diff --git a/flake.lock b/flake.lock
index 59fb64a..eb5423a 100644
--- a/flake.lock
+++ b/flake.lock
@@ -257,11 +257,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1688859638,
-        "narHash": "sha256-GyRhX8GlTQqDWx43uBFEYEQ/WKEqDwjzABHxUCatAno=",
+        "lastModified": 1688894907,
+        "narHash": "sha256-U7hEDDhzAhLp6T+DEUbfwAsL+BtqFFGn+S1pa/0XrZY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d485da9d0034a72ceb9679c2ab0156c073f66b82",
+        "rev": "4ddf98349c793377c76806ebfbdfb2b96dd4ef5d",
         "type": "github"
       },
       "original": {
diff --git a/modules/matrix/default.nix b/modules/matrix/default.nix
index c026063..8dddd7b 100644
--- a/modules/matrix/default.nix
+++ b/modules/matrix/default.nix
@@ -1,6 +1,10 @@
 { config, pkgs, ... }:
 
 {
+  imports = [
+    ../../services/matrix-sliding-sync.nix
+  ];
+
   environment.systemPackages = with pkgs; [
     matrix-synapse-tools.synadm
   ];
@@ -17,7 +21,7 @@
             LC_CTYPE = "C";
       '';
     };
-    postgresqlBackup.databases = [ "matrix" ];
+    postgresqlBackup.databases = [ "matrix" "matrix-syncv3" ];
 
     matrix-synapse = {
       enable = true;
@@ -48,6 +52,8 @@
         config.sops.secrets.matrix-registration-secret.path
       ];
     };
+
+    matrix-syncv3.enable = true;
   };
 
   sops.secrets.matrix-registration-secret = {
diff --git a/modules/matrix/nginx.nix b/modules/matrix/nginx.nix
index 3ef5ec4..8acb861 100644
--- a/modules/matrix/nginx.nix
+++ b/modules/matrix/nginx.nix
@@ -10,6 +10,12 @@
         locations."/" = { proxyPass = "http://100.111.208.75:8008"; };
       };
 
+      "syncv3.walkah.chat" = {
+        forceSSL = true;
+        enableACME = true;
+        locations."/" = { proxyPass = "http://100.111.208.75:8088"; };
+      };
+
       "walkah.chat" = {
         forceSSL = true;
         enableACME = true;
@@ -25,6 +31,7 @@
           let
             client = {
               "m.homeserver" = { "base_url" = "https://matrix.walkah.chat"; };
+              "org.matrix.msc3575.proxy" = { "url" = "https://syncv3.walkah.chat"; };
             };
           in
           ''
diff --git a/services/matrix-sliding-sync.nix b/services/matrix-sliding-sync.nix
new file mode 100644
index 0000000..a96465e
--- /dev/null
+++ b/services/matrix-sliding-sync.nix
@@ -0,0 +1,63 @@
+{ config, lib, pkgs, options, ... }:
+with lib;
+let
+  cfg = config.services.matrix-syncv3;
+in
+{
+  options = {
+    services.matrix-syncv3 = {
+      enable = mkEnableOption "SyncV3 for matrix";
+      package = mkPackageOption pkgs "matrix-sliding-sync" { };
+
+      port = mkOption {
+        type = types.int;
+        default = 8088;
+        description = ''
+          The port to listen on.
+        '';
+      };
+
+      environmentFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        description = ''
+          Must contain the `SYNCV3_SECRET` environment variable. 
+          Generated with ``openssl rand -hex 32``.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services = {
+      postgresql = {
+        ensureDatabases = [ "matrix-syncv3" ];
+        ensureUsers = [{
+          name = "matrix-syncv3";
+          ensurePermissions."DATABASE \"matrix-syncv3\"" = "ALL PRIVILEGES";
+        }];
+      };
+    };
+
+    systemd.services.matrix-syncv3 = {
+      after = [ "matrix-synapse.service" "postgresql.service" ];
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        DynamicUser = true;
+        StateDirectory = "matrix-syncv3";
+        WorkingDirectory = "/var/lib/matrix-syncv3";
+        Environment = [
+          "SYNCV3_SERVER=https://matrix.walkah.chat"
+          "SYNCV3_DB=postgresql:///matrix-syncv3?host=/run/postgresql"
+          "SYNCV3_BINDADDR=0.0.0.0:${toString cfg.port}"
+        ];
+      };
+      script = ''
+        path=/var/lib/matrix-syncv3/secret
+        [ -f $path ] || ${pkgs.openssl}/bin/openssl rand -hex 32 > $path
+        export SYNCV3_SECRET=$(cat $path)
+        exec ${cfg.package}/bin/syncv3
+      '';
+    };
+  };
+}