A Glossary of Key Terms in API, Webhooks & Data Exchange in HR Automation

In the rapidly evolving landscape of HR and recruiting, leveraging technology to streamline operations is no longer optional—it’s essential for competitive advantage. Understanding the foundational concepts of how different systems communicate and exchange data is crucial for any professional looking to automate and optimize their processes. This glossary provides clear, authoritative definitions for key terms related to Application Programming Interfaces (APIs), webhooks, and data exchange, specifically tailored for HR and recruiting leaders. Mastering this terminology empowers you to make informed decisions, implement robust automation strategies, and ultimately, save valuable time and resources.

API (Application Programming Interface)

An API, or Application Programming Interface, is a set of rules and protocols that allows different software applications to communicate with each other. In HR, APIs are the backbone of integration, enabling your Applicant Tracking System (ATS), Human Resources Information System (HRIS), payroll software, and other tools to share data seamlessly. For example, an API might allow a new hire’s data from your ATS to automatically populate fields in your HRIS, eliminating manual data entry and reducing errors. This machine-to-machine communication is fundamental for creating interconnected HR tech stacks, facilitating everything from candidate screening to onboarding workflows, and ensuring a single source of truth for employee data.

Webhook

A webhook is an automated message sent from an application when a specific event occurs, essentially acting as a “user-defined HTTP callback.” Unlike traditional APIs where you constantly poll for updates, a webhook pushes data to you in real-time. In recruiting, this could mean that when a candidate status changes in your ATS (e.g., from “Applied” to “Interview Scheduled”), a webhook instantly notifies another system, like a CRM or communication platform. This real-time data exchange is invaluable for triggering immediate actions, such as sending automated follow-up emails, scheduling interviews, or updating dashboards, significantly enhancing responsiveness and efficiency in the hiring process.

Data Exchange

Data exchange refers to the process of sending and receiving data between different computer systems, often involving translation or transformation to ensure compatibility. In HR automation, effective data exchange is critical for maintaining consistency and accuracy across all platforms—from talent acquisition to employee management. This can involve structured data formats like JSON or XML being transferred via APIs or webhooks between an ATS and an HRIS, or between a performance management system and a learning platform. Efficient data exchange eliminates manual re-entry, reduces the likelihood of data discrepancies, and provides a holistic view of employee information, empowering better strategic decision-making.

JSON (JavaScript Object Notation)

JSON is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is widely used in modern web applications, particularly with RESTful APIs, for transmitting structured data. In HR, when your ATS sends candidate information to a background check service via an API, that data is often formatted as JSON. This format allows for clear, hierarchical representation of data such as a candidate’s name, contact details, past employment, and desired salary, ensuring that different systems can accurately interpret and process the information without ambiguity, thereby streamlining complex recruitment workflows.

Payload

In the context of APIs and webhooks, a “payload” refers to the actual data being transmitted in a request or response, excluding any header or metadata. It’s the core information package that carries the message from one system to another. For HR, if your HRIS sends an update about a new employee’s onboarding status to a task management system, the payload would contain all the relevant details: employee name, start date, department, and current onboarding stage. Understanding the structure and content of payloads is essential for configuring integrations and automations correctly, ensuring that the right data is extracted and utilized by the receiving application to trigger subsequent actions.

Authentication

Authentication is the process of verifying the identity of a user or system attempting to access a resource. For APIs and webhooks in HR automation, authentication mechanisms are paramount for security, ensuring that only authorized applications or users can send or receive sensitive data. Common methods include API keys, OAuth 2.0, or token-based authentication. For instance, when your recruiting platform integrates with a payroll system, strong authentication protocols prevent unauthorized access to financial data. Implementing robust authentication is a critical step in protecting confidential employee information and maintaining compliance with data privacy regulations.

Endpoint

An endpoint is a specific URL where an API can be accessed to perform a particular operation. It’s like a unique address for a specific resource or function within an application. For example, an HRIS API might have an endpoint like `/employees` to retrieve a list of all employees, and `/employees/{id}` to access details for a specific employee. Each endpoint corresponds to a specific action (e.g., getting data, creating a record, updating information). Knowing the correct endpoints is fundamental for developers and automation specialists to construct API calls accurately, enabling systems to interact precisely as intended for tasks like updating candidate profiles or retrieving hiring metrics.

Integration

Integration refers to the process of connecting disparate IT systems, applications, or data sources so they can work together and share information seamlessly. In HR, integration means linking tools like an ATS, HRIS, payroll, background check services, and learning management systems. This creates a unified ecosystem where data flows freely, eliminating manual data entry, reducing errors, and improving overall efficiency. For instance, integrating your ATS with an assessment platform allows candidate scores to be automatically pulled into their profiles, streamlining the evaluation process. Effective integration is the cornerstone of a truly automated and intelligent HR function.

ETL (Extract, Transform, Load)

ETL, which stands for Extract, Transform, Load, is a process used in data warehousing to move data from one system to another. ‘Extract’ involves collecting data from various sources (e.g., different HR systems). ‘Transform’ means converting and cleaning the data into a format suitable for the target system (e.g., standardizing date formats, merging duplicate records). ‘Load’ is the final step of writing the transformed data into the destination system. In HR, ETL processes are crucial for migrating legacy HR data to a new HRIS, consolidating employee data from various departments, or preparing data for analytics and reporting, ensuring data quality and usability for strategic insights.

HRIS Integration (Human Resources Information System Integration)

HRIS Integration is the specialized process of connecting a Human Resources Information System with other enterprise applications, such as payroll, benefits administration, performance management, or an ATS. This integration allows for the automated exchange of employee data, ensuring that information—like new hires, promotions, salary changes, or terminations—is consistently updated across all linked systems. For example, when a new employee is onboarded in the HRIS, their data can automatically flow to the payroll system, benefits providers, and even an internal directory, eliminating manual input, reducing administrative burden, and enhancing data accuracy for the entire employee lifecycle.

ATS Integration (Applicant Tracking System Integration)

ATS Integration involves connecting an Applicant Tracking System with other recruiting and HR technologies, such as job boards, candidate assessment platforms, video interviewing tools, or an HRIS. This allows for a streamlined recruitment workflow, where candidate data, application statuses, and interview feedback can be automatically shared between systems. For instance, an ATS integrated with a job board can automatically post vacancies and pull in applications, while an integration with an HRIS can seamlessly transfer new hire data once an offer is accepted. This reduces manual tasks, speeds up time-to-hire, and provides a comprehensive view of the recruitment pipeline.

No-Code/Low-Code Automation Platforms

No-code/low-code automation platforms are visual development environments that allow users to create applications and automate workflows with little to no traditional coding. Tools like Make.com (formerly Integromat) and Zapier fall into this category, empowering HR professionals to build sophisticated integrations and automations themselves. These platforms provide intuitive drag-and-drop interfaces to connect various HR tools (ATS, HRIS, communication apps, spreadsheets), trigger actions based on specific events (e.g., new candidate application), and automate repetitive tasks. They democratize automation, enabling HR teams to quickly respond to operational needs and innovate without heavy reliance on IT resources.

Middleware

Middleware is software that acts as a bridge between operating systems or databases and applications, providing services to applications beyond those available from the operating system. In the context of HR automation, middleware often refers to integration platforms (like iPaaS solutions such as Make.com) that facilitate communication and data exchange between diverse HR systems that weren’t originally designed to work together. It translates data formats, handles authentication, and manages the flow of information, effectively enabling disparate HR applications to function as a cohesive unit. This allows organizations to build comprehensive, automated HR ecosystems without needing to overhaul existing legacy systems.

Data Mapping

Data mapping is the process of matching fields from one data source to corresponding fields in another data source. It’s a critical step in any data integration or migration project. In HR, when transferring candidate data from an ATS to an HRIS, data mapping ensures that a field like “Candidate Name” in the ATS correctly corresponds to “Employee Full Name” in the HRIS, and “Application Date” maps to “Hire Date.” Accurate data mapping is essential to prevent data loss, ensure data integrity, and guarantee that information is correctly interpreted by the receiving system, thereby enabling smooth transitions and reliable reporting across all HR functions.

REST API (Representational State Transfer API)

A REST API is an architectural style for designing networked applications. It’s a common and flexible way to exchange data between client and server, utilizing standard HTTP methods (GET, POST, PUT, DELETE) for performing operations on resources identified by URLs. Most modern HR software (ATS, HRIS, payroll) offers RESTful APIs for integration. For example, a “GET” request to a candidate endpoint might retrieve candidate details, while a “POST” request could create a new candidate record. REST APIs are favored for their statelessness, scalability, and ease of use, making them a popular choice for building robust and agile HR automation solutions.

If you would like to read more, we recommend this article: The Automated Recruiter’s 2025 Verdict: Make.com vs Zapier for Hyper-Automation