diff --git a/app/models/soa.rb b/app/models/soa.rb
new file mode 100644
index 0000000..8cf823d
--- /dev/null
+++ b/app/models/soa.rb
@@ -0,0 +1,73 @@
+class SOA < Record
+  validates :domain_id, uniqueness: true
+  validates_numericality_of :serial, :refresh, :retry, :expire
+  validates_presence_of :contact
+
+  SOA_DEFAULTS = WebDNS.settings[:soa_defaults]
+  SOA_FIELDS = SOA_DEFAULTS.keys
+
+  SOA_FIELDS.each { |soa_entry|
+    attr_accessor soa_entry
+  }
+
+  # Handle SOA Fields
+  after_initialize :set_soa_fields
+
+  # Load soa fields on reload
+  def reload_with_soa_fields(*args)
+    reload_without_soa_fields(*args).tap {
+      set_soa_fields
+    }
+  end
+  alias_method_chain :reload, :soa_fields
+
+  before_validation :set_content
+  before_validation :update_serial, on: :update
+
+  def bump_serial!
+    with_lock {
+      reload
+      self.serial += 1
+      save!
+    }
+  end
+
+  def serial_changed?
+    return false if not self.content_changed?
+
+    serial_index = SOA_FIELDS.index(:serial)
+    old, new = content_change.map { |c|
+      (c || '').split(/\s+/)[serial_index]
+    }
+
+    old != new
+  end
+
+  private
+
+  # Callbacks
+
+  def set_soa_fields
+    content_values = (content || '').split(/\s+/)
+    SOA_DEFAULTS.each { |field, default_value|
+      val = content_values.shift || default_value
+      val = Integer(val) if default_value.is_a?(Integer)
+      send("#{field}=", val)
+    }
+  end
+
+  def set_content
+    self.content = SOA_FIELDS.map { |field| send(field) }.join(' ')
+  end
+
+  def update_serial
+    # Don't update if nothing has changed
+    return if not self.content_changed?
+    # Don't updade if serial is already changed
+    return if self.serial_changed?
+
+    self.serial += 1
+    set_content
+  end
+
+end
diff --git a/config/initializers/00_settings.rb b/config/initializers/00_settings.rb
index e69de29..991c443 100644
--- a/config/initializers/00_settings.rb
+++ b/config/initializers/00_settings.rb
@@ -0,0 +1,12 @@
+WebDNS = Base
+
+WebDNS.settings[:soa_defaults] = {
+  primary_ns: 'ns.example.com',
+  contact: 'domainmaster@example.com',
+  serial: 1,
+  refresh: 10_800,
+  retry: 3600,
+  expire: 604_800,
+  nx: 3600
+}
+