diff --git a/jupyterhub/apihandlers/proxy.py b/jupyterhub/apihandlers/proxy.py
index 54d75500..a2b705f3 100644
--- a/jupyterhub/apihandlers/proxy.py
+++ b/jupyterhub/apihandlers/proxy.py
@@ -28,7 +28,7 @@ class ProxyAPIHandler(APIHandler):
     @gen.coroutine
     def post(self):
         """POST checks the proxy to ensure"""
-        yield self.proxy.check_routes(self.users)
+        yield self.proxy.check_routes(self.users, self.services)
         
     
     @admin_only
@@ -59,7 +59,7 @@ class ProxyAPIHandler(APIHandler):
             self.proxy.auth_token = model['auth_token']
         self.db.commit()
         self.log.info("Updated proxy at %s", server.bind_url)
-        yield self.proxy.check_routes(self.users)
+        yield self.proxy.check_routes(self.users, self.services)
         
 
 
diff --git a/jupyterhub/app.py b/jupyterhub/app.py
index 41886ab0..37dd80a8 100644
--- a/jupyterhub/app.py
+++ b/jupyterhub/app.py
@@ -976,8 +976,12 @@ class JupyterHub(Application):
                 proxy=self.proxy, hub=self.hub, base_url=self.base_url,
                 db=self.db, orm=orm_service,
                 parent=self,
-                hub_api_url=self.hub.api_url,
-                **spec)
+                hub_api_url=self.hub.api_url)
+            traits = service.traits(input=True)
+            for key, value in spec.items():
+                if key not in traits:
+                    raise AttributeError("No such service field: %s" % key)
+                setattr(service, key, value)
             self._service_map[name] = service
             if service.managed:
                 if not service.api_token:
@@ -986,6 +990,14 @@ class JupyterHub(Application):
                 else:
                     # ensure provided token is registered
                     self.service_tokens[service.api_token] = service.name
+            else:
+                self.service_tokens[service.api_token] = service.name
+
+        # delete services from db not in service config:
+        for service in self.db.query(orm.Service):
+            if service.name not in self._service_map:
+                self.db.delete(service)
+        self.db.commit()
 
     @gen.coroutine
     def init_spawners(self):
@@ -1155,6 +1167,7 @@ class JupyterHub(Application):
         yield self.start_proxy()
         self.log.info("Setting up routes on new proxy")
         yield self.proxy.add_all_users(self.users)
+        yield self.proxy.add_all_services(self.services)
         self.log.info("New proxy back up, and good to go")
 
     def init_tornado_settings(self):
@@ -1213,6 +1226,7 @@ class JupyterHub(Application):
         self.tornado_settings = settings
         # constructing users requires access to tornado_settings
         self.tornado_settings['users'] = self.users
+        self.tornado_settings['services'] = self._service_map
 
     def init_tornado_application(self):
         """Instantiate the tornado Application object"""
@@ -1354,7 +1368,7 @@ class JupyterHub(Application):
         self.statsd.gauge('users.active', active_users_count)
 
         self.db.commit()
-        yield self.proxy.check_routes(self.users, routes)
+        yield self.proxy.check_routes(self.users, self._service_map, routes)
 
     @gen.coroutine
     def start(self):
@@ -1396,6 +1410,7 @@ class JupyterHub(Application):
                 self.exit(1)
 
         loop.add_callback(self.proxy.add_all_users, self.users)
+        loop.add_callback(self.proxy.add_all_services, self._service_map)
 
         if self.proxy_process:
             # only check / restart the proxy if we started it in the first place.
diff --git a/jupyterhub/handlers/base.py b/jupyterhub/handlers/base.py
index 07651787..f03f817b 100644
--- a/jupyterhub/handlers/base.py
+++ b/jupyterhub/handlers/base.py
@@ -68,6 +68,9 @@ class BaseHandler(RequestHandler):
         return self.settings.setdefault('users', {})
 
     @property
+    def services(self):
+        return self.settings.setdefault('services', {})
+    @property
     def hub(self):
         return self.settings['hub']
 
@@ -236,6 +239,10 @@ class BaseHandler(RequestHandler):
             **kwargs
         )
 
+    def set_service_cookie(self, user):
+        """set the login cookie for services"""
+        self._set_user_cookie(user, self.service_server)
+
     def set_server_cookie(self, user):
         """set the login cookie for the single-user server"""
         self._set_user_cookie(user, user.server)
@@ -254,6 +261,10 @@ class BaseHandler(RequestHandler):
         if user.server:
             self.set_server_cookie(user)
 
+        # set single cookie for services
+        if self.db.query(orm.Service).first():
+            self.set_service_cookie(user)
+
         # create and set a new cookie token for the hub
         if not self.get_current_user_cookie():
             self.set_hub_cookie(user)
diff --git a/jupyterhub/orm.py b/jupyterhub/orm.py
index f7241b9a..5e581e19 100644
--- a/jupyterhub/orm.py
+++ b/jupyterhub/orm.py
@@ -152,6 +152,35 @@ class Proxy(Base):
 
         return client.fetch(req)
 
+    @gen.coroutine
+    def add_service(self, service, client=None):
+        """Add a service's server to the proxy table."""
+        if not service.server:
+            raise RuntimeError(
+                "Service %s does not have an http endpoint to add to the proxy.", service.name)
+
+        self.log.info("Adding service %s to proxy %s => %s",
+            service.name, service.proxy_path, service.server.host,
+        )
+
+        yield self.api_request(service.proxy_path,
+            method='POST',
+            body=dict(
+                target=service.server.host,
+                service=service.name,
+            ),
+            client=client,
+        )
+
+    @gen.coroutine
+    def delete_service(self, service, client=None):
+        """Remove a service's server from the proxy table."""
+        self.log.info("Removing service %s from proxy", service.name)
+        yield self.api_request(service.proxy_path,
+            method='DELETE',
+            client=client,
+        )
+
     @gen.coroutine
     def add_user(self, user, client=None):
         """Add a user's server to the proxy table."""
@@ -174,7 +203,7 @@ class Proxy(Base):
 
     @gen.coroutine
     def delete_user(self, user, client=None):
-        """Remove a user's server to the proxy table."""
+        """Remove a user's server from the proxy table."""
         self.log.info("Removing user %s from proxy", user.name)
         yield self.api_request(user.proxy_path,
             method='DELETE',
@@ -182,10 +211,20 @@ class Proxy(Base):
         )
 
     @gen.coroutine
-    def get_routes(self, client=None):
-        """Fetch the proxy's routes"""
-        resp = yield self.api_request('', client=client)
-        return json.loads(resp.body.decode('utf8', 'replace'))
+    def add_all_services(self, service_dict):
+        """Update the proxy table from the database.
+
+        Used when loading up a new proxy.
+        """
+        db = inspect(self).session
+        futures = []
+        for orm_service in db.query(Service):
+            service = service_dict[orm_service.name]
+            if service.server:
+                futures.append(self.add_service(service))
+        # wait after submitting them all
+        for f in futures:
+            yield f
 
     @gen.coroutine
     def add_all_users(self, user_dict):
@@ -204,12 +243,18 @@ class Proxy(Base):
             yield f
 
     @gen.coroutine
-    def check_routes(self, user_dict, routes=None):
+    def get_routes(self, client=None):
+        """Fetch the proxy's routes"""
+        resp = yield self.api_request('', client=client)
+        return json.loads(resp.body.decode('utf8', 'replace'))
+
+    @gen.coroutine
+    def check_routes(self, user_dict, service_dict, routes=None):
         """Check that all users are properly routed on the proxy"""
         if not routes:
             routes = yield self.get_routes()
 
-        have_routes = { r['user'] for r in routes.values() if 'user' in r }
+        user_routes = { r['user'] for r in routes.values() if 'user' in r }
         futures = []
         db = inspect(self).session
         for orm_user in db.query(User).filter(User.server != None):
@@ -222,9 +267,22 @@ class Proxy(Base):
                 # catch filter bug, either in sqlalchemy or my understanding of its behavior
                 self.log.error("User %s has no server, but wasn't filtered out.", user)
                 continue
-            if user.name not in have_routes:
+            if user.name not in user_routes:
                 self.log.warning("Adding missing route for %s (%s)", user.name, user.server)
                 futures.append(self.add_user(user))
+        
+        # check service routes
+        service_routes = { r['service'] for r in routes.values() if 'service' in r }
+        for orm_service in db.query(Service).filter(Service.server != None):
+            service = service_dict[orm_service.name]
+            if service.server is None:
+                # This should never be True, but seems to be on rare occasion.
+                # catch filter bug, either in sqlalchemy or my understanding of its behavior
+                self.log.error("Service %s has no server, but wasn't filtered out.", service)
+                continue
+            if service.name not in service_routes:
+                self.log.warning("Adding missing route for %s (%s)", service.name, service.server)
+                futures.append(self.add_service(service))
         for f in futures:
             yield f
 
@@ -351,13 +409,6 @@ class User(Base):
         return db.query(cls).filter(cls.name==name).first()
 
 
-# service:server many:many mapping table
-service_server_map = Table('service_server_map', Base.metadata,
-    Column('service_id', ForeignKey('services.id')),
-    Column('server_id', ForeignKey('servers.id')),
-)
-
-
 class Service(Base):
     """A service run with JupyterHub
 
@@ -369,10 +420,10 @@ class Service(Base):
     - name
     - admin
     - api tokens
+    - server (if proxied http endpoint)
 
     In addition to what it has in common with users, a Service has extra info:
 
-    - servers: list of HTTP endpoints for the service
     - pid: the process id (if managed)
 
     """
@@ -386,7 +437,8 @@ class Service(Base):
     api_tokens = relationship("APIToken", backref="service")
 
     # service-specific interface
-    servers = relationship('Server', secondary='service_server_map')
+    _server_id = Column(Integer, ForeignKey('servers.id'))
+    server = relationship(Server, primaryjoin=_server_id == Server.id)
     pid = Column(Integer)
 
     def new_api_token(self, token=None):
diff --git a/jupyterhub/services/service.py b/jupyterhub/services/service.py
index b4cbe0fa..63b6c17b 100644
--- a/jupyterhub/services/service.py
+++ b/jupyterhub/services/service.py
@@ -50,7 +50,7 @@ from tornado import gen
 from traitlets import (
     HasTraits,
     Any, Bool, Dict, Unicode, Instance,
-    observe,
+    default, observe,
 )
 from traitlets.config import LoggingConfigurable
 
@@ -74,6 +74,7 @@ class _ServiceSpawner(LocalProcessSpawner):
     Removes notebook-specific-ness from LocalProcessSpawner.
     """
     cwd = Unicode()
+    cmd = Command(minlen=0)
     
     def make_preexec_fn(self, name):
         if not name or name == getuser():
@@ -81,7 +82,6 @@ class _ServiceSpawner(LocalProcessSpawner):
             return
         return super().make_preexec_fn(name)
 
-    @gen.coroutine
     def start(self):
         """Start the process"""
         env = self.get_env()
@@ -92,7 +92,7 @@ class _ServiceSpawner(LocalProcessSpawner):
             self.proc = Popen(self.cmd, env=env,
                 preexec_fn=self.make_preexec_fn(self.user.name),
                 start_new_session=True, # don't forward signals
-                cwd=self.cwd,
+                cwd=self.cwd or None,
             )
         except PermissionError:
             # use which to get abspath
@@ -137,47 +137,46 @@ class Service(LoggingConfigurable):
         
         If the service has an http endpoint, it
         """
-    )
+    ).tag(input=True)
     admin = Bool(False,
         help="Does the service need admin-access to the Hub API?"
-    )
+    ).tag(input=True)
     url = Unicode(
         help="""URL of the service.
         
         Only specify if the service runs an HTTP(s) endpoint that.
         If managed, will be passed as JUPYTERHUB_SERVICE_URL env.
         """
-    )
+    ).tag(input=True)
     @observe('url')
     def _url_changed(self, change):
         url = change['new']
         if not url:
             self.orm.server = None
         else:
-            if self.orm.server is None:
-                parsed = urlparse(url)
-                if parsed.port is not None:
-                    port = parsed.port
-                elif parsed.scheme == 'http':
-                    port = 80
-                elif parsed.scheme == 'https':
-                    port = 443
-                server = self.orm.server = orm.Server(
-                    proto=parsed.scheme,
-                    ip=parsed.host,
-                    port=port,
-                    cookie_name='jupyterhub-services',
-                    base_url=self.proxy_path,
-                )
-                self.db.add(server)
-                self.db.commit()
+            parsed = urlparse(url)
+            if parsed.port is not None:
+                port = parsed.port
+            elif parsed.scheme == 'http':
+                port = 80
+            elif parsed.scheme == 'https':
+                port = 443
+            server = self.orm.server = orm.Server(
+                proto=parsed.scheme,
+                ip=parsed.hostname,
+                port=port,
+                cookie_name='jupyterhub-services',
+                base_url=self.proxy_path,
+            )
+            self.db.add(server)
+            self.db.commit()
 
     api_token = Unicode(
         help="""The API token to use for the service.
         
         If unspecified, an API token will be generated for managed services.
         """
-    )
+    ).tag(input=True)
     # Managed service API:
 
     @property
@@ -185,28 +184,37 @@ class Service(LoggingConfigurable):
         """Am I managed by the Hub?"""
         return bool(self.command)
 
-    command = Command(
+    command = Command(minlen=0,
         help="Command to spawn this service, if managed."
-    )
+    ).tag(input=True)
     cwd = Unicode(
         help="""The working directory in which to run the service."""
-    )
+    ).tag(input=True)
     environment = Dict(
         help="""Environment variables to pass to the service.
         Only used if the Hub is spawning the service.
         """
-    )
+    ).tag(input=True)
     user = Unicode(getuser(),
         help="""The user to become when launching the service.
 
         If unspecified, run the service as the same user as the Hub.
         """
-    )
+    ).tag(input=True)
     
     # handles on globals:
     proxy = Any()
     hub = Any()
     base_url = Unicode()
+    db = Any()
+    orm = Any()
+    @default('orm')
+    def _orm_default(self):
+        return self.db.query(orm.Service).filter(orm.Service.name==self.name).first()
+    
+    @property
+    def server(self):
+        return self.orm.server
 
     @property
     def proxy_path(self):
@@ -219,7 +227,6 @@ class Service(LoggingConfigurable):
             managed=' managed' if self.managed else '',
         )
 
-    @gen.coroutine
     def start(self):
         """Start a managed service"""
         if not self.managed:
@@ -233,6 +240,7 @@ class Service(LoggingConfigurable):
         env['JUPYTERHUB_API_URL'] = self.hub_api_url
         env['JUPYTERHUB_BASE_URL'] = self.base_url
         env['JUPYTERHUB_SERVICE_PATH'] = self.proxy_path
+        env['JUPYTERHUB_SERVICE_URL'] = self.url
 
         self.spawner = _ServiceSpawner(
             cmd=self.command,
@@ -245,7 +253,7 @@ class Service(LoggingConfigurable):
                 server=self.orm.server,
             ),
         )
-        yield self.spawner.start()
+        self.spawner.start()
         self.proc = self.spawner.proc
         self.spawner.add_poll_callback(self._proc_stopped)
         self.spawner.start_polling()
@@ -253,7 +261,6 @@ class Service(LoggingConfigurable):
     def _proc_stopped(self):
         """Called when the service process unexpectedly exits"""
         self.log.error("Service %s exited with status %i", self.name, self.proc.returncode)
-        self.proc = None
         self.start()
         
     def stop(self):
diff --git a/jupyterhub/tests/mockservice.py b/jupyterhub/tests/mockservice.py
new file mode 100644
index 00000000..e989c1e5
--- /dev/null
+++ b/jupyterhub/tests/mockservice.py
@@ -0,0 +1,59 @@
+"""Mock service for testing
+
+basic HTTP Server that echos URLs back,
+and allow retrieval of sys.argv.
+"""
+
+import argparse
+import json
+import os
+import sys
+from urllib.parse import urlparse
+
+import requests
+from tornado import web, httpserver, ioloop
+
+
+class EchoHandler(web.RequestHandler):
+    def get(self):
+        self.write(self.request.path)
+
+
+class EnvHandler(web.RequestHandler):
+    def get(self):
+        self.set_header('Content-Type', 'application/json')
+        self.write(json.dumps(dict(os.environ)))
+
+
+class APIHandler(web.RequestHandler):
+    def get(self, path):
+        api_token = os.environ['JUPYTERHUB_API_TOKEN']
+        api_url = os.environ['JUPYTERHUB_API_URL']
+        r = requests.get(api_url + path, headers={
+            'Authorization': 'token %s' % api_token
+        })
+        r.raise_for_status()
+        self.set_header('Content-Type', 'application/json')
+        self.write(r.text)
+
+
+def main():
+    if os.environ['JUPYTERHUB_SERVICE_URL']:
+        url = urlparse(os.environ['JUPYTERHUB_SERVICE_URL'])
+        app = web.Application([
+            (r'.*/env', EnvHandler),
+            (r'.*/api/(.*)', APIHandler),
+            (r'.*', EchoHandler),
+        ])
+
+        server = httpserver.HTTPServer(app)
+        server.listen(url.port, url.hostname)
+    try:
+        ioloop.IOLoop.instance().start()
+    except KeyboardInterrupt:
+        print('\nInterrupted')
+
+if __name__ == '__main__':
+    from tornado.options import parse_command_line
+    parse_command_line()
+    main()
diff --git a/jupyterhub/tests/test_orm.py b/jupyterhub/tests/test_orm.py
index 6a369ad5..182160e4 100644
--- a/jupyterhub/tests/test_orm.py
+++ b/jupyterhub/tests/test_orm.py
@@ -124,19 +124,17 @@ def test_service_tokens(db):
     assert service2.id != service.id
 
 
-def test_service_servers(db):
+def test_service_server(db):
     service = orm.Service(name='has_servers')
     db.add(service)
     db.commit()
     
-    assert service.servers == []
-    servers = service.servers = [
-        orm.Server(),
-        orm.Server(),
-    ]
-    assert [ s.id for s in servers ] == [ None, None ]
+    assert service.server is None
+    server = service.server = orm.Server()
+    assert service
+    assert server.id is None
     db.commit()
-    assert [ type(s.id) for s in servers ] == [ int, int ]
+    assert isinstance(server.id, int)
     
 
 def test_token_find(db):
diff --git a/jupyterhub/tests/test_proxy.py b/jupyterhub/tests/test_proxy.py
index 07e389a8..4ce1c1ef 100644
--- a/jupyterhub/tests/test_proxy.py
+++ b/jupyterhub/tests/test_proxy.py
@@ -137,11 +137,11 @@ def test_check_routes(app, io_loop):
     zoe = app.users[zoe]
     before = sorted(io_loop.run_sync(app.proxy.get_routes))
     assert unquote(zoe.proxy_path) in before
-    io_loop.run_sync(lambda : app.proxy.check_routes(app.users))
+    io_loop.run_sync(lambda : app.proxy.check_routes(app.users, app._service_map))
     io_loop.run_sync(lambda : proxy.delete_user(zoe))
     during = sorted(io_loop.run_sync(app.proxy.get_routes))
     assert unquote(zoe.proxy_path) not in during
-    io_loop.run_sync(lambda : app.proxy.check_routes(app.users))
+    io_loop.run_sync(lambda : app.proxy.check_routes(app.users, app._service_map))
     after = sorted(io_loop.run_sync(app.proxy.get_routes))
     assert unquote(zoe.proxy_path) in after
     assert before == after
diff --git a/jupyterhub/tests/test_services.py b/jupyterhub/tests/test_services.py
new file mode 100644
index 00000000..84f67b20
--- /dev/null
+++ b/jupyterhub/tests/test_services.py
@@ -0,0 +1,137 @@
+"""Tests for services"""
+
+from binascii import hexlify
+from contextlib import contextmanager
+import os
+from subprocess import Popen, TimeoutExpired
+import sys
+from threading import Event
+import time
+try:
+    from unittest import mock
+except ImportError:
+    import mock
+from urllib.parse import unquote
+
+import pytest
+from tornado import gen
+from tornado.ioloop import IOLoop
+
+
+import jupyterhub.services.service
+from .test_pages import get_page
+from ..utils import url_path_join, wait_for_http_server
+
+here = os.path.dirname(os.path.abspath(__file__))
+mockservice_py = os.path.join(here, 'mockservice.py')
+mockservice_cmd = [sys.executable, mockservice_py]
+
+from ..utils import random_port
+
+@contextmanager
+def external_service(app, name='mockservice'):
+    env = {
+        'JUPYTERHUB_API_TOKEN': hexlify(os.urandom(5)),
+        'JUPYTERHUB_SERVICE_NAME': name,
+        'JUPYTERHUB_API_URL': url_path_join(app.hub.server.url, 'api/'),
+        'JUPYTERHUB_SERVICE_URL': 'http://127.0.0.1:%i' % random_port(),
+    }
+    p = Popen(mockservice_cmd, env=env)
+    IOLoop().run_sync(lambda : wait_for_http_server(env['JUPYTERHUB_SERVICE_URL']))
+    try:
+        yield env
+    finally:
+        p.terminate()
+
+
+# mock services for testing.
+# Shorter intervals, etc.
+class MockServiceSpawner(jupyterhub.services.service._ServiceSpawner):
+    poll_interval = 1
+
+@pytest.yield_fixture
+def mockservice(request, app):
+    name = 'mock-service'
+    with mock.patch.object(jupyterhub.services.service, '_ServiceSpawner', MockServiceSpawner):
+        app.services = [{
+            'name': name,
+            'command': mockservice_cmd,
+            'url': 'http://127.0.0.1:%i' % random_port(),
+            'admin': True,
+        }]
+        app.init_services()
+        app.io_loop.add_callback(app.proxy.add_all_services, app._service_map)
+        assert name in app._service_map
+        service = app._service_map[name]
+        app.io_loop.add_callback(service.start)
+        request.addfinalizer(service.stop)
+        for i in range(20):
+            if not getattr(service, 'proc', False):
+                time.sleep(0.2)
+        # ensure process finishes starting
+        with pytest.raises(TimeoutExpired):
+            service.proc.wait(1)
+        yield service
+
+
+def test_managed_service(app, mockservice):
+    service = mockservice
+    proc = service.proc
+    first_pid = proc.pid
+    assert proc.poll() is None
+    # shut it down:
+    proc.terminate()
+    proc.wait(10)
+    assert proc.poll() is not None
+    # ensure Hub notices and brings it back up:
+    for i in range(20):
+        if service.proc is not proc:
+            break
+        else:
+            time.sleep(0.2)
+    
+    assert service.proc.pid != first_pid
+    assert service.proc.poll() is None
+
+
+def test_proxy_service(app, mockservice, io_loop):
+    name = mockservice.name
+    routes = io_loop.run_sync(app.proxy.get_routes)
+    assert unquote(mockservice.proxy_path) in routes
+    io_loop.run_sync(mockservice.server.wait_up)
+    path = '/services/{}/foo'.format(name)
+    r = get_page(path, app, hub=False, allow_redirects=False)
+    r.raise_for_status()
+    assert r.status_code == 200
+    assert r.text.endswith(path)
+
+
+@pytest.mark.now
+def test_external_service(app, io_loop):
+    name = 'external'
+    with external_service(app, name=name) as env:
+        app.services = [{
+            'name': name,
+            'admin': True,
+            'url': env['JUPYTERHUB_SERVICE_URL'],
+            'api_token': env['JUPYTERHUB_API_TOKEN'],
+        }]
+        app.init_services()
+        app.init_api_tokens()
+        evt = Event()
+        @gen.coroutine
+        def add_services():
+            yield app.proxy.add_all_services(app._service_map)
+            evt.set()
+        app.io_loop.add_callback(add_services)
+        assert evt.wait(10)
+        path = '/services/{}/api/users'.format(name)
+        r = get_page(path, app, hub=False, allow_redirects=False)
+        print(r.headers, r.status_code)
+        r.raise_for_status()
+        assert r.status_code == 200
+        resp = r.json()
+        assert isinstance(resp, list)
+        assert len(resp) >= 1
+        assert isinstance(resp[0], dict)
+        assert 'name' in resp[0]