The Human Services Data Specification (HSDS) is an open data standard, stewarded by Open Referral, for describing health, human, and social services and where to find them. It defines a common tabular/relational model for organizations, the services they provide, and the locations where those services are delivered, so that community resource directories can be published, exchanged, and kept current in a machine-readable way.
Human Services Data Specification (HSDS)
The Human Services Data Specification (HSDS) is the data model at the heart of Open Referral — a community effort to make information about health, human, and social services as open and reusable as any other public data. HSDS gives cities, nonprofits, and 211/information-and-referral providers a shared way to describe what services exist, who provides them, and where to get them.
- Common data model - Organizations, services, locations, contacts, and the taxonomies that classify them, expressed as a clear relational/tabular schema.
- Publishable and exchangeable - A directory of community resources can be exported, shared, and merged across agencies instead of being locked inside a single system.
- Companion API - HSDS is the data specification; the Human Services Data API (HSDA) is the paired interface standard for querying and updating it over HTTP.
- Open governance - Stewarded in the open by Open Referral, with real municipal and nonprofit implementations behind it.
I spent a meaningful chunk of my API work helping define OpenAPI-based interfaces for HSDS and building out the surrounding API definitions — it remains one of the clearest examples of why a shared, machine-readable data standard matters for the public good, and why an API on top of that standard is what actually makes the data usable.
Industry: Social Services
Also in the data model catalog
This standard shows up on both sides of the house — as a standard applied in API operations here, and as a data model defining what information exists. Same standard, two lenses.
See it as a data model →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.
