diff --git a/not_my_board/_hub.py b/not_my_board/_hub.py
index 98f70d7..d2f7546 100644
--- a/not_my_board/_hub.py
+++ b/not_my_board/_hub.py
@@ -30,39 +30,22 @@ async def asgi_app(request):
         return
     elif isinstance(request, asgineer.HttpRequest):
         if request.path == "/api/v1/places":
-            return {"places": [p.desc for p in Place.all()]}
+            return await _hub.get_places()
     return 404, {}, "Page not found"
 
 
 async def _handle_agent(ws):
     await _authorize_ws(ws)
     client_ip = ws.scope["client"][0]
-    async with Place.reservation_context(client_ip) as ctx:
-        api = AgentAPI(ctx)
-        server = jsonrpc.Server(ws.send, ws.receive_iter(), api)
-        await server.serve_forever()
-
-
-class AgentAPI:
-    def __init__(self, reservation_context):
-        self._reservation_context = reservation_context
-
-    async def reserve(self, candidate_ids):
-        place = await Place.reserve(candidate_ids, self._reservation_context)
-        return place.desc["id"]
-
-    async def return_reservation(self, place_id):
-        await Place.return_by_id(place_id, self._reservation_context)
+    server = jsonrpc.Server(ws.send, ws.receive_iter())
+    await _hub.agent_communicate(client_ip, server)
 
 
 async def _handle_exporter(ws):
     await _authorize_ws(ws)
     client_ip = ws.scope["client"][0]
     exporter = jsonrpc.Proxy(ws.send, ws.receive_iter())
-    async with util.background_task(exporter.io_loop()) as io_loop:
-        place = await exporter.get_place()
-        with Place.register(place, exporter, client_ip):
-            await io_loop
+    await _hub.exporter_communicate(client_ip, exporter)
 
 
 async def _authorize_ws(ws):
@@ -81,6 +64,38 @@ async def _authorize_ws(ws):
     await ws.accept()
 
 
+class Hub:
+    async def get_places(self):
+        return {"places": [p.desc for p in Place.all()]}
+
+    async def agent_communicate(self, client_ip, rpc):
+        async with Place.reservation_context(client_ip) as ctx:
+            api = AgentAPI(ctx)
+            rpc.set_api_object(api)
+            await rpc.serve_forever()
+
+    async def exporter_communicate(self, client_ip, rpc):
+        async with util.background_task(rpc.io_loop()) as io_loop:
+            place = await rpc.get_place()
+            with Place.register(place, rpc, client_ip):
+                await io_loop
+
+
+_hub = Hub()
+
+
+class AgentAPI:
+    def __init__(self, reservation_context):
+        self._reservation_context = reservation_context
+
+    async def reserve(self, candidate_ids):
+        place = await Place.reserve(candidate_ids, self._reservation_context)
+        return place.desc["id"]
+
+    async def return_reservation(self, place_id):
+        await Place.return_by_id(place_id, self._reservation_context)
+
+
 class Place:
     _all_places = {}
     _next_id = 1
diff --git a/not_my_board/_jsonrpc.py b/not_my_board/_jsonrpc.py
index bafc1a4..b79349f 100644
--- a/not_my_board/_jsonrpc.py
+++ b/not_my_board/_jsonrpc.py
@@ -30,7 +30,7 @@ def __init__(self, code, message, data):
 
 
 class Server:
-    def __init__(self, send, receive_iter, api_obj):
+    def __init__(self, send, receive_iter, api_obj=None):
         super().__init__()
         self._send = send
         self._receive_iter = receive_iter
@@ -38,6 +38,9 @@ def __init__(self, send, receive_iter, api_obj):
         self._tasks = set()
         self._tasks_by_id = {}
 
+    def set_api_object(self, api_obj):
+        self._api_obj = api_obj
+
     async def serve_forever(self):
         try:
             async for raw_data in self._receive_iter: