Feature matrix
Exactly what's available in each runtime. The Platform API is identical; runtimes differ only in rendering, input, and networking.
This is the answer to "does this work on Unreal?" The Platform API is identical across runtimes by design — the differences are confined to rendering, input, and networking. We track them here rather than scattering "N/A on this runtime" notes through the reference.
Web is canonical
The Web SDK is the frozen contract. A ✅ in the Web column is the source of truth; the Unreal column reflects mirror status. Anything not yet at parity is marked 🟡.
Platform API
| Capability | Web | Unreal |
|---|---|---|
Authentication & Identity (Helix.auth, Helix.profile) | ✅ | ✅ |
LIX & Economy (Helix.wallet, Helix.marketplace) | ✅ | ✅ |
Data Store (Helix.dataStore) | ✅ | ✅ |
Memory Store (Helix.memoryStore) | ✅ | ✅ |
Inventory & Items (Helix.inventory) | ✅ | ✅ |
Social & Presence (Helix.social) | ✅ | ✅ |
Chat (Helix.chat) | ✅ | ✅ |
Voice / proximity (Helix.voice) | ✅ | ✅ |
Avatars (Helix.avatar) | ✅ | ✅ |
Analytics (Helix.analytics) | ✅ | ✅ |
Runtime-specific
| Capability | Web | Unreal |
|---|---|---|
| Instant play from a link (no install) | ✅ | — |
HELIX multiplayer & networking (Helix.network) | ✅ | — |
| Engine-native dedicated-server networking | — | ✅ |
| Replication wrappers | — | ✅ |
| Rendering / scene graph | Web stack (Three.js etc.) | Unreal |
| Languages | TypeScript / JS | C++ · Blueprint · Lua |
Legend: ✅ available · 🟡 in progress · — not applicable to this runtime.
Parity is enforced, not hoped for
A CI check compares the generated Web reference against the generated Unreal reference and flags any Platform API method that exists on one but not the other. This matrix is generated from that check, so it can't silently drift.