Matrix SDK

Matrix SDK is the package-author layer for building Matrix actors, browser surfaces, and broker-connected applications without depending on a managed platform repo.

This repository contains the SDK packages under their target @open-matrix/* package names. The workspace is proven as a standalone workspace: a fresh clone can install, build, test, type-check, pack every package, and compile an external consumer against the packed tarballs.

What You Can Build

• Headless actors with MatrixActor
• Browser custom elements with MatrixActorHtmlElement
• In-memory actor graphs for tests and local development
• NATS-backed transports for broker-connected actors
• Browser host integrations for Matrix web surfaces
• Package-author CLIs and project scaffolds

Matrix SDK is provider-neutral. It does not require a managed platform account, device-link ceremony, host-link implementation, managed host service, local platform install, Postgres database, or provider-owned broker authority. A provider overlay can issue broker credentials and host runtimes on top of the SDK, but the SDK itself must remain usable against any compatible broker.

See STANDALONE-AUDIT.md for the current standalone boundary audit, including the remaining Omega/oracle extraction debt that is not part of the package-author SDK proof.

Packages

Package	Purpose
@open-matrix/sdk	Public umbrella facade for actor/package authors
@open-matrix/core	Actor kernel, runtime, transports, serialization, browser actor base classes
@open-matrix/cli	Package-author matrix CLI
@open-matrix/browser-kit	Browser app shims, theme tokens, Vite helpers, shell components
@open-matrix/browser-host	Browser runtime host shell and app-ready integration
@open-matrix/contracts	Shared type contracts for placement, service registry, and runtime presence
@open-matrix/federation	Cross-realm messaging, MX envelope handling, and routing helpers
@open-matrix/omega-core	Narrow Omega interpreter facade used by Matrix membranes

Prefer narrow imports when possible:

import { MatrixActor } from '@open-matrix/core';

Use the umbrella package when you intentionally want the public SDK facade:

import { MatrixActor } from '@open-matrix/sdk';

Quick Start

git clone git@github.com:matrix-sdk/matrix-sdk.git
cd matrix-sdk
pnpm install --frozen-lockfile
pnpm prove

pnpm prove runs the standalone proof:

clean -> build -> test -> type-check -> pack all packages

For the external-consumer proof:

pnpm prove:external-consumer

That proof packs the SDK packages, creates a temporary consumer outside this repo, installs the packed tarballs, compiles TypeScript, starts a MatrixActor, and calls it through the Matrix runtime/transport path.

Minimal Actor

import {
  InMemoryBroker,
  InMemoryTransport,
  MatrixActor,
  MatrixRuntime,
  TopicRouter,
} from '@open-matrix/core';

class EchoActor extends MatrixActor {
  static accepts = {
    echo: {},
  };

  onEcho(payload: { message?: string }) {
    return {
      ok: true,
      message: payload.message ?? null,
    };
  }
}

const broker = new InMemoryBroker();
const transport = new InMemoryTransport(broker, { name: 'demo' });
const runtime = new MatrixRuntime({ transport, logging: false });

await runtime.create(EchoActor, 'demo.echo');

const replyTo = '$replies.demo';
const response = new Promise((resolve) => {
  const unsubscribe = transport.subscribe(replyTo, (value) => {
    unsubscribe();
    resolve(value);
  });
});

transport.publish(TopicRouter.inbox('demo.echo'), {
  op: 'echo',
  payload: { message: 'hello' },
  replyTo,
  correlationId: 'demo-1',
});

console.log(await response);
await runtime.shutdown();

CLI

The SDK CLI package owns the package-author matrix binary.

matrix init [dir]
matrix add actor <name>
matrix actor <name>
matrix configure --key <key> --cloud <url> --space <space>
matrix run <entry> --mount <mount>
matrix invoke <mount> <op> [json]

The current SDK CLI acceptance proof is:

pnpm prove:cli-uat

The command name uses uat, but its scope is only the SDK package-author CLI flow. It is not managed-platform product UAT, browser signup/login UAT, API-key UI UAT, or live deployment proof.

The CLI is intended to let a package author initialize a folder, add actors, configure broker access, run actors, and invoke them without importing provider overlay packages into the SDK layer. Managed-host promotion is optional and is only exercised when MATRIX_SDK_RUNTIME_HOST_BIN is supplied.

Demos

Standalone SDK demo, no provider account or key required:

pnpm demo:standalone

This builds the SDK and examples/standalone-greeter, starts the actor with matrix run, calls it with matrix invoke, and shuts it down.

HiveCast API-key login/config demo:

export MATRIX_CLOUD=https://dev.hivecast.ai
export MATRIX_SPACE=<your-space-root>
export MATRIX_API_KEY=<your-api-key>
pnpm demo:hivecast-login

This validates the key with HiveCast and writes the SDK package-local .matrix/config.json plus .matrix/credentials/matrix-api-key.json shape without printing or committing the key. By default the demo uses a temporary home and deletes it after success.

Current boundary: this HiveCast demo proves SDK-side key validation and config storage. It does not yet prove a package running directly on a HiveCast-issued broker credential. That requires the provider-owned login/credential-exchange slice so matrix login can replace manual matrix configure and issue/store the broker credentials needed by the SDK transport.

Repository Layout

packages/
  browser-host/
  browser-kit/
  cli/
  contracts/
  core/
  federation/
  omega-core/
  sdk/
scripts/
  demo:standalone
  demo:hivecast-login
  prove-external-consumer.mjs
  prove-sdk-cli-uat.mjs

Current Status

Done and proven:

• The SDK packages build independently from their original source monorepo.
• Package identities use final @open-matrix/* names.
• @open-matrix/sdk re-exports the public actor facade.
• A fresh clone passes pnpm install --frozen-lockfile && pnpm prove.
• A temporary external consumer can install packed SDK tarballs, compile, start a MatrixActor, and call it through Matrix runtime/transport.

Still planned:

• Provider-neutral credential resolution for matrix configure and SDK users.
• Provider login commands that write the same config shape as matrix configure.
• Direct broker mode with explicit broker URL/JWT/seed credentials.
• Managed-provider mode where an overlay issues scoped broker credentials.

Publishing is intentionally not part of this repository's normal developer workflow yet. The repo proves source, package, and consumer behavior with pnpm pack; public package release is an owner-controlled release decision and must be added as an explicit release policy before any npm publication.

Relationship To Provider Overlays

Matrix SDK is the provider-neutral actor SDK.

Provider overlays can provide account management, namespaces, API keys, broker credential issuance, runtime hosting, package distribution, and operator UI. SDK users should still be able to connect to another broker directly when they already manage their own broker credentials.