BPeek

Blueprint and asset introspection for Unreal Engine 5.4+. A single editor plugin that scans your project and writes a tree of cross-linked markdown — one file per Blueprint, widget, enum, struct, data table, level, level sequence, input mapping, gameplay ability, flow asset, behavior tree, and more. Feed it to an AI agent and ask questions about the project without opening the editor or clicking through BP graphs.

No external .exe. No .NET. Works on vanilla binary UE installs.

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Quickstart

From a pre-built release (vanilla engine users)

1. Download the latest BPeek-vX.Y.Z-UE5.4-Win64.zip from the GitHub Releases page.

2. Extract it into <YourProject>/Plugins/BPeek/ — you should end up with <YourProject>/Plugins/BPeek/BPeek.uplugin at that path.

3. Add BPeek to your .uproject plugins:

   "Plugins": [
       { "Name": "BPeek", "Enabled": true }
   ]

4. Open the project in UE. No compile step — the release zip ships pre-built Win64 DLLs.

5. Tools → BPeek → Scan project. Markdown lands in <YourProject>/Saved/BPeek/.

From source (Flow users or contributors)

The release zip ships Source/ alongside the pre-built binaries — you can recompile in-place against your engine + plugin set without re-cloning. Or clone the repo directly.

1. Drop the unzipped package (or the cloned repo) into <YourProject>/Plugins/BPeek/.

2. Delete Plugins/BPeek/Binaries/ so UBT rebuilds against your local engine.

3. Add the same .uproject entry as above.

4. Open the project — UBT compiles the plugin on first launch (~30–40 s cold, ~3 s warm).

5. Scan via Tools → BPeek menu or the headless commandlet:

   UnrealEditor-Cmd.exe YourProject.uproject -run=BPeekScan -unattended -nosplash -nop4

Source rebuild picks up the community Flow plugin automatically: if Engine/Plugins/Marketplace/Flow/ exists, BPeekFlow.Build.cs flips BPEEK_WITH_FLOW=1 and FlowAsset rendering switches on. The default release zip ships a Flow stub (loads cleanly on hosts without Flow); a parallel -Flow zip with the full integration is also published for projects that already use Flow.

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What BPeek renders

BPeek covers the engine's native asset types plus a handful of popular optional plugins. Each group activates separately — a domain submodule is a no-op if its target plugin isn't available at build time, and everything else keeps rendering.

Engine types (always available). These ship with every UE 5.4 install and don't need any extra plugins:

Asset type	Rendered by
Blueprint (inc. Widget / Anim BP)	core
UserDefinedEnum	core
UserDefinedStruct	core
DataTable	core
Level (UWorld)	core
LevelSequence	core
DataAsset / PrimaryDataAsset	core (generic fallback)
Gameplay tag registry + usages	core

Engine built-in plugins (always available on a vanilla 5.4 install). These plugins ship with the engine but have to be enabled per-project; BPeek renders their assets if the host project uses them:

Asset type	From plugin	Rendered by
InputMappingContext	EnhancedInput	EnhancedInput submodule
GameplayAbility / Effect / AttributeSet	GameplayAbilities	GAS submodule
BehaviorTree / BlackboardData	AIModule	BehaviorTree submodule

Community / marketplace plugins (optional, build-time detected). These aren't part of UE itself — they're installed separately. Release zips don't include their renderers because community plugins have major-version breaks that can't be covered by a single binary; install BPeek from source and the correct binary gets produced automatically.

Asset type	From plugin	Rendered by
FlowAsset + FlowNodeBlueprint	Flow (Moth Cocoon)	Flow submodule

More renderers are straightforward to add — see Docs/WRITING-AN-EXTENSION.md.

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How it works, in one paragraph

The BPeekScan commandlet walks the Asset Registry and the in-memory UObject graph, collects per-asset metadata, then dispatches every asset through an IBPeekExtension registry. Core ships built-in renderers for the engine-native asset types; submodules handle domain-specific types (GAS / IMC / Flow / BT). Output mirrors the project's mount-point layout — /Game/UI/W_Menu.W_Menu becomes Saved/BPeek/Game/UI/W_Menu.md. Per-file layouts are tuned for AI consumption (compact tables, inline one-liners, .logic.md companions for Blueprint pseudo-code).

Long version: Docs/02-how-it-works.md.

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Commandlet

UnrealEditor-Cmd.exe <Project>.uproject -run=BPeekScan [flags]

Flag	Effect
-bpeekmd=<path>	Override output directory (default <Project>/Saved/BPeek/)
-only-changed	Incremental — hash-diff + regen only changed assets
-recompile	Per-BP CompileBlueprint pass; surface compiler errors
-asset=<path1>,<path2>,…	Scope: specific asset paths only
-bpeekmdfilter=<prefix>;<prefix>	Scope: restrict to given path prefixes
-verbose	Expanded layout (full tables, single-file BP output)

The Tools → BPeek menu wraps the same commandlet with preset scopes: whole project, changed-only, compile audit, active level + sublevels, open Blueprints, folder or asset selection.

Full reference: Docs/03-commands.md.

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Configuration

Filter what gets scanned via Project Settings → Plugins → BPeek, or by committing a Config/DefaultBPeek.ini in your project:

[/Script/BPeek.BPeekSettings]

+IncludePatterns=/Game/**
+IncludePatterns=/MyGameFeature/**

+ExcludePatterns=/Game/Megascans/**
+ExcludePatterns=**/BakedStaticMeshActor*

+Key=Value appends to the default list. !IncludePatterns=ClearArray resets first if you need to replace the defaults entirely. Glob syntax: * (not /), ** (any segments), ? (single char).

Shipped default patterns live in Config/BaseBPeek.ini — commented-out reference for every setting the plugin understands.

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Documentation

File	Topic
Docs/README.md	Docs index
Docs/01-architecture.md	Modules, extension registry, config layering
Docs/02-how-it-works.md	Scan pipeline from commandlet launch to markdown
Docs/03-commands.md	Commandlet flags, editor menu, helper scripts
Docs/04-output-formats.md	What each markdown file looks like
Docs/05-limitations.md	What the scanner can't see and why
Docs/06-development.md	Dev setup, build, tests, logging, troubleshooting
Docs/WRITING-AN-EXTENSION.md	Adding a new renderer as a submodule

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Engine support

• UE 5.4, 5.5, 5.6, 5.7 — pre-built release zips published per engine version (BPeek-vX.Y.Z-UE5.<minor>-Win64.zip, plus …-UE5.<minor>-Win64-Flow.zip variants with the community Flow plugin linked in).
• Newer engine versions: build from source. .Build.cs files gate UE-version-specific polyfills via BPEEK_UE_5_X_OR_LATER preprocessor macros. No branches, no per-engine forks.
• Verified hosts per engine:
  • 5.4 / 5.5 — Lyra Starter Game, Cropout Sample Project, FlowSolo demo.
  • 5.6 / 5.7 — Lyra Starter Game, Cropout Sample Project, FlowGame demo (Flow 2.2).

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License

MIT — see LICENSE.