# nginx.conf (relevant bits)
events {}

http {
  # This now governs idle close for HTTP/2, since http2_idle_timeout is obsolete.
  keepalive_timeout 75s;   # ← set to 60–80s to reproduce your prod-ish drop

  # Good defaults for streaming
  sendfile off;            # avoid sendfile delays for tiny frames
  tcp_nodelay on;

  upstream app_upstream {
    server host.docker.internal:3030;
    keepalive 16;
  }

  server {
    listen 8443 ssl;       # ← no ‘http2’ here…
    http2 on;              # ← …use the standalone directive instead
    server_name localhost;

    ssl_certificate     /etc/nginx/certs/cert.pem;
    ssl_certificate_key /etc/nginx/certs/key.pem;

    location / {
      # Make SSE actually stream through NGINX:
      proxy_buffering off;                    # don’t buffer
      gzip off;                               # don’t compress
      add_header X-Accel-Buffering no;        # belt & suspenders for NGINX buffering
      proxy_set_header Accept-Encoding "";    # stop upstream gzip (SSE + gzip = sad)

      # Plain h1 to upstream is fine for SSE
      proxy_http_version 1.1;
      proxy_set_header Connection "";

      proxy_read_timeout 30s;
      proxy_send_timeout 30s;

      proxy_set_header Host $host;
      proxy_set_header X-Forwarded-For $remote_addr;

      proxy_pass http://app_upstream;
    }
  }
}