diff --git a/lemoncurry/tests/__init__.py b/lemoncurry/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/lemoncurry/tests/breadcrumbs.py b/lemoncurry/tests/breadcrumbs.py
new file mode 100644
index 0000000..c11ffd6
--- /dev/null
+++ b/lemoncurry/tests/breadcrumbs.py
@@ -0,0 +1,48 @@
+from collections import namedtuple
+import pytest
+
+from .. import breadcrumbs as b
+
+
+@pytest.fixture
+def nested_crumbs():
+    x = {'route': 'nc.x', 'label': 'x', 'parent': None}
+    y = {'route': 'nc.y', 'label': 'y', 'parent': 'nc.x'}
+    z = {'route': 'nc.z', 'label': 'z', 'parent': 'nc.y'}
+    crumbs = (x, y, z)
+
+    for crumb in crumbs:
+        b.breadcrumbs[crumb['route']] = crumb
+    yield namedtuple('NestedCrumbs', 'x y z')(*crumbs)
+    for crumb in crumbs:
+        del b.breadcrumbs[crumb['route']]
+
+
+class TestAdd:
+    def test_inserts_a_breadcrumb_without_parent(self):
+        route = 'tests.add.insert'
+        assert route not in b.breadcrumbs
+        b.add(route, 'some label')
+        assert route in b.breadcrumbs
+        assert b.breadcrumbs[route] == {
+            'route': route, 'label': 'some label', 'parent': None
+        }
+
+    def test_inserts_a_breadcrumb_with_parent(self):
+        route = 'tests.add.with_parent'
+        parent = 'tests.add.insert'
+        assert route not in b.breadcrumbs
+        b.add(route, 'child label', parent)
+        assert route in b.breadcrumbs
+        assert b.breadcrumbs[route] == {
+            'route': route, 'label': 'child label', 'parent': parent
+        }
+
+
+class TestFind:
+    def test_finds_chain_of_crumbs(self, nested_crumbs):
+        crumbs = b.find(nested_crumbs.z['route'])
+        assert len(crumbs) == 3
+        assert crumbs[0] == nested_crumbs.x
+        assert crumbs[1] == nested_crumbs.y
+        assert crumbs[2] == nested_crumbs.z
diff --git a/lemoncurry/tests/utils.py b/lemoncurry/tests/utils.py
new file mode 100644
index 0000000..5745087
--- /dev/null
+++ b/lemoncurry/tests/utils.py
@@ -0,0 +1,26 @@
+from unittest.mock import Mock
+from .. import utils
+
+
+class TestOrigin:
+    def test_simple_http(self):
+        """should return the correct origin for a vanilla HTTP site"""
+        req = Mock(scheme='http', site=Mock(domain='lemoncurry.test'))
+        assert utils.origin(req) == 'http://lemoncurry.test'
+
+    def test_simple_https(self):
+        """should return the correct origin for a vanilla HTTPS site"""
+        req = Mock(scheme='https', site=Mock(domain='secure.lemoncurry.test'))
+        assert utils.origin(req) == 'https://secure.lemoncurry.test'
+
+
+class TestUri:
+    def test_siteroot(self):
+        """should return correct full URI for requests to the site root"""
+        req = Mock(scheme='https', path='/', site=Mock(domain='l.test'))
+        assert utils.uri(req) == 'https://l.test/'
+
+    def test_path(self):
+        """should return correct full URI for requests with a path"""
+        req = Mock(scheme='https', path='/notes/23', site=Mock(domain='l.tst'))
+        assert utils.uri(req) == 'https://l.tst/notes/23'