Microservices & Federation

ObjectQL provides a built-in mechanism to aggregate data from multiple services into a single unified graph. This is similar to GraphQL Federation or Salesforce's External Objects, but strictly for the ObjectQL protocol.

Concept: Remote Remotes

You can configure an ObjectQL instance to act as a Gateway. It connects to other ObjectQL instances, downloads their metadata (Schema), and automatically creates proxy drivers for them.

• Source of Truth: The microservice defines the object (user.object.yml).
• Proxy: The gateway sees a virtual object (user) and forwards all queries (Find, Update, Actions) to the microservice.

Configuration

The Subgraph (Service A)

This is a standard ObjectQL service running standard drivers (SQL/Mongo). It exposes the metadata API via protocol plugins.

// user-service/index.ts
import { ObjectStackKernel } from '@objectstack/runtime';
import { HonoServerPlugin } from '@objectstack/plugin-hono-server';

const kernel = new ObjectStackKernel([
    { name: 'user-service', objects: { /* user, role */ } },
    new SqlDriver({ /* ... */ }),
    new ObjectQLPlugin(),
    new HonoServerPlugin({ port: 3000 })
]);
// Exposes http://user-service:3000/api/metadata/objects
await kernel.start();

The Gateway

The gateway aggregates multiple services.

// gateway/index.ts
const app = new ObjectQL({
    // No local source needed, just remotes
    remotes: [
        'http://user-service:3000',
        'http://order-service:3000'
    ]
});

await app.init();

Usage

Once initialized, the Gateway behaves exactly like a monolith.

// Code running on Gateway
// Transparently forwards request to User Service via HTTP
const users = await app.object('user').find({
    filters: { status: 'active' }
});

Benefits

1. Decoupling: Services manage their own schema migrations and domain logic.
2. Unity: Frontend or upper layers see a single API surface.
3. Hybrid: A Gateway can also have local objects. You can mix "local cache tables" with "remote live tables" in the same application.