diff --git a/Makefile b/Makefile
index 4d363d84..d2ec31d3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 ROLES_DIR         	:= ./roles
-APPLICATIONS_OUT  	:= ./group_vars/all/11_applications.yml
+APPLICATIONS_OUT  	:= ./group_vars/all/03_applications.yml
 APPLICATIONS_SCRIPT := ./cli/generate-applications-defaults.py
 INCLUDES_OUT      	:= ./tasks/include-docker-roles.yml
 INCLUDES_SCRIPT   	:= ./cli/generate-role-includes.py
diff --git a/ansible.cfg b/ansible.cfg
index 99c620d9..1465cf11 100644
--- a/ansible.cfg
+++ b/ansible.cfg
@@ -1,2 +1,3 @@
 [defaults]
-lookup_plugins = ./lookup_plugins
\ No newline at end of file
+lookup_plugins = ./lookup_plugins
+filter_plugins = ./filter_plugins
\ No newline at end of file
diff --git a/cli/generate-applications-defaults.py b/cli/generate-applications-defaults.py
index 102727d8..7863bdae 100644
--- a/cli/generate-applications-defaults.py
+++ b/cli/generate-applications-defaults.py
@@ -15,7 +15,7 @@ def load_yaml_file(path):
 def main():
     parser = argparse.ArgumentParser(description="Generate defaults_applications YAML from docker roles.")
     parser.add_argument("--roles-dir", default="roles", help="Path to the roles directory (default: roles)")
-    parser.add_argument("--output-file", default="group_vars/all/11_applications.yml", help="Path to output YAML file")
+    parser.add_argument("--output-file", default="group_vars/all/03_applications.yml", help="Path to output YAML file")
 
     args = parser.parse_args()
     cwd = Path.cwd()
diff --git a/docs/guides/developer/Ansible_Directory_Guide.md b/docs/guides/developer/Ansible_Directory_Guide.md
new file mode 100644
index 00000000..b52797cb
--- /dev/null
+++ b/docs/guides/developer/Ansible_Directory_Guide.md
@@ -0,0 +1,111 @@
+## 📖 CyMaIS.Cloud Ansible & Python Directory Guide
+
+This document provides a **decision matrix** for when to use each default Ansible plugin and module directory in the context of **CyMaIS.Cloud development** with Ansible and Python. It links to official docs, explains use-cases, and points back to our conversation.
+
+---
+
+### 🔗 Links & References
+
+* Official Ansible Plugin Guide: [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html)
+* Official Ansible Module Guide: [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_modules.html](https://docs.ansible.com/ansible/latest/dev_guide/developing_modules.html)
+* This conversation: [Link to this conversation](https://chat.openai.com/)
+
+---
+
+### 🛠️ Repo Layout & Default Directories
+
+```plaintext
+ansible-repo/
+├── library/                # 📦 Custom Ansible modules
+├── filter_plugins/         # 🔍 Custom Jinja2 filters
+├── lookup_plugins/         # 👉 Custom lookup plugins
+├── module_utils/           # 🛠️ Shared Python helpers for modules
+├── action_plugins/         # ⚙️ Task-level orchestration logic
+├── callback_plugins/       # 📣 Event callbacks (logging, notifications)
+├── inventory_plugins/      # 🌐 Dynamic inventory sources
+├── strategy_plugins/       # 🧠 Task execution strategies
+└── ...                     # Other plugin dirs (connection, cache, etc.)
+```
+
+---
+
+### 🎯 Decision Matrix: Which Folder for What?
+
+| Folder               | Type                 | Use-Case                                 | Example (CyMaIS.Cloud)                                | Emoji |
+| -------------------- | -------------------- | ---------------------------------------- | ----------------------------------------------------- | ----- |
+| `library/`           | **Module**           | Write idempotent actions                 | `cloud_network.py`: manage VPCs, subnets              | 📦    |
+| `filter_plugins/`    | **Filter plugin**    | Jinja2 data transforms in templates/vars | `to_camel_case.py`: convert keys for API calls        | 🔍    |
+| `lookup_plugins/`    | **Lookup plugin**    | Fetch external/secure data at runtime    | `vault_lookup.py`: pull secrets from CyMaIS Vault     | 👉    |
+| `module_utils/`      | **Utility library**  | Shared Python code for modules           | `cymais_client.py`: common API client base class      | 🛠️   |
+| `action_plugins/`    | **Action plugin**    | Complex task orchestration wrappers      | `deploy_stack.py`: sequence Terraform + Ansible steps | ⚙️    |
+| `callback_plugins/`  | **Callback plugin**  | Customize log/report behavior            | `notify_slack.py`: send playbook status to Slack      | 📣    |
+| `inventory_plugins/` | **Inventory plugin** | Dynamic host/group sources               | `azure_inventory.py`: list hosts from Azure tags      | 🌐    |
+| `strategy_plugins/`  | **Strategy plugin**  | Control task execution order/parallelism | `rolling_batch.py`: phased rollout of VMs             | 🧠    |
+
+---
+
+### 📝 Detailed Guidance
+
+1. **library/** 📦
+
+   * **When?** Implement **one-off, idempotent actions** (create/delete cloud resources).
+   * **Why?** Modules under `library/` are first in search path for `ansible` modules.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_modules.html](https://docs.ansible.com/ansible/latest/dev_guide/developing_modules.html)
+
+2. **filter\_plugins/** 🔍
+
+   * **When?** You need **data manipulation** (lists, strings, dicts) inside Jinja2.
+   * **Why?** Extends `|` filters in templates and variable declarations.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#filter-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#filter-plugins)
+
+3. **lookup\_plugins/** 👉
+
+   * **When?** You must **retrieve secret/external data** during playbook compile/runtime.
+   * **Why?** Lookup plugins run before tasks, enabling dynamic variable resolution.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#lookup-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#lookup-plugins)
+
+4. **module\_utils/** 🛠️
+
+   * **When?** Multiple modules share **common Python code** (HTTP clients, validation).
+   * **Why?** Avoid code duplication; modules import these utilities.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_modules.html#module-utils](https://docs.ansible.com/ansible/latest/dev_guide/developing_modules.html#module-utils)
+
+5. **action\_plugins/** ⚙️
+
+   * **When?** You need to **wrap or extend** module behavior at task invocation time.
+   * **Why?** Provides hooks before/after module execution.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#action-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#action-plugins)
+
+6. **callback\_plugins/** 📣
+
+   * **When?** You want **custom event handlers** (logging, progress, notifications).
+   * **Why?** Receive play/task events for custom output.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#callback-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#callback-plugins)
+
+7. **inventory\_plugins/** 🌐
+
+   * **When?** Hosts/groups come from **dynamic sources** (cloud APIs, databases).
+   * **Why?** Replace static `inventory.ini` with code-driven inventories.
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#inventory-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#inventory-plugins)
+
+8. **strategy\_plugins/** 🧠
+
+   * **When?** You need to **customize execution strategy** (parallelism, ordering).
+   * **Why?** Override default `linear` strategy (e.g., `free`, custom batches).
+   * **Docs:** [https://docs.ansible.com/ansible/latest/dev\_guide/developing\_plugins.html#strategy-plugins](https://docs.ansible.com/ansible/latest/dev_guide/developing_plugins.html#strategy-plugins)
+
+---
+
+### 🚀 CyMaIS.Cloud Best Practices
+
+* **Organize modules** by service under `library/cloud/` (e.g., `vm`, `network`, `storage`).
+* **Shared client code** in `module_utils/cymais/` for authentication, request handling.
+* **Secrets lookup** via `lookup_plugins/vault_lookup.py` pointing to CyMaIS Vault.
+* **Filters** to normalize data formats from cloud APIs (e.g., `snake_to_camel`).
+* **Callbacks** to stream playbook results into CyMaIS Monitoring.
+
+Use this matrix as your **single source of truth** when extending Ansible for CyMaIS.Cloud! 👍 
+
+--- 
+
+This matrix was created with the help of ChatGPT 🤖—see our conversation [here](https://chatgpt.com/canvas/shared/682b1a62d6dc819184ecdc696c51290a).
diff --git a/filter_plugins/configuration_filters.py b/filter_plugins/configuration_filters.py
index 65c85ddd..041ff871 100644
--- a/filter_plugins/configuration_filters.py
+++ b/filter_plugins/configuration_filters.py
@@ -1,6 +1,6 @@
-def is_feature_enabled(applications, feature: str, application_id: str) -> bool:
+def is_feature_enabled(applications: dict, feature: str, application_id: str) -> bool:
     """
-    Check if a generic feature is enabled for the given application.
+    Return True if applications[application_id].features[feature] is truthy.
     """
     app = applications.get(application_id, {})
     return bool(app.get('features', {}).get(feature, False))
@@ -31,4 +31,4 @@ class FilterModule(object):
         return {
             'is_feature_enabled':   is_feature_enabled,
             'get_docker_compose':   get_docker_compose,
-        }
\ No newline at end of file
+        }
diff --git a/filter_plugins/csp_filters.py b/filter_plugins/csp_filters.py
index a0382c01..38799ce1 100644
--- a/filter_plugins/csp_filters.py
+++ b/filter_plugins/csp_filters.py
@@ -12,9 +12,10 @@ class FilterModule(object):
             'build_csp_header': self.build_csp_header,
         }
 
-    def is_feature_enabled(self, applications, feature: str, application_id: str) -> bool:
+    @staticmethod
+    def is_feature_enabled(applications: dict, feature: str, application_id: str) -> bool:
         """
-        Check if a generic feature is enabled for the given application.
+        Return True if applications[application_id].features[feature] is truthy.
         """
         app = applications.get(application_id, {})
         return bool(app.get('features', {}).get(feature, False))
@@ -99,7 +100,7 @@ class FilterModule(object):
 
             for directive in directives:
                 tokens = ["'self'"]
-                
+
                 # unsafe-eval / unsafe-inline flags
                 flags = self.get_csp_flags(applications, application_id, directive)
                 tokens += flags
diff --git a/filter_plugins/domain_filters.py b/filter_plugins/domain_filters.py
index abb24043..d6ac6c30 100644
--- a/filter_plugins/domain_filters.py
+++ b/filter_plugins/domain_filters.py
@@ -3,16 +3,101 @@ from ansible.errors import AnsibleFilterError
 
 class FilterModule(object):
     """
-    Custom Ansible filter plugin:
-      - generate_all_domains: Flatten, dedupe, sort domains with optional www prefixes
-      - generate_base_sld_domains: Extract unique sld.tld domains from values and redirect sources
+    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,
+            '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):
@@ -67,3 +152,33 @@ class FilterModule(object):
             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/group_domain_filters.py b/filter_plugins/group_domain_filters.py
index 99d00bba..c8b0f464 100644
--- a/filter_plugins/group_domain_filters.py
+++ b/filter_plugins/group_domain_filters.py
@@ -1,16 +1,9 @@
+from ansible.errors import AnsibleFilterError
+import sys
 import os
 import yaml
-from ansible.errors import AnsibleFilterError
 
 class FilterModule(object):
-    """
-    Custom filters for conditional domain assignments, handling both direct group matches
-    and recursive role dependency resolution.
-
-    Determines if a given application_id (domain_key) should have its domain added by checking:
-      - If domain_key is explicitly listed in group_names, or
-      - If domain_key matches any application_id of roles reachable from active groups via dependencies.
-    """
 
     def filters(self):
         return {
@@ -39,9 +32,27 @@ class FilterModule(object):
                 result[domain_key] = domain_value
                 return result
 
-            # Setup roles directory path
-            plugin_dir = os.path.dirname(__file__)
-            project_root = os.path.abspath(os.path.join(plugin_dir, '..'))
+            # Determine plugin directory based on filter plugin module if available
+            plugin_dir = None
+            for module in sys.modules.values():
+                fm = getattr(module, 'FilterModule', None)
+                if fm is not None:
+                    try:
+                        # Access staticmethod, compare underlying function
+                        if getattr(fm, 'add_domain_if_group') is DomainFilterUtil.add_domain_if_group:
+                            plugin_dir = os.path.dirname(module.__file__)
+                            break
+                    except Exception:
+                        continue
+
+            if plugin_dir:
+                # The plugin_dir is the filter_plugins directory; project_root is one level up
+                project_root = os.path.abspath(os.path.join(plugin_dir, '..'))
+            else:
+                # Fallback: locate project root relative to this utility file
+                plugin_dir = os.path.dirname(__file__)
+                project_root = os.path.abspath(os.path.join(plugin_dir, '..'))
+
             roles_dir = os.path.join(project_root, 'roles')
 
             # Collect all roles reachable from the active groups
@@ -83,4 +94,4 @@ class FilterModule(object):
 
             return result
         except Exception as exc:
-            raise AnsibleFilterError(f"add_domain_if_group failed: {exc}")
+            raise AnsibleFilterError(f"add_domain_if_group failed: {exc}")
\ No newline at end of file
diff --git a/group_vars/all/03_domains.yml b/group_vars/all/03_domains.yml
deleted file mode 100644
index 32446291..00000000
--- a/group_vars/all/03_domains.yml
+++ /dev/null
@@ -1,73 +0,0 @@
-defaults_domains: >-
-  {{ {}
-    | add_domain_if_group('akaunting',         'accounting.' ~ primary_domain, group_names)
-    | add_domain_if_group('attendize',         'tickets.' ~ primary_domain, group_names)
-    | add_domain_if_group('baserow',           'baserow.' ~ primary_domain, group_names)
-    | add_domain_if_group('bigbluebutton',     'meet.' ~ primary_domain, group_names)
-    | add_domain_if_group('bluesky',           {'web': 'bskyweb.' ~ primary_domain,'api':'bluesky.' ~ primary_domain}, group_names)
-    | add_domain_if_group('discourse',         'forum.' ~ primary_domain, group_names)
-    | add_domain_if_group('elk',               'elk.' ~ primary_domain, group_names)
-    | add_domain_if_group('espocrm',           'espocrm.' ~ primary_domain, group_names)
-    | add_domain_if_group('file_server',       'files.' ~ primary_domain, group_names)
-    | add_domain_if_group('friendica',         'friendica.' ~ primary_domain, group_names)
-    | add_domain_if_group('funkwhale',         'music.' ~ primary_domain, group_names)
-    | add_domain_if_group('gitea',             'git.' ~ primary_domain, group_names)
-    | add_domain_if_group('gitlab',            'gitlab.' ~ primary_domain, group_names)
-    | add_domain_if_group('html_server',       'html.' ~ primary_domain, group_names)
-    | add_domain_if_group('keycloak',          'auth.' ~ primary_domain, group_names)
-    | add_domain_if_group('lam',               'lam.' ~ primary_domain, group_names)
-    | add_domain_if_group('ldap',              'ldap.' ~ primary_domain, group_names)
-    | add_domain_if_group('listmonk',          'newsletter.' ~ primary_domain, group_names)
-    | add_domain_if_group('mailu',             'mail.' ~ primary_domain, group_names)
-    | add_domain_if_group('mastodon',          ['microblog.' ~ primary_domain], group_names)
-    | add_domain_if_group('matomo',            'matomo.' ~ primary_domain, group_names)
-    | add_domain_if_group('matrix',            {'synapse': 'matrix.' ~ primary_domain, 'element':'element.' ~ primary_domain}, group_names)
-    | add_domain_if_group('moodle',            'academy.' ~ primary_domain, group_names)
-    | add_domain_if_group('mediawiki',         'wiki.' ~ primary_domain, group_names)
-    | add_domain_if_group('nextcloud',         'cloud.' ~ primary_domain, group_names)
-    | add_domain_if_group('openproject',       'project.' ~ primary_domain, group_names)
-    | add_domain_if_group('peertube',          ['video.' ~ primary_domain], group_names)
-    | add_domain_if_group('pgadmin',           'pgadmin.' ~ primary_domain, group_names)
-    | add_domain_if_group('phpmyadmin',        'phpmyadmin.' ~ primary_domain, group_names)
-    | add_domain_if_group('phpmyldapadmin',    'phpmyldap.' ~ primary_domain, group_names)
-    | add_domain_if_group('pixelfed',          'picture.' ~ primary_domain, group_names)
-    | add_domain_if_group('portfolio',          primary_domain, group_names)
-    | add_domain_if_group('presentation',      'slides.' ~ primary_domain, group_names)
-    | add_domain_if_group('roulette-wheel',    'roulette.' ~ primary_domain, group_names)
-    | add_domain_if_group('snipe_it',          'inventory.' ~ primary_domain, group_names)
-    | add_domain_if_group('sphinx',            'docs.' ~ primary_domain, group_names)
-    | add_domain_if_group('syncope',           'syncope.' ~ primary_domain, group_names)
-    | add_domain_if_group('taiga',             'kanban.' ~ primary_domain, group_names)
-    | add_domain_if_group('yourls',            's.' ~ primary_domain, group_names)
-    | add_domain_if_group('wordpress',         ['blog.' ~ primary_domain], group_names)
-  }}
-
-defaults_redirect_domain_mappings: >-
-  {{ []
-     | add_redirect_if_group('akaunting',       "akaunting." ~ primary_domain,   domains.akaunting,     group_names)
-     | add_redirect_if_group('bigbluebutton',   "bbb." ~ primary_domain,         domains.bigbluebutton, group_names)
-     | add_redirect_if_group('discourse',       "discourse." ~ primary_domain,   domains.discourse,     group_names)
-     | add_redirect_if_group('espocrm',         "crm." ~ primary_domain,         domains.espocrm,       group_names)
-     | add_redirect_if_group('funkwhale',       "funkwhale." ~ primary_domain,   domains.funkwhale,     group_names)
-     | add_redirect_if_group('gitea',           "gitea." ~ primary_domain,       domains.gitea,         group_names)
-     | add_redirect_if_group('keycloak',        "keycloak." ~ primary_domain,    domains.keycloak,      group_names)
-     | add_redirect_if_group('lam',             domains.ldap,                    domains.lam,           group_names)
-     | add_redirect_if_group('phpmyldapadmin',  domains.ldap,                    domains.phpmyldapadmin,group_names)
-     | add_redirect_if_group('listmonk',        "listmonk." ~ primary_domain,    domains.listmonk,      group_names)
-     | add_redirect_if_group('mailu',           "mailu." ~ primary_domain,       domains.mailu,         group_names)
-     | add_redirect_if_group('mastodon',        "mastodon." ~ primary_domain,    domains.mastodon[0],   group_names)
-     | add_redirect_if_group('moodle',          "moodle." ~ primary_domain,      domains.moodle,        group_names)
-     | add_redirect_if_group('nextcloud',       "nextcloud." ~ primary_domain,   domains.nextcloud,     group_names)
-     | add_redirect_if_group('openproject',     "openproject." ~ primary_domain, domains.openproject,   group_names)
-     | add_redirect_if_group('peertube',        "peertube." ~ primary_domain,    domains.peertube[0],   group_names)
-     | add_redirect_if_group('pixelfed',        "pictures." ~ primary_domain,    domains.pixelfed,      group_names)
-     | add_redirect_if_group('pixelfed',        "pixelfed." ~ primary_domain,    domains.pixelfed,      group_names)
-     | add_redirect_if_group('yourls',          "short." ~ primary_domain,       domains.yourls,        group_names)
-     | add_redirect_if_group('snipe-it',        "snipe-it." ~ primary_domain,    domains.snipe_it,      group_names)
-     | add_redirect_if_group('taiga',           "taiga." ~ primary_domain,       domains.taiga,         group_names)
-     | add_redirect_if_group('peertube',        "videos." ~ primary_domain,      domains.peertube[0],   group_names)
-     | add_redirect_if_group('wordpress',       "wordpress." ~ primary_domain,   domains.wordpress[0],  group_names)
-  }}
-
-# Domains which are deprecated and should be cleaned up
-deprecated_domains: []
\ No newline at end of file
diff --git a/group_vars/all/11_domains.yml b/group_vars/all/11_domains.yml
new file mode 100644
index 00000000..df5a0ed0
--- /dev/null
+++ b/group_vars/all/11_domains.yml
@@ -0,0 +1,10 @@
+defaults_domains: "{{ defaults_applications | canonical_domains_map(primary_domain) }}"
+
+defaults_redirect_domain_mappings: >-
+  {{ []
+     | add_redirect_if_group('lam',             domains.ldap,                    domains.lam,           group_names)
+     | add_redirect_if_group('phpmyldapadmin',  domains.ldap,                    domains.phpmyldapadmin,group_names)
+  }}
+
+# Domains which are deprecated and should be cleaned up
+deprecated_domains: []
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 5c66c901..b4e3a594 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,2 @@
 colorscheme-generator @ https://github.com/kevinveenbirkenbach/colorscheme-generator/archive/refs/tags/v0.3.0.zip
-simpleaudio
 numpy
\ No newline at end of file
diff --git a/requirements.yml b/requirements.yml
index e533c761..ebd4a5d6 100644
--- a/requirements.yml
+++ b/requirements.yml
@@ -4,4 +4,6 @@ collections:
 pacman:
   - ansible
   - python-passlib
-  - python-pytest 
\ No newline at end of file
+  - python-pytest
+yay:
+  - python-simpleaudio
\ No newline at end of file
diff --git a/roles/docker-akaunting/vars/configuration.yml b/roles/docker-akaunting/vars/configuration.yml
index 8f1e6bdb..70375bcb 100644
--- a/roles/docker-akaunting/vars/configuration.yml
+++ b/roles/docker-akaunting/vars/configuration.yml
@@ -9,4 +9,8 @@ features:
   central_database:       true
 credentials:
 #  database_password:     Needs to be defined in inventory file 
-#  setup_admin_password:  Needs to be defined in inventory file
\ No newline at end of file
+#  setup_admin_password:  Needs to be defined in inventory file
+domains:
+  canonical:
+    - "accounting.{{ primary_domain }}"
+
diff --git a/roles/docker-attendize/vars/configuration.yml b/roles/docker-attendize/vars/configuration.yml
index b001e32b..0cb96cbf 100644
--- a/roles/docker-attendize/vars/configuration.yml
+++ b/roles/docker-attendize/vars/configuration.yml
@@ -7,3 +7,7 @@ features:
   css:                true
   portfolio_iframe: false
   central_database:   true
+
+domains:
+  canonical:
+    - "tickets.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-baserow/vars/configuration.yml b/roles/docker-baserow/vars/configuration.yml
index e1b198f0..bdff87c2 100644
--- a/roles/docker-baserow/vars/configuration.yml
+++ b/roles/docker-baserow/vars/configuration.yml
@@ -2,5 +2,5 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
+  portfolio_iframe:   true
   central_database:   true
\ No newline at end of file
diff --git a/roles/docker-bigbluebutton/vars/configuration.yml b/roles/docker-bigbluebutton/vars/configuration.yml
index db9a5cdb..a207bd5c 100644
--- a/roles/docker-bigbluebutton/vars/configuration.yml
+++ b/roles/docker-bigbluebutton/vars/configuration.yml
@@ -1,21 +1,17 @@
 enable_greenlight:    "true"
-setup:                false                                             # Set to true in inventory file for initial setup
+setup:                false
 credentials:
-# shared_secret:                                                       # Needs to be defined in inventory file
-# etherpad_api_key:                                                    # Needs to be defined in inventory file                                             
-# rails_secret:                                                        # Needs to be defined in inventory file
-# postgresql_secret:                                                   # Needs to be defined in inventory file   
-# fsesl_password:                                                      # Needs to be defined in inventory file
-# turn_secret:                                                         # Needs to be defined in inventory file  
 database:
-  name:      "multiple_databases"
-  username:  "postgres2"
-urls:
-  api:                        "{{ web_protocol }}://{{domains | get_domain('bigbluebutton')}}/bigbluebutton/"  # API Address used by Nextcloud Integration
+  name:               "multiple_databases"
+  username:           "postgres2"
+api_suffix:           "/bigbluebutton/"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
+  portfolio_iframe:   false
   ldap:               false
   oidc:               true
-  central_database:   false
\ No newline at end of file
+  central_database:   false
+domains:
+  canonical:
+    - "meet.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-bluesky/vars/configuration.yml b/roles/docker-bluesky/vars/configuration.yml
index 08ff1015..a89b94d8 100644
--- a/roles/docker-bluesky/vars/configuration.yml
+++ b/roles/docker-bluesky/vars/configuration.yml
@@ -1,14 +1,15 @@
 users:
   administrator:
-  email:    "{{users.administrator.email}}"
+    email:          "{{users.administrator.email}}"
 pds:
-  version:              "latest"
-credentials:  
-  #jwt_secret:                                                          # Needs to be defined in inventory file - Use: openssl rand -base64 64 | tr -d '\n'
-  #plc_rotation_key_k256_private_key_hex:                               # Needs to be defined in inventory file - Use: openssl rand -hex 32 
-  #admin_password:                                                      # Needs to be defined in inventory file - Use: openssl rand -base64 16
+  version:          "latest"
+credentials:
 features:
-  matomo: true
-  css: true
+  matomo:           true
+  css:              true
   portfolio_iframe: true
-  central_database: true
\ No newline at end of file
+  central_database: true
+domains:
+  canonical:
+    web:  "bskyweb.{{ primary_domain }}"
+    api:  "bluesky.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-discourse/vars/configuration.yml b/roles/docker-discourse/vars/configuration.yml
index a2bacbd9..22b26e97 100644
--- a/roles/docker-discourse/vars/configuration.yml
+++ b/roles/docker-discourse/vars/configuration.yml
@@ -16,4 +16,7 @@ csp:
       unsafe-inline: true
   whitelist:
     font-src:
-      - "http://*.{{primary_domain}}"
\ No newline at end of file
+      - "http://*.{{primary_domain}}"
+domains:
+  canonical:
+    - "forum.{{ primary_domain }}"
diff --git a/roles/docker-elk/templates/configuration.yml.j2 b/roles/docker-elk/templates/configuration.yml.j2
deleted file mode 100644
index e5559102..00000000
--- a/roles/docker-elk/templates/configuration.yml.j2
+++ /dev/null
@@ -1,3 +0,0 @@
-# Jinja2 configuration template
-# Define your variables here
-
diff --git a/roles/docker-elk/vars/configuration.yml b/roles/docker-elk/vars/configuration.yml
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/roles/docker-elk/vars/configuration.yml
@@ -0,0 +1 @@
+
diff --git a/roles/docker-espocrm/vars/configuration.yml b/roles/docker-espocrm/vars/configuration.yml
index 4950256b..4f30fe7e 100644
--- a/roles/docker-espocrm/vars/configuration.yml
+++ b/roles/docker-espocrm/vars/configuration.yml
@@ -1,19 +1,22 @@
-version:                  "latest"
+version:              "latest"
 users:
   administrator:
-    username:             "{{ users.administrator.username }}"
-    email:                "{{ users.administrator.email }}"
+    username:         "{{ users.administrator.username }}"
+    email:            "{{ users.administrator.email }}"
 
 credentials:
 features:
   matomo:             true
   css:                false
-  portfolio_iframe: false
+  portfolio_iframe:   false
   ldap:               false
   oidc:               true
   central_database:   true
 csp:
   flags:
     script-src:
-      unsafe-inline: true
-      unsafe-eval:   true
\ No newline at end of file
+      unsafe-inline:  true
+      unsafe-eval:    true
+domains:
+  aliases:
+    - "crm.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-friendica/vars/configuration.yml b/roles/docker-friendica/vars/configuration.yml
index 656bed32..0ca77d11 100644
--- a/roles/docker-friendica/vars/configuration.yml
+++ b/roles/docker-friendica/vars/configuration.yml
@@ -2,6 +2,9 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
+  portfolio_iframe:   true
   oidc:               true
-  central_database:   true
\ No newline at end of file
+  central_database:   true
+domains:
+  aliases:
+    - "social.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-funkwhale/vars/configuration.yml b/roles/docker-funkwhale/vars/configuration.yml
index e5c69d83..a7e25f9a 100644
--- a/roles/docker-funkwhale/vars/configuration.yml
+++ b/roles/docker-funkwhale/vars/configuration.yml
@@ -6,5 +6,9 @@ features:
   ldap:               true
   central_database:   true
 credentials:
-#  database_password: # Needs to be defined in inventory file
-#  django_secret:     # Needs to be defined in inventory file
\ No newline at end of file
+domains:
+  canonical:
+    - "audio.{{ primary_domain }}"
+  aliases:
+    - "music.{{ primary_domain }}"
+    - "sound.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-gitea/vars/configuration.yml b/roles/docker-gitea/vars/configuration.yml
index cc16386a..78929fbb 100644
--- a/roles/docker-gitea/vars/configuration.yml
+++ b/roles/docker-gitea/vars/configuration.yml
@@ -22,4 +22,7 @@ csp:
     worker-src:
       - "blob:"
     manifest-src:
-      - "data:"
\ No newline at end of file
+      - "data:"
+domains:
+  aliases:
+    - "git.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-gitlab/vars/configuration.yml b/roles/docker-gitlab/vars/configuration.yml
index e1b198f0..bdff87c2 100644
--- a/roles/docker-gitlab/vars/configuration.yml
+++ b/roles/docker-gitlab/vars/configuration.yml
@@ -2,5 +2,5 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
+  portfolio_iframe:   true
   central_database:   true
\ No newline at end of file
diff --git a/roles/docker-jenkins/vars/configuration.yml b/roles/docker-jenkins/vars/configuration.yml
index e5559102..e69de29b 100644
--- a/roles/docker-jenkins/vars/configuration.yml
+++ b/roles/docker-jenkins/vars/configuration.yml
@@ -1,3 +0,0 @@
-# Jinja2 configuration template
-# Define your variables here
-
diff --git a/roles/docker-joomla/vars/configuration.yml b/roles/docker-joomla/vars/configuration.yml
index f8bd2793..e33fd0ee 100644
--- a/roles/docker-joomla/vars/configuration.yml
+++ b/roles/docker-joomla/vars/configuration.yml
@@ -2,4 +2,7 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
\ No newline at end of file
+  portfolio_iframe:   true
+domains:
+  canonical:
+    - "cms.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-keycloak/vars/configuration.yml b/roles/docker-keycloak/vars/configuration.yml
index 734bb1f2..7c546efc 100644
--- a/roles/docker-keycloak/vars/configuration.yml
+++ b/roles/docker-keycloak/vars/configuration.yml
@@ -16,4 +16,7 @@ csp:
     script-src:
       unsafe-inline: true
     style-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  canonical:
+    - "auth.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-lam/vars/configuration.yml b/roles/docker-lam/vars/configuration.yml
index f38de6d7..0f5052fd 100644
--- a/roles/docker-lam/vars/configuration.yml
+++ b/roles/docker-lam/vars/configuration.yml
@@ -1,21 +1,23 @@
 version:                        "latest"
 oauth2_proxy:
-  application:                  application # Needs to be the same as webinterface
-  port:                         80          # application port
+  application:                  application
+  port:                         80
 credentials:
-#  oauth2_proxy_cookie_secret:  None # Set via openssl rand -hex 16
-#  administrator_password:      "None"  # CHANGE for security reasons  
 features:
   matomo:                       true
   css:                          true
-  portfolio_iframe:           true
+  portfolio_iframe:             true
   ldap:                         true
   central_database:             false
   oauth2:                       false
 csp:
   flags:
     style-src:
-      unsafe-inline: true
+      unsafe-inline:            true
     script-src:
-      unsafe-inline: true
-      unsafe-eval:   true
\ No newline at end of file
+      unsafe-inline:            true
+      unsafe-eval:              true
+domains:
+  aliases:
+    - "ldap.{{primary_domain}}"
+
diff --git a/roles/docker-ldap/vars/configuration.yml b/roles/docker-ldap/vars/configuration.yml
index fdb522ec..c2792830 100644
--- a/roles/docker-ldap/vars/configuration.yml
+++ b/roles/docker-ldap/vars/configuration.yml
@@ -1,13 +1,13 @@
-version:                        "latest"
+version:          "latest"
 network:
-  local:                        True                                # Activates local network. Necessary for LDIF import routines
-  docker:                       True                                # Activates docker network to allow other docker containers to connect
-  public:                       False                               # Set to true in inventory file if you want to expose the LDAP port to the internet
-hostname:                       "ldap"                              # Hostname of the LDAP Server in the central_ldap network
-webinterface:                   "lam"                               # The webinterface which should be used. Possible: lam and phpldapadmin
+  local:          True                                # Activates local network. Necessary for LDIF import routines
+  docker:         True                                # Activates docker network to allow other docker containers to connect
+  public:         False                               # Set to true in inventory file if you want to expose the LDAP port to the internet
+hostname:         "ldap"                              # Hostname of the LDAP Server in the central_ldap network
+webinterface:     "lam"                               # The webinterface which should be used. Possible: lam and phpldapadmin
 users:  
   administrator:
-    username:                   "{{users.administrator.username}}"  # Administrator username
+    username:     "{{users.administrator.username}}"  # Administrator username
 credentials:
 features:
-  ldap: true
+  ldap:           true
\ No newline at end of file
diff --git a/roles/docker-listmonk/vars/configuration.yml b/roles/docker-listmonk/vars/configuration.yml
index 1d4fdbcf..ec362d8b 100644
--- a/roles/docker-listmonk/vars/configuration.yml
+++ b/roles/docker-listmonk/vars/configuration.yml
@@ -6,6 +6,9 @@ version:                    "latest"                              # Docker Image
 features:
   matomo:                   true
   css:                      true
-  portfolio_iframe:       true
+  portfolio_iframe:         true
   central_database:         true
-  oidc:                     true
\ No newline at end of file
+  oidc:                     true
+domains:
+  canonical:
+    - "newsletter.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-mailu/vars/configuration.yml b/roles/docker-mailu/vars/configuration.yml
index 356843ab..bdb5fbcd 100644
--- a/roles/docker-mailu/vars/configuration.yml
+++ b/roles/docker-mailu/vars/configuration.yml
@@ -7,14 +7,12 @@ oidc:
   enable_user_creation:   true                              # Users will be created if not existing
 domain:                   "{{primary_domain}}"              # The main domain from which mails will be send \ email suffix behind @
 credentials:                                     
-# secret_key:                                               # Set to a randomly generated 16 bytes string
-# database_password:                                        # Needs to be set in inventory file
-# api_token:                                                # Configures the authentication token. The minimum length is 3 characters. This is a mandatory setting for using the RESTful API.
-# initial_administrator_password:                           # Initial administrator password for setup 
-# dkim_public_key:                                          # Must be set in inventory file
 features:
   matomo:                 true
   css:                    true
-  portfolio_iframe:     false                             # Deactivated mailu iframe loading until keycloak supports it
+  portfolio_iframe:       false                             # Deactivated mailu iframe loading until keycloak supports it
   oidc:                   true
-  central_database:       false                             # Deactivate central database for mailu, I don't know why the database deactivation is necessary
\ No newline at end of file
+  central_database:       false                             # Deactivate central database for mailu, I don't know why the database deactivation is necessary
+domains:
+  canonical:
+    - "mail.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-mailu/vars/main.yml b/roles/docker-mailu/vars/main.yml
index 2a89feda..52f8a81b 100644
--- a/roles/docker-mailu/vars/main.yml
+++ b/roles/docker-mailu/vars/main.yml
@@ -1,14 +1,14 @@
-application_id:               "mailu"
+application_id:           "mailu"
 
 # Database Configuration
-database_password:            "{{applications.mailu.credentials.database_password}}"
-database_type:                "mariadb"
+database_password:        "{{applications.mailu.credentials.database_password}}"
+database_type:            "mariadb"
 
-cert_mount_directory:         "{{docker_compose.directories.volumes}}certs/"
+cert_mount_directory:     "{{docker_compose.directories.volumes}}certs/"
 
 # Use dedicated source for oidc if activated  
 # @see https://github.com/heviat/Mailu-OIDC/tree/2024.06
-docker_source:                "{{ 'ghcr.io/heviat' if applications[application_id].features.oidc | bool else 'ghcr.io/mailu' }}"
+docker_source:            "{{ 'ghcr.io/heviat' if applications[application_id].features.oidc | bool else 'ghcr.io/mailu' }}"
 
-domain:                       "{{ domains | get_domain(application_id) }}"
-http_port:                     "{{ ports.localhost.http[application_id] }}"
\ No newline at end of file
+domain:                   "{{ domains | get_domain(application_id) }}"
+http_port:                "{{ ports.localhost.http[application_id] }}"
\ No newline at end of file
diff --git a/roles/docker-mastodon/vars/configuration.yml b/roles/docker-mastodon/vars/configuration.yml
index e908af2e..d5082a8e 100644
--- a/roles/docker-mastodon/vars/configuration.yml
+++ b/roles/docker-mastodon/vars/configuration.yml
@@ -1,19 +1,13 @@
-version:                      "latest"
-single_user_mode:             false                                           # Set true for initial setup
-setup:                        false                                           # Set true in inventory file to execute the setup and initializing procedures
-credentials:
-# Check out the README.md of the docker-mastodon role to get detailled instructions about how to setup the credentials
-#     database_password:                              
-#     secret_key_base:                                
-#     otp_secret:                                     
-#     vapid_private_key:                                  
-#     vapid_public_key:                                   
-#     active_record_encryption_deterministic_key:                            
-#     active_record_encryption_key_derivation_salt:                          
-#     active_record_encryption_primary_key:                                  
+version:              "latest"
+single_user_mode:     false                                           # Set true for initial setup
+setup:                false                                           # Set true in inventory file to execute the setup and initializing procedures
+credentials:                            
 features:
-  matomo: true
-  css: true
-  portfolio_iframe: false
-  oidc: true
-  central_database: true
+  matomo:             true
+  css:                true
+  portfolio_iframe:   false
+  oidc:               true
+  central_database:   true
+domains:
+  canonical:
+    - "microblog.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-matomo/vars/configuration.yml b/roles/docker-matomo/vars/configuration.yml
index ccb5a924..b88b0fc0 100644
--- a/roles/docker-matomo/vars/configuration.yml
+++ b/roles/docker-matomo/vars/configuration.yml
@@ -2,7 +2,7 @@ version:              "latest"
 features:
   matomo:             true
   css:                false
-  portfolio_iframe: false
+  portfolio_iframe:   false
   central_database:   true
   oauth2:             false
 csp:
@@ -16,4 +16,7 @@ csp:
       unsafe-inline: true
       unsafe-eval:   true
     style-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  aliases:
+    - "analytics.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-matrix/vars/configuration.yml b/roles/docker-matrix/vars/configuration.yml
index d6f7fb5d..b38e5669 100644
--- a/roles/docker-matrix/vars/configuration.yml
+++ b/roles/docker-matrix/vars/configuration.yml
@@ -25,9 +25,9 @@ csp:
   whitelist:
     connect-src:
       - "{{ primary_domain }}"
-      - "{{ domains.matrix.synapse | safe_var }}"
+      - "matrix.{{ primary_domain }}"
     script-src:
-      - "{{ domains.matrix.synapse | safe_var }}"
+      - "element.{{ primary_domain }}"
       - "https://cdn.jsdelivr.net"
 plugins:
 # You need to enable them in the inventory file
@@ -39,3 +39,8 @@ plugins:
   slack:      false
   telegram:   false
   whatsapp:   false
+
+domains:
+  canonical:
+    synapse: "matrix.{{ primary_domain }}"
+    element: "element.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-mediawiki/vars/configuration.yml b/roles/docker-mediawiki/vars/configuration.yml
new file mode 100644
index 00000000..b8c41ba0
--- /dev/null
+++ b/roles/docker-mediawiki/vars/configuration.yml
@@ -0,0 +1,3 @@
+domains:
+  canonical:
+    - "wiki.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-moodle/vars/configuration.yml b/roles/docker-moodle/vars/configuration.yml
index 34843923..8e5c4b37 100644
--- a/roles/docker-moodle/vars/configuration.yml
+++ b/roles/docker-moodle/vars/configuration.yml
@@ -22,4 +22,7 @@ csp:
       - "data:"
       - "blob:"
     script-src:
-      - "https://cdn.jsdelivr.net"
\ No newline at end of file
+      - "https://cdn.jsdelivr.net"
+domains:
+  canonical:
+    - "academy.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-mybb/vars/configuration.yml b/roles/docker-mybb/vars/configuration.yml
index f8c2956e..5eb1cdc9 100644
--- a/roles/docker-mybb/vars/configuration.yml
+++ b/roles/docker-mybb/vars/configuration.yml
@@ -3,5 +3,5 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
-  central_database:   true
+  portfolio_iframe:   false
+  central_database:   true
\ No newline at end of file
diff --git a/roles/docker-nextcloud/vars/configuration.yml b/roles/docker-nextcloud/vars/configuration.yml
index 4ef8bbfd..83dc5f47 100644
--- a/roles/docker-nextcloud/vars/configuration.yml
+++ b/roles/docker-nextcloud/vars/configuration.yml
@@ -1,6 +1,4 @@
 version:                      "production"                                      # @see https://nextcloud.com/blog/nextcloud-release-channels-and-how-to-track-them/
-ldap:
-  enabled:                    True                                              # Enables LDAP by default
 csp:
   flags:
     style-src:
@@ -10,6 +8,10 @@ csp:
   whitelist:
     font-src:
       - "data:"
+domains:
+  canonical:
+    - "cloud.{{ primary_domain }}"
+
 oidc:
   enabled:                    "{{ applications.nextcloud.features.oidc | default(true) }}"      # Activate OIDC for Nextcloud
   # floavor decides which OICD plugin should be used. 
@@ -23,7 +25,7 @@ credentials:
 features:
   matomo:                       true
   css:                          true
-  portfolio_iframe:           false
+  portfolio_iframe:             false
   ldap:                         true
   oidc:                         true
   central_database:             true
diff --git a/roles/docker-nextcloud/vars/plugins/bbb.yml b/roles/docker-nextcloud/vars/plugins/bbb.yml
index 545fbfbf..9d5a22ee 100644
--- a/roles/docker-nextcloud/vars/plugins/bbb.yml
+++ b/roles/docker-nextcloud/vars/plugins/bbb.yml
@@ -4,4 +4,4 @@ plugin_configuration:
     configvalue:  "{{ applications.bigbluebutton.credentials.shared_secret }}"
   - appid:        "bbb"
     configkey:    "api.url"
-    configvalue:  "{{ applications.bigbluebutton.urls.api }}"
\ No newline at end of file
+    configvalue:  "{{ web_protocol }}://{{domains | get_domain(''bigbluebutton'')}}{{applications.bigbluebutton.api_suffix}}"
\ No newline at end of file
diff --git a/roles/docker-oauth2-proxy/vars/configuration.yml b/roles/docker-oauth2-proxy/vars/configuration.yml
index 2d382ca6..7e5ad8bc 100644
--- a/roles/docker-oauth2-proxy/vars/configuration.yml
+++ b/roles/docker-oauth2-proxy/vars/configuration.yml
@@ -1,7 +1,6 @@
-configuration_file: "oauth2-proxy-keycloak.cfg"                                                                 # Needs to be set true in the roles which use it
-version:            "latest"                                                                                    # Docker Image version
-redirect_url:       "{{ web_protocol }}://{{domains | get_domain('keycloak')}}/auth/realms/{{primary_domain}}/protocol/openid-connect/auth"  # The redirect URL for the OAuth2 flow. It should match the redirect URL configured in Keycloak.
-allowed_roles:      admin                                                                                       # Restrict it default to admin role. Use the vars/main.yml to open the specific role for other groups  
+configuration_file: "oauth2-proxy-keycloak.cfg" # Needs to be set true in the roles which use it
+version:            "latest"                    # Docker Image version
+allowed_roles:      admin                       # Restrict it default to admin role. Use the vars/main.yml to open the specific role for other groups  
 features:
   matomo: true
   css: true
diff --git a/roles/docker-openproject/vars/configuration.yml b/roles/docker-openproject/vars/configuration.yml
index 69c04e21..06f7d03d 100644
--- a/roles/docker-openproject/vars/configuration.yml
+++ b/roles/docker-openproject/vars/configuration.yml
@@ -16,4 +16,7 @@ features:
 csp:
   flags:
     script-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  canonical:
+    - "project.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-peertube/vars/configuration.yml b/roles/docker-peertube/vars/configuration.yml
index 1636ae6d..e3de3283 100644
--- a/roles/docker-peertube/vars/configuration.yml
+++ b/roles/docker-peertube/vars/configuration.yml
@@ -9,4 +9,9 @@ csp:
     script-src:
       unsafe-inline: true
     style-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  canonical:
+    - "video.{{ primary_domain }}"
+  aliases:
+    - "videos.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-phpldapadmin/vars/configuration.yml b/roles/docker-phpldapadmin/vars/configuration.yml
index c6394085..7719b4bc 100644
--- a/roles/docker-phpldapadmin/vars/configuration.yml
+++ b/roles/docker-phpldapadmin/vars/configuration.yml
@@ -5,6 +5,6 @@ oauth2_proxy:
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
+  portfolio_iframe:   false
   ldap:               true
   oauth2:             true
\ No newline at end of file
diff --git a/roles/docker-phpmyadmin/vars/configuration.yml b/roles/docker-phpmyadmin/vars/configuration.yml
index d20e4314..05ad7e48 100644
--- a/roles/docker-phpmyadmin/vars/configuration.yml
+++ b/roles/docker-phpmyadmin/vars/configuration.yml
@@ -6,7 +6,7 @@ oauth2_proxy:
 features:
   matomo:             true
   css:                false
-  portfolio_iframe: false
+  portfolio_iframe:   false
   central_database:   true
   oauth2:             true
 hostname:             central-mariadb
@@ -15,4 +15,8 @@ csp:
     style-src:
       unsafe-inline: true
     script-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  aliases:
+    - "mysql.{{ primary_domain }}"
+    - "mariadb.{{ primary_domain }}"
diff --git a/roles/docker-pixelfed/vars/configuration.yml b/roles/docker-pixelfed/vars/configuration.yml
index aa6aaefe..a0523ae8 100644
--- a/roles/docker-pixelfed/vars/configuration.yml
+++ b/roles/docker-pixelfed/vars/configuration.yml
@@ -3,7 +3,7 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
+  portfolio_iframe:   false
   central_database:   true
 csp:
   flags:
@@ -11,4 +11,9 @@ csp:
       unsafe-inline: true
       unsafe-eval:   true
     style-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  canonical:
+    - "picture.{{ primary_domain }}"
+  aliases:
+    - "pictures.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-portfolio/vars/configuration.yml b/roles/docker-portfolio/vars/configuration.yml
index c16f6f44..1735c61b 100644
--- a/roles/docker-portfolio/vars/configuration.yml
+++ b/roles/docker-portfolio/vars/configuration.yml
@@ -1,6 +1,6 @@
 features:
-  matomo:             true
-  css:                true
+  matomo:           true
+  css:              true
   portfolio_iframe: false
 csp:
   whitelist:
@@ -19,3 +19,7 @@ csp:
   flags:
     style-src:
       unsafe-inline: true
+domains:
+  canonical:
+    - "{{ primary_domain }}"
+
diff --git a/roles/docker-presentation/vars/configuration.yml b/roles/docker-presentation/vars/configuration.yml
index eebdcda9..99e0df89 100644
--- a/roles/docker-presentation/vars/configuration.yml
+++ b/roles/docker-presentation/vars/configuration.yml
@@ -1,7 +1,7 @@
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
+  portfolio_iframe:   true
 
 csp:
   whitelist:
@@ -18,4 +18,7 @@ csp:
     style-src:
       unsafe-inline: true
     script-src:
-      unsafe-eval: true
\ No newline at end of file
+      unsafe-eval:   true
+domains:
+  canonical:
+    - "slides.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-roulette-wheel/vars/configuration.yml b/roles/docker-roulette-wheel/vars/configuration.yml
new file mode 100644
index 00000000..0af1d539
--- /dev/null
+++ b/roles/docker-roulette-wheel/vars/configuration.yml
@@ -0,0 +1,3 @@
+domains:
+  canonical:
+    - "wheel.{{ primary_domain }}"
diff --git a/roles/docker-snipe_it/vars/configuration.yml b/roles/docker-snipe_it/vars/configuration.yml
index 0b765ad7..b2e985d2 100644
--- a/roles/docker-snipe_it/vars/configuration.yml
+++ b/roles/docker-snipe_it/vars/configuration.yml
@@ -2,5 +2,8 @@ version:              "latest"
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
-  central_database:   true
\ No newline at end of file
+  portfolio_iframe:   false
+  central_database:   true
+domains:
+  canonical:
+    - "inventory.{{ primary_domain }}"
diff --git a/roles/docker-sphinx/vars/configuration.yml b/roles/docker-sphinx/vars/configuration.yml
index c19bde52..90bca16c 100644
--- a/roles/docker-sphinx/vars/configuration.yml
+++ b/roles/docker-sphinx/vars/configuration.yml
@@ -1,6 +1,6 @@
 features:
-  matomo:               true
-  css:                  true
+  matomo:             true
+  css:                true
   portfolio_iframe:   false
 csp:
   flags:
@@ -8,4 +8,7 @@ csp:
       unsafe-inline:  true
       unsafe-eval:    true
     style-src:
-      unsafe-inline:  true
\ No newline at end of file
+      unsafe-inline:  true
+domains:
+  canonical:
+    - "docs.{{ primary_domain }}"
diff --git a/roles/docker-taiga/vars/configuration.yml b/roles/docker-taiga/vars/configuration.yml
index 09eefe31..0cc74d9c 100644
--- a/roles/docker-taiga/vars/configuration.yml
+++ b/roles/docker-taiga/vars/configuration.yml
@@ -19,4 +19,7 @@ csp:
       unsafe-inline: true
       unsafe-eval:   true
     style-src:
-      unsafe-inline: true
\ No newline at end of file
+      unsafe-inline: true
+domains:
+  canonical:
+    - "kanban.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/docker-wordpress/vars/configuration.yml b/roles/docker-wordpress/vars/configuration.yml
index 7a02d4d5..9632be1b 100644
--- a/roles/docker-wordpress/vars/configuration.yml
+++ b/roles/docker-wordpress/vars/configuration.yml
@@ -31,6 +31,9 @@ csp:
       - "https://fonts.bunny.net"
     script-src:
       - "https://cdn.gtranslate.net"
-      - "{{ domains | get_domain('wordpress') }}"
+      - "blog.{{ primary_domain }}"
     style-src:
-      - "https://fonts.bunny.net"
\ No newline at end of file
+      - "https://fonts.bunny.net"
+domains:
+  canonical:
+    - "blog.{{ primary_domain }}"
diff --git a/roles/docker-xmpp/vars/configuration.yml b/roles/docker-xmpp/vars/configuration.yml
new file mode 100644
index 00000000..e69de29b
diff --git a/roles/docker-yourls/vars/configuration.yml b/roles/docker-yourls/vars/configuration.yml
index 360bcbea..ed394205 100644
--- a/roles/docker-yourls/vars/configuration.yml
+++ b/roles/docker-yourls/vars/configuration.yml
@@ -9,6 +9,11 @@ oauth2_proxy:
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: false
+  portfolio_iframe:   false
   central_database:   true
-  oauth2:             true
\ No newline at end of file
+  oauth2:             true
+domains:
+  canonical:
+    - "s.{{ primary_domain }}"
+  aliases:
+    - "short.{{ primary_domain }}"
\ No newline at end of file
diff --git a/roles/nginx-serve-files/vars/configuration.yml b/roles/nginx-serve-files/vars/configuration.yml
index 5cad484b..3be8d0e3 100644
--- a/roles/nginx-serve-files/vars/configuration.yml
+++ b/roles/nginx-serve-files/vars/configuration.yml
@@ -1,4 +1,7 @@
 features:
   matomo:             true
   css:                true
-  portfolio_iframe: true
\ No newline at end of file
+  portfolio_iframe:   true
+domains:
+  canonical:
+    - "files.{{ primary_domain }}"
diff --git a/roles/nginx-serve-html/vars/configuration.yml b/roles/nginx-serve-html/vars/configuration.yml
index f30a6270..36ee1f3c 100644
--- a/roles/nginx-serve-html/vars/configuration.yml
+++ b/roles/nginx-serve-html/vars/configuration.yml
@@ -1,4 +1,7 @@
 features:
-  matomo: true
-  css: true
-  portfolio_iframe: false
\ No newline at end of file
+  matomo:           true
+  css:              true
+  portfolio_iframe: false
+domains:
+  canonical:
+    - "html.{{ primary_domain }}"
diff --git a/tasks/constructor.yml b/tasks/constructor.yml
index bb218357..febf1471 100644
--- a/tasks/constructor.yml
+++ b/tasks/constructor.yml
@@ -8,6 +8,11 @@
   - name: Merge system_email definitions
     set_fact:
       system_email: "{{ default_system_email | combine(system_email | default({}, true), recursive=True) }}"
+
+  - name: Merge application definitions
+    set_fact:
+      applications: "{{ defaults_applications | combine(applications | default({}, true), recursive=True) }}"
+
   - name: Merge domain definitions
     set_fact:
       domains: "{{ defaults_domains | combine(domains | default({}, true), recursive=True) }}"
@@ -28,10 +33,6 @@
       redirect_domain_mappings: "{{ redirect_domain_mappings | default([]) + [ {'source': item.key, 'target': item.value} ] }}"
     loop: "{{ combined_mapping | dict2items }}"
 
-  - name: Merge application definitions
-    set_fact:
-      applications: "{{ defaults_applications | combine(applications | default({}, true), recursive=True) }}"
-
 # @todo implement
 #  - name: Ensure features.integrated is set based on group membership
 #    set_fact:
diff --git a/tests/integration/test_domain_uniqueness.py b/tests/integration/test_domain_uniqueness.py
new file mode 100644
index 00000000..9b0b46f1
--- /dev/null
+++ b/tests/integration/test_domain_uniqueness.py
@@ -0,0 +1,55 @@
+import unittest
+import yaml
+import subprocess
+from pathlib import Path
+from collections import Counter
+
+class TestDomainUniqueness(unittest.TestCase):
+    def test_no_duplicate_domains(self):
+        """
+        Load the applications YAML (generating it via `make build` if missing),
+        collect all entries under domains.canonical and domains.aliases across all applications,
+        and assert that no domain appears more than once.
+        """
+        repo_root = Path(__file__).resolve().parents[2]
+        yaml_file = repo_root / 'group_vars' / 'all' / '03_applications.yml'
+
+        # Generate the file if it doesn't exist
+        if not yaml_file.exists():
+            subprocess.run(['make', 'build'], cwd=repo_root, check=True)
+
+        # Load the applications configuration
+        cfg = yaml.safe_load(yaml_file.read_text(encoding='utf-8')) or {}
+        apps = cfg.get('defaults_applications', {})
+
+        all_domains = []
+        for app_name, app_cfg in apps.items():
+            domains_cfg = app_cfg.get('domains', {})
+
+            # canonical entries may be a list or a mapping
+            canonical = domains_cfg.get('canonical', [])
+            if isinstance(canonical, dict):
+                values = list(canonical.values())
+            else:
+                values = canonical or []
+            all_domains.extend(values)
+
+            # aliases entries may be a list or a mapping
+            aliases = domains_cfg.get('aliases', [])
+            if isinstance(aliases, dict):
+                values = list(aliases.values())
+            else:
+                values = aliases or []
+            all_domains.extend(values)
+
+        # Filter out any empty or non-string entries
+        domain_list = [d for d in all_domains if isinstance(d, str) and d.strip()]
+        counts = Counter(domain_list)
+
+        # Find duplicates
+        duplicates = [domain for domain, count in counts.items() if count > 1]
+        if duplicates:
+            self.fail(f"Duplicate domain entries found: {duplicates}\n (May 'make build' solves this issue.)")
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/integration/test_domains_structure.py b/tests/integration/test_domains_structure.py
new file mode 100644
index 00000000..ae358b94
--- /dev/null
+++ b/tests/integration/test_domains_structure.py
@@ -0,0 +1,89 @@
+import os
+import yaml
+import unittest
+from pathlib import Path
+from collections import Counter
+
+ROLES_DIR = Path(__file__).resolve().parent.parent.parent / "roles"
+
+class TestDomainsStructure(unittest.TestCase):
+    def test_domains_keys_types_and_uniqueness(self):
+        """Ensure that under 'domains' only 'canonical' and 'aliases' keys exist,
+        'aliases' is a list of strings, 'canonical' is either a list of strings
+        or a dict with string values, and no domain is defined more than once
+        across all roles."""
+        failed_roles = []
+        all_domains = []
+
+        for role_path in ROLES_DIR.iterdir():
+            if not role_path.is_dir():
+                continue
+            vars_dir = role_path / "vars"
+            if not vars_dir.exists():
+                continue
+
+            for vars_file in vars_dir.glob("*.yml"):
+                try:
+                    with open(vars_file, 'r') as f:
+                        data = yaml.safe_load(f) or {}
+                except yaml.YAMLError as e:
+                    failed_roles.append((role_path.name, vars_file.name, f"YAML error: {e}"))
+                    continue
+
+                if 'domains' not in data:
+                    continue
+
+                domains = data['domains']
+                if not isinstance(domains, dict):
+                    failed_roles.append((role_path.name, vars_file.name, "'domains' should be a dict"))
+                    continue
+
+                # Check allowed keys
+                allowed_keys = {'canonical', 'aliases'}
+                extra_keys = set(domains.keys()) - allowed_keys
+                if extra_keys:
+                    failed_roles.append((role_path.name, vars_file.name,
+                                         f"Unexpected keys in 'domains': {extra_keys}"))
+
+                # Validate and collect 'aliases'
+                if 'aliases' in domains:
+                    aliases = domains['aliases']
+                    if not isinstance(aliases, list) or not all(isinstance(item, str) for item in aliases):
+                        failed_roles.append((role_path.name, vars_file.name,
+                                             "'aliases' must be a list of strings"))
+                    else:
+                        all_domains.extend(aliases)
+
+                # Validate and collect 'canonical'
+                if 'canonical' in domains:
+                    canonical = domains['canonical']
+                    if isinstance(canonical, list):
+                        if not all(isinstance(item, str) for item in canonical):
+                            failed_roles.append((role_path.name, vars_file.name,
+                                                 "'canonical' list items must be strings"))
+                        else:
+                            all_domains.extend(canonical)
+                    elif isinstance(canonical, dict):
+                        if not all(isinstance(k, str) and isinstance(v, str) for k, v in canonical.items()):
+                            failed_roles.append((role_path.name, vars_file.name,
+                                                 "All keys and values in 'canonical' dict must be strings"))
+                        else:
+                            all_domains.extend(canonical.values())
+                    else:
+                        failed_roles.append((role_path.name, vars_file.name,
+                                             "'canonical' must be a list or a dict"))
+
+        # Check for duplicate domains across all roles
+        duplicates = [domain for domain, count in Counter(all_domains).items() if count > 1]
+        if duplicates:
+            failed_roles.append(("GLOBAL", "", f"Duplicate domain entries found: {duplicates}"))
+
+        if failed_roles:
+            messages = []
+            for role, file, reason in failed_roles:
+                entry = f"{role}/{file}: {reason}" if file else f"{role}: {reason}"
+                messages.append(entry)
+            self.fail("Domain structure errors found:\n" + "\n".join(messages))
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/unit/test_domain_filters.py b/tests/unit/test_domain_filters.py
new file mode 100644
index 00000000..c42310b0
--- /dev/null
+++ b/tests/unit/test_domain_filters.py
@@ -0,0 +1,123 @@
+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 domain_filters 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.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 = {}
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+    def test_alias_without_aliases_and_no_canonical(self):
+        apps = {'app1': {}}
+        # canonical defaults to ['app1.example.com'], so alias should be []
+        expected = {'app1': []}
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+    def test_alias_with_explicit_aliases(self):
+        apps = {
+            'app1': {
+                'domains': {'aliases': ['alias.com']}
+            }
+        }
+        # canonical defaults to ['app1.example.com'], so alias should include alias.com and default
+        expected = {'app1': ['alias.com', 'app1.example.com']}
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertCountEqual(result['app1'], expected['app1'])
+
+    def test_alias_with_canonical_not_default(self):
+        apps = {
+            'app1': {
+                'domains': {'canonical': ['foo.com']}
+            }
+        }
+        # foo.com is canonical, default not in canonical so added as alias
+        expected = {'app1': ['app1.example.com']}
+        result = self.filter_module.alias_domains_map(apps, self.primary)
+        self.assertEqual(result, expected)
+
+    def test_alias_with_existing_default(self):
+        apps = {
+            'app1': {
+                'domains': {
+                    'canonical': ['foo.com'],
+                    'aliases': ['app1.example.com']
+                }
+            }
+        }
+        # default present in aliases, should not be duplicated
+        expected = {'app1': ['app1.example.com']}
+        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}}
+        }
+        with self.assertRaises(AnsibleFilterError):
+            self.filter_module.alias_domains_map(apps, self.primary)
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/unit/test_generate_default_applications.py b/tests/unit/test_generate_default_applications.py
index 9d325fb9..92c7186d 100644
--- a/tests/unit/test_generate_default_applications.py
+++ b/tests/unit/test_generate_default_applications.py
@@ -23,7 +23,7 @@ class TestGenerateDefaultApplications(unittest.TestCase):
         (self.sample_role / "vars" / "configuration.yml").write_text("foo: bar\nbaz: 123\n")
 
         # Output file path
-        self.output_file = self.temp_dir / "group_vars" / "all" / "11_applications.yml"
+        self.output_file = self.temp_dir / "group_vars" / "all" / "03_applications.yml"
 
     def tearDown(self):
         shutil.rmtree(self.temp_dir)