Who invented health APIs?

The origin of health Application Programming Interfaces (APIs) is not tied to a single inventor or a specific moment in time, but rather represents a layered evolution in how healthcare information is managed, accessed, and shared. To understand who "invented" them, we must trace the path from rudimentary electronic record-keeping to the modern web standards that govern data exchange today. ^[4][10] This history is fundamentally a story of overcoming silos—the challenge of getting disparate computer systems, built by different vendors over many decades, to speak the same language. ^[3][9]

# Data Evolution

The groundwork for health APIs began long before the term "API" became commonplace in clinical settings. Computerization of patient data stretches back to the 1970s with early systems designed to manage hospital information. ^[4] However, these early attempts, while digitizing records, did not inherently solve the problem of interoperability. Data remained locked within the specific vendor's system where it was created. ^[10]

The push for standardizing this exchange led to significant, albeit sometimes cumbersome, protocols. The development of standards like HL7 version 2 (v2) and the Clinical Document Architecture (CDA) marked crucial steps forward. ^[1] These older standards provided established formats for sending messages and documents between systems, such as admitting, transferring, or discharging a patient. They served their purpose by establishing conventions, but they were often based on older messaging paradigms rather than modern, lightweight web technologies. ^[1]

Consider the practical reality of implementing these older standards: setting up two systems to communicate via HL7 v2 often required meticulous, point-to-point configuration between the two specific applications involved, a process that demanded specialized knowledge and significant effort from both IT teams. This created a system where, for every new connection, you were effectively starting a mini-custom project, rather than plugging into a universal standard. ^[1]

# Interface Definition

Before diving into the health-specific invention, it is useful to define the tool itself. At its simplest, an API—an Application Programming Interface—is a set of rules that allows different software applications to communicate with one another. ^[2] Think of it as a waiter in a restaurant: you, the customer (one application), tell the waiter (the API) what you want from the kitchen (the other system or database), and the waiter handles the complex transaction and brings back the result, without you needing to know the specifics of how the kitchen operates. ^[8]

In healthcare, the primary function of an API is to enable this data exchange securely and efficiently. When a patient's data needs to move from a primary care physician's Electronic Health Record (EHR) to a specialist's system, or when a patient uses a third-party wellness app to view their lab results, an API acts as the controlled gateway for that information flow. ^[3][9] Crucially, modern health APIs must operate within strict regulatory guardrails, particularly concerning privacy laws like HIPAA. ^[3]

# Standardization Emerges

The transition from rigid, document-centric exchanges (like CDA) to modern, interactive APIs required a new standard built on current internet architecture. This is where the narrative of the modern health API truly solidifies, pointing toward a group rather than an individual inventor.

The primary force behind the current wave of health APIs is HL7 International, a standards development organization. ^[1] They recognized the need to modernize data exchange using widely adopted web technologies—specifically, RESTful principles using formats like JSON and XML. ^[1]

The result of this effort is Fast Healthcare Interoperability Resources (FHIR). While the foundational work for HL7 v2 and CDA preceded it, FHIR is widely recognized as the standard that brought true, accessible API functionality to healthcare data. The specification process for FHIR began, and the first ballot for the standard occurred around 2014. ^[1]

FHIR did not just create a new way to send data; it redefined the granularity of the data. Instead of exchanging entire clinical documents, FHIR structures information around discrete, addressable "Resources" (like a Patient Resource, an Encounter Resource, or an Observation Resource). ^[1] This resource-based approach is inherently conducive to the query/response model of RESTful APIs.

# FHIR’s Role

FHIR essentially provided the common dialect spoken by modern health APIs. ^[1] It synthesizes lessons learned from earlier standards and marries them with the ubiquity of the web. ^[1] This created an environment where a developer familiar with building any standard web application could more easily pivot to building healthcare applications, dramatically lowering the barrier to entry for innovation. ^[9]

The speed at which FHIR has been adopted contrasts sharply with the decades it took for earlier standards to become entrenched. While earlier standards focused on messaging discrete events, FHIR focuses on accessing structured data elements via standard web methods (like GET, POST, PUT). ^[1] This shift moves the ecosystem from batch updates toward real-time data retrieval, a necessity for mobile and patient-facing applications. ^[9]

It is important to note that the definition of a "health API" is broader than just FHIR; any secure interface that allows two healthcare systems to exchange data programmatically qualifies. However, FHIR has become the de facto invented language that makes those APIs functional and widely accepted by regulators and providers. ^[1][3]

# Developer Experience and Openness

The shift championed by FHIR represents a conscious move away from closed, proprietary ecosystems toward open standards that encourage development. Before the widespread adoption of open API standards, access to patient data often required expensive, proprietary licensing agreements or engaging in complex, non-standard data mapping exercises. ^[10] This significantly limited who could build applications and what kind of innovation was possible.

The concept of an API in health, therefore, was invented multiple times:

1. The Conceptual API: Early attempts at system-to-system communication via custom protocols.
2. The Standards-Based API: The creation of HL7 v2 and CDA messaging structures.
3. The Modern Web API: The standardization of FHIR by HL7 International around 2014, leveraging REST and JSON/XML. ^[1]

This third iteration is what most industry professionals mean today when they discuss "health APIs." It’s the moment when the necessary toolset (REST) was formally married to the necessary payload (FHIR Resources) within the regulatory environment of healthcare. ^[1][3]

If we were to look at the impact of this standardization through a purely economic lens, one could observe that the total cost of ownership for interoperability decreases as the adherence to a universal standard—like FHIR—increases across the market. When 80% of vendors speak FHIR, a new vendor only needs to learn one language, saving immense development time compared to needing to support five different, semi-proprietary formats. ^[6]

# Regulations Driving Adoption

The story of health APIs is incomplete without mentioning the regulatory push, which acts as an accelerant for any "invention" in this space. Governments and regulatory bodies, recognizing that data blocking and lack of interoperability harm patient care and increase costs, have mandated the use of standardized APIs. ^[3] In the United States, initiatives like the 21st Century Cures Act have explicitly tied access to federal incentive programs to the adoption of FHIR-based APIs. ^[3] This regulatory environment essentially forced the widespread deployment of the modern health API architecture, turning a technical standard into a required business utility. ^[3]

# Beyond the Standard

Even with FHIR providing the core structure, the invention of a functional health API involves more than just the standard itself. A complete system requires several integrated components:

• Security Layers: Implementing OAuth 2.0 for authorization and ensuring compliance with transport layer security (TLS). ^[9]
• Data Governance: Establishing clear policies on who can access what data, managed through scopes and permissions defined within the API calls. ^[9]
• Platform Infrastructure: The servers and infrastructure that host the API endpoints and manage the high volume of requests securely. ^[2]

Therefore, while HL7 International standardized the specification (the blueprint), the actual invention of a working, secure health API ecosystem is a distributed effort involving platform vendors, security experts, and regulatory compliance teams working around the FHIR specification since its inception. ^[1][9] The final product is a complex interplay between the standardized resource model and secure implementation practices. ^[3]

The evolution continues as new specifications emerge, aiming to refine how data, such as clinical trial results or complex imaging reports, can be accessed via these same API principles. The initial invention was the standard; the ongoing process is refining its application across every facet of patient care.