diff --git a/filter/kyofilter b/filter/kyofilter
new file mode 100755
index 0000000..92228b2
--- /dev/null
+++ b/filter/kyofilter
@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+"""CUPS filter for TA 3505ci - injects department account code into PostScript stream."""
+import sys
+
+
+def parse_options(options_str):
+    options = {}
+    for token in options_str.split():
+        if '=' in token:
+            k, v = token.split('=', 1)
+            options[k] = v
+        else:
+            options[token] = 'true'
+    return options
+
+
+if __name__ == '__main__':
+    pass
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..20aff12
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,8 @@
+import importlib.util, pathlib, sys
+from importlib.machinery import SourceFileLoader
+
+_path = pathlib.Path(__file__).parent.parent / "filter" / "kyofilter"
+_spec = importlib.util.spec_from_loader("kyofilter", SourceFileLoader("kyofilter", str(_path)))
+_mod = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(_mod)
+sys.modules["kyofilter"] = _mod
diff --git a/tests/test_kyofilter.py b/tests/test_kyofilter.py
new file mode 100644
index 0000000..9bf95f7
--- /dev/null
+++ b/tests/test_kyofilter.py
@@ -0,0 +1,16 @@
+import kyofilter
+
+
+class TestParseOptions:
+    def test_single_key_value(self):
+        assert kyofilter.parse_options("KmManagment=MG12345") == {"KmManagment": "MG12345"}
+
+    def test_multiple_options(self):
+        result = kyofilter.parse_options("KmManagment=MG12345 Duplex=DuplexNoTumble")
+        assert result == {"KmManagment": "MG12345", "Duplex": "DuplexNoTumble"}
+
+    def test_empty_string(self):
+        assert kyofilter.parse_options("") == {}
+
+    def test_flag_without_value(self):
+        assert kyofilter.parse_options("SomeFlag") == {"SomeFlag": "true"}