and callees), verify include paths — all against a local index, fully offline. The native C++ indexer runs automatically on editor startup. No Python, no setup. Optionally index your project's own C++ source for the same coverage on your code. The AI never has to guess at a function signature again.

Project (7 actions) — SQLite FTS5 full-text search across every indexed asset in your project. Find assets by name, type, path, or content. Trace references between assets. Search gameplay tags. Get detailed asset metadata. The index updates live as assets change and covers marketplace/Fab plugin content too — 15 deep indexers registered including DataAsset subclasses.

Mesh (242 actions) — The biggest module by far. 197 core actions across 22 capability tiers, plus 45 procedural town generation actions (work-in-progress -- disabled by default, and unless you're willing to dig in and help improve it, best left alone for now). Mesh inspection and comparison. Full actor CRUD with scene manipulation. Physics-based spatial queries (raycasts, sweeps, overlaps) that work in-editor without PIE. Level blockout workflow with auto-matching and atomic replacement. GeometryScript mesh operations (boolean, simplify, remesh, LOD gen, UV projection). Horror spatial analysis — sightlines, hiding spots, ambush points, zone tension, pacing curves (WIP). Accessibility validation with A-F grading. Lighting analysis (WIP), audio/acoustics with Sabine RT60 and stealth maps (WIP), performance budgeting (WIP). Decal placement with storytelling presets. Level design tools for lights, volumes, sublevels, prefabs, HISM instancing. Tech art pipeline for mesh import, LOD gen, texel density, collision authoring. Context-aware prop scatter on any surface. Procedural geometry — parametric furniture (15 types), horror props (7 types), architectural structures, mazes, pipes, terrain. Genre preset system for any game type. Encounter design with patrol routes, safe room evaluation, and scare sequence generation. Full accessibility reporting.

GAS (130 actions) — Complete Gameplay Ability System integration. Create and manage Gameplay Abilities with activation policies, cooldowns, costs, and tags. Full AttributeSet CRUD — both C++ and Blueprint-based (via optional GBA plugin). Gameplay Effect authoring with modifiers, duration policies, stacking, period, and conditional application. Ability System Component (ASC) management — grant/revoke abilities, apply/remove effects, query active abilities and effects. Gameplay Tag utilities. Gameplay Cue management — create, trigger, inspect cues for audio/visual feedback. Target data generation and targeting tasks. Input binding for ability activation. Runtime inspection and debugging tools. Scaffolding actions that generate complete GAS setups from templates. Accessibility-focused infinite-duration GEs for reduced difficulty modes.

AI (229 actions) — The most comprehensive AI tooling available through any MCP server. Full lifecycle management for Behavior Trees, Blackboards, State Trees, Environment Query System (EQS), Smart Objects, AI Controllers, AI Perception, Navigation, and runtime debugging. Crown jewel actions: build_behavior_tree_from_spec and build_state_tree_from_spec — hand the AI a JSON description of your desired AI behavior and it builds the entire asset programmatically. Create BT nodes (tasks, decorators, services), wire them into trees, configure blackboard keys, set up EQS queries with generators and