diff --git a/fediversity/default.nix b/fediversity/default.nix
index dfdffc8c..d31df294 100644
--- a/fediversity/default.nix
+++ b/fediversity/default.nix
@@ -53,5 +53,9 @@ in {
         urlFor = bucket: "http://${bucket}.${rootDomainAndPort}";
       };
     };
+
+    pixelfed.domain = "pixelfed.${config.fediversity.domain}";
+    mastodon.domain = "mastdodon.${config.fediversity.domain}";
+    peertube.domain = "peertube.${config.fediversity.domain}";
   };
 }
diff --git a/fediversity/mastodon.nix b/fediversity/mastodon.nix
index e866b848..8740c8c7 100644
--- a/fediversity/mastodon.nix
+++ b/fediversity/mastodon.nix
@@ -63,12 +63,14 @@ lib.mkIf (config.fediversity.enable && config.fediversity.mastodon.enable) {
   services.mastodon = {
     enable = true;
 
-    # TODO: set up a domain name, and a DNS service so that this can run not in a vm
-    # localDomain = "domain.social";
+    localDomain = config.fediversity.mastodon.domain;
     configureNginx = true;
 
     # TODO: configure a mailserver so this works
-    # smtp.fromAddress = "mastodon@domain.social";
+    smtp = {
+      fromAddress = "noreply@${config.fediversity.mastodon.domain}";
+      createLocally = false;
+    };
 
     # TODO: this is hardware-dependent. let's figure it out when we have hardware
     # streamingProcesses = 1;
@@ -81,4 +83,3 @@ lib.mkIf (config.fediversity.enable && config.fediversity.mastodon.enable) {
     # defaults.email = "test@example.com";
   };
 }
-
diff --git a/fediversity/peertube.nix b/fediversity/peertube.nix
index 021e52f0..41c6cd16 100644
--- a/fediversity/peertube.nix
+++ b/fediversity/peertube.nix
@@ -53,6 +53,14 @@ lib.mkIf (config.fediversity.enable && config.fediversity.peertube.enable) {
   };
 
   services.peertube = {
+    enable = true;
+    localDomain = config.fediversity.peertube.domain;
+
+    # TODO: in most of nixpkgs, these are true by default. upstream that unless there's a good reason not to.
+    redis.createLocally = true;
+    database.createLocally = true;
+    configureNginx = true;
+
     settings = {
       object_storage = {
         enabled = true;
diff --git a/fediversity/pixelfed.nix b/fediversity/pixelfed.nix
index 38153f54..95703ba5 100644
--- a/fediversity/pixelfed.nix
+++ b/fediversity/pixelfed.nix
@@ -35,7 +35,10 @@ lib.mkIf (config.fediversity.enable && config.fediversity.pixelfed.enable) {
     };
   };
 
-  services.pixelfed.enable = true;
+  services.pixelfed = {
+    enable = true;
+    domain = config.fediversity.pixelfed.domain;
+  };
 
   services.pixelfed.settings = {
     # DANGEROUSLY_SET_FILESYSTEM_DRIVER = "s3";
diff --git a/vm/mastodon-vm.nix b/vm/mastodon-vm.nix
index 0bc12aa6..caf1ca6c 100644
--- a/vm/mastodon-vm.nix
+++ b/vm/mastodon-vm.nix
@@ -14,14 +14,6 @@
       };
 
       services.mastodon = {
-        # redirects to localhost, but allows it to have a proper domain name
-        localDomain = "mastodon.localhost";
-
-        smtp = {
-          fromAddress = "mastodon@mastodon.localhost";
-          createLocally = false;
-        };
-
         extraConfig = {
           EMAIL_DOMAIN_ALLOWLIST = "example.com";
         };
@@ -65,7 +57,7 @@
           BIND = "0.0.0.0";
           # for letter_opener (still doesn't work though)
           REMOTE_DEV = "true";
-          LOCAL_DOMAIN = "mastodon.localhost:8443";
+          LOCAL_DOMAIN = "${config.fediversity.mastodon.domain}:8443";
         };
       };
 
diff --git a/vm/peertube-vm.nix b/vm/peertube-vm.nix
index d38a625c..5f40f4f1 100644
--- a/vm/peertube-vm.nix
+++ b/vm/peertube-vm.nix
@@ -1,9 +1,11 @@
 { pkgs, modulesPath, ... }: {
-  imports = [ (modulesPath + "/virtualisation/qemu-vm.nix") ];
+
+  imports = [
+    ../fediversity
+    (modulesPath + "/virtualisation/qemu-vm.nix")
+  ];
+
   services.peertube = {
-    enable = true;
-    # redirects to localhost, but allows it to have a proper domain name
-    localDomain = "peertube.localhost";
     enableWebHttps = false;
     settings = {
       listen.hostname = "0.0.0.0";
@@ -13,11 +15,6 @@
     secrets.secretsFile = pkgs.writeText "secret" ''
       574e093907d1157ac0f8e760a6deb1035402003af5763135bae9cbd6abe32b24
     '';
-
-    # TODO: in most of nixpkgs, these are true by default. upstream that unless there's a good reason not to.
-    redis.createLocally = true;
-    database.createLocally = true;
-    configureNginx = true;
   };
 
   virtualisation.forwardPorts = [
diff --git a/vm/pixelfed-vm.nix b/vm/pixelfed-vm.nix
index be04bfc7..f12b9c51 100644
--- a/vm/pixelfed-vm.nix
+++ b/vm/pixelfed-vm.nix
@@ -13,7 +13,6 @@
 
   networking.firewall.allowedTCPPorts = [ 80 ];
   services.pixelfed = {
-    domain = "pixelfed.localhost";
     # TODO: secrets management!
     secretFile = pkgs.writeText "secrets.env" ''
       APP_KEY=adKK9EcY8Hcj3PLU7rzG9rJ6KKTOtYfA