diff --git a/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
index e5e7c112c617..3387cb6bede3 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2111.section.xml
@@ -449,6 +449,16 @@
           RandomX benchmark.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          Auto nice daemons
+          <link xlink:href="https://github.com/Nefelim4ag/Ananicy">ananicy</link>
+          and
+          <link xlink:href="https://gitlab.com/ananicy-cpp/ananicy-cpp/">ananicy-cpp</link>.
+          Available as
+          <link linkend="opt-services.ananicy.enable">services.ananicy</link>.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-21.11-incompatibilities">
diff --git a/nixos/doc/manual/release-notes/rl-2111.section.md b/nixos/doc/manual/release-notes/rl-2111.section.md
index 144e08340157..906a2bd0a90b 100644
--- a/nixos/doc/manual/release-notes/rl-2111.section.md
+++ b/nixos/doc/manual/release-notes/rl-2111.section.md
@@ -133,6 +133,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - [xmrig](https://github.com/xmrig/xmrig), a high performance, open source, cross platform RandomX, KawPow, CryptoNight and AstroBWT unified CPU/GPU miner and RandomX benchmark.
 
+- Auto nice daemons [ananicy](https://github.com/Nefelim4ag/Ananicy) and [ananicy-cpp](https://gitlab.com/ananicy-cpp/ananicy-cpp/). Available as [services.ananicy](#opt-services.ananicy.enable).
+
 ## Backward Incompatibilities {#sec-release-21.11-incompatibilities}
 
 - The NixOS VM test framework, `pkgs.nixosTest`/`make-test-python.nix`, now requires detaching commands such as `succeed("foo &")` and `succeed("foo | xclip -i")` to close stdout.
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index 8021682e3ffe..c158a888e354 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -485,6 +485,7 @@
   ./services/mail/roundcube.nix
   ./services/mail/sympa.nix
   ./services/mail/nullmailer.nix
+  ./services/misc/ananicy.nix
   ./services/misc/airsonic.nix
   ./services/misc/ankisyncd.nix
   ./services/misc/apache-kafka.nix
diff --git a/nixos/modules/services/misc/ananicy.nix b/nixos/modules/services/misc/ananicy.nix
new file mode 100644
index 000000000000..f76f534fb450
--- /dev/null
+++ b/nixos/modules/services/misc/ananicy.nix
@@ -0,0 +1,107 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.ananicy;
+  configFile = pkgs.writeText "ananicy.conf" (generators.toKeyValue { } cfg.settings);
+  extraRules = pkgs.writeText "extraRules" cfg.extraRules;
+  servicename = if ((lib.getName cfg.package) == (lib.getName pkgs.ananicy-cpp)) then "ananicy-cpp" else "ananicy";
+in
+{
+  options = {
+    services.ananicy = {
+      enable = mkEnableOption "Ananicy, an auto nice daemon";
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.ananicy;
+        defaultText = literalExpression "pkgs.ananicy";
+        example = literalExpression "pkgs.ananicy-cpp";
+        description = ''
+          Which ananicy package to use.
+        '';
+      };
+
+      settings = mkOption {
+        type = with types; attrsOf (oneOf [ int bool str ]);
+        default = { };
+        example = {
+          apply_nice = false;
+        };
+        description = ''
+          See <link xlink:href="https://github.com/Nefelim4ag/Ananicy/blob/master/ananicy.d/ananicy.conf"/>
+        '';
+      };
+
+      extraRules = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          Extra rules in json format on separate lines. See:
+          <link xlink:href="https://github.com/Nefelim4ag/Ananicy#configuration"/>
+          <link xlink:href="https://gitlab.com/ananicy-cpp/ananicy-cpp/#global-configuration"/>
+        '';
+        example = literalExpression ''
+          '''
+            { "name": "eog", "type": "Image-View" }
+            { "name": "fdupes", "type": "BG_CPUIO" }
+          '''
+        '';
+
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment = {
+      systemPackages = [ cfg.package ];
+      etc."ananicy.d".source = pkgs.runCommandLocal "ananicyfiles" { } ''
+        mkdir -p $out
+        # ananicy-cpp does not include rules or settings on purpose
+        cp -r ${pkgs.ananicy}/etc/ananicy.d/* $out
+        rm $out/ananicy.conf
+        cp ${configFile} $out/ananicy.conf
+        ${optionalString (cfg.extraRules != "") "cp ${extraRules} $out/nixRules.rules"}
+      '';
+    };
+
+    # ananicy and ananicy-cpp have different default settings
+    services.ananicy.settings =
+      let
+        mkOD = mkOptionDefault;
+      in
+      {
+        cgroup_load = mkOD true;
+        type_load = mkOD true;
+        rule_load = mkOD true;
+        apply_nice = mkOD true;
+        apply_ioclass = mkOD true;
+        apply_ionice = mkOD true;
+        apply_sched = mkOD true;
+        apply_oom_score_adj = mkOD true;
+        apply_cgroup = mkOD true;
+      } // (if ((lib.getName cfg.package) == (lib.getName pkgs.ananicy-cpp)) then {
+        # https://gitlab.com/ananicy-cpp/ananicy-cpp/-/blob/master/src/config.cpp#L12
+        loglevel = mkOD "warn"; # default is info but its spammy
+        cgroup_realtime_workaround = mkOD true;
+      } else {
+        # https://github.com/Nefelim4ag/Ananicy/blob/master/ananicy.d/ananicy.conf
+        check_disks_schedulers = mkOD true;
+        check_freq = mkOD 5;
+      });
+
+    systemd = {
+      # https://gitlab.com/ananicy-cpp/ananicy-cpp/#cgroups applies to both ananicy and -cpp
+      enableUnifiedCgroupHierarchy = mkDefault false;
+      packages = [ cfg.package ];
+      services."${servicename}" = {
+        wantedBy = [ "default.target" ];
+      };
+    };
+  };
+
+  meta = {
+    maintainers = with maintainers; [ artturin ];
+  };
+}