Add codex-acp overlay

nix/packages/codex-acp.nix

@@ -0,0 +1,25 @@
+{ lib, buildNpmPackage, fetchFromGitHub }:
+
+# The nixpkgs package still builds the Rust adapter. Version 1.x uses Node
+# and ships a compatible Codex CLI through its locked npm dependencies.
+buildNpmPackage (finalAttrs: {
+  pname = "codex-acp";
+  version = "1.10.0";
+
+  src = fetchFromGitHub {
+    owner = "agentclientprotocol";
+    repo = "codex-acp";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-D8uYd30NRXQYUSBFCi66Oq0iRZXpl8P7nWv2m3+KBig=";
+  };
+
+  npmDepsHash = "sha256-df1/kPiZFBEq9Um26Qbo9XaYj2J8BOXQmunCQWquDTo=";
+
+  meta = {
+    description = "ACP adapter for Codex CLI";
+    homepage = "https://github.com/agentclientprotocol/codex-acp";
+    license = lib.licenses.asl20;
+    mainProgram = "codex-acp";
+    platforms = [ "aarch64-darwin" "x86_64-darwin" "aarch64-linux" "x86_64-linux" ];
+  };
+})