Config apple-app-site-association file with WordPress

Since the apple-app-site-association file is not a WordPress file, you have to configure the content type at the server level. This is different depending on environment (Apache vs. nginx, for example). This can be hard, if your host doesn't allow access to low level configuration.

Apache configuration

Modify the /etc/apache2/sites-available/default-ssl (or equivalent) file to include the snippet:

<Directory /path/to/root/directory/>...<Files apple-app-site-association>Header set Content-type "application/pkcs7-mime"</Files></Directory>

nginx configuration

Modify the /etc/nginx/sites-available/ssl.example.com (or equivalent) file to include the location /apple-app-assocation snippet:

server {   ...   location /apple-app-site-association {      default_type application/pkcs7-mime;   }}

Source: https://gist.github.com/anhar/6d50c023f442fb2437e1#modifying-the-content-type

In theory I believe it is possible to do the Apache configuration via a .htaccess file, but I've never tried.

You may prefer to look into a free hosted deep link service like Branch (full disclosure: I'm in the Branch team) or Firebase Dynamic Links to handle all of this for you.

In case anyone is in the same situation I was where my website is hosted on Bitnami WordPress (e.g. through AWS), your root directory path is /opt/bitnami/apps/wordpress/htdocs. Once you've copied your association file there, the place to make the configuration change for the content type header described in Alex's answer is /opt/bitnami/apps/wordpress/conf/httpd-app.conf. Finally, you'll need to restart Apache for the configuration change to kick in, using the command sudo apachectl -k graceful. You can verify that your setup is correct using this validator tool.

See my post here for more details.

The easiest way to have the apple-app-site-association file delivered with content type application/json or application/pkcs7-mime in Apache is to add an .htaccess file in the same directory with the following contents:

<Files apple-app-site-association>ForceType application/json</Files>

or

<Files apple-app-site-association>ForceType application/pkcs7-mime</Files>

Then you don't have to add it to your server configuration.

Credit goes to http://redquark.com/wp/?p=209