HAT for Devs

HAT Applications

The applications in MarketSquare are all built on the HAT, a private data account that lets users store their personal data for themselves so that they have full control, access to, and ownership over it. HAT applications don’t use normal centralised databases to store their users’ data - they access it from the private data accounts, which are owned by the individual instead.

Building a HAT Application

HAT private data accounts are wrapped inside a set of containerised microservers that give your users full control, access and ownership over the information inside. To build an application on top of these containers, all you have to do is call for the data you need to run your services through standard API endpoints that let you access your users’ HATs.

Removing hurdles

One of the biggest challenges to building consumer applications has been getting permission from customers to access their sensitive information. When you were storing that information yourself, your customers had to trust you enough to hand it over, and if you wanted data from a number of different sources you had to get permission to access it from the source and the user both. Now, you don’t have to do that anymore - all of your users’ information is centrally stored, and controlled, by them inside their HAT, so all you have to do is ask them for it.

All new ideas

Accessing all of a users’ personal information from a centralised repository like this gives you access to some incredibly rich, horizontal, and contextual data.

A virtuous cycle of data exchange

If you’re a trusted HAT Application, you can use that data to create a whole new category of consumer technology - and best of all, your users will actually be the primary beneficiaries of that innovation, creating a virtuous cycle in which they’re encouraged to share with you more.


HAT Applications are certified by the HAT Community Foundation, a members-run organisation that helps maintain the user-centric principles of HAT Applications and the companies that host and issue HATs to consumers. The applications that you build on the HAT will be certified by this group, and rated for how carefully you treat your users’ data.

The HAT Ecosystem

All of the HAT apps and services in MarketSquare, plus our partners at HAT Innovation, the team at HATDeX, and the academics who work with the HAT at HAT Research form an ecosystem of businesses, customers, and partners that can greatly benefit you as an app builder. Every new service helps bring more data, and more users, into the ecosystem which makes it easier and easier for you to scale.

Get help from HAT Innovation

As the digital economy begins to shift, HAT Innovation is committed to partnering with innovative new technologies and the organisations that support them in bringing about the new personal data economy. You can get funding, engineering support, advice, and insights from the HAT community by applying to join the HAT Innovation programme.

Go to HAT Innovation

Join the Developers’ Community

Still not sure what to build, or how to build it? Or do you have a brilliant idea, and are looking for advice from the people who built the HAT technology? Join the HAT Developers’ Community on Slack and build the applications of the future with our team of world-leading technologists.

Join us