diff --git a/pkgs/server/prometheus-folder-size-exporter.nix b/pkgs/server/prometheus-folder-size-exporter.nix
new file mode 100644
index 000000000..0e403fa8b
--- /dev/null
+++ b/pkgs/server/prometheus-folder-size-exporter.nix
@@ -0,0 +1,38 @@
+{ lib
+, rustPlatform
+, fetchFromGitHub
+, stdenv
+, darwin
+}:
+
+rustPlatform.buildRustPackage rec {
+  pname = "prometheus-folder-size-exporter";
+  version = "0.5.0";
+
+  src = fetchFromGitHub {
+    owner = "MindFlavor";
+    repo = "prometheus_folder_size_exporter";
+    rev = version;
+    hash = "sha256-G1oWGiTyftloPxgOuiYFO7hofHdbwPCG4QDXK1t5qWk=";
+  };
+
+  postPatch = ''
+    # patch to use gauge instead of counter
+    # from https://github.com/MindFlavor/prometheus_folder_size_exporter/pull/18/files
+    sed -i -E 's/(MetricType::)Counter/\1Gauge/g' ./src/main.rs
+  '';
+
+  cargoHash = "sha256-M9kvf0XNDtBzvCHVDs+JPC+oNTsWuDFKdjqVgNUnRLg=";
+
+  buildInputs = lib.optionals stdenv.isDarwin [
+    darwin.apple_sdk.frameworks.Security
+  ];
+
+  meta = with lib; {
+    description = "A Rust only folder size exporter for Prometheus (Grafana";
+    homepage = "https://github.com/MindFlavor/prometheus_folder_size_exporter";
+    license = licenses.mit;
+    maintainers = with maintainers; [ jpetrucciani ];
+    mainProgram = "prometheus_folder_size_exporter";
+  };
+}