diff --git a/modules/ai-tools.nix b/modules/ai-tools.nix
index 044cb11..30c1db4 100644
--- a/modules/ai-tools.nix
+++ b/modules/ai-tools.nix
@@ -7,6 +7,7 @@
 	}: {
 		home.packages = [
 			inputs'.llm-agents.packages.claude-code
+			pkgs.cog-cli
 			pkgs.nono
 		];
 
diff --git a/modules/overlays.nix b/modules/overlays.nix
index ed6a841..5197fde 100644
--- a/modules/overlays.nix
+++ b/modules/overlays.nix
@@ -43,6 +43,49 @@
 						doCheck = false;
 					};
 			})
+		# cog-cli
+		(final: prev: let
+				version = "0.20.0";
+				srcs = {
+					x86_64-linux =
+						prev.fetchurl {
+							url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-linux-x86_64.tar.gz";
+							hash = "sha256-tsuL2VntvG5AsWh8+CMAWtJqDJiaKu/pQ+xY516eiOY=";
+						};
+					aarch64-darwin =
+						prev.fetchurl {
+							url = "https://github.com/trycog/cog-cli/releases/download/v${version}/cog-darwin-arm64.tar.gz";
+							hash = "sha256-k6HsTQS6/MVduT9WstD77X+xPHPj3XlFIoS3qjfblZw=";
+						};
+				};
+			in {
+				cog-cli =
+					prev.stdenvNoCC.mkDerivation {
+						pname = "cog-cli";
+						inherit version;
+						src =
+							srcs.${prev.stdenv.hostPlatform.system}
+						or (throw "Unsupported system for cog-cli: ${prev.stdenv.hostPlatform.system}");
+
+						dontConfigure = true;
+						dontBuild = true;
+
+						installPhase = ''
+							runHook preInstall
+							install -Dm755 cog "$out/bin/cog"
+							runHook postInstall
+						'';
+
+						meta = with prev.lib; {
+							description = "Memory, code intelligence, and debugging for AI agents";
+							homepage = "https://github.com/trycog/cog-cli";
+							license = licenses.mit;
+							mainProgram = "cog";
+							platforms = builtins.attrNames srcs;
+							sourceProvenance = [sourceTypes.binaryNativeCode];
+						};
+					};
+			})
 		# jj-starship (passes through upstream overlay)
 		inputs.jj-starship.overlays.default
 		# zjstatus
diff --git a/modules/user.nix b/modules/user.nix
index 6063b00..8e7dc79 100644
--- a/modules/user.nix
+++ b/modules/user.nix
@@ -1,4 +1,8 @@
-{den, lib, ...}: {
+{
+	den,
+	lib,
+	...
+}: {
 	den.aspects.cschmatzler.includes = [
 		den.provides.primary-user
 		den.aspects.shell
@@ -12,9 +16,10 @@
 		den.aspects.secrets
 		den.aspects.zellij
 		den.aspects.zk
-		({host, ...}: lib.optionalAttrs (host.class == "darwin") {
-			includes = [den.aspects.desktop];
-		})
+		({host, ...}:
+				lib.optionalAttrs (host.class == "darwin") {
+					includes = [den.aspects.desktop];
+				})
 	];
 
 	den.aspects.cschmatzler.homeManager = {