A GraphQL query provides the data access between the service layer that contains the business logic and the UI components on your custom page. GraphQL queries can be large and used to serve data for many components, or they can be more granular and used for a specific component, such as componentX.

In Cúram, the GraphQL infrastructure is built into the REST application and is deployed as part of the REST EAR. In your Tomcat development environment, build and deploy the GraphQL APIs to work on GraphQL queries.

Alternatively, the UI Addon Development Environment provides a lightweight mock GraphQL service, so you can develop and test your Carbon components before the GraphQL queries are available.

Use the following guidance to familiarize yourself with GraphQL queries in Cúram. You can look at an existing GraphQL API and run some simple test queries to return data.

When you understand how GraphQL queries work, you can create your own queries, see Sending a GraphQL query from a client.

For data that is not available through existing GraphQL APIs, create your own GraphQL APIs, see Developing a GraphQL API.

While the REST Service provides the real data from the GraphQL queries in Cúram, you can use a lightweight mock GraphQL service to enable rapid development almost exclusively in your front-end environment. To develop your Carbon components before the real GraphQL queries are available, you can use the mock GraphQL service with Carbon components in Storybook or when testing the integration with Cúram.

To add mock data to the mock GraphQL service, complete the following steps in the graphql-mocks package. Refer to the provided examples in the directories for guidance.