server 
{
    listen       80;
    server_name  localhost;

    root   /usr/share/nginx/html;
    index index.html;
    error_page   500 502 503 504  /50x.html;

    location /api {
        proxy_pass $codex_url;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
    location / {
        try_files $uri /index.html;
        add_header Cache-Control "no-cache";
    }
}