From 2f06b726061b7e1aa69f718e943da9ffcecd6397 Mon Sep 17 00:00:00 2001
From: bandithedoge <bandithedoge@protonmail.com>
Date: Fri, 2 Jan 2026 00:58:41 +0100
Subject: [PATCH] mpd: set network settings as environment variables

https://mpd.readthedocs.io/en/stable/client.html#connecting-to-mpd

These environment variables are picked up by, amongst others, clients
based on libmpdclient:

- https://github.com/MusicPlayerDaemon/libmpdclient/blob/2a42a100674bb85fdaa442e639bc20b0976df8b5/src/settings.c#L108
- https://github.com/MusicPlayerDaemon/libmpdclient/blob/2a42a100674bb85fdaa442e639bc20b0976df8b5/src/settings.c#L135
---
 .../misc/news/2026/01/2026-01-02_00-03-48.nix   | 10 ++++++++++
 modules/services/mpd.nix                        | 17 ++++++++++++++++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 modules/misc/news/2026/01/2026-01-02_00-03-48.nix

diff --git a/modules/misc/news/2026/01/2026-01-02_00-03-48.nix b/modules/misc/news/2026/01/2026-01-02_00-03-48.nix
new file mode 100644
index 00000000..72d6640a
--- /dev/null
+++ b/modules/misc/news/2026/01/2026-01-02_00-03-48.nix
@@ -0,0 +1,10 @@
+{ config, ... }:
+{
+  time = "2026-01-02T00:03:48+00:00";
+  condition = config.services.mpd.enable;
+  message = ''
+    `MPD_HOST` and `MPD_PORT` environment variables are now set automatically.
+
+    This can be disabled with `services.mpd.enableSessionVariables = false`.
+  '';
+}
diff --git a/modules/services/mpd.nix b/modules/services/mpd.nix
index eba7d672..981fb6c2 100644
--- a/modules/services/mpd.nix
+++ b/modules/services/mpd.nix
@@ -22,6 +22,15 @@ in
 
       package = lib.mkPackageOption pkgs "mpd" { };
 
+      enableSessionVariables = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to set {env}`MPD_HOST` {env}`MPD_PORT` environment variables
+          according to {option}`services.mpd.network`.
+        '';
+      };
+
       musicDirectory = mkOption {
         type = with types; either path str;
         defaultText = lib.literalExpression ''
@@ -155,7 +164,13 @@ in
       );
     in
     mkIf cfg.enable {
-      home.packages = [ cfg.package ];
+      home = {
+        packages = [ cfg.package ];
+        sessionVariables = mkIf cfg.enableSessionVariables {
+          MPD_HOST = mkIf (cfg.network.listenAddress != "any") cfg.network.listenAddress;
+          MPD_PORT = builtins.toString cfg.network.port;
+        };
+      };
 
       services.mpd = lib.mkMerge [
         (mkIf (lib.versionAtLeast config.home.stateVersion "22.11" && config.xdg.userDirs.enable) {