diff --git a/aircox_streamer/controllers/__init__.py b/aircox_streamer/controllers/__init__.py
index 6fd5578..8b0bd03 100644
--- a/aircox_streamer/controllers/__init__.py
+++ b/aircox_streamer/controllers/__init__.py
@@ -3,13 +3,19 @@
 
 from .metadata import Metadata, Request
 from .streamer import Streamer
+from .streamers import Streamers
 from .sources import Source, PlaylistSource, QueueSource
 
 
+streamers = Streamers()
+"""Default controller used by views and viewsets."""
+
+
 __all__ = (
     "Metadata",
     "Request",
     "Streamer",
+    "Streamers",
     "Source",
     "PlaylistSource",
     "QueueSource",
diff --git a/aircox_streamer/tests/conftest.py b/aircox_streamer/tests/conftest.py
index 49ba3c9..791309e 100644
--- a/aircox_streamer/tests/conftest.py
+++ b/aircox_streamer/tests/conftest.py
@@ -1,3 +1,4 @@
+import itertools
 import os
 
 from datetime import datetime, time
@@ -74,21 +75,53 @@ def station():
 
 
 @pytest.fixture
-def station_ports(station):
-    items = [
-        models.Port(
-            station=station,
-            direction=models.Port.DIRECTION_INPUT,
-            type=models.Port.TYPE_HTTP,
+def stations(station):
+    objs = [
+        models.Station(
+            name=f"test-{i}",
+            slug=f"test-{i}",
+            path=working_dir,
+            default=(i == 0),
             active=True,
-        ),
-        models.Port(
-            station=station,
-            direction=models.Port.DIRECTION_OUTPUT,
-            type=models.Port.TYPE_FILE,
-            active=True,
-        ),
+        )
+        for i in range(0, 3)
     ]
+    models.Station.objects.bulk_create(objs)
+    return [station] + objs
+
+
+@pytest.fixture
+def station_ports(station):
+    return _stations_ports(station)
+
+
+@pytest.fixture
+def stations_ports(stations):
+    return _stations_ports(*stations)
+
+
+def _stations_ports(*stations):
+    items = list(
+        itertools.chain(
+            *[
+                (
+                    models.Port(
+                        station=station,
+                        direction=models.Port.DIRECTION_INPUT,
+                        type=models.Port.TYPE_HTTP,
+                        active=True,
+                    ),
+                    models.Port(
+                        station=station,
+                        direction=models.Port.DIRECTION_OUTPUT,
+                        type=models.Port.TYPE_FILE,
+                        active=True,
+                    ),
+                )
+                for station in stations
+            ]
+        )
+    )
     models.Port.objects.bulk_create(items)
     return items
 
@@ -180,3 +213,50 @@ def metadata_string(metadata_data):
         "\n".join(f"{key}={value}" for key, value in metadata_data.items())
         + "\nEND"
     )
+
+
+# -- streamers
+class FakeStreamer(controllers.Streamer):
+    calls = {}
+
+    def fetch(self):
+        self.calls["fetch"] = True
+
+
+class FakeSource(controllers.Source):
+    def __init__(self, id, *args, **kwargs):
+        self.id = id
+        self.args = args
+        self.kwargs = kwargs
+        self.calls = {}
+
+    def fetch(self):
+        self.calls["sync"] = True
+
+    def sync(self):
+        self.calls["sync"] = True
+
+    def push(self, path):
+        self.calls["push"] = path
+        return path
+
+    def skip(self):
+        self.calls["skip"] = True
+
+    def restart(self):
+        self.calls["restart"] = True
+
+    def seek(self, c):
+        self.calls["seek"] = c
+
+
+@pytest.fixture
+def streamers(stations, stations_ports):
+    streamers = controllers.Streamers(streamer_class=FakeStreamer)
+    # avoid unecessary db calls
+    streamers.streamers = {
+        station.pk: FakeStreamer(station) for station in stations
+    }
+    for streamer in streamers.values():
+        streamer.sources = [FakeSource(i) for i in range(0, 3)]
+    return streamers
diff --git a/aircox_streamer/tests/test_controllers_streamers.py b/aircox_streamer/tests/test_controllers_streamers.py
new file mode 100644
index 0000000..b488043
--- /dev/null
+++ b/aircox_streamer/tests/test_controllers_streamers.py
@@ -0,0 +1,37 @@
+from datetime import timedelta
+
+from django.utils import timezone as tz
+import pytest
+
+
+class TestStreamers:
+    @pytest.fixture
+    def test___init__(self, streamers):
+        assert isinstance(streamers.timeout, timedelta)
+
+    @pytest.fixture
+    def test_reset(self, streamers, stations):
+        streamers.reset()
+        assert all(
+            streamers.streamers[station.pk] == station for station in stations
+        )
+
+    @pytest.fixture
+    def test_fetch(self, streamers):
+        streamers.next_date = tz.now() - tz.timedelta(seconds=30)
+        streamers.streamers = None
+
+        now = tz.now()
+        streamers.fetch()
+
+        assert all(streamer.calls.get("fetch") for streamer in streamers)
+        assert streamers.next_date > now
+
+    @pytest.fixture
+    def test_fetch_timeout_not_reached(self, streamers):
+        next_date = tz.now() + tz.timedelta(seconds=30)
+        streamers.next_date = next_date
+
+        streamers.fetch()
+        assert all(not streamer.calls.get("fetch") for streamer in streamers)
+        assert streamers.next_date == next_date
diff --git a/aircox_streamer/tests/test_viewsets.py b/aircox_streamer/tests/test_viewsets.py
new file mode 100644
index 0000000..5493aaa
--- /dev/null
+++ b/aircox_streamer/tests/test_viewsets.py
@@ -0,0 +1,185 @@
+import pytest
+
+from django.http import Http404
+
+from rest_framework.exceptions import ValidationError
+from aircox_streamer.viewsets import (
+    ControllerViewSet,
+    SourceViewSet,
+    StreamerViewSet,
+    QueueSourceViewSet,
+)
+
+
+class FakeSerializer:
+    def __init__(self, instance, *args, **kwargs):
+        self.instance = instance
+        self.data = {"instance": self.instance}
+        self.args = args
+        self.kwargs = kwargs
+
+
+class FakeRequest:
+    def __init__(self, **kwargs):
+        self.__dict__.update(**kwargs)
+
+
+@pytest.fixture
+def controller_viewset(streamers, station):
+    return ControllerViewSet(
+        streamers=streamers,
+        streamer=streamers[station.pk],
+        serializer_class=FakeSerializer,
+    )
+
+
+@pytest.fixture
+def streamer_viewset(streamers, station):
+    return StreamerViewSet(
+        streamers=streamers,
+        streamer=streamers[station.pk],
+        serializer_class=FakeSerializer,
+    )
+
+
+@pytest.fixture
+def source_viewset(streamers, station):
+    return SourceViewSet(
+        streamers=streamers,
+        streamer=streamers[station.pk],
+        serializer_class=FakeSerializer,
+    )
+
+
+@pytest.fixture
+def queue_source_viewset(streamers, station):
+    return QueueSourceViewSet(
+        streamers=streamers,
+        streamer=streamers[station.pk],
+        serializer_class=FakeSerializer,
+    )
+
+
+class TestControllerViewSet:
+    @pytest.mark.django_db
+    def test_get_streamer(self, controller_viewset, stations):
+        station = stations[0]
+        streamer = controller_viewset.get_streamer(station.pk)
+        assert streamer.station.pk == station.pk
+        assert streamer.calls.get("fetch")
+
+    @pytest.mark.django_db
+    def test_get_streamer_station_not_found(self, controller_viewset):
+        controller_viewset.streamers.streamers = {}
+        with pytest.raises(Http404):
+            controller_viewset.get_streamer(1)
+
+    @pytest.mark.django_db
+    def test_get_serializer(self, controller_viewset):
+        controller_viewset.object = {"object": "value"}
+        serializer = controller_viewset.get_serializer(test=True)
+        assert serializer.kwargs["test"]
+        assert serializer.instance == controller_viewset.object
+
+    @pytest.mark.django_db
+    def test_serialize(self, controller_viewset):
+        instance = {}
+        data = controller_viewset.serialize(instance, test=True)
+        assert data == {"instance": instance}
+
+
+class TestStreamerViewSet:
+    @pytest.mark.django_db
+    def test_retrieve(self, streamer_viewset):
+        streamer_viewset.streamer = {"streamer": "test"}
+        resp = streamer_viewset.retrieve(None, None)
+        assert resp.data == {"instance": streamer_viewset.streamer}
+
+    @pytest.mark.django_db
+    def test_list(self, streamer_viewset):
+        streamers = {"a": 1, "b": 2}
+        streamer_viewset.streamers.streamers = streamers
+        resp = streamer_viewset.list(None)
+        assert set(resp.data["results"]["instance"]) == set(streamers.values())
+
+
+class TestSourceViewSet:
+    @pytest.mark.django_db
+    def test_get_sources(self, source_viewset, streamers):
+        source_viewset.streamer.sources.append(45)
+        sources = source_viewset.get_sources()
+        assert 45 not in set(sources)
+
+    @pytest.mark.django_db
+    def test_get_source(self, source_viewset):
+        source = source_viewset.get_source(1)
+        assert source.id == 1
+
+    @pytest.mark.django_db
+    def test_get_source_not_found(self, source_viewset):
+        with pytest.raises(Http404):
+            source_viewset.get_source(1000)
+
+    @pytest.mark.django_db
+    def test_retrieve(self, source_viewset, station):
+        resp = source_viewset.retrieve(None, 0)
+        source = source_viewset.streamers[station.pk].sources[0]
+        # this is FakeSerializer being used which provides us the proof
+        assert resp.data["instance"] == source
+
+    @pytest.mark.django_db
+    def test_list(self, source_viewset, station):
+        sources = source_viewset.streamers[station.pk].sources
+        resp = source_viewset.list(None)
+        assert list(resp.data["results"]["instance"]) == sources
+
+    @pytest.mark.django_db
+    def test__run(self, source_viewset):
+        calls = {}
+
+        def action(x):
+            return calls.setdefault("action", True)
+
+        source_viewset._run(0, action)
+        assert calls.get("action")
+
+    @pytest.mark.django_db
+    def test_all_api_source_actions(self, source_viewset, station):
+        source = source_viewset.streamers[station.pk].sources[0]
+        request = FakeRequest(POST={"seek": 1})
+        source_viewset.get_source = lambda x: source
+
+        for action in ("sync", "skip", "restart", "seek"):
+            func = getattr(source_viewset, action)
+            func(request, 1)
+            assert source.calls.get(action)
+
+
+class TestQueueSourceViewSet:
+    @pytest.mark.django_db
+    def test_get_sound_queryset(self, queue_source_viewset, station, sounds):
+        ids = {sound.pk for sound in sounds}
+        request = FakeRequest(station=station)
+        query = queue_source_viewset.get_sound_queryset(request)
+        assert set(query.values_list("pk", flat=True)) == ids
+
+    @pytest.mark.django_db
+    def test_push(self, queue_source_viewset, station, sounds):
+        calls = {}
+        sound = sounds[0]
+        request = FakeRequest(station=station, data={"sound_id": sound.pk})
+        queue_source_viewset._run = lambda pk, func: calls.setdefault(
+            "_run", (pk, func)
+        )
+        result = queue_source_viewset.push(request, 13)
+        assert "_run" in calls
+        assert result[0] == 13
+        assert callable(result[1])
+
+    @pytest.mark.django_db
+    def test_push_missing_sound_in_request_post(
+        self, queue_source_viewset, station
+    ):
+        request = FakeRequest(station=station, data={})
+        with pytest.raises(ValidationError):
+            queue_source_viewset.push(request, 0)
diff --git a/aircox_streamer/urls.py b/aircox_streamer/urls.py
index 2a159b6..fdd86ec 100644
--- a/aircox_streamer/urls.py
+++ b/aircox_streamer/urls.py
@@ -4,11 +4,11 @@ from django.utils.translation import gettext_lazy as _
 from aircox.viewsets import SoundViewSet
 
 from . import viewsets
-from .views import StreamerAdminMixin
+from .views import StreamerAdminView
 
 admin.site.route_view(
     "tools/streamer",
-    StreamerAdminMixin.as_view(),
+    StreamerAdminView.as_view(),
     "tools-streamer",
     label=_("Streamer Monitor"),
 )
diff --git a/aircox_streamer/views.py b/aircox_streamer/views.py
index 03df665..43832e0 100644
--- a/aircox_streamer/views.py
+++ b/aircox_streamer/views.py
@@ -2,8 +2,17 @@ from django.utils.translation import gettext_lazy as _
 from django.views.generic import TemplateView
 
 from aircox.views.admin import AdminMixin
+from .controllers import streamers
 
 
-class StreamerAdminMixin(AdminMixin, TemplateView):
+class StreamerAdminView(AdminMixin, TemplateView):
     template_name = "aircox_streamer/streamer.html"
     title = _("Streamer Monitor")
+    streamers = streamers
+
+    def dispatch(self, *args, **kwargs):
+        # Note: this might raise concurrency racing problem with viewsets,
+        # since streamers.streamers is reset to a new dict. Still am i not
+        # sure, and needs analysis.
+        self.streamers.reset()
+        return super().dispatch(*args, **kwargs)
diff --git a/aircox_streamer/viewsets.py b/aircox_streamer/viewsets.py
index 1a11be9..bd63567 100644
--- a/aircox_streamer/viewsets.py
+++ b/aircox_streamer/viewsets.py
@@ -1,15 +1,15 @@
 from django.http import Http404
 from django.shortcuts import get_object_or_404
-from django.utils import timezone as tz
 from rest_framework import viewsets
 from rest_framework.decorators import action
 from rest_framework.exceptions import ValidationError
 from rest_framework.permissions import IsAdminUser
 from rest_framework.response import Response
 
-from aircox.models import Sound, Station
+from aircox.models import Sound
 
 from . import controllers
+
 from .serializers import (
     PlaylistSerializer,
     QueueSourceSerializer,
@@ -19,8 +19,7 @@ from .serializers import (
 )
 
 __all__ = [
-    "Streamers",
-    "BaseControllerAPIView",
+    "ControllerViewSet",
     "RequestViewSet",
     "StreamerViewSet",
     "SourceViewSet",
@@ -29,94 +28,45 @@ __all__ = [
 ]
 
 
-class Streamers:
-    date = None
-    """Next update datetime."""
-    streamers = None
-    """Stations by station id."""
-    timeout = None
-    """Timedelta to next update."""
-
-    def __init__(self, timeout=None):
-        self.timeout = timeout or tz.timedelta(seconds=2)
-
-    def load(self, force=False):
-        # FIXME: cf. TODO in aircox.controllers about model updates
-        stations = Station.objects.active()
-        if self.streamers is None or force:
-            self.streamers = {
-                station.pk: controllers.Streamer(station)
-                for station in stations
-            }
-            return
-
-        streamers = self.streamers
-        self.streamers = {
-            station.pk: controllers.Streamer(station)
-            if station.pk in streamers
-            else streamers[station.pk]
-            for station in stations
-        }
-
-    def fetch(self):
-        if self.streamers is None:
-            self.load()
-
-        now = tz.now()
-        if self.date is not None and now < self.date:
-            return
-
-        for streamer in self.streamers.values():
-            streamer.fetch()
-        self.date = now + self.timeout
-
-    def get(self, key, default=None):
-        return self.streamers.get(key, default)
-
-    def values(self):
-        return self.streamers.values()
-
-    def __getitem__(self, key):
-        return self.streamers[key]
-
-    def __contains__(self, key):
-        return key in self.streamers
-
-
-streamers = Streamers()
-
-
-class BaseControllerAPIView(viewsets.ViewSet):
+class ControllerViewSet(viewsets.ViewSet):
     permission_classes = (IsAdminUser,)
     serializer_class = None
+    streamers = controllers.streamers
+    """Streamers controller instance."""
     streamer = None
+    """User's Streamer instance."""
     object = None
+    """Object to serialize."""
 
-    def get_streamer(self, request, station_pk=None, **kwargs):
-        streamers.fetch()
-        id = int(request.station.pk if station_pk is None else station_pk)
-        if id not in streamers:
+    def get_streamer(self, station_pk=None):
+        """Get user's streamer."""
+        if station_pk is None:
+            station_pk = self.request.station.pk
+        self.streamers.fetch()
+        if station_pk not in self.streamers:
             raise Http404("station not found")
-        return streamers[id]
+        return self.streamers[station_pk]
 
     def get_serializer(self, **kwargs):
+        """Get serializer instance."""
         return self.serializer_class(self.object, **kwargs)
 
     def serialize(self, obj, **kwargs):
+        """Serializer controller data."""
         self.object = obj
         serializer = self.get_serializer(**kwargs)
         return serializer.data
 
     def dispatch(self, request, *args, station_pk=None, **kwargs):
-        self.streamer = self.get_streamer(request, station_pk, **kwargs)
+        self.streamer = self.get_streamer(station_pk)
         return super().dispatch(request, *args, **kwargs)
 
 
-class RequestViewSet(BaseControllerAPIView):
+class RequestViewSet(ControllerViewSet):
     serializer_class = RequestSerializer
 
 
-class StreamerViewSet(BaseControllerAPIView):
+class StreamerViewSet(ControllerViewSet):
     serializer_class = StreamerSerializer
 
     def retrieve(self, request, pk=None):
@@ -124,7 +74,7 @@ class StreamerViewSet(BaseControllerAPIView):
 
     def list(self, request, pk=None):
         return Response(
-            {"results": self.serialize(streamers.values(), many=True)}
+            {"results": self.serialize(self.streamers.values(), many=True)}
         )
 
     def dispatch(self, request, *args, pk=None, **kwargs):
@@ -135,7 +85,7 @@ class StreamerViewSet(BaseControllerAPIView):
         return super().dispatch(request, *args, **kwargs)
 
 
-class SourceViewSet(BaseControllerAPIView):
+class SourceViewSet(ControllerViewSet):
     serializer_class = SourceSerializer
     model = controllers.Source
 
@@ -151,8 +101,8 @@ class SourceViewSet(BaseControllerAPIView):
         return source
 
     def retrieve(self, request, pk=None):
-        self.object = self.get_source(pk)
-        return Response(self.serialize())
+        source = self.get_source(pk)
+        return Response(self.serialize(source))
 
     def list(self, request):
         return Response(
@@ -192,8 +142,8 @@ class QueueSourceViewSet(SourceViewSet):
     serializer_class = QueueSourceSerializer
     model = controllers.QueueSource
 
-    def get_sound_queryset(self):
-        return Sound.objects.station(self.request.station).archive()
+    def get_sound_queryset(self, request):
+        return Sound.objects.station(request.station).archive()
 
     @action(detail=True, methods=["POST"])
     def push(self, request, pk):
@@ -201,7 +151,7 @@ class QueueSourceViewSet(SourceViewSet):
             raise ValidationError('missing "sound_id" POST data')
 
         sound = get_object_or_404(
-            self.get_sound_queryset(), pk=request.data["sound_id"]
+            self.get_sound_queryset(request), pk=request.data["sound_id"]
         )
         return self._run(
             pk, lambda s: s.push(sound.file.path) if sound.file.path else None