diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index 07e6c76..aa1f12f 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -32,17 +32,16 @@ jobs:
         pip install flake8 pytest Pyqt6 pytest-qt
         sudo apt-get update
         sudo apt-get install -y libegl1 xvfb
-        if [ -f slitmaskgui/requirements.txt ]; then pip install -r slitmaskgui/requirements.txt; fi
+        if [ -f gui/slitmaskgui/requirements.txt ]; then pip install -r gui/slitmaskgui/requirements.txt; fi
 
     - name: Lint with flake8
       run: |
         source .venv/bin/activate
-        flake8 slitmaskgui/ --count --select=E9,F63,F7,F82 --show-source --statistics --exclude=.venv
-        flake8 slitmaskgui/ --count --exit-zero --max-complexity=10 --statistics #--max-line-length=120 --exclude=.venv
-        
+        flake8 gui/slitmaskgui/ --count --select=E9,F63,F7,F82 --show-source --statistics --exclude=.venv
+        flake8 gui/slitmaskgui/ --count --exit-zero --max-complexity=10 --statistics
+
     - name: Test
       run: |
         source .venv/bin/activate
         export QT_QPA_PLATFORM=offscreen
-        xvfb-run -a python3 -m pytest slitmaskgui/tests/
-  #test:
+        xvfb-run -a python3 -m pytest tests/
diff --git a/.gitmodules b/.gitmodules
index 98b658d..7b4cb61 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,9 +1,9 @@
-[submodule "src/lris2/util/lris2-csu"]
-	path = src/lris2/util/lris2-csu
-	url = git@github.com:CaltechOpticalObservatories/lris2-csu.git
-[submodule "src/lris2/util/coo-ethercat"]
-	path = src/lris2/util/coo-ethercat
-	url = git@github.com:CaltechOpticalObservatories/coo-ethercat.git
-[submodule "src/lris2/util/sunpower"]
-	path = src/lris2/util/sunpower
+[submodule "src/driver/sunpower"]
+	path = src/driver/sunpower
 	url = git@github.com:COO-Utilities/sunpower.git
+[submodule "src/driver/coo_ethercat"]
+	path = src/driver/coo_ethercat
+	url = git@github.com:CaltechOpticalObservatories/coo-ethercat.git
+[submodule "src/driver/lris2_csu"]
+	path = src/driver/lris2_csu
+	url = git@github.com:CaltechOpticalObservatories/lris2-csu.git
diff --git a/README.md b/README.md
index b1198e7..c29dd1a 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,73 @@
-# lris2
\ No newline at end of file
+# lris2
+
+LRIS2 Instrument Control Software
+
+## Structure
+
+- `daemons/` – mKTL service daemons
+- `gui/` – Graphical interfaces (`slitmaskgui`, `demo`)
+- `scripts/` – AIT and utility scripts
+- `src/driver/` – Hardware driver submodules
+- `tests/` – Unit tests
+
+## Quick start
+
+```bash
+# 1) Clone
+git clone <repo-url>
+cd lris2
+
+# 2) Make sure submodule URLs are in sync
+git submodule sync --recursive
+git submodule update --init --recursive
+
+# 3) Install the package for development
+pip install -U pip
+pip install -e ".[dev]"
+```
+
+## Submodules
+
+This repo uses submodules under `src/driver/`:
+
+| Submodule | Path | Import |
+|-----------|------|--------|
+| coo-ethercat | `src/driver/coo_ethercat` | `lris2.driver.coo_ethercat` |
+| lris2-csu | `src/driver/lris2_csu` | `lris2.driver.lris2_csu` |
+| sunpower | `src/driver/sunpower` | `lris2.driver.sunpower` |
+
+### Pull the submodules
+
+```bash
+git submodule sync --recursive
+git submodule update --init --recursive
+```
+
+### Update to the latest on a tracked branch (e.g., main)
+
+> Only do this if you intend to move submodule pointers and commit them.
+
+```bash
+# One-off refresh to submodules' tracked branches
+git submodule update --remote --merge --recursive
+
+# Record updated pointers in parent repo
+git add .gitmodules .
+git commit -m "Update submodules to latest on main"
+```
+
+## Testing
+
+Tests mirror the `src/` layout under `tests/`.
+
+To run tests from the project root:
+
+```bash
+pytest
+```
+
+## Contributing
+
+1. Create a feature branch.
+2. Include tests for new behavior.
+3. Run `pytest` before opening a PR.
\ No newline at end of file
diff --git a/gui/slitmaskgui/tests/__init__.py b/gui/slitmaskgui/__init__.py
similarity index 100%
rename from gui/slitmaskgui/tests/__init__.py
rename to gui/slitmaskgui/__init__.py
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..c9dd99e
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,29 @@
+[build-system]
+requires = ["setuptools>=42"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "lris2"
+version = "0.1.0"
+description = "LRIS2 Instrument Control Software"
+requires-python = ">=3.12"
+authors = [
+    {name = "Michael Langmayr", email = "langmayr@caltech.edu"}
+]
+license = {text = "MIT"}
+readme = "README.md"
+
+[project.optional-dependencies]
+dev = [
+    "pytest",
+]
+
+[tool.setuptools.package-dir]
+lris2 = "src"
+
+[tool.setuptools]
+packages = ["lris2", "lris2.driver"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+pythonpath = ["gui"]
diff --git a/src/__init__.py b/src/__init__.py
new file mode 100644
index 0000000..76fa704
--- /dev/null
+++ b/src/__init__.py
@@ -0,0 +1 @@
+"""LRIS2 Instrument Control Software."""
diff --git a/src/driver/__init__.py b/src/driver/__init__.py
new file mode 100644
index 0000000..3feaf16
--- /dev/null
+++ b/src/driver/__init__.py
@@ -0,0 +1 @@
+"""LRIS2 hardware driver submodules."""
diff --git a/src/lris2/util/coo-ethercat b/src/driver/coo_ethercat
similarity index 100%
rename from src/lris2/util/coo-ethercat
rename to src/driver/coo_ethercat
diff --git a/src/lris2/util/lris2-csu b/src/driver/lris2_csu
similarity index 100%
rename from src/lris2/util/lris2-csu
rename to src/driver/lris2_csu
diff --git a/src/lris2/util/sunpower b/src/driver/sunpower
similarity index 100%
rename from src/lris2/util/sunpower
rename to src/driver/sunpower
diff --git a/gui/slitmaskgui/tests/test_input_targets.py b/tests/gui/slitmaskgui/test_input_targets.py
similarity index 100%
rename from gui/slitmaskgui/tests/test_input_targets.py
rename to tests/gui/slitmaskgui/test_input_targets.py
diff --git a/gui/slitmaskgui/tests/test_mask_configurations.py b/tests/gui/slitmaskgui/test_mask_configurations.py
similarity index 100%
rename from gui/slitmaskgui/tests/test_mask_configurations.py
rename to tests/gui/slitmaskgui/test_mask_configurations.py
diff --git a/gui/slitmaskgui/tests/test_offline_mode.py b/tests/gui/slitmaskgui/test_offline_mode.py
similarity index 100%
rename from gui/slitmaskgui/tests/test_offline_mode.py
rename to tests/gui/slitmaskgui/test_offline_mode.py
diff --git a/gui/slitmaskgui/tests/test_slit_position_table.py b/tests/gui/slitmaskgui/test_slit_position_table.py
similarity index 100%
rename from gui/slitmaskgui/tests/test_slit_position_table.py
rename to tests/gui/slitmaskgui/test_slit_position_table.py
diff --git a/gui/slitmaskgui/tests/test_star_list.py b/tests/gui/slitmaskgui/test_star_list.py
similarity index 100%
rename from gui/slitmaskgui/tests/test_star_list.py
rename to tests/gui/slitmaskgui/test_star_list.py
diff --git a/gui/slitmaskgui/tests/testfiles/gaia_mask_config.json b/tests/gui/slitmaskgui/testfiles/gaia_mask_config.json
similarity index 100%
rename from gui/slitmaskgui/tests/testfiles/gaia_mask_config.json
rename to tests/gui/slitmaskgui/testfiles/gaia_mask_config.json
diff --git a/gui/slitmaskgui/tests/testfiles/gaia_starlist.txt b/tests/gui/slitmaskgui/testfiles/gaia_starlist.txt
similarity index 100%
rename from gui/slitmaskgui/tests/testfiles/gaia_starlist.txt
rename to tests/gui/slitmaskgui/testfiles/gaia_starlist.txt
diff --git a/gui/slitmaskgui/tests/testfiles/gaia_target_list.json b/tests/gui/slitmaskgui/testfiles/gaia_target_list.json
similarity index 100%
rename from gui/slitmaskgui/tests/testfiles/gaia_target_list.json
rename to tests/gui/slitmaskgui/testfiles/gaia_target_list.json
diff --git a/gui/slitmaskgui/tests/testfiles/make_much_stars.py b/tests/gui/slitmaskgui/testfiles/make_much_stars.py
similarity index 100%
rename from gui/slitmaskgui/tests/testfiles/make_much_stars.py
rename to tests/gui/slitmaskgui/testfiles/make_much_stars.py