diff --git a/pkgs/development/python-modules/feather-format/default.nix b/pkgs/development/python-modules/feather-format/default.nix
new file mode 100644
index 000000000000..956b107695ad
--- /dev/null
+++ b/pkgs/development/python-modules/feather-format/default.nix
@@ -0,0 +1,32 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchPypi,
+  setuptools,
+  pyarrow,
+}:
+
+buildPythonPackage rec {
+  pname = "feather-format";
+  version = "0.4.1";
+  pyproject = true;
+
+  src = fetchPypi {
+    inherit pname version;
+
+    hash = "sha256-RfZ+N0XTlNTxYMptY2u/1Pi2jQEZncFkm25IfT6HiQM=";
+  };
+
+  build-system = [ setuptools ];
+  dependencies = [ pyarrow ];
+
+  pythonImportsCheck = [ "feather" ];
+  doCheck = false; # no tests
+
+  meta = {
+    description = "Simple wrapper library to the Apache Arrow-based Feather File Format";
+    homepage = "https://github.com/wesm/feather";
+    license = lib.licenses.asl20;
+    maintainers = with lib.maintainers; [ sigmanificient ];
+  };
+}
diff --git a/pkgs/development/python-modules/nemosis/default.nix b/pkgs/development/python-modules/nemosis/default.nix
new file mode 100644
index 000000000000..1d7252b12a91
--- /dev/null
+++ b/pkgs/development/python-modules/nemosis/default.nix
@@ -0,0 +1,49 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchFromGitHub,
+  setuptools,
+  requests,
+  beautifulsoup4,
+  feather-format,
+  joblib,
+  openpyxl,
+  pandas,
+  pyarrow,
+  xlrd,
+}:
+
+buildPythonPackage rec {
+  pname = "nemosis";
+  version = "3.7.0";
+  pyproject = true;
+
+  src = fetchFromGitHub {
+    owner = "UNSW-CEEM";
+    repo = "NEMOSIS";
+    rev = "refs/tags/v${version}";
+    hash = "sha256-7jIPBTvL7Y3945GEpa1/DQVdbPsSxVdYoOFTIaIgPag=";
+  };
+
+  build-system = [ setuptools ];
+  dependencies = [
+    beautifulsoup4
+    feather-format
+    joblib
+    openpyxl
+    pandas
+    pyarrow
+    requests
+    xlrd
+  ];
+
+  pythonImportsCheck = [ "nemosis" ];
+  doCheck = false; # require network and patching
+
+  meta = {
+    description = "Downloader of historical data published by the Australian Energy Market Operator";
+    homepage = "https://github.com/UNSW-CEEM/NEMOSIS";
+    license = lib.licenses.gpl3Only;
+    maintainers = with lib.maintainers; [ sigmanificient ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index bc1d43a3ae14..350a7d4225ba 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -4302,6 +4302,8 @@ self: super: with self; {
 
   fe25519 = callPackage ../development/python-modules/fe25519 { };
 
+  feather-format = callPackage ../development/python-modules/feather-format { };
+
   feedfinder2 = callPackage ../development/python-modules/feedfinder2 { };
 
   feedgen = callPackage ../development/python-modules/feedgen { };
@@ -9034,6 +9036,8 @@ self: super: with self; {
 
   nebula3-python = callPackage ../development/python-modules/nebula3-python { };
 
+  nemosis = callPackage ../development/python-modules/nemosis { };
+
   nengo = callPackage ../development/python-modules/nengo { };
 
   neo = callPackage ../development/python-modules/neo { };