Grafbase Federation Demo

This demo repository showcases Grafbase extensions and how they enable easy composition and schema consistency across different types of subgraphs: GraphQL subgraphs (products), databases (PostgreSQL), message queues (NATS), and REST APIs (rest-factories).

Services Overview

This demo includes the following services:

• Products: GraphQL subgraph for product management
• Inventory: GraphQL subgraph for inventory tracking
• Orders: GraphQL subgraph for order processing
• Orders-PG: PostgreSQL database exposed as a GraphQL subgraph via Grafbase PostgreSQL extension
• Sales: NATS message queue exposed as a GraphQL subgraph via Grafbase NATS extension
• REST Factories: REST API exposed as a GraphQL subgraph via Grafbase REST extension
• gRPC Services: A separate demo setup with gRPC-based subgraphs (see grpc/README.md)

Getting Started

Prerequisites

Install the Grafbase CLI using one of the following methods:

# Using npx
npx grafbase

# Using curl
curl -fsSL https://grafbase.com/downloads/gateway | bash

# Or see full installation instructions
# https://grafbase.com/docs/gateway/installation

Running the Demo

1. Start all services with Docker Compose:

   docker compose up

2. Run the Grafbase development server:

   grafbase dev

3. Access the grafbase dev UI at http://localhost:5000

Example queries

Simple query to the products subgraph:

query ListProducts {
  products {
    brand
    name
  }
}

Postgres query:

query OrdersSortedByAmount {
  orders(
    first: 5
    orderBy: [{ totalAmount: DESC }]
  ) {
    edges {
      node {
        orderId
        orderDate
        status
        totalAmount
        customer {
          name
          email
        }
        orderItems(first: 2) {
          edges {
            node {
              productName
              quantity
              unitPrice
            }
          }
        }
      }
    }
  }
}

Join from REST (factories) to GraphQL (products) to Postgres (orders):

query RestToGraphQLToPostgres {
  factories {
    lng
    lat
    product {
      brand
      color
      latestCustomer {
        address
      }
    }
  }
}

Post to NATS:

mutation SellProduct {
  sellProduct(input: { productId: "converse-1", price: 200 })
}

To subscribe to the sales NATS topic defined in the sales subgraph, use the subscription.sh script. It starts a Server Sent Events based GraphQL subscription against localhost:5000/graphql with curl. You should see the event from the mutation above when running this.

Repository Structure

• /gateway - Gateway configuration for deployment to Fly.io (ignore this in local setups)
• /grpc - Separate demo with gRPC-based subgraphs
• /products, /inventory, /orders - GraphQL subgraphs
• /orders-pg - PostgreSQL backed subgraph with an orders database
• /sales - NATS message queue subgraph
• /rest-factories - REST API service

Learn More

• Grafbase Documentation
• Open source extensions marketplace and repository