diff --git a/hosts/nachtigall/configuration.nix b/hosts/nachtigall/configuration.nix
index dac4fc6..8bfba8d 100644
--- a/hosts/nachtigall/configuration.nix
+++ b/hosts/nachtigall/configuration.nix
@@ -82,28 +82,39 @@
     owner = "matrix-synapse";
   };
 
-  pub-solar-os.matrix-synapse = {
-    enable = true;
-    sliding-sync.enable = true;
-    signing_key_path = config.age.secrets."matrix-synapse-signing-key".path;
-    extra-config-files = [
-      config.age.secrets."matrix-synapse-secret-config.yaml".path
+  age.secrets."matrix-authentication-service-secret-config.yml" = {
+    file = "${flake.self}/secrets/matrix-authentication-service-secret-config.yml.age";
+    mode = "400";
+    owner = "matrix-authentication-service";
+  };
 
-      # The registration file is automatically generated after starting the
-      # appservice for the first time.
-      # cp /var/lib/mautrix-telegram/telegram-registration.yaml \
-      #   /var/lib/matrix-synapse/
-      # chown matrix-synapse:matrix-synapse \
-      #   /var/lib/matrix-synapse/telegram-registration.yaml
-      "/var/lib/matrix-synapse/telegram-registration.yaml"
-    ];
-    app-service-config-files = [
-      "/var/lib/matrix-synapse/telegram-registration.yaml"
-      "/var/lib/matrix-appservice-irc/registration.yml"
-      # "/matrix-appservice-slack-registration.yaml"
-      # "/hookshot-registration.yml"
-      # "/matrix-mautrix-signal-registration.yaml"
-      # "/matrix-mautrix-telegram-registration.yaml"
+  pub-solar-os.matrix = {
+    enable = true;
+    synapse = {
+      sliding-sync.enable = true;
+      signing_key_path = config.age.secrets."matrix-synapse-signing-key".path;
+      extra-config-files = [
+        config.age.secrets."matrix-synapse-secret-config.yaml".path
+
+        # The registration file is automatically generated after starting the
+        # appservice for the first time.
+        # cp /var/lib/mautrix-telegram/telegram-registration.yaml \
+        #   /var/lib/matrix-synapse/
+        # chown matrix-synapse:matrix-synapse \
+        #   /var/lib/matrix-synapse/telegram-registration.yaml
+        "/var/lib/matrix-synapse/telegram-registration.yaml"
+      ];
+      app-service-config-files = [
+        "/var/lib/matrix-synapse/telegram-registration.yaml"
+        "/var/lib/matrix-appservice-irc/registration.yml"
+        # "/matrix-appservice-slack-registration.yaml"
+        # "/hookshot-registration.yml"
+        # "/matrix-mautrix-signal-registration.yaml"
+        # "/matrix-mautrix-telegram-registration.yaml"
+      ];
+    };
+    matrix-authentication-service.extra-config-files = [
+      config.age.secrets."matrix-authentication-service-secret-config.yml".path
     ];
   };
 
diff --git a/hosts/nachtigall/default.nix b/hosts/nachtigall/default.nix
index 9a69c4f..100759a 100644
--- a/hosts/nachtigall/default.nix
+++ b/hosts/nachtigall/default.nix
@@ -9,10 +9,12 @@
     ./networking.nix
     ./wireguard.nix
     ./backups.nix
+    "${flake.inputs.fork}/nixos/modules/services//matrix/matrix-authentication-service.nix"
     "${flake.inputs.unstable}/nixos/modules/services/web-apps/mastodon.nix"
   ];
 
   disabledModules = [
+    "services/matrix/matrix-authentication-service.nix "
     "services/web-apps/mastodon.nix"
   ];
 }
diff --git a/hosts/underground/configuration.nix b/hosts/underground/configuration.nix
index 74b1d79..ff1c809 100644
--- a/hosts/underground/configuration.nix
+++ b/hosts/underground/configuration.nix
@@ -42,72 +42,28 @@
     owner = "matrix-authentication-service";
   };
 
-  pub-solar-os.matrix-synapse = {
+  pub-solar-os.matrix = {
     enable = true;
-    extra-config-files = [
-      config.age.secrets."staging-matrix-synapse-secret-config.yaml".path
+    synapse = {
+      extra-config-files = [
+        config.age.secrets."staging-matrix-synapse-secret-config.yaml".path
 
-      # The registration file is automatically generated after starting the
-      # appservice for the first time.
-      # cp /var/lib/mautrix-telegram/telegram-registration.yaml \
-      #   /var/lib/matrix-synapse/
-      # chown matrix-synapse:matrix-synapse \
-      #   /var/lib/matrix-synapse/telegram-registration.yaml
-      #"/var/lib/matrix-synapse/telegram-registration.yaml"
-    ];
-    app-service-config-files = [
-      "/var/lib/matrix-appservice-irc/registration.yml"
-      #"/var/lib/matrix-synapse/telegram-registration.yaml"
-    ];
-  };
-
-  services.matrix-authentication-service = {
-    enable = true;
-    createDatabase = true;
-    extraConfigFiles = [
+        # The registration file is automatically generated after starting the
+        # appservice for the first time.
+        # cp /var/lib/mautrix-telegram/telegram-registration.yaml \
+        #   /var/lib/matrix-synapse/
+        # chown matrix-synapse:matrix-synapse \
+        #   /var/lib/matrix-synapse/telegram-registration.yaml
+        #"/var/lib/matrix-synapse/telegram-registration.yaml"
+      ];
+      app-service-config-files = [
+        "/var/lib/matrix-appservice-irc/registration.yml"
+        #"/var/lib/matrix-synapse/telegram-registration.yaml"
+      ];
+    };
+    matrix-authentication-service.extra-config-files = [
       config.age.secrets."staging-matrix-authentication-service-secret-config.yml".path
     ];
-    settings = {
-      http.public_base = "https://mas.${config.pub-solar-os.networking.domain}";
-      http.issuer = "https://mas.${config.pub-solar-os.networking.domain}";
-      http.listeners = [
-        {
-          name = "web";
-          resources = [
-            { name = "discovery"; }
-            { name = "human"; }
-            { name = "oauth"; }
-            { name = "compat"; }
-            { name = "graphql"; }
-            {
-              name = "assets";
-              path = "${config.services.matrix-authentication-service.package}/share/matrix-authentication-service/assets";
-            }
-          ];
-          binds = [
-            {
-              host = "0.0.0.0";
-              port = 8090;
-            }
-          ];
-          proxy_protocol = false;
-        }
-        {
-          name = "internal";
-          resources = [
-            { name = "health"; }
-          ];
-          binds = [
-            {
-              host = "0.0.0.0";
-              port = 8081;
-            }
-          ];
-          proxy_protocol = false;
-        }
-      ];
-      passwords.enabled = false;
-    };
   };
 
   services.openssh.openFirewall = true;
diff --git a/modules/matrix/default.nix b/modules/matrix/default.nix
index 1d95597..0f6963c 100644
--- a/modules/matrix/default.nix
+++ b/modules/matrix/default.nix
@@ -10,33 +10,46 @@ let
   serverDomain = "${config.pub-solar-os.networking.domain}";
 in
 {
-  options.pub-solar-os.matrix-synapse = {
-    enable = lib.mkEnableOption "Enable matrix-synapse to run on the node";
+  options.pub-solar-os = {
+    matrix = {
+      enable = lib.mkEnableOption "Enable matrix-synapse and matrix-authentication-service to run on the node";
 
-    app-service-config-files = lib.mkOption {
-      description = "List of app service config files";
-      type = lib.types.listOf lib.types.str;
-      default = [ ];
-    };
+      synapse = {
+        app-service-config-files = lib.mkOption {
+          description = "List of app service config files";
+          type = lib.types.listOf lib.types.str;
+          default = [ ];
+        };
 
-    extra-config-files = lib.mkOption {
-      description = "List of extra synapse config files";
-      type = lib.types.listOf lib.types.str;
-      default = [ ];
-    };
+        extra-config-files = lib.mkOption {
+          description = "List of extra synapse config files";
+          type = lib.types.listOf lib.types.str;
+          default = [ ];
+        };
 
-    signing_key_path = lib.mkOption {
-      description = "Path to file containing the signing key";
-      type = lib.types.str;
-      default = "${config.services.matrix-synapse.dataDir}/homeserver.signing.key";
-    };
-    sliding-sync.enable = lib.mkEnableOption {
-      description = "Whether to enable a sliding-sync proxy, no longer needed with synapse version 1.114+";
-      default = false;
+        signing_key_path = lib.mkOption {
+          description = "Path to file containing the signing key";
+          type = lib.types.str;
+          default = "${config.services.matrix-synapse.dataDir}/homeserver.signing.key";
+        };
+
+        sliding-sync.enable = lib.mkEnableOption {
+          description = "Whether to enable a sliding-sync proxy, no longer needed with synapse version 1.114+";
+          default = false;
+        };
+      };
+
+      matrix-authentication-service = {
+        extra-config-files = lib.mkOption {
+          description = "List of extra mas config files";
+          type = lib.types.listOf lib.types.str;
+          default = [ ];
+        };
+      };
     };
   };
 
-  config = lib.mkIf config.pub-solar-os.matrix-synapse.enable {
+  config = lib.mkIf config.pub-solar-os.matrix.enable {
     services.matrix-synapse = {
       enable = true;
       settings = {
@@ -265,6 +278,54 @@ in
       plugins = [ config.services.matrix-synapse.package.plugins.matrix-synapse-shared-secret-auth ];
     };
 
+    services.matrix-authentication-service = {
+      enable = true;
+      createDatabase = true;
+      extraConfigFiles = config.pub-solar-os.matrix.matrix-authentication-service.extra-config-files;
+
+      settings = {
+        http.public_base = "https://mas.${config.pub-solar-os.networking.domain}";
+        http.issuer = "https://mas.${config.pub-solar-os.networking.domain}";
+        http.listeners = [
+          {
+            name = "web";
+            resources = [
+              { name = "discovery"; }
+              { name = "human"; }
+              { name = "oauth"; }
+              { name = "compat"; }
+              { name = "graphql"; }
+              {
+                name = "assets";
+                path = "${config.services.matrix-authentication-service.package}/share/matrix-authentication-service/assets";
+              }
+            ];
+            binds = [
+              {
+                host = "0.0.0.0";
+                port = 8090;
+              }
+            ];
+            proxy_protocol = false;
+          }
+          {
+            name = "internal";
+            resources = [
+              { name = "health"; }
+            ];
+            binds = [
+              {
+                host = "0.0.0.0";
+                port = 8081;
+              }
+            ];
+            proxy_protocol = false;
+          }
+        ];
+        passwords.enabled = false;
+      };
+    };
+
     services.matrix-sliding-sync = {
       enable = config.pub-solar-os.matrix-synapse.sliding-sync.enable;
       settings = {
diff --git a/secrets/matrix-authentication-service-secret-config.yml.age b/secrets/matrix-authentication-service-secret-config.yml.age
new file mode 100644
index 0000000..50cd3f2
Binary files /dev/null and b/secrets/matrix-authentication-service-secret-config.yml.age differ
diff --git a/secrets/secrets.nix b/secrets/secrets.nix
index 6eaede2..88a632a 100644
--- a/secrets/secrets.nix
+++ b/secrets/secrets.nix
@@ -68,6 +68,7 @@ in
   "matrix-synapse-signing-key.age".publicKeys = nachtigallKeys ++ adminKeys;
   "matrix-synapse-secret-config.yaml.age".publicKeys = nachtigallKeys ++ adminKeys;
   "matrix-synapse-sliding-sync-secret.age".publicKeys = nachtigallKeys ++ adminKeys;
+  "matrix-authentication-service-secret-config.yml.age".publicKeys = nachtigallKeys ++ adminKeys;
 
   "staging-matrix-synapse-secret-config.yaml.age".publicKeys = undergroundKeys ++ adminKeys;
   "staging-matrix-authentication-service-secret-config.yml.age".publicKeys =