This package provides a middleware for integrating Apollo Server v4 with Express v4, allowing GraphQL operations to be executed within Express applications. It's designed for developers building GraphQL APIs using Express v4 who want to leverage Apollo Server's features like schema validation, query execution, and developer tooling. The integration requires Node.js v20+, Express v4, and Apollo Server v4, and is intended as a temporary solution until Apollo Server v4's built-in Express support is deprecated in favor of separate integrations for different Express versions.