Frequently Asked Questions

This FAQ provides context for the Open Referral Initiative and its Human Services Data Specification (HSDS). You can read more about Open Referral at

What is Open Referral?

The Open Referral Initiative is a network of people and organizations working to promote the accessibility of information about health, human, and social services — i.e. community resource directory data.

Our Human Service Data Specification (HSDS, AKA ‘the Open Referral format’) is a data exchange format that enables resource directory data to be shared among heterogeneous information systems.

Open Referral’s ecosystem includes a range of open source tools and web applications that facilitate the flow of resource directory information. See examples of these tools and apps here.

More tools are in development by members of Open Referral’s network, members of which are primarily assembled in our Google Group and our Slack team.

Who started Open Referral?

Greg Bloom is the instigator and lead organizer of Open Referral, which emerged from work done in the DC Open211 project, and which was first described Towards a Community Data Commons, an essay published in Code for America’s 2013 book Beyond Transparency.

Our work was initially co-sponsored by Code for America and the Ohana Project, with funding from the Knight Foundation.

Who is the audience for Open Referral? Who benefits?

There are three types of ultimate stakeholders for Open Referral: 1) people in need of help of some kind (‘help-seekers’); 2) people who are in some kind of position to assist such help-seekers (‘service providers’); and 3) ‘analysts’ — i.e. researchers, policymakers, funders and anyone seeking to understand the patterns of resource allocation in their community.

The primary users of Open Referral are database administrators – anyone involved in aggregating, maintaining, and/or developing systems that produce or consume community resource directory data. Our objective is to help such database administrators share higher quality resource directory data at lower cost, with the goal of making it easier for people to find such information across a wide array of channels.

Read more about each of these types of users here in our User Personas documentation.

How is this project relevant to me?

Open Referral helps people and organizations grapple with the complex problem of maintaining and publishing reliable information about the health, human, and social services available to people in need.

Most of our work does not involve writing code. We facilitate collaborative action among institutions that have mutual interest in cooperation.

That said, Open Referral is an open network. Anyone is free to use our data specification and tools in pursuit of our shared goals.

If you have resource directory data that you wish to make more available — or if there’s an organization in your community that might make its data more broadly accessible, then you could get to work right away.

Read more in our Contributors Guide. Reach out to to get directly in touch.

If I maintain a community resource directory — or if I partner with an organization that does — how would I get started?

You can start by testing the viability of our format for your context. That may entail mapping your database’s schema to the Human Services Data Specification.

Once you’ve mapped your schema to ours, analyze the gaps. (You can ask questions or submit suggestions for improvements to our schema in our Issues Queue. Read more in our Contributors Guide.)

Then you can write a script to transform your data into this open format.

Finally, you can deploy an open source resource database (like ORServices), load your transformed data in, and start building new tools that can help people in your community use this data in new ways.

If you have questions about how this might be useful in your community, please reach out to

How are decisions made about the Open Referral specifications?

Our governance model is structured around three activities: 1) a semi-regular Assembly video call, open to all participants [see an archive of these videos here], 2) convenings of diverse stakeholders in Open Referral workshops [read the reportback here], and 3) ad hoc ‘workgroups’ consisting of leaders with a varied set of perspectives and experiences [see the workgroup archive here].

Of all the feedback received from many different contributors, we assign priority to the perspectives of the lead stakeholders of our pilot projects. This feedback is submitted to Open Referral’s deputized technical leads, who ultimately make decisions with documentation and established methods for future review.

[Open Referral’s initial governance model is described in more detail in this memo. You can also read more about the nature of this ‘polycentric’ approach to governance in Derek Coursen’s blog post here.]

What is the Human Services Data Specification (HSDS)?

AKA ‘the Open Referral format,’ the HSDS is a data interchange format that enables resource directory data to be published in bulk for use by many systems. HSDS provides a common vocabulary for information about services, the organizations that provide them, and the locations where they can be accessed. HSDS is essentially an interlingua — in other words, it’s a common language that can be used by anyone to enable community resource directories to ’talk’ to each other. [See the data specification in Github or on our Documentation Site.]

What is in the Human Services Data Specification (HSDS)?

First, HSDS identifies a vocabulary of terms that describe what a service is, the institution that provides it, where the service can be accessed, and how to access it. These terms are designated as ‘required’ (meaning they must be included for data to be compliant) or ‘optional.’ The spec provides instructions for formatting these terms, with examples.

On a more technical level, HSDS also includes a logical model that diagrams the relationships between these terms.

Finally, HSDS provides guidance for structuring and packaging data so that it can be published on the web and/or exchanged between systems (see: Github or our documentation site).

What is not in the Human Services Data Specification (HSDS)?

HSDS does not attempt to describe every type of information that might be relevant to people working with resource directory data. We have attempted to maintain a strict focus on specifying only relevant factual attributes that are shared by most services. That means we excluded many kinds of information that are unique to specific kinds of services (such as the accreditation of child care providers, or the availability of beds in a shelter).

HSDS also does not specify a taxonomy of types of services and types of personal attributes that determine eligibility for various types of services. Many such taxonomies already exist, so HSDS merely provides instructions for how to overlay a taxonomy of the user’s choosing. By default, information systems that use HSDS can use the open source Open Eligibility taxonomy. (Expect future cycles of the Open Referral initiative to take on these issues more directly; however, for now we are merely looking to learn from the different ways in which various users address these common problems.)

Finally, HSDS does not specify any information regarding how referrals actually get made (i.e. setting appointments, following up, etc) or feedback regarding the quality of those services. These kinds of information are critically important, but inherently so variable and context-dependent that we don’t think it’s feasible or appropriate to specify them at this point in time.

That said, this model can and should be extended! Users can expand HSDS to meet their own needs, in their own systems. Groups of stakeholders from particular subdomains can develop extended ‘profiles’ that are tailored to their situation. (A group of civil legal service providers have already begun working on precisely that.) In future iterations of the Open Referral process, these expansions will then be considered for inclusion as part of the primary model.

What is the format of the HSDS? Why JSON?

Version 3.0 of HSDS has established JSON as the primary standard format. (The initial versions of HSDS used the CSV format, with multiple tables wrapped by a JSON datapackage.) This change brings many benefits to the standard, which are detailed here alongside a discussion of risks and mitigations of those risks.

The decision to change the primary format to JSON was the result of an involved, participatory, and collaborative decision making process which took place over several months and involved a working group made up of key stakeholders across the Open Referral community.

As outlined in the document linked above, a range of reasons motivated this change. First and most generally, JSON Schema is a vastly more common format than datapackages – familiar for both interchange and validation – so we can benefit from a much greater range of tooling and expertise to make HSDS better to use in almost all aspects.

More specifically, JSON schema also improves our ability to:

Enable users to query an HSDS data source to find a service and act on the information:

  • We can standardise the output of APIs to the new JSON format and we can develop API specifications around them; meaning they will be kept in sync with the core HSDS specification.

  • It is not really possible to do these queries in just the Tabular Datapackage format.

Align multiple datasets: to enable resource data federation, matching/synthesizing/syncing multiple sources of HSDS:

  • Having JSON output formats that align across publishers can make data federation/syncing feasible.

  • Easier to write extension/profiling tooling for JSON Schema as some already exist.

  • The JSON outputs could not just be through APIs, but also with bulk JSON versions, making federation/syncing feasible outside API use.

  • This is tricky to do if only the Tabular Datapackage format was allowed, as federation/syncing relational database structures, with different schemas, has no feasible automated solutions.

Analyze and improve resource data quality:

  • JSON Schema can provide clear validation results.

  • JSON has readily available tooling for building validators and offering additional checks beyond basic validation rules.

  • Reliable tooling available for generating documentation.

Edit individual records:

  • When updated using JSON representations a single API endpoint can be used to update a service and all related fields; not just a table at a time.

The outdated HSDS representation format of JSON Tables bundling CSV files is an important artefact for many HSDS users, and so will be maintained: we automatically generate a JSON Table Schema from a JSON Schema, so we expect that the shift will not cause any issues for any implementations that expect the datapackage from deprecated HSDS versions.

How do you address the matter of taxonomy (of types of services and situations)?

Open Referral recognizes the existence of a diverse array of taxonomies to describe types of services, organizations, and people for whom services are available. Given that such categories are inherently subjective, whereas Open Referral’s format is describing only factual data, we do not prescribe a specific taxonomy. We do recognize the existence of an array of taxonomies currently in use, and our HSDS format includes specifications for including any taxonomy in open data.

How does Open Referral handle eligibility criteria?

Good question. We don’t currently specify a standardized method for structuring eligibility criteria. The kinds of eligibility rules are so variable and often complex and nuanced that we have not tried to develop a standardized set of them. By default, information systems that use HSDS can use the open source Open Eligibility taxonomy. (Expect future cycles of the Open Referral initiative to take on these issues more directly; however, for now we are merely looking to learn from the different ways in which various users address these common problems.)

What if I collect important information that isn’t included in the Human Service Data specification?

That’s ok! The Human Services Data Specification is an extensible format to which additional layers of information can be added — see guidance here. (But we’d like to learn from your experience, so please share these insights!)

What if the Human Service Data Specification requires kinds of information that I don’t collect?

The Open Referral format has been developed to require a pretty minimal set of information. If your resource directory doesn’t contain certain required elements, we may need to get creative. Ask in our Issues queue for clarification and context, and we’ll try to answer you promptly.

What if I need help collecting this data in the first place?

Open Referral is working to build tools that can help people produce and verify accurate resource directory data. For the most part, we don’t host these tools ourselves – but we can help you deploy, customize, and leverage them to achieve your goals.

For instance, you might be able to quickly get set up with a free resource database by deploying the Open Referral Airtable template. You might also deploy one of the open source content management systems in our ecosystem (like ORServices). We also have helped communities develop open source policies and procedures (like the DC Community Resource Information Exchange’s style guide and verification process documents) which you are free to copy and adapt.

If you’re interested in deploying or helping to develop such tools, we want to hear from you! Please reach out to our network via our Community Forum or Slack channel to discuss.

Who has adapted this project and can I see examples?

We have a network of projects around the United States, Canada, and beyond. See this network map here.

Some domain-specific groups have adapted our data specification to their context, such as the Human Services Data Model (in the field of Humanitarian Crisis Response).

Who do I contact if I need help with this project?

You can contact Greg Bloom (@greggish |, the founder and lead organizer of Open Referral. Alternatively, you can reach out to our network via our Community Forum or Slack channel.

What languages is this project in?

Currently Open Referral is in English, though we would welcome opportunities to support language localisation.

Oh, do you mean machine language? Our data specification calls is expressed in JSON schema, though we also support for a datapackage of CSV files. Our primary reference implementation, ORServices, is in Laravel.

Is the project in active development?

The Human Services Data Specification under the interim leadership of the Open Data Services Co-operative. We conducted a major upgrade cycle in 2022-23; minor upgrades may be in progress. Check out our issues queue.

We are seeking sponsorship to support long-term institutional development of Open Referral and our data specification. Please reach out to for more information.

What is the licensing on this project?

Human Services Data Specification v3.0 is now available as CC BY-SA 4.0.