diff --git a/container/Chat.nix b/container/Chat.nix
new file mode 100644
index 00000000..b34abf12
--- /dev/null
+++ b/container/Chat.nix
@@ -0,0 +1,81 @@
+{
+  container,
+  lib,
+  config,
+  pkgs,
+  ...
+}:
+let
+  cfg = config.container.module.chat;
+  db = config.container.module.postgres;
+in
+{
+  options = {
+    container.module.chat = {
+      enable = lib.mkEnableOption "chat container.";
+      address = lib.mkOption {
+        default = "10.1.0.20";
+        type = lib.types.str;
+      };
+      port = lib.mkOption {
+        default = 8065;
+        type = lib.types.int;
+      };
+      domain = lib.mkOption {
+        default = "chat.${config.container.domain}";
+        type = lib.types.str;
+      };
+      storage = lib.mkOption {
+        default = "${config.container.storage}/chat";
+        type = lib.types.str;
+      };
+    };
+  };
+
+  # WIP: https://search.nixos.org/options?channel=24.05&from=0&size=50&sort=relevance&type=packages&query=mattermost
+  config = lib.mkIf cfg.enable {
+    systemd.tmpfiles.rules = container.mkContainerDir cfg [ "data" ];
+
+    containers.chat = container.mkContainer cfg {
+      bindMounts = {
+        "/var/lib/mattermost" = {
+          hostPath = "${cfg.storage}/data";
+          isReadOnly = false;
+        };
+      };
+
+      config =
+        { ... }:
+        container.mkContainerConfig cfg {
+          services.mattermost = {
+            enable = true;
+            listenAddress = ":${toString cfg.port}";
+            localDatabaseCreate = false;
+            mutableConfig = false;
+            package = pkgs.mattermost;
+            siteName = "Chat";
+            siteUrl = "https://${cfg.domain}";
+            statePath = "/var/lib/mattermost";
+            plugins =
+              let
+                calls =
+                  let
+                    version = "1.2.0";
+                  in
+                  pkgs.fetchurl {
+                    url = "https://github.com/mattermost/mattermost-plugin-calls/releases/download/v${version}/mattermost-plugin-calls-v${version}.tar.gz";
+                    hash = "sha256-yQGBpBPgXxC+Pm6dHlbwlNEdvn6wg9neSpNNTC4YYAA=";
+                  };
+              in
+              [ calls ];
+            extraConfig = {
+              SqlSettings = {
+                DataSource = "postgres://mattermost:any@${db.address}:${toString db.port}/mattermost?sslmode=disable&connect_timeout=10";
+                DriverName = "postgres";
+              };
+            };
+          };
+        };
+    };
+  };
+}
diff --git a/container/Postgres.nix b/container/Postgres.nix
index 6939e17e..afd5c06d 100644
--- a/container/Postgres.nix
+++ b/container/Postgres.nix
@@ -48,6 +48,7 @@ in
               configurations = with config.container.module; {
                 forgejo = git;
                 invidious = yt;
+                mattermost = chat;
                 nextcloud = cloud;
                 onlyoffice = office;
                 paperless = paper;
diff --git a/container/proxy/host/Chat.nix b/container/proxy/host/Chat.nix
new file mode 100644
index 00000000..eccbe2cb
--- /dev/null
+++ b/container/proxy/host/Chat.nix
@@ -0,0 +1,28 @@
+{ config, container, ... }:
+let
+  cfg = config.container.module.chat;
+  name = "chat";
+in
+{
+  ${cfg.domain} = container.mkServer {
+    extraConfig = ''
+      listen 443 ssl;
+      set ''$${name} ${cfg.address}:${toString cfg.port};
+
+      location / {
+        allow ${config.container.localAccess};
+        allow ${config.container.module.status.address};
+        allow ${config.container.module.vpn.address};
+        allow ${config.container.module.frkn.address};
+        deny all;
+
+        proxy_pass http://''$${name}$request_uri;
+      }
+
+      ssl_certificate /etc/letsencrypt/live/${config.container.domain}/fullchain.pem;
+      ssl_certificate_key /etc/letsencrypt/live/${config.container.domain}/privkey.pem;
+      include /etc/letsencrypt/conf/options-ssl-nginx.conf;
+      ssl_dhparam /etc/letsencrypt/conf/ssl-dhparams.pem;
+    '';
+  };
+}
diff --git a/host/x86_64-linux/home/Container.nix b/host/x86_64-linux/home/Container.nix
index 3499d6f0..7a6c61c2 100644
--- a/host/x86_64-linux/home/Container.nix
+++ b/host/x86_64-linux/home/Container.nix
@@ -7,6 +7,7 @@
     module = {
       # ISSUE: hdd.enable      = true;
       change.enable = true;
+      chat.enable = true;
       cloud.enable = true;
       ddns.enable = true;
       dns.enable = true;