25 HRIS APIs to Integrate With in 2026: Workday, BambooHR, ADP and Unified HR Integration APIs

Human Resource Information Systems (HRIS) are essential for managing workforce infrastructure, handling tasks such as employee records, payroll, and benefits. As SaaS products increasingly integrate with HR platforms to streamline processes like onboarding and payroll workflows, HRIS APIs have become integral to product architecture. However, each HR platform's unique API structures and authentication processes pose significant challenges for developers. To address these complexities, many SaaS companies are transitioning to Unified HR APIs, which standardize data models and authentication across various HR systems, allowing developers to integrate once and support numerous platforms efficiently. This approach reduces the burden of managing multiple integrations and provides real-time data access without storing sensitive employee information, thereby enhancing compliance and reducing integration complexity. Unified HR APIs facilitate faster, scalable, and more efficient integration with HR systems such as Workday, BambooHR, ADP, and Personio, supporting over 224 HR and directory integrations through a single API.