location /api {
               rewrite /api/(.*) /$1 break;
               proxy_pass http://example.com/api;
                proxy_set_header X-Real-IP $remote_addr;
               proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $http_host;
                proxy_redirect off;
               proxy_buffering off;

location ~* ^/api/(.*)$ {
                rewrite ^/api/(.*)$ http://example.com/api/$1 last;
        }