OpenBPX is a CLI toolkit designed to read and safely edit Unreal Engine .uasset and .umap files while preserving binary data. It provides developers with a robust toolset for inspecting, modifying, and validating package assets without launching the Unreal Editor.
Key Features:
Binary Preservation Safeguards: Ensures unknown bytes are preserved during edits, maintaining byte-identical round-trip fidelity.
AI Agent Integration: Supports structured output formats (JSON/TOML) and deterministic safety-first write flows with features like --dry-run and --backup.
Cross-Platform Support: Runs on Windows, macOS, and Linux, supporting amd64 and arm64 architectures.
Safety-First Editing: Explicitly rejects unsupported or high-risk operations, treating all input assets as untrusted binary data.
Command-Line Automation: Enables scripted workflows for inspecting properties, DataTables, and Blueprint data.
Audience & Benefit:
Ideal for game developers, automation systems, and AI agents working with Unreal Engine 5.0 to 5.7. OpenBPX empowers users to enhance development efficiency while minimizing risks of asset corruption or unintended changes. Its deterministic operations and safety-focused design make it a reliable tool for integrating package asset editing into broader workflows.
Install via winget on Windows: winget install --id WilddogJP.OpenBPX --exact.
README
OpenBPX: Blueprint Toolkit for Unreal Engine (bpx)
A safety-first CLI for reading and editing Unreal package assets (.uasset, .umap) without launching Unreal Editor.
BPX is designed for automation and scripting workflows where binary safety matters: unknown bytes are preserved, no-op round-trip stays byte-identical, and unsupported/high-risk operations fail explicitly.
Template init, rootless parent-class rewrites, read/add/remove/write for the current supported widget class/property set; broader move/clone and richer styling remain out of scope
High-risk structural rewrites
Partially blocked by design
How It Works
Parse package data into a binary-safe model.
Decode known structures while retaining unknown/raw regions.
Apply deterministic, scoped edits only to the intended region.
Re-serialize with offset/size updates and validation checks.
BPX is created and maintained by Wild Dog, Inc. (株式会社ワイルドドッグ), an indie game development studio based in Japan, operated by a team of 20 members. Our mission is to deliver player-first games where fun always comes first.
