Manage Subgraphs

Learn how to effectively manage subgraphs in GraphOS Studio. This guide covers viewing subgraphs, modifying routing URLs, safely deleting subgraphs, and managing contact information and schema tagging for a well-organized supergraph.

Viewing subgraphs

After you create a supergraph or new variant, you can view a list of its associated subgraphs from the variant's Subgraphs page:

The list includes each subgraph's name and routing URL, along with type and field counts for each subgraph's schema.

Viewing subgraph SDL

The Schema > SDL page in Studio displays the raw SDL for each schema type associated with your supergraph—an API schema, a supergraph schema, and subgraph schemas.

From this page, you can:

• View metadata about the composed supergraph, along with metadata about each subgraph (such its endpoint URL and most recent schema registration date)

• Identify which subgraphs define any type or field in your API and share a link with team members

• Search for types and fields

• Download a copy of your subgraph's SDL for local development

• Filter out comments and deprecated fields for improved scanning

Viewing a field's originating subgraph

The Schema > Reference page in Studio displays a table of your supergraph's types and fields. This table includes a Subgraph column, which lists the subgraphs that define each type and field:

Clicking the subgraph link for a type or field takes you to the line where it's defined in the corresponding subgraph schema:

If you're using the @contact directive to specify owner contact information for your subgraphs, hovering over a subgraph name displays its contact information, enabling you to follow up with the appropriate team:

Modifying a subgraph

From your variant's Subgraphs page, you can modify an existing subgraph's routing URL:

1. Open the ••• menu for the subgraph you want to modify:

   

2. Click Edit routing URL.

3. In the dialog that appears, provide a new URL and click Update.

   • Your router automatically begins using the new URL to communicate with your subgraph.

If you need to make any other modifications to an existing subgraph, use the Rover CLI. Learn about rover subgraph commands.

Deleting a subgraph

You can delete an existing subgraph from a variant of your cloud supergraph. If you do:

1. The variant automatically attempts to compose an updated supergraph schema using the schemas from all remaining subgraphs.

   • Studio displays the result of this attempt, and you can cancel the deletion if there are errors.

2. If composition succeeds, the variant's router automatically begins using the updated supergraph schema. This means clients can no longer query the router for fields that are defined only in the deleted subgraph.

   If composition fails, the router continues using its existing supergraph schema. This means clients can continue querying the router for fields from the deleted subgraph, until the remaining subgraph schemas are updated to compose successfully.

Important considerations

• Deleting a subgraph can break existing clients! This action is equivalent to removing all the subgraph's types and fields from your supergraph (unless they're also defined in another subgraph). If a client sends an operation that includes any of those types and fields, the router will reject that operation.

  • To help you remove schema definitions safely, learn about schema checks.

• Deleting a subgraph in Studio has no effect on your actual running subgraph instance. It only removes your router's knowledge of that instance and its corresponding schema fields.

Steps to delete within Studio

1. Go to the Subgraphs page for the subgraph's corresponding variant.

2. Click the ••• button on the right of the subgraph you want to delete:

   

3. Click Delete subgraph. Studio attempts to compose a new supergraph schema that doesn't include the subgraph you want to delete.

4. A confirmation dialog appears that displays any composition errors that occurred. If you're sure you want to delete the subgraph, enter its name and click Delete subgraph.

Contact info for subgraphs

You can use the @contact directive to add your team's contact info to a subgraph schema. This info is displayed in Studio, which helps other teams know who to contact for assistance with the subgraph:

The contact info includes a name (of a team or individual), along with an optional description and custom URL.

Adding the @contact directive

To use the @contact directive in your subgraph schema, you first need to define the directive in your schema. Add the following definition to each of your subgraph schemas:

1"Annotate a schema with contact information for the subgraph owner"
2directive @contact(
3  "Contact title of the subgraph owner"
4  name: String!
5  "URL where the subgraph's owner can be reached"
6  url: String
7  "Other relevant notes can be included here; supports markdown links"
8  description: String
9) on SCHEMA

You can now apply the @contact directive to each subgraph schema's special schema object. If your schema doesn't already define this object, you can add it like so:

1extend schema
2  @contact(
3    name: "Acephei Server Team"
4    url: "https://myteam.slack.com/archives/teams-chat-room-url"
5    description: "send urgent issues to [#oncall](https://yourteam.slack.com/archives/oncall)."
6  )

Supported @contact fields

Viewing contact info

After you publish a subgraph schema that includes the @contact directive, the contact information is included in the metadata shown in Studio's Schema > SDL tab:

In the Schema > Reference tab, you'll also see a contact card when you hover over the subgraph link of a type or field:

Known @contact limitations

• To provide the @contact directive to Apollo, you must publish your subgraph schemas by providing a local .graphql file as the --schema option of rover subgraph publish.

  • If you provide an introspection result to the command instead, the @contact directive is not included in that result.

Schema tagging

In your subgraph schemas, you can use the @tag directive to tag a type or field with an arbitrary string value:

1type Product {
2  id: ID!
3  name: String!
4  codename: String! @tag(name: "internal")
5}

By default, these tags are removed from the API schema that's generated as part of composition. This means that tag information isn't visible to clients querying your supergraph.

If tag information should be visible to clients (for example, to help document your API), you can enable this for a variant in Studio with the following steps:

1. Go to the Settings page for your variant in GraphOS Studio.

2. On the General tab, click Edit Configuration. The Update Build Configuration dialog appears.

3. If you have a Federation 1 supergraph, enable the toggle for the @tag directive under Directives (this step isn't necessary for Federation 2 supergraphs).

4. Under Build Settings, enable the toggle labeled Show all uses of @tag directives to consumers in Schema Reference and Explorer.

5. Click Save.

After you make your @tag directives visible, you can view them inline with both the Schema and Explorer tabs in Studio.

In the Schema > Reference tab, tags are shown inline with each type and field: