Apollo Connectors preview.4 release

About the Community Announcements
1

Hello! We released a new preview version of connectors with one breaking change and one super useful new feature. Check out the changelog here!

To use the new version:

  • Update your supergraph.yaml files to point to federation_version: =2.10.0-preview.4
  • Pass APOLLO_ROVER_DEV_ROUTER_VERSION=2.0.0-preview.4 to rover dev
  • Continue using Federation Next as the build pipeline version for your variants in GraphOS. You’ll pick up preview.4 on your next publish.

New feature: ->methods in URLs and headers

Methods for value transformations are a powerful feature of connectors. Previously, they were available only in @connect(selection:) and @connect(http: {body:}), but you can now use them in the {dynamic} segments of URL paths and header values.

type Query {
  products(status: Status): [Product]
    @connect(
      http: { 
        GET: "http://my.api/products?status={$args.status->match(["AVAILABLE", "in stock"], [@, @])}"
        headers: [
          { name: "x-header", value: "{$context.value->slice(0, 100)}" }
        ]
      }
      selection: "id status: status->match(["in stock", "AVAILABLE"], [@, @])"
    )
}

Breaking change when using @key directives

The breaking change clarifies the relationship between @key directives and @connect(entity: true). When you add a @key directive to a type, you’re declaring that you can resolve instances of that type when given the keys fields. In a subgraph, you would implement that with something like __resolveReference() in Apollo Server.

When using Apollo Connectors, adding entity: true to certain connectors is the basically the same as defining __resolveReference(). So if you don’t have an entity: true connector, we now tell you that you’ve defined a @key but have not defined a resolver for that key. The error message looks like:

MISSING_ENTITY_CONNECTOR: [storefront] Entity resolution for 
`@key(fields: "id")` on `Product` is not implemented by a connector.
See https://go.apollo.dev/connectors/directives/#rules-for-entity-true

The most common remediation is to add resolvable: false to your @key, which marks the type as an entity, but informs federation that this subgraph doesn’t provide an entity resolver.

General availability is coming soon!

We’re dotting our Is and crossing our Ts so we can remove the “preview” label from Apollo Connector fairly soon, marking the feature as generally available and ready for use in production. Stay tuned for more info on the release, and please post questions and feedback here using the connectors tag. Thank you!

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