diff --git a/misc/build.func b/misc/build.func
index 3db6c7615..1f517903e 100644
--- a/misc/build.func
+++ b/misc/build.func
@@ -986,13 +986,23 @@ base_settings() {
 
   # Runtime check: Verify APT cacher is reachable if configured
   if [[ -n "$APT_CACHER_IP" && "$APT_CACHER" == "yes" ]]; then
-    if ! curl -s --connect-timeout 2 "http://${APT_CACHER_IP}:3142" >/dev/null 2>&1; then
-      msg_warn "APT Cacher configured but not reachable at ${APT_CACHER_IP}:3142"
+    local _check_host _check_port _check_url
+    _check_host=$(echo "$APT_CACHER_IP" | sed -e 's|https\?://||' -e 's|/.*||' | cut -d: -f1)
+    _check_port=$(echo "$APT_CACHER_IP" | sed -e 's|https\?://||' -e 's|/.*||' | cut -s -d: -f2)
+    if [[ "$APT_CACHER_IP" =~ ^https?:// ]]; then
+      _check_url="$APT_CACHER_IP"
+      _check_port="${_check_port:-80}"
+    else
+      _check_port="${_check_port:-3142}"
+      _check_url="http://${APT_CACHER_IP}:${_check_port}"
+    fi
+    if ! curl -s --connect-timeout 2 "${_check_url}" >/dev/null 2>&1; then
+      msg_warn "APT Cacher configured but not reachable at ${_check_url}"
       msg_custom "⚠️" "${YW}" "Disabling APT Cacher for this installation"
       APT_CACHER=""
       APT_CACHER_IP=""
     else
-      msg_ok "APT Cacher verified at ${APT_CACHER_IP}:3142"
+      msg_ok "APT Cacher verified at ${_check_url}"
     fi
   fi
 
@@ -1199,6 +1209,13 @@ load_vars_file() {
             continue
           fi
           ;;
+        var_apt_cacher_ip)
+          # Allow: plain IP/hostname, http://host, https://host:port
+          if [[ -n "$var_val" ]] && ! [[ "$var_val" =~ ^(https?://)?[a-zA-Z0-9._-]+(:[0-9]+)?(/.*)?$ ]]; then
+            msg_warn "Invalid APT Cacher address '$var_val' in $file, ignoring"
+            continue
+          fi
+          ;;
         var_container_storage | var_template_storage)
           # Validate that the storage exists and is active on the current node
           local _storage_status
@@ -1311,9 +1328,11 @@ var_ipv6_method=none
 var_ssh=no
 # var_ssh_authorized_key=
 
-# APT cacher (optional - with example)
+# APT cacher (optional - IP or URL)
 # var_apt_cacher=yes
 # var_apt_cacher_ip=192.168.1.10
+# var_apt_cacher_ip=http://proxy.local
+# var_apt_cacher_ip=https://proxy.local:443
 
 # Features/Tags/verbosity
 var_fuse=no
@@ -2526,7 +2545,7 @@ advanced_settings() {
         # Ask for IP if enabled
         if result=$(whiptail --backtitle "Proxmox VE Helper Scripts [Step $STEP/$MAX_STEP]" \
           --title "APT CACHER IP" \
-          --inputbox "\nEnter APT Cacher-NG server IP address:" 10 58 "$_apt_cacher_ip" \
+          --inputbox "\nEnter APT Cacher-NG IP or URL:\n(e.g. 192.168.1.10, http://host, https://host:443)" 12 62 "$_apt_cacher_ip" \
           3>&1 1>&2 2>&3); then
           _apt_cacher_ip="$result"
         fi
diff --git a/misc/install.func b/misc/install.func
index 30cf93f2c..a1a1e0ff3 100644
--- a/misc/install.func
+++ b/misc/install.func
@@ -390,10 +390,24 @@ update_os() {
   msg_info "Updating Container OS"
   if [[ "$CACHER" == "yes" ]]; then
     echo 'Acquire::http::Proxy-Auto-Detect "/usr/local/bin/apt-proxy-detect.sh";' >/etc/apt/apt.conf.d/00aptproxy
+    local _proxy_raw="${CACHER_IP}"
+    local _proxy_host _proxy_port _proxy_url
+    # Parse host and port from URL or plain IP/hostname
+    _proxy_host=$(echo "$_proxy_raw" | sed -e 's|https\?://||' -e 's|/.*||' | cut -d: -f1)
+    _proxy_port=$(echo "$_proxy_raw" | sed -e 's|https\?://||' -e 's|/.*||' | cut -s -d: -f2)
+    if [[ "$_proxy_raw" =~ ^https?:// ]]; then
+      # Full URL provided — use as-is for proxy output, extract port for nc check
+      _proxy_url="$_proxy_raw"
+      _proxy_port="${_proxy_port:-80}"
+    else
+      # Legacy: plain IP or hostname — default to http + port 3142
+      _proxy_port="${_proxy_port:-3142}"
+      _proxy_url="http://${_proxy_raw}:${_proxy_port}"
+    fi
     cat <<EOF >/usr/local/bin/apt-proxy-detect.sh
 #!/bin/bash
-if nc -w1 -z "${CACHER_IP}" 3142; then
-  echo -n "http://${CACHER_IP}:3142"
+if nc -w1 -z "${_proxy_host}" ${_proxy_port}; then
+  echo -n "${_proxy_url}"
 else
   echo -n "DIRECT"
 fi