Overview

Poetic Plates is meant to be a public API, ready to receive and resolve requests from anyone through a web app, mobile app, or another API– the possibilities are endless!

To enable this, we want to allow folks to easily explore the schema and query the supergraph. We've seen how straightforward it is to build queries using Explorer, so we'll enable this for others as well!

We also want to allow client app developers to send requests to the supergraph. By default, the current CORS policies are blocking them from doing so.

In this lesson, we will:

• Create a public variant
• Configure the cloud router to accept requests from any origin

Graph variants

A variant represents a different environment where the supergraph runs. For example, you could have a variant for staging or pre-production, a common environment where we can test our schema changes before they go live. You could have another variant for production, the version that clients are using and can be confident in.

In GraphOS, each variant of a supergraph has its own schema, metrics, change history, and operation history.

So far, we've been working with only one version of our supergraph: the version that's currently running in production. This is actually our very first variant, and its default name is main. By default, this variant is private and only visible to members of our Studio organization.

We want to allow folks who want to use our API to explore the schema freely and send queries using Explorer, so we'll need to make this variant public.

By making a public variant, our API consumers will be able to see these pages:

• Home: shows the variant's README. Much like a repository README, this is helpful for introducing folks to the Poetic Plates API, onboarding them to get started with it.
• Schema: shows the types and fields that make up the supergraph.
• Explorer: enables consumers to send queries to the supergraph, just like we have!
• Changelog: shows the recent changes to your supergraph.

The pages showing your supergraph's metrics (Fields, Operations) and settings won't be viewable!

Creating a public variant

Let's go ahead and make our main variant public.

1. Go to your variant's Settings page and open the This Variant tab.

2. Find the Public card and click Change.

   https://studio.apollographql.com

   

3. Select On and save your changes.

   https://studio.apollographql.com

   

4. You'll notice that the header at the top now shows a button labeled "Public". Click on it to navigate to the public version of the supergraph.

Notice that we're only able to see the four pages we mentioned earlier. We're good to go and we can share this public variant link for others to explore!

Configuring the cloud router cors options

Next, we need to allow any web-based app consumer to send requests to the supergraph. We want Poetic Plates to be used widely, after all! We'll need to configure the cloud router cors options to enable this.

Back in Studio, in our supergraph's Settings page, under This Variant we'll click on the Cloud Routing tab.

This is where we can configure how the cloud router runs. We've already got some default configuration under the Router Configuration YAML section.

The first key, cors contains another key (origins), which contains the list of URLs that are allowed to query the router. Right now, only Studio is allowed to query the router!

We can also see headers configuration for the recipes subgraph, which propagates every single request header. We won't worry too much about that, but we do want to change the cors property!

Let's remove the origins list because we're not going to specify every single origin to allow. Below (still nested within the cors property), we're going to add a new property called allow_any_origin and set it to true.

Then, hit Save.

If we didn't set this option, client app developers would see an error in their browser, noting that their localhost or production URL has been blocked by CORS policy.

Now you're free to share your router URL with your client app developers!

Practice

Key takeaways

• To enable others to explore and query a public-facing API, you can create a public variant in Studio.
• To enable any web app consumer to connect to your public-facing API, you can configure the cloud router's cors settings and set allow_any_origin to true.

Up next

We can share our supergraph to the world, amazing! Let's learn how we're going to monitor the usage of our supergraph now that it's out in the wild.