# CyclePack

> Zero-copy asset streaming from memory-mapped archives for Unreal Engine 5, Unity 6, Godot 4.3+, and custom C/C++ runtimes.

CyclePack (https://cyclechain.io/labs/cyclepack/) is an enterprise virtual file system (VFS) and asset streaming SDK written in Rust. It eliminates intermediate RAM allocations by returning direct pointers into memory mappings, protects game assets with whole-archive AES-256-GCM / ChaCha20-Poly1305 encryption, ensures integrity with BLAKE3 per-entry digests, and enables delta game patching with FastCDC.

## Core Documentation & Pages

- [CyclePack Landing Page](https://cyclechain.io/labs/cyclepack/): Feature overview, engine snippets, interactive capabilities, and verified benchmarks.
- [CyclePack Architecture Whitepaper](https://cyclechain.io/labs/cyclepack/whitepaper.html): Comprehensive systems architecture paper covering the VFS read path, archive layout (Format v3), encryption models, and hardware capabilities.
- [Engine Plugins & Integrations](https://cyclechain.io/labs/cyclepack/#engines): Unreal Engine 5 (IPlatformFile & IoDispatcher), Unity 6 (UPM package), Godot 4.3+ (GDExtension), C/C++, and WASM.
- [Evidence & Benchmarks](https://cyclechain.io/labs/cyclepack/#benchmarks): 135 defects fixed, 80.2% test coverage, 166 panic-safe C exports, 25+34 test suites.
- [Pricing & Licensing](https://cyclechain.io/labs/cyclepack/#pricing): Indie ($0), Pro ($2,500/title), Enterprise (from $15,000). 0% runtime royalties, 100% offline.

## Frequently Asked Questions

1. **What is CyclePack, and what problem does it solve?**
   CyclePack is an SDK for packaging, protecting, and loading game assets—including models, textures, and audio—as they are needed at runtime. It integrates with your game engine to reduce unnecessary memory copies, manage asset access, and deliver smaller updates.

2. **What does "zero-copy" mean? Does it work with every file?**
   Zero-copy lets your engine access asset data directly from a memory-mapped archive without copying it into an additional memory buffer. In CyclePack, this applies to uncompressed, unencrypted entries. Compressed or encrypted assets must first be decoded into memory. Zero-copy reduces unnecessary duplication; it does not mean zero RAM usage.

3. **Can I use CyclePack with my existing game engine?**
   CyclePack provides integrations for Unreal Engine 5.4+, Unity 6, and Godot 4.3+. Custom engines can integrate through the C ABI, while browser applications can use the WebAssembly reader. Release v0.10.0 is verified on macOS arm64; Linux and Windows builds are available through source. Consoles are not supported, and mobile builds are not yet available. Some advanced features, including DirectStorage and GPUDirect, currently use emulated implementations. Run `cyclepack doctor` to check which capabilities are native on your system.

4. **Do small changes require players to download the entire asset package again?**
   CyclePack’s FastCDC-based patching identifies changed chunks within files, allowing updates to distribute those chunks instead of the entire package. This can substantially reduce download sizes when only a small portion of a large asset changes. Actual savings depend on the content and the changes made. Snapshots and rollback mechanisms also support restoring earlier content after a faulty update.

5. **How does CyclePack protect assets and detect corruption?**
   Archives can be encrypted with AES-256-GCM or ChaCha20-Poly1305, keeping file paths, sizes, and file counts confidential without the key. BLAKE3 digests detect content corruption, while signed patch manifests authenticate updates. Zero-copy reads do not repeat integrity checks on every access, so archives should be validated during installation using `cyclepack verify`.

6. **Is CyclePack free? Are there royalties or an internet requirement?**
   Studios with combined revenue and funding below $200,000 over the previous 12 months can apply for a free Indie licence. Pro costs $2,500 per title as a one-time payment, while Enterprise starts at $15,000 per title. No tier charges runtime royalties, and the SDK works offline. Pro includes 12 months of SDK updates; renewal is optional, and shipped games continue working with their existing version. SDK access is available by request. The free Indie licence is not an open-source licence.

## Deep Context

- [CyclePack Full Reference Manual (llms-full.txt)](https://cyclechain.io/labs/cyclepack/llms-full.txt): Complete technical architecture, C ABI signatures, CLI tool transcripts, and systems manual.
- [CycleChain Organization Knowledge Base](https://cyclechain.io/llms.txt): Studio context and open-source systems software.