The **site metafields** feature allows you to add custom properties to your sites. Following the Locomotive philosophy, each site could have its own set of custom properties.
For instance, it's very useful if you want to store additional information about your site such as the full address or the opening hours of the restaurant site you're building for your client.
That could also be the right place to store the links to the Facebook page or to the twitter account.
## Describe your metafields in Wagon
Site metafields are described in a YAML file at this location `
config/metafields_schema.yml` inside your Wagon site.
Metafields are grouped inside **namespaces**. Then, each metafield has a name and several properties (label, hint, type, ...etc) defining the look&feel of the inputs in the back-office.
## Use metafields in Liquid
First, you can assign default values in your Wagon site by simply modifying your `
config/site.yml` file. Here is an example based on the schema displayed above.
Accessing those values in any liquid template (page or snippet) is fairly easy.
You can also loop over the metafields of a namespace.
## Editing metafields values in the back-office
Once your Wagon site has been deployed, you will see a new section named **Properties** in the left sidebar of your site back-office. In the example below we named the tab Website theme.
If you click on it, you will then see the UI generated from your YAML schema file.