@voluntas-progressus/gbp-stack-wasm — Browser/WASM bindings for the Group Protocol Stack
Browser-native WebAssembly bindings for the Group Protocol Stack: a layered, end-to-end encrypted group-messaging protocol family built on top of MLS (RFC 9420).
All cryptography runs entirely in the browser — no native binaries, no server-side key material. The WASM module is compiled from the same Rust source as the other language bindings and exposes an ergonomic JS/TS API via wasm-bindgen.
Layers
┌── application ──────────────────────────────────────────────────────┐
│ GtpClient · GapClient · GspClient (TCP / UDP / SCTP-like) │
├─────────────────────────────────────────────────────────────────────┤
│ GroupNode (GBP — IP-like base) │
├─────────────────────────────────────────────────────────────────────┤
│ MlsContext (RFC 9420) │
└─────────────────────────────────────────────────────────────────────┘
Bundler compatibility
The package is built with wasm-pack --target bundler. It works out of the box with:
| Bundler | Notes |
|---|---|
| Vite | Add @vitejs/plugin-react or use vite-plugin-wasm |
| webpack 5 | Requires experiments: { asyncWebAssembly: true } |
| Rollup | Use @rollup/plugin-wasm |
| Next.js | Wrap imports in dynamic(() => import('...'), { ssr: false }) |
Install
Quick start
import init, { MlsContext, GroupNode, GtpClient } from "@voluntas-progressus/gbp-stack-wasm";
// Load and compile the WASM module once at startup.
await init();
// ── MLS key exchange ────────────────────────────────────────────────
const aliceMls = MlsContext.create("alice");
const bobMls = MlsContext.create("bob");
// Bob exports a key package so Alice can invite him.
// (In a real app Bob sends this over the signaling channel.)
const welcome = aliceMls.invite(bobMls.keyPackage);
bobMls.acceptWelcome(welcome);
// aliceMls.epoch === bobMls.epoch === 1n
// ── GBP group nodes ─────────────────────────────────────────────────
const groupId = aliceMls.groupId; // shared 16-byte id
const aliceNode = GroupNode.create(1, groupId);
const bobNode = GroupNode.create(2, groupId);
aliceNode.bootstrapAsCreator(aliceMls.epoch);
bobNode.bootstrapAsJoiner(bobMls.epoch, 0);
// ── GTP clients ─────────────────────────────────────────────────────
const gtpAlice = GtpClient.create();
const gtpBob = GtpClient.create();
// Alice sends a message to Bob (target = 2, messageId = 1n)
const frame = gtpAlice.send(aliceNode, aliceMls, 2, 1n, "hello bob!");
// frame.wire: Uint8Array — hand to your WebSocket / WebRTC transport
// Bob receives it
for (const ev of bobNode.onWire(bobMls, frame.wire)) {
if (ev.kind === "payload_received" && ev.streamType === 2 /* Text */) {
const r = gtpBob.accept(ev.plaintext, bobMls.epoch);
if (r) console.log(r.text); // → "hello bob!"
}
}
API reference
MlsContext
| Member | Description |
|---|---|
MlsContext.create(userId: string) |
Creates a new member identity and an empty MLS group |
.keyPackage: Uint8Array |
TLS-serialised key package (pass to the inviter's invite) |
.epoch: bigint |
Current MLS group epoch |
.groupId: Uint8Array |
16-byte group identifier |
.invite(keyPackageBytes: Uint8Array): Uint8Array |
Invites another member; returns Welcome bytes |
.acceptWelcome(welcomeBytes: Uint8Array): void |
Joins a group from a Welcome produced by invite |
GroupNode
| Member | Description |
|---|---|
GroupNode.create(leafIndex: number, groupId: Uint8Array) |
Creates a GBP node for the given member id and 16-byte group id |
.bootstrapAsCreator(epoch: bigint) |
Drives the node to ACTIVE as the group creator |
.bootstrapAsJoiner(epoch: bigint, expectedFirstTid: number) |
Drives the node to ACTIVE as a joiner |
.onWire(mls: MlsContext, wireBytes: Uint8Array): NodeEvent[] |
Delivers a wire frame; returns decoded events |
.checkTimeouts(): NodeEvent[] |
Polls timeout events — call ~every 500 ms from the app loop |
.lastTransitionId: number |
transition_id of the last applied epoch transition |
.currentEpoch: bigint |
Current epoch as seen by the GBP layer |
.memberId: number |
This node's member id (leaf index) |
GtpClient
| Member | Description |
|---|---|
GtpClient.create() |
Creates an empty GTP client |
.send(node, mls, target, messageId, text) |
Encrypts and frames a text message; returns { wire: Uint8Array, to: number } |
.accept(plaintext, epoch) |
Decodes a GTP payload; returns { text, messageId, senderId, status } or null |
.reset() |
Clears the idempotency set |
accept return value:
| Field | Type | Description |
|---|---|---|
text |
string |
Decoded message text |
messageId |
bigint |
Sender-assigned message identifier |
senderId |
number |
Leaf index of the sender |
status |
"new" | "duplicate" |
Whether this message id was seen before |
NodeEvent shape
Every event object from onWire / checkTimeouts carries kind: string.
kind |
Extra fields |
|---|---|
"payload_received" |
streamType: number, plaintext: Uint8Array, sequenceNo: number, codec: number |
"state_changed" |
from: string, to: string |
"epoch_advanced" |
epoch: bigint, transitionId: number |
"error" |
code: number, reason: string, fatal: boolean, retryable: boolean |
"control" |
from: number, opcode: number, transitionId: number |
Stream types
| Value | Name | Sub-protocol |
|---|---|---|
0 |
Control | GBP control plane |
1 |
Audio | GAP (Group Audio Protocol) |
2 |
Text | GTP (Group Text Protocol) |
3 |
Signal | GSP (Group Signaling Protocol) |
Examples
| File | Description |
|---|---|
examples/gtpChat.ts |
Two-member encrypted text chat (TypeScript, Node.js ≥ 18) |
examples/gtpChat.html |
Standalone browser demo (no bundler needed) |
Testing
Tests are written with wasm-bindgen-test and run inside Node.js:
# Install wasm-pack if needed
# Run all WASM tests
The test suite covers:
MlsContext: create, epoch, keyPackage, groupId, invite / acceptWelcomeGroupNode: bootstrap (creator + joiner), onWire, checkTimeouts, gettersGtpClient: send, accept (roundtrip, unicode, duplicate, sequential, reset)- Two-member group: Alice→Bob, Bob→Alice, bidirectional, epoch sync
Vite configuration example
// vite.config.ts
import { defineConfig } from "vite";
import wasm from "vite-plugin-wasm";
import topLevelAwait from "vite-plugin-top-level-await";
export default defineConfig({
plugins: [wasm(), topLevelAwait()],
});
Then in your entry point:
import init from "@voluntas-progressus/gbp-stack-wasm";
await init();
License
Licensed under Apache License, Version 2.0.