From 81614f914cf4a4cf9f280289e7ec7925d0e8e591 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <frantisek.bohacek@braiinsforge.com>
Date: Sun, 27 Sep 2026 12:42:25 +0200
Subject: [PATCH] Add claude.plugins: plugin directories loaded with
 --plugin-dir

---
 README.md          |  1 +
 checks/default.nix | 11 +++++++++--
 modules/claude.nix | 18 ++++++++++++++----
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index ea1ac478eb400ff93c6a77684194c1ecfbc076a6..90a86dc304952030e6202150445859f0a9a4ad88 100644
--- a/README.md
+++ b/README.md
@@ -66,6 +66,7 @@ Runnable examples: [`examples/basic`](examples/basic) and
 | `claude.enable`, `codex.enable` | Make the agent available to launchers. |
 | `claude.package`, `codex.package` | Agent package; defaults come from this flake's inputs. |
 | `claude.settings` | JSON passed with `--settings` (layered over the account's `settings.json`). |
+| `claude.plugins` | Plugin directories loaded with `--plugin-dir`; nothing is installed into the account. |
 | `codex.settings` | TOML linked as `$CODEX_HOME/agent-environments.config.toml` and selected with `--profile agent-environments` (layered over the account's `config.toml`). |
 | `instructions.<name>.{text,order}` | Fragments of `CLAUDE.md` / `AGENTS.md`, sorted by `order` (default 1000), then name. |
 | `skills.packages` | `mkSkill` packages to enable. Their skill dependencies are added automatically. |
diff --git a/checks/default.nix b/checks/default.nix
index 70e3e1da7f8570f5192e7e1655a087e75b2937a0..5d17fe5d9c0521986cef7f9ab03993788ad32353 100644
--- a/checks/default.nix
+++ b/checks/default.nix
@@ -46,6 +46,10 @@ let
     skills = [ leaf ];
   };
 
+  fixturePlugin = pkgs.writeTextDir ".claude-plugin/plugin.json" (
+    builtins.toJSON { name = "fixture"; }
+  );
+
   full = mkEnvironment {
     inherit pkgs;
     modules = [
@@ -65,6 +69,7 @@ let
           order = 10;
         };
         claude.settings.model = "opus";
+        claude.plugins = [ fixturePlugin ];
         codex.settings.model = "gpt-5";
         launchers = {
           claude-work.agent = "claude";
@@ -130,10 +135,12 @@ in
     [ -f $s/skills/leaf/SKILL.md ] || fail "dependency skill leaf missing"
     grep -qxF "HELLO=yes" $STUB_LOG.env || fail "skill runtime input not on PATH"
 
-    # Settings layered via --settings, user args passed through after it.
+    # Settings layered via --settings, plugins loaded with --plugin-dir, user args
+    # passed through after them.
     [ "$(sed -n 1p $STUB_LOG.args)" = "--settings" ] || fail "missing --settings"
     grep -q '"model": *"opus"' "$(sed -n 2p $STUB_LOG.args)" || fail "settings file content"
-    [ "$(sed -n '3,$p' $STUB_LOG.args)" = "$(printf -- '--resume\nx')" ] || fail "user args not passed through"
+    [ "$(sed -n 3,4p $STUB_LOG.args)" = "$(printf -- "--plugin-dir\n${fixturePlugin}")" ] || fail "plugin not loaded"
+    [ "$(sed -n '5,$p' $STUB_LOG.args)" = "$(printf -- '--resume\nx')" ] || fail "user args not passed through"
     [ ! -e $s/settings.json ] || fail "launcher must not own settings.json"
 
     ${full.launchers.codex-work}/bin/codex-work exec hi
diff --git a/modules/claude.nix b/modules/claude.nix
index a267b3be851c7941de1db408b800e8c983c9ea46..f6c348165262939f2484a00b1a9263af390fbb66 100644
--- a/modules/claude.nix
+++ b/modules/claude.nix
@@ -20,6 +20,11 @@ in
       default = { };
       description = "Settings layered over the account's settings.json via --settings.";
     };
+    plugins = lib.mkOption {
+      type = lib.types.listOf lib.types.path;
+      default = [ ];
+      description = "Plugin directories, loaded with --plugin-dir. Nothing is installed into the account.";
+    };
   };
 
   config.build.agents.claude = lib.mkIf cfg.enable {
@@ -28,9 +33,14 @@ in
     instructionsFile = "CLAUDE.md";
     # Managed links: path relative to the state dir -> store path.
     files = { };
-    flags = lib.optionals (cfg.settings != { }) [
-      "--settings"
-      "${settingsFile}"
-    ];
+    flags =
+      lib.optionals (cfg.settings != { }) [
+        "--settings"
+        "${settingsFile}"
+      ]
+      ++ lib.concatMap (p: [
+        "--plugin-dir"
+        "${p}"
+      ]) cfg.plugins;
   };
 }