Runtime Configuration Overview

In this guide, you'll learn how to configure the GraphOS Router for Apollo Connectors by configuring connectors and other options in your router's configuration.

Configuration

Configuring a self-hosted router for Connectors requires setting options in the router's YAML configuration file. When using Rover, you can call rover dev to start a router locally and use its --router-config option to pass your configuration file. For example:

APOLLO_KEY=... \
APOLLO_GRAPH_REF=... \
APOLLO_ROVER_DEV_ROUTER_VERSION=2.0.0 \
rover dev --supergraph-config supergraph.yaml
--router-config router.yaml

Connectors configuration are nested under the connectors key. Some configurations are applicable globally to all Connectors, some are applicable to specific Connector sources, and some can be configured for both. For example, you can apply request limits both globally across all Connectors and on specific Connector sources.

connectors:
  # This applies globally to all Connectors
  max_requests_per_operation_per_source: 100
  # This applies to Connectors with the "v1" source in the "example" subgraph
  sources:
    subgraph1.endpoint1:
      max_requests_per_operation: 50

To specify a source, you must include the subgraph name and source name, separated by a .—for example, subgraph_name.connector_name.

To learn more about other router configurations, go to the router configuration reference.

Accessing router configuration in Connectors

You can pass configuration values—such as API keys or base paths—to your Connectors schema using the $config section in your router configuration. This keeps sensitive or environment-specific values out of your schema.

Define values under $config for each source, then reference them in your schema with the $config variable:

connectors:
  sources:
    subgraph1.endpoint1:
      $config:
        api_key: my-secret-key  # use ${env.API_KEY} in production
        base_path: v2

Reference these values in your schema using {$config.<key>} syntax.

extend schema
  @source(
    name: "endpoint1"
    http: {
      baseURL: "https://api.example.com/{$config.base_path}"
      headers: [{ name: "Authorization", value: "Bearer {$config.api_key}" }]
    }
  )

type Query {
  products: [Product!]!
    @connect(
      source: "endpoint1"
      http: { GET: "/products" }
      selection: "id name"
    )
}

In this example, {$config.api_key} resolves to "my-secret-key" and {$config.base_path} resolves to "v2", giving a base URL of https://api.example.com/v2. For secrets like API keys, use environment variables instead of inline values.

Nested values

Use nested YAML keys to organize related values. Dots in $config references act as path separators to traverse the YAML structure:

connectors:
  sources:
    subgraph1.endpoint1:
      $config:
        auth:
          token: my-token

In this example, $config.auth.token resolves to "my-token" by traversing the path auth → token.

Environment variables

Use ${env.VARIABLE_NAME} syntax to inject environment variables into $config values. This is the recommended approach for secrets:

connectors:
  sources:
    subgraph1.endpoint1:
      $config:
        api_key: ${env.API_KEY}

Next steps

• Explore all router configuration options in the router configuration reference

• See the other pages in this section for Connectors-specific security, performance, and observability configurations