OESIS Framework is a cross-platform, modular software development kit that enables developers and technology vendors to integrate endpoint protection capabilities into their products. The framework provides pre-built security modules and APIs for implementing various endpoint security functions. The framework supports device posture assessment across 5,000+ applications, allowing discovery, detection, and policy enforcement. It includes patch management capabilities that automatically detect missing patches and remediate vulnerabilities for third-party applications and operating systems. The vulnerability assessment module identifies and maps over 47,000 unique CVEs and 100,000+ vulnerability instances. Additional modules include AppRemover for uninstalling non-compliant applications without user intervention, and removable media protection for defending against threats from USB drives, CDs, DVDs, and other peripheral devices. The framework operates on Windows Desktop (7-11), Windows Server (2008 R2-2025), macOS (10.10-15/26), and various Linux distributions including Red Hat, Ubuntu, CentOS, Fedora, Debian, SUSE, and others. It provides C++ libraries for native integration and uses a JSON-based protocol for invoking functionalities. The SDK is designed to reduce development time and costs by providing ready-to-integrate security components, minimizing the need for in-house security development and reducing long-term maintenance requirements.