diff --git a/filter_plugins/alias_domains_map.py b/filter_plugins/alias_domains_map.py
new file mode 100644
index 00000000..d2b51972
--- /dev/null
+++ b/filter_plugins/alias_domains_map.py
@@ -0,0 +1,86 @@
+from ansible.errors import AnsibleFilterError
+
+class FilterModule(object):
+    def filters(self):
+        return {'alias_domains_map': self.alias_domains_map}
+
+    def alias_domains_map(self, apps, primary_domain):
+        """
+        Build a map of application IDs to their alias domains.
+
+        - If no `domains` key → []  
+        - If `domains` exists but is an empty dict → return the original cfg  
+        - Explicit `aliases` are used (default appended if missing)  
+        - If only `canonical` defined and it doesn't include default, default is added  
+        - Invalid types raise AnsibleFilterError
+        """
+        def parse_entry(domains_cfg, key, app_id):
+            if key not in domains_cfg:
+                return None
+            entry = domains_cfg[key]
+            if isinstance(entry, dict):
+                values = list(entry.values())
+            elif isinstance(entry, list):
+                values = entry
+            else:
+                raise AnsibleFilterError(
+                    f"Unexpected type for 'domains.{key}' in application '{app_id}': {type(entry).__name__}"
+                )
+            for d in values:
+                if not isinstance(d, str) or not d.strip():
+                    raise AnsibleFilterError(
+                        f"Invalid domain entry in '{key}' for application '{app_id}': {d!r}"
+                    )
+            return values
+
+        def default_domain(app_id, primary):
+            return f"{app_id}.{primary}"
+
+        # 1) Precompute canonical domains per app (fallback to default)
+        canonical_map = {}
+        for app_id, cfg in apps.items():
+            domains_cfg = cfg.get('domains') or {}
+            entry = domains_cfg.get('canonical')
+            if entry is None:
+                canonical_map[app_id] = [default_domain(app_id, primary_domain)]
+            elif isinstance(entry, dict):
+                canonical_map[app_id] = list(entry.values())
+            elif isinstance(entry, list):
+                canonical_map[app_id] = list(entry)
+            else:
+                raise AnsibleFilterError(
+                    f"Unexpected type for 'domains.canonical' in application '{app_id}': {type(entry).__name__}"
+                )
+
+        # 2) Build alias list per app
+        result = {}
+        for app_id, cfg in apps.items():
+            domains_cfg = cfg.get('domains')
+
+            # no domains key → no aliases
+            if domains_cfg is None:
+                result[app_id] = []
+                continue
+
+            # empty domains dict → return the original cfg
+            if isinstance(domains_cfg, dict) and not domains_cfg:
+                result[app_id] = cfg
+                continue
+
+            # otherwise, compute aliases
+            aliases = parse_entry(domains_cfg, 'aliases', app_id) or []
+            default = default_domain(app_id, primary_domain)
+            has_aliases = 'aliases' in domains_cfg
+            has_canon   = 'canonical' in domains_cfg
+
+            if has_aliases:
+                if default not in aliases:
+                    aliases.append(default)
+            elif has_canon:
+                canon = canonical_map.get(app_id, [])
+                if default not in canon and default not in aliases:
+                    aliases.append(default)
+
+            result[app_id] = aliases
+
+        return result
\ No newline at end of file
diff --git a/filter_plugins/canonical_domains_map.py b/filter_plugins/canonical_domains_map.py
new file mode 100644
index 00000000..afbb0c10
--- /dev/null
+++ b/filter_plugins/canonical_domains_map.py
@@ -0,0 +1,75 @@
+from ansible.errors import AnsibleFilterError
+
+class FilterModule(object):
+    def filters(self):
+        return {'canonical_domains_map': self.canonical_domains_map}
+
+    def canonical_domains_map(self, apps, primary_domain):
+        def parse_entry(domains_cfg, key, app_id):
+            if key not in domains_cfg:
+                return None
+            entry = domains_cfg[key]
+            if isinstance(entry, dict):
+                values = list(entry.values())
+            elif isinstance(entry, list):
+                values = entry
+            else:
+                raise AnsibleFilterError(
+                    f"Unexpected type for 'domains.{key}' in application '{app_id}': {type(entry).__name__}"
+                )
+            for d in values:
+                if not isinstance(d, str) or not d.strip():
+                    raise AnsibleFilterError(
+                        f"Invalid domain entry in '{key}' for application '{app_id}': {d!r}"
+                    )
+            return values
+
+        result = {}
+        seen = {}
+
+        for app_id, cfg in apps.items():
+            domains_cfg = cfg.get('domains')
+            if not domains_cfg or 'canonical' not in domains_cfg:
+                default = f"{app_id}.{primary_domain}"
+                if default in seen:
+                    raise AnsibleFilterError(
+                        f"Domain '{default}' is already configured for '{seen[default]}' and '{app_id}'"
+                    )
+                seen[default] = app_id
+                result[app_id] = [default]
+                continue
+
+            entry = domains_cfg['canonical']
+
+            if isinstance(entry, dict):
+                for name, domain in entry.items():
+                    if not isinstance(domain, str) or not domain.strip():
+                        raise AnsibleFilterError(
+                            f"Invalid domain entry in 'canonical' for application '{app_id}': {domain!r}"
+                        )
+                    if domain in seen:
+                        raise AnsibleFilterError(
+                            f"Domain '{domain}' is already configured for '{seen[domain]}' and '{app_id}'"
+                        )
+                    seen[domain] = app_id
+                result[app_id] = entry.copy()
+
+            elif isinstance(entry, list):
+                for domain in entry:
+                    if not isinstance(domain, str) or not domain.strip():
+                        raise AnsibleFilterError(
+                            f"Invalid domain entry in 'canonical' for application '{app_id}': {domain!r}"
+                        )
+                    if domain in seen:
+                        raise AnsibleFilterError(
+                            f"Domain '{domain}' is already configured for '{seen[domain]}' and '{app_id}'"
+                        )
+                    seen[domain] = app_id
+                result[app_id] = list(entry)
+
+            else:
+                raise AnsibleFilterError(
+                    f"Unexpected type for 'domains.canonical' in application '{app_id}': {type(entry).__name__}"
+                )
+
+        return result
diff --git a/filter_plugins/domain_filters.py b/filter_plugins/domain_filters.py
deleted file mode 100644
index d6ac6c30..00000000
--- a/filter_plugins/domain_filters.py
+++ /dev/null
@@ -1,184 +0,0 @@
-import re
-from ansible.errors import AnsibleFilterError
-
-class FilterModule(object):
-    """
-    Ansible Filter Plugin for Domain Processing
-
-    This plugin provides filters to manage and transform domain configurations for applications:
-
-    - generate_all_domains(domains_dict, include_www=True):
-      Flattens nested domain values (string, list, or dict), optionally adds 'www.' prefixes,
-      removes duplicates, and returns a sorted list of unique domains.
-
-    - generate_base_sld_domains(domains_dict, redirect_mappings):
-      Flattens domains and redirect mappings, extracts second-level + top-level domains (SLDs),
-      deduplicates, and returns a sorted list of base domains.
-
-    - canonical_domains_map(apps, primary_domain):
-      Builds a mapping of application IDs to their canonical domains using
-      DomainUtils.canonical_list, enforcing uniqueness and detecting conflicts.
-
-    - alias_domains_map(apps, primary_domain):
-      Generates alias domains for each application via DomainUtils.alias_list,
-      based on their canonical domains and provided configurations.
-    """
-
-    def filters(self):
-        return {
-            'generate_all_domains':         self.generate_all_domains,
-            'generate_base_sld_domains':    self.generate_base_sld_domains,
-            'canonical_domains_map':        self.canonical_domains_map,
-            'alias_domains_map':            self.alias_domains_map,
-        }
-        
-    @staticmethod
-    def parse_entry(domains_cfg, key, app_id):
-        """
-        Extract list of strings from domains_cfg[key], which may be dict or list.
-        Returns None if key not in domains_cfg.
-        Raises AnsibleFilterError on invalid type or empty/invalid values.
-        """
-        if key not in domains_cfg:
-            return None
-        entry = domains_cfg[key]
-        if isinstance(entry, dict):
-            values = list(entry.values())
-        elif isinstance(entry, list):
-            values = entry
-        else:
-            raise AnsibleFilterError(
-                f"Unexpected type for 'domains.{key}' in application '{app_id}': {type(entry).__name__}"
-            )
-        for d in values:
-            if not isinstance(d, str) or not d.strip():
-                raise AnsibleFilterError(
-                    f"Invalid domain entry in '{key}' for application '{app_id}': {d!r}"
-                )
-        return values
-
-    @staticmethod
-    def default_domain(app_id, primary_domain):
-        """
-        Returns the default domain string for an application.
-        """
-        return f"{app_id}.{primary_domain}"
-
-    @classmethod
-    def canonical_list(cls, domains_cfg, app_id, primary_domain):
-        """
-        Returns the list of canonical domains: parsed entry or default.
-        """
-        domains = cls.parse_entry(domains_cfg, 'canonical', app_id)
-        if domains is None:
-            return [cls.default_domain(app_id, primary_domain)]
-        return domains
-
-    @classmethod
-    def alias_list(cls, domains_cfg, app_id, primary_domain, canonical_domains=None):
-        """
-        Returns the list of alias domains based on:
-          - explicit aliases entry
-          - presence of canonical entry and default not in canonical
-        Always ensures default domain in aliases when appropriate.
-        """
-        default = cls.default_domain(app_id, primary_domain)
-        aliases = cls.parse_entry(domains_cfg, 'aliases', app_id) or []
-        has_aliases = 'aliases' in domains_cfg
-        has_canonical = 'canonical' in domains_cfg
-
-        if has_aliases:
-            if default not in aliases:
-                aliases.append(default)
-        elif has_canonical:
-            # use provided canonical_domains if given otherwise parse
-            canon = canonical_domains if canonical_domains is not None else cls.parse_entry(domains_cfg, 'canonical', app_id)
-            if default not in (canon or []):
-                aliases.append(default)
-        # else: neither defined -> empty list
-        return aliases
-
-
-    @staticmethod
-    def generate_all_domains(domains_dict, include_www=True):
-        """
-        Transform a dict of domains (values: str, list, dict) into a flat list,
-        optionally add 'www.' prefixes, dedupe and sort alphabetically.
-
-        Avoids infinite loops by snapshotting initial domain list for www prefixes.
-        """
-        try:
-            flat = FilterModule._flatten_domain_values(domains_dict)
-            if include_www:
-                # Snapshot original list to avoid extending while iterating
-                original = list(flat)
-                flat.extend([f"www.{d}" for d in original])
-            return sorted(set(flat))
-        except Exception as exc:
-            raise AnsibleFilterError(f"generate_all_domains failed: {exc}")
-
-    @staticmethod
-    def generate_base_sld_domains(domains_dict, redirect_mappings):
-        """
-        Flatten domains_dict and redirect_mappings, extract second-level + top-level domains.
-        redirect_mappings: list of dicts with key 'source'
-        """
-        try:
-            flat = FilterModule._flatten_domain_values(domains_dict)
-            for mapping in redirect_mappings or []:
-                src = mapping.get('source')
-                if isinstance(src, str):
-                    flat.append(src)
-                elif isinstance(src, list):
-                    flat.extend(src)
-
-            pattern = re.compile(r'^(?:.*\.)?([^.]+\.[^.]+)$')
-            slds = {m.group(1) for d in flat if (m := pattern.match(d))}
-            return sorted(slds)
-        except Exception as exc:
-            raise AnsibleFilterError(f"generate_base_sld_domains failed: {exc}")
-
-    @staticmethod
-    def _flatten_domain_values(domains_dict):
-        """
-        Helper to extract domain strings from dict values (str, list, dict).
-        """
-        flat = []
-        for val in (domains_dict or {}).values():
-            if isinstance(val, str):
-                flat.append(val)
-            elif isinstance(val, list):
-                flat.extend(val)
-            elif isinstance(val, dict):
-                flat.extend(val.values())
-        return flat
-
-    def canonical_domains_map(self, apps, primary_domain):
-        result = {}
-        seen = {}
-        for app_id, app_cfg in apps.items():
-            domains_cfg = app_cfg.get('domains', {}) or {}
-            domains = self.canonical_list(domains_cfg, app_id, primary_domain)
-            for d in domains:
-                if d in seen:
-                    raise AnsibleFilterError(
-                        f"Domain '{d}' is configured for both '{seen[d]}' and '{app_id}'"
-                    )
-                seen[d] = app_id
-            result[app_id] = domains
-        return result
-
-    def alias_domains_map(self, apps, primary_domain):
-        result = {}
-        # wir können die canonical_map vorab holen…
-        canonical_map = self.canonical_domains_map(apps, primary_domain)
-        for app_id, app_cfg in apps.items():
-            domains_cfg = app_cfg.get('domains', {}) or {}
-            aliases = self.alias_list(
-                domains_cfg,
-                app_id,
-                primary_domain,
-                canonical_domains=canonical_map.get(app_id),
-            )
-            result[app_id] = aliases
-        return result
diff --git a/filter_plugins/generate_all_domains.py b/filter_plugins/generate_all_domains.py
new file mode 100644
index 00000000..2bf25ef2
--- /dev/null
+++ b/filter_plugins/generate_all_domains.py
@@ -0,0 +1,31 @@
+from ansible.errors import AnsibleFilterError
+
+class FilterModule(object):
+    def filters(self):
+        return {'generate_all_domains': self.generate_all_domains}
+
+    def generate_all_domains(self, domains_dict, include_www=True):
+        """
+        Transform a dict of domains (values: str, list, dict) into a flat list,
+        optionally add 'www.' prefixes, dedupe and sort alphabetically.
+        """
+        # lokaler Helfer zum Flatten
+        def _flatten(domains):
+            flat = []
+            for v in (domains or {}).values():
+                if isinstance(v, str):
+                    flat.append(v)
+                elif isinstance(v, list):
+                    flat.extend(v)
+                elif isinstance(v, dict):
+                    flat.extend(v.values())
+            return flat
+
+        try:
+            flat = _flatten(domains_dict)
+            if include_www:
+                original = list(flat)
+                flat.extend([f"www.{d}" for d in original])
+            return sorted(set(flat))
+        except Exception as exc:
+            raise AnsibleFilterError(f"generate_all_domains failed: {exc}")
diff --git a/filter_plugins/generate_base_sld_domains.py b/filter_plugins/generate_base_sld_domains.py
new file mode 100644
index 00000000..6c72e332
--- /dev/null
+++ b/filter_plugins/generate_base_sld_domains.py
@@ -0,0 +1,37 @@
+import re
+from ansible.errors import AnsibleFilterError
+
+class FilterModule(object):
+    def filters(self):
+        return {'generate_base_sld_domains': self.generate_base_sld_domains}
+
+    def generate_base_sld_domains(self, domains_dict, redirect_mappings):
+        """
+        Flatten domains_dict und redirect_mappings, extrahiere SLDs (z.B. example.com),
+        dedupe und sortiere.
+        """
+        def _flatten(domains):
+            flat = []
+            for v in (domains or {}).values():
+                if isinstance(v, str):
+                    flat.append(v)
+                elif isinstance(v, list):
+                    flat.extend(v)
+                elif isinstance(v, dict):
+                    flat.extend(v.values())
+            return flat
+
+        try:
+            flat = _flatten(domains_dict)
+            for mapping in redirect_mappings or []:
+                src = mapping.get('source')
+                if isinstance(src, str):
+                    flat.append(src)
+                elif isinstance(src, list):
+                    flat.extend(src)
+
+            pattern = re.compile(r'^(?:.*\.)?([^.]+\.[^.]+)$')
+            slds = {m.group(1) for d in flat if (m := pattern.match(d))}
+            return sorted(slds)
+        except Exception as exc:
+            raise AnsibleFilterError(f"generate_base_sld_domains failed: {exc}")
diff --git a/tasks/constructor.yml b/tasks/constructor.yml
index febf1471..ca1e8bf8 100644
--- a/tasks/constructor.yml
+++ b/tasks/constructor.yml
@@ -17,6 +17,13 @@
     set_fact:
       domains: "{{ defaults_domains | combine(domains | default({}, true), recursive=True) }}"
 
+  - name: "Merged Variables"
+    # Add new merged variables here
+    debug:
+      msg:
+        domains:          "{{ defaults_domains }}"
+    when: enable_debug | bool
+
   - name: Merge redirect domain definitions into dictionary
     set_fact:
       combined_mapping: >-
diff --git a/tests/unit/test_domain_filters.py b/tests/unit/test_domain_filters_alias.py
similarity index 65%
rename from tests/unit/test_domain_filters.py
rename to tests/unit/test_domain_filters_alias.py
index c42310b0..75b18ad2 100644
--- a/tests/unit/test_domain_filters.py
+++ b/tests/unit/test_domain_filters_alias.py
@@ -9,7 +9,7 @@ dir_path = os.path.abspath(
 sys.path.insert(0, dir_path)
 
 from ansible.errors import AnsibleFilterError
-from domain_filters import FilterModule
+from alias_domains_map import FilterModule
 
 class TestDomainFilters(unittest.TestCase):
     def setUp(self):
@@ -17,45 +17,6 @@ class TestDomainFilters(unittest.TestCase):
         # Sample primary domain
         self.primary = 'example.com'
 
-    def test_canonical_empty_apps(self):
-        apps = {}
-        expected = {}
-        result = self.filter_module.canonical_domains_map(apps, self.primary)
-        self.assertEqual(result, expected)
-
-    def test_canonical_without_domains(self):
-        apps = {'app1': {}}
-        expected = {'app1': ['app1.example.com']}
-        result = self.filter_module.canonical_domains_map(apps, self.primary)
-        self.assertEqual(result, expected)
-
-    def test_canonical_with_list(self):
-        apps = {
-            'app1': {
-                'domains': {'canonical': ['foo.com', 'bar.com']}
-            }
-        }
-        result = self.filter_module.canonical_domains_map(apps, self.primary)
-        self.assertCountEqual(result['app1'], ['foo.com', 'bar.com'])
-
-    def test_canonical_with_dict(self):
-        apps = {
-            'app1': {
-                'domains': {'canonical': {'one': 'one.com', 'two': 'two.com'}}
-            }
-        }
-        result = self.filter_module.canonical_domains_map(apps, self.primary)
-        self.assertCountEqual(result['app1'], ['one.com', 'two.com'])
-
-    def test_canonical_duplicate_raises(self):
-        apps = {
-            'app1': {'domains': {'canonical': ['dup.com']}},
-            'app2': {'domains': {'canonical': ['dup.com']}},
-        }
-        with self.assertRaises(AnsibleFilterError) as cm:
-            self.filter_module.canonical_domains_map(apps, self.primary)
-        self.assertIn("configured for both", str(cm.exception))
-
     def test_alias_empty_apps(self):
         apps = {}
         expected = {}
@@ -105,13 +66,6 @@ class TestDomainFilters(unittest.TestCase):
         result = self.filter_module.alias_domains_map(apps, self.primary)
         self.assertEqual(result, expected)
 
-    def test_invalid_canonical_type(self):
-        apps = {
-            'app1': {'domains': {'canonical': 123}}
-        }
-        with self.assertRaises(AnsibleFilterError):
-            self.filter_module.canonical_domains_map(apps, self.primary)
-
     def test_invalid_aliases_type(self):
         apps = {
             'app1': {'domains': {'aliases': 123}}
@@ -119,5 +73,31 @@ class TestDomainFilters(unittest.TestCase):
         with self.assertRaises(AnsibleFilterError):
             self.filter_module.alias_domains_map(apps, self.primary)
 
+    def test_alias_with_empty_domains_cfg(self):
+        apps = {
+            'app1': {
+                'domains': {}
+            }
+        }
+        expected = apps
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+        
+    def test_alias_with_canonical_dict_not_default(self):
+        apps = {
+            'app1': {
+                'domains': {
+                    'canonical': {
+                        'one': 'one.com',
+                        'two': 'two.com'
+                    }
+                }
+            }
+        }
+        expected = {'app1': ['app1.example.com']}
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+
 if __name__ == "__main__":
-    unittest.main()
+    unittest.main()
\ No newline at end of file
diff --git a/tests/unit/test_domain_filters_all_domains.py b/tests/unit/test_domain_filters_all_domains.py
index 5a17f7c0..d8b5a984 100644
--- a/tests/unit/test_domain_filters_all_domains.py
+++ b/tests/unit/test_domain_filters_all_domains.py
@@ -8,7 +8,7 @@ sys.path.insert(
     os.path.abspath(os.path.join(os.path.dirname(__file__), '../../filter_plugins'))
 )
 
-from domain_filters import FilterModule
+from generate_all_domains import FilterModule
 
 class TestGenerateAllDomains(unittest.TestCase):
     def setUp(self):
diff --git a/tests/unit/test_domain_filters_base_sld_domains.py b/tests/unit/test_domain_filters_base_sld_domains.py
index 81a8253f..fd4ce1ff 100644
--- a/tests/unit/test_domain_filters_base_sld_domains.py
+++ b/tests/unit/test_domain_filters_base_sld_domains.py
@@ -8,7 +8,7 @@ sys.path.insert(
     os.path.abspath(os.path.join(os.path.dirname(__file__), '../../filter_plugins'))
 )
 
-from domain_filters import FilterModule
+from generate_base_sld_domains import FilterModule
 
 class TestGenerateBaseSldDomains(unittest.TestCase):
     def setUp(self):
diff --git a/tests/unit/test_domain_filters_canonical.py b/tests/unit/test_domain_filters_canonical.py
new file mode 100644
index 00000000..f25eed83
--- /dev/null
+++ b/tests/unit/test_domain_filters_canonical.py
@@ -0,0 +1,74 @@
+import os
+import sys
+import unittest
+
+# Add the filter_plugins directory to the import path
+dir_path = os.path.abspath(
+    os.path.join(os.path.dirname(__file__), '../../filter_plugins')
+)
+sys.path.insert(0, dir_path)
+
+from ansible.errors import AnsibleFilterError
+from canonical_domains_map import FilterModule
+
+class TestDomainFilters(unittest.TestCase):
+    def setUp(self):
+        self.filter_module = FilterModule()
+        # Sample primary domain
+        self.primary = 'example.com'
+
+    def test_canonical_empty_apps(self):
+        apps = {}
+        expected = {}
+        result = self.filter_module.canonical_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+    def test_canonical_without_domains(self):
+        apps = {'app1': {}}
+        expected = {'app1': ['app1.example.com']}
+        result = self.filter_module.canonical_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+    def test_canonical_with_list(self):
+        apps = {
+            'app1': {
+                'domains': {'canonical': ['foo.com', 'bar.com']}
+            }
+        }
+        result = self.filter_module.canonical_domains_map(apps, self.primary)
+        self.assertCountEqual(
+            result['app1'],
+            ['foo.com', 'bar.com']
+        )
+
+    def test_canonical_with_dict(self):
+        apps = {
+            'app1': {
+                'domains': {'canonical': {'one': 'one.com', 'two': 'two.com'}}
+            }
+        }
+        result = self.filter_module.canonical_domains_map(apps, self.primary)
+        self.assertEqual(
+            result['app1'],
+            {'one': 'one.com', 'two': 'two.com'}
+        )
+
+    def test_canonical_duplicate_raises(self):
+        apps = {
+            'app1': {'domains': {'canonical': ['dup.com']}},
+            'app2': {'domains': {'canonical': ['dup.com']}},
+        }
+        with self.assertRaises(AnsibleFilterError) as cm:
+            self.filter_module.canonical_domains_map(apps, self.primary)
+        # Updated to match new exception message
+        self.assertIn("already configured for", str(cm.exception))
+
+    def test_invalid_canonical_type(self):
+        apps = {
+            'app1': {'domains': {'canonical': 123}}
+        }
+        with self.assertRaises(AnsibleFilterError):
+            self.filter_module.canonical_domains_map(apps, self.primary)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file