From 4b97e6c5f117b36c49c609669f1b6f073b2c2304 Mon Sep 17 00:00:00 2001
From: Kat Huang <kkathuang@gmail.com>
Date: Sat, 25 Apr 2026 16:28:17 -0700
Subject: [PATCH] codex: manage generated skills with home-manager

---
 home-manager/codex-generated-skills.nix | 67 +++++++++++++++++++++++++
 nix-darwin/home/common.nix              |  7 ++-
 nixos/dotfiles-links.nix                |  4 ++
 3 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 home-manager/codex-generated-skills.nix

diff --git a/home-manager/codex-generated-skills.nix b/home-manager/codex-generated-skills.nix
new file mode 100644
index 00000000..d6a3d445
--- /dev/null
+++ b/home-manager/codex-generated-skills.nix
@@ -0,0 +1,67 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  cfg = config.myModules.codexGeneratedSkills;
+in {
+  options.myModules.codexGeneratedSkills = {
+    enable = lib.mkEnableOption "generated Codex skill setup";
+
+    codexHome = lib.mkOption {
+      type = lib.types.str;
+      default = "${config.home.homeDirectory}/.codex";
+      description = "Codex home directory.";
+    };
+
+    skillsDir = lib.mkOption {
+      type = lib.types.str;
+      default = "${cfg.codexHome}/skills";
+      description = "Codex skills directory.";
+    };
+
+    primaryRuntimeDir = lib.mkOption {
+      type = lib.types.str;
+      default = "${config.home.homeDirectory}/.cache/codex-runtimes/codex-primary-runtime";
+      description = "Codex primary runtime cache directory.";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home.activation.setupCodexGeneratedSkills = lib.hm.dag.entryAfter ["writeBoundary"] ''
+      codex_home=${lib.escapeShellArg cfg.codexHome}
+      skills_dir=${lib.escapeShellArg cfg.skillsDir}
+      runtime_skills_root=${lib.escapeShellArg "${cfg.primaryRuntimeDir}/skills/skills"}
+
+      mkdir -p "$skills_dir"
+
+      if [ -x ${lib.escapeShellArg "${pkgs.codex}/bin/codex"} ]; then
+        if ! CODEX_HOME="$codex_home" ${lib.escapeShellArg "${pkgs.codex}/bin/codex"} debug prompt-input "bootstrap generated Codex skills" >/dev/null; then
+          echo "setupCodexGeneratedSkills: codex failed to bootstrap .system skills" >&2
+        fi
+      else
+        echo "setupCodexGeneratedSkills: codex binary not found; skipping .system skill bootstrap" >&2
+      fi
+
+      if [ -d "$runtime_skills_root" ]; then
+        tmp_dir="$(mktemp -d "''${TMPDIR:-/tmp}/codex-primary-runtime.XXXXXX")"
+        trap 'rm -rf "$tmp_dir"' EXIT
+
+        mkdir -p "$tmp_dir/codex-primary-runtime"
+        for skill_name in slides spreadsheets; do
+          if [ -d "$runtime_skills_root/$skill_name" ]; then
+            cp -R "$runtime_skills_root/$skill_name" "$tmp_dir/codex-primary-runtime/$skill_name"
+          fi
+        done
+
+        if [ "$(find "$tmp_dir/codex-primary-runtime" -mindepth 1 -maxdepth 1 -type d | wc -l | tr -d ' ')" != "0" ]; then
+          rm -rf "$skills_dir/codex-primary-runtime"
+          mv "$tmp_dir/codex-primary-runtime" "$skills_dir/codex-primary-runtime"
+        fi
+      else
+        echo "setupCodexGeneratedSkills: runtime skills not found at $runtime_skills_root; skipping codex-primary-runtime" >&2
+      fi
+    '';
+  };
+}
diff --git a/nix-darwin/home/common.nix b/nix-darwin/home/common.nix
index 6c9bb177..37f2c848 100644
--- a/nix-darwin/home/common.nix
+++ b/nix-darwin/home/common.nix
@@ -88,13 +88,18 @@
 in {
   programs.home-manager.enable = true;
 
-  imports = [inputs.agenix.homeManagerModules.default];
+  imports = [
+    inputs.agenix.homeManagerModules.default
+    ../../home-manager/codex-generated-skills.nix
+  ];
 
   age.identityPaths = ["${config.home.homeDirectory}/.ssh/id_ed25519"];
   age.secrets.gpg-keys.file = ../../nixos/secrets/gpg-keys.age;
   age.secrets.gpg-passphrase.file = ../../nixos/secrets/gpg-passphrase.age;
   home.file = dotfilesLinks;
 
+  myModules.codexGeneratedSkills.enable = true;
+
   home.activation.linkEmacsDotdir = lib.hm.dag.entryAfter ["writeBoundary"] ''
     live_emacs_dir="$HOME/dotfiles/dotfiles/emacs.d"
     target_emacs_dir="${dotfilesDir}/emacs.d"
diff --git a/nixos/dotfiles-links.nix b/nixos/dotfiles-links.nix
index bb1d1805..65ad1980 100644
--- a/nixos/dotfiles-links.nix
+++ b/nixos/dotfiles-links.nix
@@ -55,9 +55,13 @@ let
     };
 in
 {
+  imports = [ ../home-manager/codex-generated-skills.nix ];
+
   home.file =
     builtins.listToAttrs (map mkManaged managedRelFiles);
 
+  myModules.codexGeneratedSkills.enable = true;
+
   # Home Manager directory links for .emacs.d resolve through the store on this
   # machine, which breaks Elpaca's writable state under ~/.emacs.d/elpaca.
   # Manage placement here instead so ~/.emacs.d always points at the live