diff --git a/.github/workflows/bundle_windows.yml b/.github/workflows/bundle_windows.yml
index 679b645..fbd0a49 100644
--- a/.github/workflows/bundle_windows.yml
+++ b/.github/workflows/bundle_windows.yml
@@ -40,7 +40,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install -e .
+        pip install -e .[gui]
         pip install cx_freeze
 
     - name: Bundle with cx_Freeze
diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index 9cf24c5..fb834fd 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -33,7 +33,7 @@ jobs:
         pip install -r requirements.txt
         pip install -r requirements-test.txt
         sudo apt-get install libopenjp2-7
-        pip install -e .
+        pip install -e .[gui]
     - name: Run Flake8
       run: |
         flake8 .
diff --git a/README.md b/README.md
index 2068c10..faa3a28 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,9 @@ with low-level SL details. See the [Local Animation addon example](https://githu
 * Activate the virtualenv by running the appropriate activation script
 * * Under Linux this would be something like `source <virtualenv_dir>/bin/activate`
 * * Under Windows it's `<virtualenv_dir>\Scripts\activate.bat`
-* Run `pip install hippolyzer`, or run `pip install -e .` in a cloned repo to install an editable version
+* Run `pip install hippolyzer[gui]` for a full install, or run `pip install -e .[gui]` in a cloned repo to install an editable version
+* * If you only want the core library without proxy or GUI support, use `pip install hippolyzer` or `pip install -e .`
+* * If you only want proxy/CLI support without the GUI, use `pip install hippolyzer[proxy]` or `pip install -e .[proxy]`
 
 ### Binary Windows Builds
 
diff --git a/pyproject.toml b/pyproject.toml
index d2f3153..c82745d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,24 +26,31 @@ classifiers = [
 ]
 dependencies = [
     "aiohttp<4.0.0",
-    "arpeggio",
     "defusedxml",
     "gltflib",
     "Glymur<0.9.7",
     "idna<3,>=2.5",
     "lazy-object-proxy",
     "llsd<1.1.0",
-    "mitmproxy>=11.0.0,<12",
     "numpy<2.0",
-    "outleap<1.0",
-    "ptpython<4.0",
     "pycollada",
-    "pyside6-essentials",
-    "qasync",
     "recordclass>=0.23.1,<0.24",
     "transformations",
+]
+
+[project.optional-dependencies]
+proxy = [
+    "arpeggio",
+    "mitmproxy>=11.0.0,<12",
+    "outleap<1.0",
+    "ptpython<4.0",
     "Werkzeug<4.0",
 ]
+gui = [
+    "hippolyzer[proxy]",
+    "pyside6-essentials",
+    "qasync",
+]
 
 [tool.setuptools.packages.find]
 where = ["."]