Apollo Federation

Federation helps companies implement GraphQL at scale and allows you to combine multiple GraphQL APIs (subgraphs) into a single Supergraph. WunderGraph has native support for Apollo federation, it supports Queries, Mutations as well as Subscriptions.

It brings a lot of useful features to implement Graphs across multiple teams in a "federated" way, hence the name. It was invented and specified by Apollo .

WunderGraph is extremely fast executing GraphQL Operations and is therefore a great fit for a Federation Gateway.

To add a Apollo Federation data source, edit .wundergraph/wundergraph.config.ts and introspect the SubGraphs like the config below.

import { configureWunderGraphApplication, introspect } from '@wundergraph/sdk';

const federatedApi = introspect.federation({
  apiNamespace: 'federated',
  upstreams: [
    {
      url: 'http://localhost:4001/graphql',
    },
    {
      url: 'http://localhost:4002/graphql',
    },
    {
      url: 'http://localhost:4003/graphql',
    },
    {
      url: 'http://localhost:4004/graphql',
    },
  ],
});

configureWunderGraphApplication({
  apis: [federatedApi],
});

Simply add all the URLs of your SubGraphs to the upstreams array.