The text discusses how to add a Python service to a GraphQL API using the Strawberry GraphQL library and GraphOS. It explains that a supergraph is a collection of subgraphs, each of which can be built in a different language and framework. The authors use Strawberry to create a Python subgraph that adds a shipping cost field to an existing monolith's `Order` type. They deploy the subgraph to Cloud Router and add it to the GraphOS supergraph, allowing them to query data through its hosted router. The article concludes by highlighting GraphOS's ability to enable developers to extend and build supergraphs using their preferred language.