Harness has integrated GraphQL into its API, providing developers with more efficient and flexible data queries and mutations, thereby addressing common challenges associated with REST APIs, such as overfetching and underfetching. As an open-source query language, GraphQL allows for declarative data fetching and models business domains in a graph structure, enabling precise data requests and minimizing data transfer between client and server. Harness' API Explorer, which operates as a GraphQL Integrated Development Environment (IDE), facilitates CRUD operations on Harness entities, offering features like schema introspection and strong typing to enhance development efficiency. Users can perform queries and mutations to manage various Harness entities, such as applications, users, and pipelines, with a focus on scoping, hierarchical organization, and future-proofing of APIs. The API Explorer promotes a shared understanding through the use of GraphQL Schema Definition Language (SDL), and its documentation provides examples for constructing queries and mutations.