The Human Services Data API (HSDA) is the interface standard that puts the Human Services Data Specification (HSDS) to work over HTTP. Defined as a set of API paths (with OpenAPI definitions) for reading and writing organizations, services, locations, taxonomies, and their sub-resources, HSDA lets applications query and maintain community resource directories through a consistent, machine-readable contract.
Human Services Data API (HSDA)
The Human Services Data API (HSDA) is the API companion to the Human Services Data Specification (HSDS). Where HSDS defines how you model health, human, and social services data, HSDA defines how you access it — the paths, parameters, and sub-resources an application uses to query and maintain a community resource directory over HTTP.
- API on top of a data standard - HSDA exposes HSDS organizations, services, locations, contacts, and taxonomies as consistent, discoverable API resources.
- OpenAPI-defined - The interface is described with OpenAPI, so the contract is machine-readable, documentable, and mockable — and can carry webhooks, bulk operations, and taxonomy support.
- Read and write - Beyond search, HSDA is meant to keep directories current, letting trusted partners contribute and update service information.
- Open Referral ecosystem - Part of the same open, community-governed effort as HSDS.
I built out much of the early HSDA surface myself — bulk APIs, taxonomy APIs, webhook patterns, and a suite of OpenAPI definitions — as a hands-on demonstration of how you turn an open human-services data standard into a living, usable API that cities and nonprofits can actually run.
Referenced on the API Evangelist blog
Where this standard shows up across sixteen years of my writing at apievangelist.com — how it fits into API design, governance, and the agentic turn.
