This is CORS problem. http://enable-cors.org/
#Add these lines to your .htaccess file Header set Access-Control-Allow-Origin "localhost" Header set Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" Header set Access-Control-Allow-Headers "X-Oc-Merchant-Language, X-Oc-Store-Id, Content-Type,X-Oc-Merchant-Id, X-Oc-Session" Header set Access-Control-Allow-Credentials: true RewriteRule .* - [E=HTTP_Authorization:%{HTTP:Authorization}]
Opencart API edited answer November 25, 2015