diff --git a/sleap/gui/learning/features.py b/sleap/gui/learning/features.py
new file mode 100644
index 0000000000..053dc6a4d1
--- /dev/null
+++ b/sleap/gui/learning/features.py
@@ -0,0 +1,33 @@
+"""Temporary feature flags for in-progress functionality.
+
+NOTE: This module is intentionally short-lived. The centroid-only models flag
+gates UI for a feature whose *inference* half is still blocked on sleap-nn
+(epic talmolab/sleap-nn#508 / PR #562). Once centroid-only inference lands and
+the feature is fully supported, delete this module and its call sites
+(grep for is_centroid_models_enabled).
+
+In the GUI, this feature is enabled via the "Experimental Features" toggle in
+the Help menu. The SLEAP_ENABLE_CENTROID_MODELS environment variable remains
+available as a developer override.
+"""
+
+import os
+
+
+def is_centroid_models_enabled(experimental_features: bool = False) -> bool:
+    """Return True if the experimental centroid-only models UI is enabled.
+
+    Enabled when EITHER:
+    - experimental_features is True (the "Experimental Features" toggle in
+      the Help menu, threaded in by the caller), or
+    - the SLEAP_ENABLE_CENTROID_MODELS environment variable is truthy
+      ("1"/"true"/"yes"/"on", case-insensitive).
+    """
+    if experimental_features:
+        return True
+    return os.environ.get("SLEAP_ENABLE_CENTROID_MODELS", "").strip().lower() in (
+        "1",
+        "true",
+        "yes",
+        "on",
+    )
diff --git a/sleap/skeletons/centroid.json b/sleap/skeletons/centroid.json
new file mode 100644
index 0000000000..907bd9d82c
--- /dev/null
+++ b/sleap/skeletons/centroid.json
@@ -0,0 +1,28 @@
+{
+ "description": "Single-node centroid skeleton for centroid-only models.",
+ "nx_graph": {
+  "directed": true,
+  "graph": {
+   "name": "centroid",
+   "num_edges_inserted": 0
+  },
+  "links": [],
+  "multigraph": true,
+  "nodes": [
+   {
+    "id": {
+     "py/object": "sleap.skeleton.Node",
+     "py/state": {
+      "py/tuple": [
+       "centroid",
+       1.0
+      ]
+     }
+    }
+   }
+  ]
+ },
+ "preview_image": {
+  "py/b64": "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"
+ }
+}
\ No newline at end of file
diff --git a/tests/gui/learning/test_features.py b/tests/gui/learning/test_features.py
new file mode 100644
index 0000000000..cbf8d26a31
--- /dev/null
+++ b/tests/gui/learning/test_features.py
@@ -0,0 +1,43 @@
+"""Tests for the temporary centroid-only models feature flag."""
+
+import pytest
+
+from sleap.gui.learning.features import is_centroid_models_enabled
+
+
+def test_disabled_by_default(monkeypatch):
+    """The flag is off when the env var is unset."""
+    monkeypatch.delenv("SLEAP_ENABLE_CENTROID_MODELS", raising=False)
+    assert is_centroid_models_enabled() is False
+    assert is_centroid_models_enabled(False) is False
+
+
+@pytest.mark.parametrize("value", ["1", "true", "yes", "on"])
+@pytest.mark.parametrize("transform", [str.lower, str.upper, str.title])
+def test_enabled_for_truthy_values(monkeypatch, value, transform):
+    """Truthy values enable the flag regardless of case."""
+    monkeypatch.setenv("SLEAP_ENABLE_CENTROID_MODELS", transform(value))
+    assert is_centroid_models_enabled() is True
+    assert is_centroid_models_enabled(False) is True
+
+
+@pytest.mark.parametrize("value", ["0", "false", ""])
+def test_disabled_for_falsy_values(monkeypatch, value):
+    """Falsy values keep the flag off."""
+    monkeypatch.setenv("SLEAP_ENABLE_CENTROID_MODELS", value)
+    assert is_centroid_models_enabled() is False
+    assert is_centroid_models_enabled(False) is False
+
+
+def test_enabled_by_experimental_features_without_env(monkeypatch):
+    """The Experimental Features toggle enables the flag without the env var."""
+    monkeypatch.delenv("SLEAP_ENABLE_CENTROID_MODELS", raising=False)
+    assert is_centroid_models_enabled(experimental_features=True) is True
+    assert is_centroid_models_enabled(True) is True
+
+
+@pytest.mark.parametrize("value", ["0", "false", ""])
+def test_experimental_features_overrides_falsy_env(monkeypatch, value):
+    """The Experimental Features toggle enables the flag even with a falsy env."""
+    monkeypatch.setenv("SLEAP_ENABLE_CENTROID_MODELS", value)
+    assert is_centroid_models_enabled(experimental_features=True) is True
diff --git a/tests/gui/test_skeleton_templates.py b/tests/gui/test_skeleton_templates.py
new file mode 100644
index 0000000000..08514a0956
--- /dev/null
+++ b/tests/gui/test_skeleton_templates.py
@@ -0,0 +1,29 @@
+"""Tests for shipped skeleton template files."""
+
+import base64
+import io
+import json
+
+from PIL import Image
+
+import sleap.util
+from sleap.gui.commands import OpenSkeleton
+
+
+def test_centroid_template_loads_single_node():
+    """The shipped centroid.json loads to a single-node, edge-less skeleton."""
+    path = sleap.util.get_package_file("skeletons/centroid.json")
+    skeleton = OpenSkeleton.load_skeleton(path)
+    assert skeleton.node_names == ["centroid"]
+    assert len(skeleton.edges) == 0
+
+
+def test_centroid_template_preview_is_rgba():
+    """The centroid.json preview image decodes to an RGBA PIL image."""
+    path = sleap.util.get_package_file("skeletons/centroid.json")
+    with open(path, "r") as f:
+        skeleton_data = json.load(f)
+
+    b64 = skeleton_data["preview_image"]["py/b64"]
+    image = Image.open(io.BytesIO(base64.b64decode(b64)))
+    assert image.mode == "RGBA"