There are thousands of datasets on Data.govt.nz. These are available in machine and human readable formats (with some variation in what agencies provide) and can be downloaded in your preferred format as files.
An API is also built into Data.govt.nz. Essentially, an API is a way to connect to the metadata and a datasets actual data (machine readable permitting) in the catalogue so you can make use of it where you want to. The advantage of an API is that every time the dataset is updated by agencies, you're use of this data will be updated as well. For example, if you had a website that showed all the bus stops in the Wellington region, when the bus stop dataset is revised to reflect any closed or new bus stops, the information you use through an API will be updated as well.
The data and metadata you access via the data.govt.nz API is licensed under the same license as the downloadable file version of the dataset. The licensing requirements are included on each dataset landing page eg Creative Commons Attribution 3.0 New Zealand.
General CKAN technical documentation
The data.govt.nz APIs are built on open source software called "Comprehensive Knowledge Archive Network" or CKAN for short (pronounced "Sea-Can").
Currently data.govt.nz is running CKAN 2.7.x.
CKAN has detailed documentation covering the use of the APIs it makes available.
- The CKAN metadata API documentation is available at: http://docs.ckan.org/en/2.7/api/index.html
- The CKAN DataStore API (accessing the actual data of a dataset) is at: http://docs.ckan.org/en/2.7/maintaining/datastore.html#the-datastore-api
There are further more specific "how-to" guides for developers covering more advanced API use, links to reusable code and examples within this developer section of data.govt.nz.
Contributing
If you have a useful example or "how-to" that others could learn from you are welcome to submit your guide via a pull request for review at: https://github.com/data-govt-nz/developers