Launch GraphOS Studio

Rover subgraph commands

A subgraph is a that contributes to the of a federated supergraph:

Supergraph (A + B + C)
Subgraph A
Subgraph B
Subgraph C

commands that interact with begin with rover subgraph.

Fetching a subgraph schema

These commands enable you to fetch the schema for a single in a . To instead fetch the for a supergraph, use

. To fetch the , use
rover supergraph fetch

subgraph fetch

This command requires


You can use Rover to fetch the current schema of any subgraph that belongs to a graph or

that Rover has access to.

Run the subgraph fetch command, like so:

rover subgraph fetch my-graph@my-variant --name accounts

The my-graph@my-variant in the example above is a

that specifies the ID of the Studio graph you're fetching from, along with which
you're fetching.

The --name option is required. It specifies which subgraph you're fetching the schema for.

Fetch subgraph schemas from proposals

To fetch a from a

, use the proposal's ID instead of a variant name like so:

rover subgraph fetch my-graph@p-101 --name accounts

A proposal's ID is always prefixed with p- and followed by a number. You can find the proposal ID in the proposal's URL in

. For example, a proposal with the following URL has an ID of p-101.


Though you can use rover subgraph fetch to pull from proposals, you can't use

to push schema changes to a proposal. Use the
proposal editor
in instead.

subgraph introspect

If you need to obtain a running subgraph's schema, you can use Rover to execute an enhanced on it. This is especially helpful if the subgraph doesn't define its schema via (as is the case with


Use the subgraph introspect command, like so:

rover subgraph introspect http://localhost:4001

The subgraph must be reachable by Rover. The subgraph does not need to have introspection enabled.

Unlike a standard introspection query, the result of rover subgraph introspect does include certain (specifically, directives related to federation like @key). This is possible because the command uses a separate introspection mechanism provided by the


Watching for schema changes

If you pass --watch to rover subgraph introspect, Rover introspects your subgraph every second. Whenever the returned schema differs from the previously returned schema, Rover outputs the updated schema. This is most useful when combined with the --output <OUTPUT_FILE> argument which will write the introspection response out to a file whenever its contents change.

Including headers

If the endpoint you're trying to reach requires HTTP headers, you can use the --header (-H) flag to pass key:value pairs of headers. If you have multiple headers to pass, provide the flag multiple times. If a header includes any spaces, the pair must be quoted.

rover subgraph introspect http://localhost:4001 --header "Authorization: Bearer token329r"

Output format

rover subgraph introspect http://localhost:4001\
| rover subgraph publish my-graph@dev\
--schema - --name accounts\

By default, both subgraph fetch and subgraph introspect output fetched

to stdout. This is useful for providing the schema as input to other Rover commands:

rover subgraph introspect http://localhost:4000 | rover subgraph check my-graph --schema -

You can also save the output to a local .graphql file like so:

# Creates accounts-schema.graphql or overwrites if it already exists
rover subgraph introspect http://localhost:4000 --output accounts-schema.graphql

For more on passing values via stdout, see


Listing subgraphs in a supergraph

subgraph list

This command requires


You can use the subgraph list to list all of a particular supergraph's available subgraphs in :

rover subgraph list my-supergraph@staging

This command lists all subgraphs for the specified variant, including their routing URLs and when they were last updated (in local time). A link to view this information in Apollo Studio is also provided.

+----------+-------------- --------------+----------------------------+
| Name | Routing Url | Last Updated |
| reviews | | 2020-10-21 12:23:28 -04:00 |
| books | | 2020-09-20 13:58:27 -04:00 |
| accounts | | 2020-09-20 12:23:36 -04:00 |
| products | | 2020-09-20 12:23:28 -04:00 |
View full details at

Publishing a subgraph schema to GraphOS

subgraph publish

This command requires


You can use Rover to publish schema changes to a subgraph in one of your GraphOS-managed


Use the subgraph publish command, like so:

rover subgraph publish my-supergraph@my-variant \
--schema "./accounts/schema.graphql" \
--name accounts \
--routing-url ""

The argument my-supergraph@my-variant in the example above is a

that specifies the ID of the GraphOS graph you're publishing to, along with which
you're publishing to.

You can omit @ and the variant name. If you do, Rover publishes the schema to the default variant, named current.

If the graph exists in the but the variant does not, a new variant is created on publish.

Options include:


Required. The path to a local .graphql or .gql file, in


Alternatively, you can provide -, in which case the command uses an SDL string piped to stdin instead (see



Required. The name of the subgraph to publish to.

Every subgraph name must:

  • Begin with a letter (capital or lowercase)
  • Include only letters, numbers, underscores (_), and hyphens (-)
  • Have a maximum of 64 characters

The URL that your supergraph uses to communicate with the subgraph in a


Required the first time you publish a particular subgraph. If your subgraph isn't deployed yet, or if you aren't using , you can pass an empty string. Passing an empty string requires you to set the --allow-invalid-routing-url flag.

Optional after your first publish. Provide only if you need to change the subgraph's routing URL.


If a monolithic schema for this variant already exists in the graph registry instead of multiple subgraph schemas, you need to run rover subgraph publish with the --convert flag to convert this variant to a federated graph with one or more subgraphs.

This permanently deletes the monolithic schema from this variant and replaces it with a single subgraph. In many cases, you need to run subgraph publish for multiple or all of your subgraphs before Studio can successfully compose a supergraph schema.

This option has no effect if you publish to a non-monolithic variant.


By default, rover subgraph publish will fail if an unparsable routing URL is associated with a subgraph. If you need to disable this warning and allow the invalid URL to be published anyway, you can pass this option.


This is shorthand for --routing-url "" --allow-invalid-routing-url. It will override any existing routing URL for the subgraph.

Validating subgraph schema changes

subgraph check

This command requires


Before you

, you can
check those changes
to confirm that you aren't introducing breaking changes to your application clients.

To do so, you can run the subgraph check command:

# using a schema file
rover subgraph check my-graph@my-variant --schema ./schema.graphql --name accounts
# using piped input to stdin
rover subgraph introspect http://localhost:4000 \
| rover subgraph check my-graph@my-variant \
--schema - --name accounts

As shown, and options are similar to


To configure the behavior of (such as the time range of past to check against), see the


If you don't want to wait for the check to complete, you can run the command with the --background flag. You can then look up the check's result in Apollo Studio on the Checks tab.

Running checks in CI

If you're running schema checks in CI, you might want to pass the --background flag to rover subgraph check. This flag instructs Rover to initiate schema checks but not await their result. If you've

, the integration detects the checks execution and adds a status to the associated pull request.

subgraph lint

This command requires


You can run the GraphOS schema linter against your local subgraph schema to identify any violations of formatting and naming best practices:

Example command
rover subgraph lint --name products --schema ./products-schema.graphql my-graph@my-variant

The argument my-graph@my-variant in the example above is a graph ref that specifies the ID of the graph you're comparing your schema changes against, along with which

you're comparing against.

Schema linting also runs as one of the checks included in

. Use this command to perform one-off linting.

Options include:


Required. The path to a local .graphql or .gql file, in


Alternatively, you can provide -, in which case the command uses an SDL string piped to stdin instead (see



Required. The name of the published subgraph to compare schema changes against.


If provided, the linter only flags violations that are present in the diff between your local schema and your published schema.

By default, this command flags all violations in your local schema.

Deleting a subgraph

subgraph delete

This command requires


You can delete a single subgraph from a federated variant by running rover subgraph delete:

# ⚠️ This action is irreversible!
rover subgraph delete my-graph@my-variant --name subgraph-to-delete

This command prompts you for confirmation because the action is irreversible. You can bypass confirmation by passing the --confirm flag.

This command fails with an error if any other subgraph references types that originate in this subgraph.

To delete an entire federated graph instead of a single subgraph, see


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