API observability is crucial for understanding how APIs are consumed in practice, offering insights into user interactions, troubleshooting, and improving developer experience, with a focus on distinguishing between REST and GraphQL APIs. While REST APIs rely on monitoring endpoints and logging errors for observability, GraphQL APIs require a different approach due to their flexible querying capabilities, which allow data from multiple sources to be requested in a single query. This flexibility, though beneficial for developers, poses challenges in observability, as GraphQL's single-endpoint design complicates error detection and resolution compared to REST APIs, where HTTP status codes clearly indicate success or failure. Observing GraphQL APIs involves monitoring payloads to track error objects, query success, and usage patterns, thereby providing valuable insights into user behavior and enabling proactive support and documentation improvements. By filtering and aggregating GraphQL queries, organizations can determine which parts of their APIs create the most value for customers, enhancing product development and customer success strategies. Tools like Moesif are designed to support both REST and GraphQL API observability, offering comprehensive analytics to facilitate these insights and promote customer success.