ansonl

Thanks for the help, after adding in the nested~ \.php block, the PHP files inside the /api directory work perfectly, however when accessing static text files, Nginx returns a nginx 404 error page instead of the wordpress error now.
For example, accessing file located at /api/newest.txt returns 404 whereas accessing /api/newest.plist serves the actual plist file which the browser downloads.

Modified config following the pastebin example below (I have removed the try_files option for /api, is try_file only necessary for PHP files? Adding try_files doesn’t seem to make a difference.):

server {
    server_name  www.geometrystash.com;
    rewrite ^(.*) http://geometrystash.com$1 permanent;
}

server {
        listen 80;
        server_name geometrystash.com;
        root /var/www/geometrystash.com/htdocs/blog;
        index index.php;
		include /etc/nginx/security;

# Logging --
access_log  off;
error_log  /var/log/nginx/geometrystash.com.error.log warn;

        location = /favicon.ico {
                log_not_found off;
                access_log off;
        }

        location = /robots.txt {
                allow all;
                log_not_found off;
                access_log off;
        }

        # serve static files directly
        location ~* ^.+.(jpg|jpeg|gif|css|png|js|ico|html|xml|txt)$ {
            access_log        off;
            expires           max;
        }

        location /api {
            root /var/www/geometrystash.com/htdocs;
            index index.php;

            location ~ \.php$ {
                try_files $uri $uri/ /index.php?$args;
                fastcgi_pass unix:/var/run/php5-fpm/geometrystash.com.socket;
                fastcgi_index index.php;
                include /etc/nginx/fastcgi_params;
                }
        }

        location ~ \.php$ {
		try_files $uri $uri/ /index.php?$args;
                fastcgi_pass unix:/var/run/php5-fpm/geometrystash.com.socket;
                fastcgi_index index.php;
                include /etc/nginx/fastcgi_params;
        }
}