Platform API overview

The engine-agnostic surface of HELIX — identity, economy, storage, inventory, and social — exposed identically on every runtime.

The Platform API is the part of HELIX that has nothing to do with rendering: identity, economy, storage, inventory and social. The Web SDK defines it, and the Unreal plugin mirrors the same method names from a generated contract table. Not every method is available on Unreal yet; the feature matrix lists the gaps. These pages describe the semantics: what each capability does, what the server guarantees, and what the error cases are.

How to read these pages

Each Platform API page is language-neutral. Code samples use the runtime tabs you've seen — pick your runtime once and it sticks. The Web (TS) signature is canonical; other runtimes mirror it.

The surface

Authentication & Identity

One account across every world. Launch tickets, sessions, guests, profiles.

LIX & Economy

The wallet, purchases, the marketplace, and in-world purchases.

Data Store

Durable, authoritative per-world key–value storage.

Memory Store

Volatile, low-latency, TTL'd state shared across instances.

Inventory & Items

Universal items and the four-tier execution model.

Social & Presence

Friends, presence, and invites.

Analytics

The event contract, vendor split, privacy boundary, and rollout plan.

The `Helix` namespace

On the Web runtime the platform is reached through a single Helix object. These members ship in @hypersoniclabs/helix-sdk today:

Helix.auth        Helix.avatar      Helix.emotes       Helix.locomotion  Helix.world
Helix.multiplayer Helix.voice       Helix.party        Helix.matchmaking Helix.listen
Helix.wallet      Helix.inventory   Helix.marketplace  Helix.purchases
Helix.dataStore   Helix.leaderboard Helix.achievements Helix.analytics
Helix.presence    Helix.notify      Helix.prompts      Helix.device      Helix.camera
Helix.materials   Helix.customizer  Helix.trial        Helix.debug

plus the top-level Helix.init(), Helix.getSessionToken(), Helix.hasLeft() and Helix.onLeave(). The exact signatures are in the generated Web SDK API reference.

The contract also specifies Helix.memoryStore, Helix.social, Helix.chat, Helix.moderation, Helix.ui and Helix.assets. Those are not shipped yet; their pages are marked as planned.

Initialize once at startup. init() takes no arguments, because the shell supplies the session:

const { embedded, world, user } = await Helix.init();
// also on the result: runtimeFidelity, customizerSubject, customizerSource

Two rules that run through everything

1. The server owns value

Anything affecting inventory, currency, or ownership is server-authoritative. Clients are trusted only for visuals and local gameplay. See the Universal Item Contract.

2. Storage has two tiers

Data Store is durable and authoritative, the source of truth. Memory Store (planned) is volatile, fast, and always requires a TTL, never the source of truth. Don't reach for one when you mean the other.