Using multiple endpoints in Apollo Client

user_14150695 0
Viewed 4978

this is my first discussion post here. I have learned Apollo + GraphQL through Odyssey. Currently, I am building my own project using Next.js which required fetching data from 2 GraphQL endpoints.

My problem: How can I fetch data from multiple GraphQL endpoints with ApolloClient?

Below is my code for my first endpoint:

import { ApolloClient, InMemoryCache, createHttpLink } from "@apollo/client";

const client = new ApolloClient({
  ssrMode: true,
  link: createHttpLink({
    uri: "https://api.hashnode.com/",
    credentials: "same-origin",
    headers: {
      Authorization: process.env.HASHNODE_AUTH,
    },
  }),
  cache: new InMemoryCache(),
});

export default client;
apollo-client apollo graphql next.js javascript
2 Answers

What you are trying to accomplish is kinda against Apollo's "One Graph" approach. Take a look at gateways and federation - https://www.apollographql.com/docs/federation/

With that being said, some hacky solution is possible but you will need to maintain a more complex structure and specify the endpoint in every query, which undermines the built-in mechanism and might cause optimization issues.

//Declare your endpoints
const endpoint1 = new HttpLink({
    uri: 'https://api.hashnode.com/graphql',
    ...
})
const endpoint2 = new HttpLink({
    uri: 'endpoint2/graphql',
    ...
})

//pass them to apollo-client config
const client = new ApolloClient({
    link: ApolloLink.split(
        operation => operation.getContext().clientName === 'endpoint2',
        endpoint2, //if above 
        endpoint1
    )
    ...
})

//pass client name in query/mutation
useQuery(QUERY, {variables, context: {clientName: 'endpoint2'}})

This package seems to do what you want: https://github.com/habx/apollo-multi-endpoint-link

Also, check the discussion here: https://github.com/apollographql/apollo-client/issues/84

user_83753320

Encountered the same problem today. I wanted to have it dynamic so this is what I came out with:

export type DynamicLinkClientName = "aApp" | "bApp" | "graphqlApp";
type Link = RestLink | HttpLink;
type DynamicLink = { link: Link; name: DynamicLinkClientName };
const LINK_MAP: DynamicLink[] = [
  { link: aRestLink, name: "aApp" },
  { link: bAppRestLink, name: "bApp" },
  { link: graphqlAppLink, name: "graphqlApp" },
];

const isClientFromContext = (client: string) => (op: Operation) =>
  op.getContext().client === client;

const DynamicApolloLink = LINK_MAP.reduce<ApolloLink | undefined>(
  (prevLink, nextLink) => {
    // When no name is specified, fallback to defaultLink.
    if (!prevLink) {
      return ApolloLink.split(
        isClientFromContext(nextLink.name),
        nextLink.link,
        defaultLink
      );
    }
    return ApolloLink.split(
      isClientFromContext(nextLink.name),
      nextLink.link,
      prevLink
    );
  },
  undefined
) as ApolloLink;
user_35356480
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