diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..692f12e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+__pycache__/
+*.pyc
+.pytest_cache/
+.venv/
diff --git a/catalog/library.jsonl b/catalog/library.jsonl
new file mode 100644
index 0000000..e69de29
diff --git a/conftest.py b/conftest.py
new file mode 100644
index 0000000..e69de29
diff --git a/hef/__init__.py b/hef/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/hef/catalog.py b/hef/catalog.py
new file mode 100644
index 0000000..92aba3f
--- /dev/null
+++ b/hef/catalog.py
@@ -0,0 +1 @@
+"""Catalog data model, validation, and JSONL IO."""
diff --git a/hef/selection.py b/hef/selection.py
new file mode 100644
index 0000000..6ddcefa
--- /dev/null
+++ b/hef/selection.py
@@ -0,0 +1 @@
+"""Nearest-match selection of a catalog record for a knob coordinate."""
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..2b17d18
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,15 @@
+[project]
+name = "human-experience-filter"
+version = "0.1.0"
+description = "Coordinate-tuned public-domain media installation"
+requires-python = ">=3.11"
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+
+[build-system]
+requires = ["setuptools>=68"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools]
+packages = ["hef"]
diff --git a/tests/test_smoke.py b/tests/test_smoke.py
new file mode 100644
index 0000000..9a5d21d
--- /dev/null
+++ b/tests/test_smoke.py
@@ -0,0 +1,5 @@
+def test_package_imports():
+    import hef
+    import hef.catalog
+    import hef.selection
+    assert hef is not None