diff --git a/ui/medashare/cli.py b/ui/medashare/cli.py
index 402ccf7..3cf8801 100644
--- a/ui/medashare/cli.py
+++ b/ui/medashare/cli.py
@@ -32,6 +32,7 @@ from edgold.ed448 import EDDSA448
 from unittest import mock
 
 from .hostid import hostuuid
+from .tags import TagCache
 from . import orm
 
 from .btv import _TestCases as bttestcase, validate_file
@@ -748,121 +749,6 @@ def enumeratedir(_dir, created_by_ref):
 	    created_by_ref) for x in sorted(os.listdir(_dir)) if not
 	    os.path.isdir(os.path.join(_dir, x)) ]
 
-class TagCache:
-	'''Takes tuples, and stores them in a cache where only
-	the most count recent ones are kept.'''
-
-	def __init__(self, tags=(), count=10):
-		self._cache = dict((x, None) for x in tags)
-		self._count = count
-		self._modified = False
-
-	@property
-	def modified(self):
-		'''Return if the cache has been modified since the last
-		time store has been called.'''
-
-		return self._modified
-
-	def add(self, tag):
-		'''Add a tag (tuple) to the cache, possibly dropping ann older
-		tag if necessary.'''
-
-		self._modified = True
-
-		try:
-			del self._cache[tag]
-		except KeyError:
-			pass
-
-		self._cache[tag] = None
-
-		while len(self._cache) > self._count:
-			del self._cache[next(iter(self._cache.keys()))]
-
-	def tags(self):
-		'''Returns the sorted list of tags in the cache.'''
-
-		return sorted(self._cache.keys())
-
-	@classmethod
-	def load(cls, fname):
-		'''Load the cache from fname.  Must be previously have saved
-		using the store method.'''
-
-		try:
-			with open(fname, 'rb') as fp:
-				cache = _asn1coder.loads(fp.read())
-		except (FileNotFoundError, IndexError):
-			# IndexError when file exists, but is invalid
-			return cls()
-
-		# fix up
-		cache['tags'] = [ tuple(x) for x in cache['tags'] ]
-
-		return cls(**cache)
-
-	def store(self, fname):
-		'''Store the cache to fname.  The modified property will
-		be cleared after this.'''
-
-		self._modified = False
-
-		cache = dict(tags=list(self._cache.keys()), count=self._count)
-
-		with open(fname, 'wb') as fp:
-			fp.write(_asn1coder.dumps(cache))
-
-class _TestTagCache(unittest.TestCase):
-	def setUp(self):
-		d = pathlib.Path(tempfile.mkdtemp()).resolve()
-		self.basetempdir = d
-
-		self.tempdir = d / 'subdir'
-
-		self.tempdir.mkdir()
-
-	def tearDown(self):
-		shutil.rmtree(self.basetempdir)
-		self.tempdir = None
-
-	def test_cache(self):
-		# test basic functionality
-		tc = TagCache(count=2)
-
-		self.assertFalse(tc.modified)
-
-		tc.add(('foo', 'foo'))
-
-		self.assertTrue(tc.modified)
-
-		tc.add(('bar', 'bar'))
-
-		self.assertEqual(tc.tags(), [ ('bar', 'bar'), ('foo', 'foo') ])
-
-		tc.add(('foo', 'foo'))
-
-		tc.add(('baz', 'baz'))
-
-		tc.add(('foo', 'foo'))
-
-		self.assertEqual(tc.tags(), [ ('baz', 'baz'), ('foo', 'foo') ])
-
-		cachefile = self.tempdir / 'somecache'
-		tc.store(cachefile)
-
-		self.assertFalse(tc.modified)
-
-		ntc = TagCache.load(cachefile)
-
-		self.assertFalse(ntc.modified)
-
-		self.assertEqual(tc.tags(), [ ('baz', 'baz'), ('foo', 'foo') ])
-
-		ntc.add(('whee', 'whee'))
-
-		self.assertEqual(ntc.tags(), [ ('foo', 'foo'), ('whee', 'whee') ])
-
 def _get_paths(options):
 	fnames = (
 	    '.medashare_identity.pasn1',
@@ -2282,6 +2168,7 @@ class _TestCases(unittest.TestCase):
 		# setup object store
 		storefname = self.tempdir / 'storefname'
 		identfname = self.tempdir / 'identfname'
+		cachefname = self.tempdir / 'cachefname'
 
 		# setup path mapping
 		def expandusermock(arg):
@@ -2289,6 +2176,8 @@ class _TestCases(unittest.TestCase):
 				return storefname
 			elif arg == '~/.medashare_identity.pasn1':
 				return identfname
+			elif arg == '~/.medashare_cache.pasn1':
+				return cachefname
 
 		# setup test fname
 		testfname = os.path.join(self.tempdir, 'test.txt')
diff --git a/ui/medashare/tags.py b/ui/medashare/tags.py
new file mode 100644
index 0000000..6c2592a
--- /dev/null
+++ b/ui/medashare/tags.py
@@ -0,0 +1,121 @@
+import pathlib
+import shutil
+import tempfile
+import unittest
+from .utils import _asn1coder
+
+class TagCache:
+	'''Takes tuples, and stores them in a cache where only
+	the most count recent ones are kept.'''
+
+	def __init__(self, tags=(), count=10):
+		self._cache = dict((x, None) for x in tags)
+		self._count = count
+		self._modified = False
+
+	@property
+	def modified(self):
+		'''Return if the cache has been modified since the last
+		time store has been called.'''
+
+		return self._modified
+
+	def add(self, tag):
+		'''Add a tag (tuple) to the cache, possibly dropping ann older
+		tag if necessary.'''
+
+		self._modified = True
+
+		try:
+			del self._cache[tag]
+		except KeyError:
+			pass
+
+		self._cache[tag] = None
+
+		while len(self._cache) > self._count:
+			del self._cache[next(iter(self._cache.keys()))]
+
+	def tags(self):
+		'''Returns the sorted list of tags in the cache.'''
+
+		return sorted(self._cache.keys())
+
+	@classmethod
+	def load(cls, fname):
+		'''Load the cache from fname.  Must be previously have saved
+		using the store method.'''
+
+		try:
+			with open(fname, 'rb') as fp:
+				cache = _asn1coder.loads(fp.read())
+		except (FileNotFoundError, IndexError):
+			# IndexError when file exists, but is invalid
+			return cls()
+
+		# fix up
+		cache['tags'] = [ tuple(x) for x in cache['tags'] ]
+
+		return cls(**cache)
+
+	def store(self, fname):
+		'''Store the cache to fname.  The modified property will
+		be cleared after this.'''
+
+		self._modified = False
+
+		cache = dict(tags=list(self._cache.keys()), count=self._count)
+
+		with open(fname, 'wb') as fp:
+			fp.write(_asn1coder.dumps(cache))
+
+class _TestTagCache(unittest.TestCase):
+	def setUp(self):
+		d = pathlib.Path(tempfile.mkdtemp()).resolve()
+		self.basetempdir = d
+
+		self.tempdir = d / 'subdir'
+
+		self.tempdir.mkdir()
+
+	def tearDown(self):
+		shutil.rmtree(self.basetempdir)
+		self.tempdir = None
+
+	def test_cache(self):
+		# test basic functionality
+		tc = TagCache(count=2)
+
+		self.assertFalse(tc.modified)
+
+		tc.add(('foo', 'foo'))
+
+		self.assertTrue(tc.modified)
+
+		tc.add(('bar', 'bar'))
+
+		self.assertEqual(tc.tags(), [ ('bar', 'bar'), ('foo', 'foo') ])
+
+		tc.add(('foo', 'foo'))
+
+		tc.add(('baz', 'baz'))
+
+		tc.add(('foo', 'foo'))
+
+		self.assertEqual(tc.tags(), [ ('baz', 'baz'), ('foo', 'foo') ])
+
+		cachefile = self.tempdir / 'somecache'
+		tc.store(cachefile)
+
+		self.assertFalse(tc.modified)
+
+		ntc = TagCache.load(cachefile)
+
+		self.assertFalse(ntc.modified)
+
+		self.assertEqual(tc.tags(), [ ('baz', 'baz'), ('foo', 'foo') ])
+
+		ntc.add(('whee', 'whee'))
+
+		self.assertEqual(ntc.tags(), [ ('foo', 'foo'), ('whee', 'whee') ])
+
diff --git a/ui/medashare/tests.py b/ui/medashare/tests.py
index ae5602a..08f2c2a 100644
--- a/ui/medashare/tests.py
+++ b/ui/medashare/tests.py
@@ -2,6 +2,7 @@ from .btv import _TestCases as btv_test_cases
 from .btv.bencode import _TestCases as bencode_test_cases
 from .mdb import _TestJSONEncoder
 from .cli import _TestCononicalCoder, _TestCases as cli_test_cases
-from .cli import _TestMigrations, _TestTagCache
+from .cli import _TestMigrations
+from .tags import _TestTagCache
 from .mtree import Test
 from .server import _TestCases, _TestPostConfig