diff --git a/pkgs/development/python-modules/expression/default.nix b/pkgs/development/python-modules/expression/default.nix
new file mode 100644
index 000000000000..f20aa388e2b9
--- /dev/null
+++ b/pkgs/development/python-modules/expression/default.nix
@@ -0,0 +1,39 @@
+{
+  lib,
+  buildPythonPackage,
+  fetchPypi,
+  typing-extensions,
+  poetry-core,
+  pydantic,
+}:
+
+buildPythonPackage (finalAttrs: {
+  pname = "expression";
+  version = "5.6.0";
+  pyproject = true;
+
+  src = fetchPypi {
+    inherit (finalAttrs) pname version;
+    sha256 = "sha256-RU9v4Tg0cZSkPH+HjZWO/puEucx3DkYgEMelLhgFgGU=";
+  };
+
+  build-system = [ poetry-core ];
+
+  dependencies = [ typing-extensions ];
+
+  optional-dependencies = {
+    pydantic = [ pydantic ];
+  };
+
+  pythonImportsCheck = [
+    "expression"
+  ];
+
+  meta = {
+    description = "Functional programming for Python";
+    homepage = "https://github.com/dbrattli/Expression";
+    changelog = "https://github.com/dbrattli/Expression/releases/tag/v${finalAttrs.version}";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ happysalada ];
+  };
+})
diff --git a/pkgs/development/python-modules/litellm/default.nix b/pkgs/development/python-modules/litellm/default.nix
index 782e669fe596..56273871efb7 100644
--- a/pkgs/development/python-modules/litellm/default.nix
+++ b/pkgs/development/python-modules/litellm/default.nix
@@ -13,6 +13,7 @@
   buildPythonPackage,
   click,
   cryptography,
+  expression,
   fastapi,
   fastapi-sso,
   fastuuid,
@@ -120,6 +121,7 @@ buildPythonPackage rec {
       backoff
       boto3
       cryptography
+      expression
       fastapi
       fastapi-sso
       gunicorn
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 268e12aa78c0..e48541d9312c 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -5739,6 +5739,8 @@ self: super: with self; {
 
   explorerscript = callPackage ../development/python-modules/explorerscript { };
 
+  expression = callPackage ../development/python-modules/expression { };
+
   exrex = callPackage ../development/python-modules/exrex { };
 
   extension-helpers = callPackage ../development/python-modules/extension-helpers { };