Engine plugins · Unity beta · untested

CAVS for Unity.

Install and update your game's content by downloading only the chunks that changed between builds — straight from a static CDN export, with no game server. A C# client (P/Invoke over the shared Rust core) plans the missing set locally, downloads it over concurrent HTTP Range requests, verifies every chunk (BLAKE3) and reconstructs your files byte-identically before you load them.

Beta, currently untested. The package compiles against the CAVS C ABI and mirrors the shipping Kotlin/Node bindings 1:1, but it has not yet been validated inside the Unity Editor or on a device. It ships with the native libraries bundled so you can try it — feedback and fixes are welcome.

Download plugin (latest) Plugin source Embeddable fetch docs

Client

Cavs.CavsClient

A C# CavsClient over libcavs_sdk via P/Invoke. Async FetchStaticAsync with progress and cancellation; a persistent content-addressable cache.

No server

static CDN export

Publish once with cavs store export --static-plans; host the tree on S3 / R2 / Pages / nginx. The client updates straight from it.

Verified

byte-identical

Every chunk BLAKE3-verified, every file reconstructed byte-identically (a torn file is never promoted) — the same guarantee as the Godot client.

Install

Drop the package
into your project.

The download bundles the native libcavs_sdk for desktop targets, so it is drop-in on Windows, macOS and Linux.

1 — add the package
Unzip and copy com.cavs.sdk/ into your project's Packages/ folder, or use Package Manager → Add package from disk… and pick its package.json.
2 — natives are bundled
The desktop libraries are already under Plugins/. For Android/iOS, build cavs-ffi for those toolchains and drop the library into the matching Plugins/ folder (see the plugin README).
3 — call it
Reference the Cavs.Sdk assembly and use CavsClient (below). A ready-to-drop updater is in Samples~/SelfUpdate/.
Publish a release

Export a static tree,
upload it anywhere.

You need the CAVS command-line tools once, to package and export builds. Build them from the repository root with cargo build --release.

bash — publish copy
# package the Unity build output (AssetBundles / player data)
$ cavs pack-dir ./Build --profile auto -o build.cavs
# ingest into a packfile store and export a static tree
$ cavs store ./store add game build.cavs --storage packfiles
$ cavs store ./store export --out ./dist --static-plans
# upload to any static host — no cavs-server runs in production
$ aws s3 sync ./dist s3://your-bucket/

Diagnose Unity update cost first with cavs analyze steampipe ./Build_old ./Build_new.

Runtime usage

Self-update
from your game.

The first launch installs the whole build; later launches download only the chunks that changed, reusing the persistent cache. Do it on your loading screen.

using Cavs;

using var client = new CavsClient();

var result = await client.FetchStaticAsync(new FetchStaticRequest {
    base_       = "https://cdn.example.com/game",   // a store export --static-plans tree
    asset       = "game",
    outputDir   = Path.Combine(Application.persistentDataPath, "cavs/install"),
    cacheDir    = Path.Combine(Application.persistentDataPath, "cavs/cache"),
    connections = 8,
}, onProgress: ev => progressBar.value = (float)ev.percentage);

Debug.Log($"fetched {result.chunksFetched}, reused {result.chunksReused}, saved {result.savedPercent:F1}%");
// The reconstructed files are under outputDir; load your AssetBundle from there.

Retries are safe by design: verified chunks stay in the content-addressable cache, so a retried fetch — even after the app was killed mid-download — only fetches what is missing.

CavsClient API

One class,
one loading screen.

MemberDescription
new CavsClient()Owns one native context; reuse across calls, dispose when done
FetchStaticAsync(req, onProgress, cancel)Install/update from a static export off the main thread
Execute(op, json) → stringCall any SDK operation (analyze, preview, packDirectory, …) synchronously
FetchStaticResultchunksFetched, chunksReused, wireBytes, logicalBytes, savedPercent
ProgressEventtype, phase, currentBytes, totalBytes, percentage
CavsException.CodeStable CAVS-E-* code (e.g. CAVS-E-CANCELLED)
Version / AbiVersionNative SDK and ABI versions
Godot plugin → Unreal plugin → All engine plugins