diff --git a/AGENTS.md b/AGENTS.md
index 48b3acc..7fe98f7 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -22,12 +22,12 @@ This repo uses Bun as the package manager and `bun2nix` for reproducible Nix bui
 - `bun.lock` is the source of truth for JS dependencies.
 - `bun.nix` is generated from `bun.lock` with `bun run update:bun-nix`.
 - `flake.nix` imports the `bun2nix` overlay and exposes `packages.<system>.default` plus `nixosModules.default`.
-- `nix/package.nix` uses `bun2nix.fetchBunDeps` with `bun.nix`, runs `bun run build`, and installs the bundled `server.js` plus frontend assets as the `leo-ed` executable.
+- `nix/package.nix` uses `bun2nix.fetchBunDeps` with `bun.nix`, runs `bun run build`, and installs the bundled `server.js` plus frontend assets as the `kotsukotsu` executable.
 
 Whenever dependencies change, update both `bun.lock` and `bun.nix` in the same commit. CI checks that `bun.nix` matches the lockfile by regenerating it and failing on diff.
 
 ## Server and Deployment Model
-This repo is the application source, not the full server configuration. Production is intended to be managed from a separate NixOS infra repo that imports this flake and sets `services.leo-ed.package = inputs.leo-ed.packages.${pkgs.system}.default;`. The included module in `nix/module.nix` defines the systemd service, runtime env (`APP_ORIGIN`, `PORT`, `SQLITE_PATH`, `SESSION_COOKIE_SECURE`), and persistent state directory.
+This repo is the application source, not the full server configuration. Production is intended to be managed from a separate NixOS infra repo that imports this flake and sets `services.kotsukotsu.package = inputs.kotsukotsu.packages.${pkgs.system}.default;`. The included module in `nix/module.nix` defines the systemd service, runtime env (`APP_ORIGIN`, `PORT`, `SQLITE_PATH`, `SESSION_COOKIE_SECURE`), and persistent state directory.
 
 `server/config.ts` exists so production behavior is explicit: WebAuthn origin/RP ID, SQLite path, bind host, and secure cookies should come from NixOS service configuration, not reverse-proxy accident.
 
diff --git a/flake.nix b/flake.nix
index 70e4954..9a27f0f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,5 +1,5 @@
 {
-  description = "leo-ed typing app";
+  description = "kotsukotsu typing app";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
@@ -7,52 +7,39 @@
     bun2nix.inputs.nixpkgs.follows = "nixpkgs";
   };
 
-  nixConfig = {
-    extra-substituters = [
-      "https://cache.nixos.org"
-      "https://nix-community.cachix.org"
-    ];
-    extra-trusted-public-keys = [
-      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
-      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
-    ];
+  outputs = {
+    self,
+    nixpkgs,
+    bun2nix,
+  }: let
+    systems = ["x86_64-linux" "aarch64-linux"];
+    forAllSystems = nixpkgs.lib.genAttrs systems;
+  in {
+    packages = forAllSystems (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [bun2nix.overlays.default];
+      };
+    in rec {
+      kotsukotsu = pkgs.callPackage ./nix/package.nix {};
+      default = kotsukotsu;
+    });
+
+    devShells = forAllSystems (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [bun2nix.overlays.default];
+      };
+    in {
+      default = pkgs.mkShell {
+        packages = with pkgs; [
+          bun
+          bun2nix
+          nodejs
+        ];
+      };
+    });
+
+    nixosModules.default = import ./nix/module.nix;
   };
-
-  outputs = { self, nixpkgs, bun2nix }:
-    let
-      systems = [ "x86_64-linux" "aarch64-linux" ];
-      forAllSystems = nixpkgs.lib.genAttrs systems;
-    in
-    {
-      packages = forAllSystems (system:
-        let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [ bun2nix.overlays.default ];
-          };
-        in
-        rec {
-          leo-ed = pkgs.callPackage ./nix/package.nix { };
-          default = leo-ed;
-        });
-
-      devShells = forAllSystems (system:
-        let
-          pkgs = import nixpkgs {
-            inherit system;
-            overlays = [ bun2nix.overlays.default ];
-          };
-        in
-        {
-          default = pkgs.mkShell {
-            packages = with pkgs; [
-              bun
-              bun2nix
-              nodejs
-            ];
-          };
-        });
-
-      nixosModules.default = import ./nix/module.nix;
-    };
 }
diff --git a/nix/module.nix b/nix/module.nix
index 41e21bf..90e2bb1 100644
--- a/nix/module.nix
+++ b/nix/module.nix
@@ -1,16 +1,16 @@
 { config, lib, pkgs, ... }:
 
 let
-  cfg = config.services.leo-ed;
+  cfg = config.services.kotsukotsu;
 in
 {
-  options.services.leo-ed = {
-    enable = lib.mkEnableOption "leo-ed typing app";
+  options.services.kotsukotsu = {
+    enable = lib.mkEnableOption "kotsukotsu typing app";
 
     package = lib.mkOption {
       type = lib.types.nullOr lib.types.package;
       default = null;
-      description = "The leo-ed package to run, typically inputs.leo-ed.packages.${pkgs.system}.default.";
+      description = "The kotsukotsu package to run, typically inputs.kotsukotsu.packages.${pkgs.system}.default.";
     };
 
     host = lib.mkOption {
@@ -34,19 +34,19 @@ in
 
     dataDir = lib.mkOption {
       type = lib.types.str;
-      default = "/var/lib/leo-ed";
+      default = "/var/lib/kotsukotsu";
       description = "Directory for the persistent SQLite database.";
     };
 
     user = lib.mkOption {
       type = lib.types.str;
-      default = "leo-ed";
+      default = "kotsukotsu";
       description = "User account for the service.";
     };
 
     group = lib.mkOption {
       type = lib.types.str;
-      default = "leo-ed";
+      default = "kotsukotsu";
       description = "Group for the service.";
     };
 
@@ -61,24 +61,24 @@ in
     assertions = [
       {
         assertion = cfg.package != null;
-        message = "services.leo-ed.package must be set, usually from this flake input.";
+        message = "services.kotsukotsu.package must be set, usually from this flake input.";
       }
       {
         assertion = cfg.domain != null && cfg.domain != "";
-        message = "services.leo-ed.domain must be set.";
+        message = "services.kotsukotsu.domain must be set.";
       }
       {
         assertion = lib.hasPrefix "/" cfg.dataDir;
-        message = "services.leo-ed.dataDir must be an absolute path.";
+        message = "services.kotsukotsu.dataDir must be an absolute path.";
       }
     ];
 
-    users.groups = lib.mkIf (cfg.group == "leo-ed") {
-      leo-ed = { };
+    users.groups = lib.mkIf (cfg.group == "kotsukotsu") {
+      kotsukotsu = { };
     };
 
-    users.users = lib.mkIf (cfg.user == "leo-ed") {
-      leo-ed = {
+    users.users = lib.mkIf (cfg.user == "kotsukotsu") {
+      kotsukotsu = {
         isSystemUser = true;
         group = cfg.group;
         home = toString cfg.dataDir;
@@ -90,8 +90,8 @@ in
       "d ${toString cfg.dataDir} 0750 ${cfg.user} ${cfg.group} -"
     ];
 
-    systemd.services.leo-ed = {
-      description = "leo-ed typing app";
+    systemd.services.kotsukotsu = {
+      description = "kotsukotsu typing app";
       after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
 
diff --git a/nix/package.nix b/nix/package.nix
index 874f926..f9819c4 100644
--- a/nix/package.nix
+++ b/nix/package.nix
@@ -9,7 +9,7 @@ let
   packageJson = lib.importJSON ../package.json;
 in
 stdenvNoCC.mkDerivation {
-  pname = "leo-ed";
+  pname = "kotsukotsu";
   version = packageJson.version;
 
   src = lib.cleanSource ../.;
@@ -35,12 +35,12 @@ stdenvNoCC.mkDerivation {
   installPhase = ''
     runHook preInstall
 
-    mkdir -p $out/share/leo-ed $out/bin
-    cp -r build/. $out/share/leo-ed/
+    mkdir -p $out/share/kotsukotsu $out/bin
+    cp -r build/. $out/share/kotsukotsu/
 
-    makeWrapper ${lib.getExe bun} $out/bin/leo-ed \
-      --run "cd $out/share/leo-ed" \
-      --add-flags "$out/share/leo-ed/server.js"
+    makeWrapper ${lib.getExe bun} $out/bin/kotsukotsu \
+      --run "cd $out/share/kotsukotsu" \
+      --add-flags "$out/share/kotsukotsu/server.js"
 
     runHook postInstall
   '';
@@ -48,7 +48,7 @@ stdenvNoCC.mkDerivation {
   meta = {
     description = "Typing practice app with passkey auth";
     homepage = "https://example.invalid";
-    mainProgram = "leo-ed";
+    mainProgram = "kotsukotsu";
     platforms = lib.platforms.linux;
   };
 }