diff --git a/README.md b/README.md
index 240f27c..900b40f 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,6 @@ Most tools come from `nixpkgs`. Fast-moving CLIs that you want to update on
 their own cadence are pinned as dedicated flake inputs:
 
 - `googleworkspace-cli`
-- `codex`
 - `claudeCode`
 
 ## Commands
@@ -69,11 +68,17 @@ just switch
 Update only Codex or Claude:
 
 ```bash
-nix flake lock --update-input codex
 nix flake lock --update-input claudeCode
 just switch
 ```
 
+Update Codex:
+
+```bash
+brew upgrade --cask codex
+just switch
+```
+
 ## What Still Needs Manual Handling
 
 - Secrets and tokens under `~/.secrets`, `~/.npmrc`, `~/.config/gcloud`, `~/.config/gh`, and similar paths
@@ -86,6 +91,7 @@ just switch
 The current Homebrew boundary is only:
 
 - `cap`
+- `codex`
 - `raycast`
 - `riptide-dev`
 - `thebrowsercompany-dia`
diff --git a/docs/architecture.md b/docs/architecture.md
index d6bdd84..9ed1e60 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -18,7 +18,8 @@ The structure is intentionally split into three layers:
 - [modules/packages.nix](/Users/rathi/Documents/GitHub/nix/modules/packages.nix)
   owns the heavier developer tooling and fonts
 - [modules/homebrew.nix](/Users/rathi/Documents/GitHub/nix/modules/homebrew.nix)
-  is the explicitly narrow Brew escape hatch for GUI casks
+  is the explicitly narrow Brew escape hatch for GUI casks, including Codex
+  because the Homebrew-distributed app is a better fit here than a source build
 - [modules/macos.nix](/Users/rathi/Documents/GitHub/nix/modules/macos.nix)
   owns system defaults and macOS-specific integration
 
@@ -47,7 +48,6 @@ Exceptions:
 Current dedicated inputs:
 
 - `googleworkspace-cli`
-- `codex`
 - `claudeCode`
 
 ## Intentional Pragmatism
diff --git a/flake.lock b/flake.lock
index 671b01b..c1e7cce 100644
--- a/flake.lock
+++ b/flake.lock
@@ -38,27 +38,6 @@
         "type": "github"
       }
     },
-    "codex": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ],
-        "rust-overlay": "rust-overlay"
-      },
-      "locked": {
-        "lastModified": 1773430824,
-        "narHash": "sha256-Rq1IozLlXBCoiOBzwgRhIUAGKojWMaueVUX2qOj5vhs=",
-        "owner": "openai",
-        "repo": "codex",
-        "rev": "914f7c73175b038b4d396219754fe21ba6678af2",
-        "type": "github"
-      },
-      "original": {
-        "owner": "openai",
-        "repo": "codex",
-        "type": "github"
-      }
-    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -194,7 +173,6 @@
     "root": {
       "inputs": {
         "claudeCode": "claudeCode",
-        "codex": "codex",
         "googleworkspace-cli": "googleworkspace-cli",
         "home-manager": "home-manager",
         "nix-darwin": "nix-darwin",
@@ -202,27 +180,6 @@
         "nixpkgs": "nixpkgs"
       }
     },
-    "rust-overlay": {
-      "inputs": {
-        "nixpkgs": [
-          "codex",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1769828398,
-        "narHash": "sha256-zmnvRUm15QrlKH0V1BZoiT3U+Q+tr+P5Osi8qgtL9fY=",
-        "owner": "oxalica",
-        "repo": "rust-overlay",
-        "rev": "a1d32c90c8a4ea43e9586b7e5894c179d5747425",
-        "type": "github"
-      },
-      "original": {
-        "owner": "oxalica",
-        "repo": "rust-overlay",
-        "type": "github"
-      }
-    },
     "systems": {
       "locked": {
         "lastModified": 1681028828,
diff --git a/flake.nix b/flake.nix
index 5197460..36de3c9 100644
--- a/flake.nix
+++ b/flake.nix
@@ -24,11 +24,6 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
 
-    codex = {
-      url = "github:openai/codex";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
-
     nix-homebrew = {
       url = "github:zhaofengli-wip/nix-homebrew";
     };
@@ -40,7 +35,6 @@
     nix-darwin,
     home-manager,
     claudeCode,
-    codex,
     nix-homebrew,
     ...
   }: let
@@ -63,6 +57,7 @@
 
           home-manager.useGlobalPkgs = true;
           home-manager.useUserPackages = true;
+          home-manager.extraSpecialArgs = {inherit inputs self username hostname;};
           home-manager.backupFileExtension = "hm-bak";
           home-manager.users.${username} = import ./home;
 
diff --git a/modules/homebrew.nix b/modules/homebrew.nix
index 57a04be..d878161 100644
--- a/modules/homebrew.nix
+++ b/modules/homebrew.nix
@@ -17,6 +17,7 @@
 
     casks = [
       "cap"
+      "codex"
       "raycast"
       "riptide-dev"
       "thebrowsercompany-dia"
diff --git a/modules/packages.nix b/modules/packages.nix
index df01ee6..2938fc0 100644
--- a/modules/packages.nix
+++ b/modules/packages.nix
@@ -8,8 +8,6 @@
     inputs.googleworkspace-cli.packages.${pkgs.stdenv.hostPlatform.system}.default;
   claudePackage =
     inputs.claudeCode.packages.${pkgs.stdenv.hostPlatform.system}.default;
-  codexPackage =
-    inputs.codex.packages.${pkgs.stdenv.hostPlatform.system}.default;
 
   memex = pkgs.stdenvNoCC.mkDerivation rec {
     pname = "memex";
@@ -84,7 +82,6 @@ in {
   environment.systemPackages = with pkgs; [
     awscli2
     claudePackage
-    codexPackage
     coreutils-prefixed
     delta
     diff-so-fancy