Configuring Element API 1.2.1 Plugin
If you're hitting /api/news.json in the browser, you'd want to define the endpoint as 'api/news.json' as well.  i.e.

&lt;?php
namespace Craft;

return [
    'endpoints' =&gt; [
        'api/news.json' =&gt; [
            'elementType' =&gt; 'Entry',
            'criteria' =&gt; ['section' =&gt; 'news'],
        ]
    ]
];