Introducing our API

We’re very pleased to announce the initial availability of our API. This is the same API that powers MNB Assess, our site assessment reporting tool focused on new-build developments. The API comprises two main parts - Tiles and Titles. You can checkout the documentation right now, or read on for an overview of these two resources.

Tiles

Working with geospatial data can involve a lot of legwork. Different sets of data come from different suppliers in different formats. To actually display this data on a map, you need to download the data from the source, clean it up and coerce it into a suitable format for displaying it on the web, and then serve the cleaned data to your clients.

One of the first things we did at MyNestBox was to build a robust Extract, Transform and Load (ETL) pipeline to help us stay on top of our data. This pipeline takes in data in many formats - usually shape files or CSVs - checks the coordinates reference system (CRS) and reprojects it into our preferred CRS if required (4326), stores the result in a relational database and finally uses that data to create Mapbox Vector Tiles for each data set (where appropriate).

The result is a collection of easy-to-use tiles served from the /tiles endpoint of our API. This makes rendering things like the radon levels, designated green belt and more (~20 data sets in total) for the whole of the U.K. a snap. Check out our interactive maps for an example of the tiles endpoint in action.

Titles

Putting data on a map is great, but when it comes to property we wanted to be able to provide more insight than just plotting a boundary. Our /titles endpoint allows us to bring back the geometry data for any title number in the HMLR database enriched with additional information. Currently this information is limited but we’ll be adding more information over time.

Right now, for any title in the country, the /titles endpoint can tell you how the title relates to its nearest green belt, Area of Outstanding Natural Beauty (AONB), Lower Super Output Area (LSOA) and Local Authority District (LAD). For each of these data sets, the /titles response for a given title number will tell you if the title is fully within or partially within an area of the given designation and, if not, tell you the distance in meters to the nearest one.

Additionally, the /titles endpoint also includes information such as the tenure of the title (if it’s freehold or leasehold), the total area of the title and the Local Authority (or Local Authorities if the title spans a border) that the title is represented by.

Responses from the /titles endpoint are in the GeoJSON “Feature” format which again makes it really easy to load them onto a map.

Search

Finally, the /titles/search endpoint allows us to search for titles within a specified radius of a given point. This is how we do our address-based search for our Initial Site Assessment product. The relationship between addresses and entries in the HMLR database is a complicated one and outside the scope of this article, but suffice to say that they don’t quite match up.

In order to get from an address to a title number (and the associated detailed information we are now able to return for that title number) we geocode the address to get a “point” and then call the /titles/search endpoint with the point and a value representing the radius around that point in which we’d like to search. The response will include the geometry and title number (only) for any titles that intersect the search area which allows us to easily render these on the map. Once the user chooses the title they are interested in assessing, we then make a second call to the /titles endpoint for the full details of the title and begin our assessment flow.

Again, search results are returned in the GeoJSON format, though this time as a “FeatureCollection” containing multiple “Feature” objects for easy display on a map.

Using the API

The API is still very much in its infancy and we expect it to evolve over time. However, we are using it in production and it has made the development of our Initial Site Assessment product not only easier, but possible. If you think the API might be useful for your idea, product or business, we would love to chat with you about that some more. Please get in touch and let us know what you’re working on.