# Matrix SDK

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

This repository contains the SDK packages that were split out of Matrix-3 and
renamed to their publishable `@open-matrix/*` package names. The split 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 HiveCast, Device Link, Host
Link, Host Service, or a local HiveCast install. HiveCast is one managed provider
that can issue broker credentials and host runtimes on top of the SDK.

## 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:

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

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

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

## Quick Start

```bash
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:

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

For the external-consumer proof:

```bash
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

```ts
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.

```bash
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:

```bash
pnpm prove:cli-uat
```

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

## Repository Layout

```text
packages/
  browser-host/
  browser-kit/
  cli/
  contracts/
  core/
  federation/
  omega-core/
  sdk/
scripts/
  prove-external-consumer.mjs
  prove-sdk-cli-uat.mjs
```

## Current Status

Done and proven:

- The SDK packages build independently from Matrix-3.
- 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.
- `matrix login --provider hivecast` to write the same config shape as
  `matrix configure`.
- Direct broker mode with explicit broker URL/JWT/seed credentials.
- HiveCast provider mode where HiveCast issues scoped broker credentials.
- Publishing the packages to npm after the provider-login contract is complete.

## Relationship To HiveCast

Matrix SDK is the open, provider-neutral actor SDK.

HiveCast is a managed overlay on top of Matrix SDK. HiveCast can provide account
management, Spaces, 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.