diff --git a/.gitignore b/.gitignore
index b6baada..578cc4d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,3 +22,4 @@
 # Generated by nix-pre-commit-hooks
 /.pre-commit-config.yaml
 
+.nixos-test-history
diff --git a/data/eval-machines.nix b/data/eval-machines.nix
index 6c342e1..24450cd 100644
--- a/data/eval-machines.nix
+++ b/data/eval-machines.nix
@@ -10,10 +10,11 @@ let
   runCommand =
     network.network.runCommand or nwPkgs.runCommand or (import <nixpkgs>
       { }).runCommand;
-in with lib;
+in
+with lib;
 
 let
-  defaults = network.defaults or {};
+  defaults = network.defaults or { };
 
   modules = { machineName, nodes, check }:
     [
@@ -58,36 +59,41 @@ let
     "_file"
   ]);
 
-in rec {
+in
+rec {
   # Unchecked configuration of all machines.
   # Using unchecked config evaluation allows each machine to access other machines
   # configuration without recursing as full evaluation is prevented
-  uncheckedNodes = listToAttrs (map (machineName: {
-    name = machineName;
-    value = import evalConfig {
-      # Force decide system in module system
-      system = null;
-      modules = modules {
-        inherit machineName;
-        check = false;
-        nodes = uncheckedNodes;
+  uncheckedNodes = listToAttrs (map
+    (machineName: {
+      name = machineName;
+      value = import evalConfig {
+        # Force decide system in module system
+        system = null;
+        modules = modules {
+          inherit machineName;
+          check = false;
+          nodes = uncheckedNodes;
+        };
       };
-    };
-  }) machineNames);
+    })
+    machineNames);
 
   # Compute the definitions of the machines.
-  nodes = listToAttrs (map (machineName: {
-    name = machineName;
-    value = import evalConfig {
-      # Force decide system in module system
-      system = null;
-      modules = modules {
-        inherit machineName;
-        check = true;
-        nodes = uncheckedNodes;
+  nodes = listToAttrs (map
+    (machineName: {
+      name = machineName;
+      value = import evalConfig {
+        # Force decide system in module system
+        system = null;
+        modules = modules {
+          inherit machineName;
+          check = true;
+          nodes = uncheckedNodes;
+        };
       };
-    };
-  }) machineNames);
+    })
+    machineNames);
 
   deploymentInfoModule = {
     deployment = {
@@ -98,58 +104,62 @@ in rec {
   };
 
   # Phase 1: evaluate only the deployment attributes.
-  info = let network' = network;
-  in rec {
-
-    machines = flip mapAttrs nodes (n: v':
-      let v = scrubOptionValue v';
-      in {
-        inherit (v.config.deployment)
-          targetHost targetPort targetUser secrets healthChecks buildOnly
-          substituteOnDestination tags;
-        name = n;
-        nixosRelease = v.config.system.nixos.release or (removeSuffix
-          v.config.system.nixos.version.suffix v.config.system.nixos.version);
-        nixConfig = mapAttrs (n: v:
-          if builtins.isString v then
-            v
-          else
-            throw "nix option '${n}' must have a string typed value")
-          (network'.network.nixConfig or { });
-      });
-
-    machineList = map (key: getAttr key machines) (attrNames machines);
-    network = network'.network or { };
-    deployment = {
-      hosts = machineList;
-      meta = {
-        description = network.description or "";
-        ordering = network.ordering or { };
+  info =
+    let network' = network;
+    in rec {
+
+      machines = flip mapAttrs nodes (n: v':
+        let v = scrubOptionValue v';
+        in {
+          inherit (v.config.deployment)
+            targetHost targetPort targetUser secrets healthChecks buildOnly
+            substituteOnDestination tags;
+          name = n;
+          nixosRelease = v.config.system.nixos.release or (removeSuffix
+            v.config.system.nixos.version.suffix
+            v.config.system.nixos.version);
+          nixConfig = mapAttrs
+            (n: v:
+              if builtins.isString v then
+                v
+              else
+                throw "nix option '${n}' must have a string typed value")
+            (network'.network.nixConfig or { });
+        });
+
+      machineList = map (key: getAttr key machines) (attrNames machines);
+      network = network'.network or { };
+      deployment = {
+        hosts = machineList;
+        meta = {
+          description = network.description or "";
+          ordering = network.ordering or { };
+        };
       };
-    };
 
-    buildShell = network.buildShell.drvPath or null;
-  };
+      buildShell = network.buildShell.drvPath or null;
+    };
 
   # Phase 2: build complete machine configurations.
   machines = { argsFile, buildTargets ? null }:
     let
       fileArgs = builtins.fromJSON (builtins.readFile argsFile);
       nodes' = filterAttrs (n: _v: elem n fileArgs.Names) nodes;
-    in runCommand "morph" { preferLocalBuild = true; }
-    (if buildTargets == null then ''
-      mkdir -p $out
-      ${toString (mapAttrsToList (nodeName: nodeDef: ''
-        ln -s ${nodeDef.config.system.build.toplevel} $out/${nodeName}
-      '') nodes')}
-    '' else ''
-      mkdir -p $out
-      ${toString (mapAttrsToList (nodeName: nodeDef: ''
-        mkdir -p $out/${nodeName}
-        ${toString (mapAttrsToList (buildName: buildFn: ''
-          ln -s ${buildFn nodeDef} $out/${nodeName}/${buildName}
-        '') buildTargets)}
-      '') nodes')}
-    '');
+    in
+    runCommand "morph" { preferLocalBuild = true; }
+      (if buildTargets == null then ''
+        mkdir -p $out
+        ${toString (mapAttrsToList (nodeName: nodeDef: ''
+          ln -s ${nodeDef.config.system.build.toplevel} $out/${nodeName}
+        '') nodes')}
+      '' else ''
+        mkdir -p $out
+        ${toString (mapAttrsToList (nodeName: nodeDef: ''
+          mkdir -p $out/${nodeName}
+          ${toString (mapAttrsToList (buildName: buildFn: ''
+            ln -s ${buildFn nodeDef} $out/${nodeName}/${buildName}
+          '') buildTargets)}
+        '') nodes')}
+      '');
 
 }
diff --git a/data/options.nix b/data/options.nix
index 64f09fa..7e0bcf8 100644
--- a/data/options.nix
+++ b/data/options.nix
@@ -165,7 +165,8 @@ let
     };
   });
 
-in {
+in
+{
   options.deployment = {
 
     targetHost = mkOption {
diff --git a/flake.nix b/flake.nix
index 666a04a..10a09af 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,26 +29,30 @@
 
         # Eval the treefmt modules from ./treefmt.nix
         treefmtEval = treefmt-nix.lib.evalModule pkgs ./treefmt.nix;
-      in {
+      in
+      rec {
         # for `nix fmt`
         formatter = treefmtEval.config.build.wrapper;
 
         # for `nix flake check`
         checks = {
+          vm_integration_tests = pkgs.callPackage ./nixos/tests/integration_tests.nix { inherit packages; };
           formatting = treefmtEval.config.build.check self;
           build = self.packages.${system}.morph;
-          pre-commit-check = let
-            # some treefmt formatters are not supported in pre-commit-hooks we
-            # filter them out for now.
-            toFilter = [ "yamlfmt" ];
-            filterFn = n: _v: (!builtins.elem n toFilter);
-            treefmtFormatters =
-              pkgs.lib.mapAttrs (_n: v: { inherit (v) enable; })
-              (pkgs.lib.filterAttrs filterFn (import ./treefmt.nix).programs);
-          in pre-commit-hooks.lib.${system}.run {
-            src = ./.;
-            hooks = treefmtFormatters;
-          };
+          pre-commit-check =
+            let
+              # some treefmt formatters are not supported in pre-commit-hooks we
+              # filter them out for now.
+              toFilter = [ "yamlfmt" ];
+              filterFn = n: _v: (!builtins.elem n toFilter);
+              treefmtFormatters =
+                pkgs.lib.mapAttrs (_n: v: { inherit (v) enable; })
+                  (pkgs.lib.filterAttrs filterFn (import ./treefmt.nix).programs);
+            in
+            pre-commit-hooks.lib.${system}.run {
+              src = ./.;
+              hooks = treefmtFormatters;
+            };
         };
 
         # Acessible through 'nix develop' or 'nix-shell' (legacy)
diff --git a/nixos/tests/integration_tests.nix b/nixos/tests/integration_tests.nix
new file mode 100644
index 0000000..69d211d
--- /dev/null
+++ b/nixos/tests/integration_tests.nix
@@ -0,0 +1,32 @@
+{ nixosTest, packages, ... }:
+
+
+nixosTest {
+  name = "morph-deployment-test";
+  nodes =
+    let
+      boot.loader = {
+        systemd-boot.enable = true;
+        efi.canTouchEfiVariables = true;
+      };
+      services.openssh = {
+        enable = true;
+        startWhenNeeded = false;
+      };
+    in
+    {
+      deployer = _: {
+        inherit services boot;
+        environment.systemPackages = [ packages.morph ];
+      };
+      target = _: {
+        inherit services boot;
+      };
+    };
+  testScript = ''
+    start_all()
+
+    deployer.wait_for_unit("sshd")
+    target.wait_for_unit("sshd")
+  '';
+}
diff --git a/nixpkgs.nix b/nixpkgs.nix
index 461a15a..364108e 100644
--- a/nixpkgs.nix
+++ b/nixpkgs.nix
@@ -1,3 +1,3 @@
 # Intentionally impure for CI against nixos-unstable
 builtins.fetchTarball
-"https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz"
+  "https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz"
diff --git a/treefmt.nix b/treefmt.nix
index 6789b19..e4f1216 100644
--- a/treefmt.nix
+++ b/treefmt.nix
@@ -1,7 +1,7 @@
 {
   projectRootFile = "flake.nix";
   programs = {
-    nixfmt.enable = true; # nix formatter
+    nixpkgs-fmt.enable = true; # nix formatter
     statix.enable = true; # nix static analysis
     deadnix.enable = true; # find dead nix code
     shellcheck.enable = true; # bash/shell
@@ -11,7 +11,7 @@
   };
   settings = {
     formatter = {
-      nixfmt.includes = [ "*.nix" "./data/*" ];
+      nixpkgs-fmt.includes = [ "*.nix" "./data/*" ];
       statix.includes = [ "*.nix" "./data/*" ];
       deadnix.includes = [ "*.nix" "./data/*" ];
     };