From 309d97c708c94852c7bf0914bd6af724a9b9f476 Mon Sep 17 00:00:00 2001
From: DannyDannyDanny <dth@taiga.ai>
Date: Wed, 25 Mar 2026 10:49:37 +0100
Subject: [PATCH] feat(nixos): add scheduled garbage collection and
 optimization for Nix :zap::art:

Implement launchd daemons for automatic Nix garbage collection and store optimization on a weekly schedule. The configuration includes intervals for both tasks to ensure efficient management of Nix store resources.
---
 nixos/hosts/daniel-macbook-air.nix | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/nixos/hosts/daniel-macbook-air.nix b/nixos/hosts/daniel-macbook-air.nix
index 63bb3f9..11ead3e 100644
--- a/nixos/hosts/daniel-macbook-air.nix
+++ b/nixos/hosts/daniel-macbook-air.nix
@@ -3,6 +3,11 @@
 let
   alacrittySyncSystemTheme = pkgs.writeShellScriptBin "alacritty-sync-system-theme"
     (builtins.readFile ../../scripts/alacritty-sync-system-theme.sh);
+
+  # nix-darwin's nix.gc / nix.optimise require nix.enable; with Determinate (nix.enable = false)
+  # we schedule the same commands via launchd using nixpkgs' nix CLI (same defaults as upstream modules).
+  nixGcInterval = [{ Weekday = 7; Hour = 3; Minute = 15; }];
+  nixOptimiseInterval = [{ Weekday = 7; Hour = 4; Minute = 15; }];
 in {
   # Apple Silicon + nix-darwin basics
   nixpkgs.hostPlatform = "aarch64-darwin";
@@ -72,6 +77,24 @@ in {
     };
   };
 
+  launchd.daemons = {
+    nix-gc-determ = {
+      command =
+        "${lib.getExe' pkgs.nix "nix-collect-garbage"} --delete-older-than 14d";
+      serviceConfig = {
+        RunAtLoad = false;
+        StartCalendarInterval = nixGcInterval;
+      };
+    };
+    nix-store-optimise-determ = {
+      command = "${lib.getExe' pkgs.nix "nix-store"} --optimise";
+      serviceConfig = {
+        RunAtLoad = false;
+        StartCalendarInterval = nixOptimiseInterval;
+      };
+    };
+  };
+
   # Keep for darwin as well (tracks defaults across upgrades)
   # current max per nix-darwin; bump only if a release notes says so
   system.stateVersion = 6;