diff --git a/docs/CONFIGURATION.rst b/docs/CONFIGURATION.rst
index aa53776..dfe518d 100644
--- a/docs/CONFIGURATION.rst
+++ b/docs/CONFIGURATION.rst
@@ -36,6 +36,7 @@ session key and hostname. Here are the default values for this section:
     host = http://localhost:8080/
     max-age = 15m
     session-key = ... # python: binascii.b2a_hex(os.urandom(24))
+    notify =
 
 dbpath
     file location to the SQLite3 database, highly recommended to change this
@@ -67,6 +68,10 @@ max-age
     time range that allows users to edit/remove their own comments. See
     :ref:`Appendum: Timedelta <appendum-timedelta>` for valid values.
 
+notify
+    Select notification backend for new comments. Currently, only SMTP
+    is available.
+
 
 Moderation
 ----------
@@ -131,8 +136,8 @@ SMTP
 ----
 
 Isso can notify you on new comments via SMTP. In the email notification, you
-also can moderate comments. If the server connection fails during startup, a
-null mailer is used.
+also can moderate (=activate or delete) comments. Don't forget to configure
+``notify = smtp`` in the general section.
 
 .. code-block:: ini
 
diff --git a/isso/__init__.py b/isso/__init__.py
index 58614f6..e918a25 100644
--- a/isso/__init__.py
+++ b/isso/__init__.py
@@ -46,21 +46,26 @@ import logging
 from os.path import dirname, join
 from argparse import ArgumentParser
 
-import misaka
 from itsdangerous import URLSafeTimedSerializer
 
-from werkzeug.routing import Map, Rule
+from werkzeug.routing import Map
 from werkzeug.exceptions import HTTPException, InternalServerError
 
 from werkzeug.wsgi import SharedDataMiddleware
+from werkzeug.local import Local, LocalManager
 from werkzeug.serving import run_simple, WSGIRequestHandler
 from werkzeug.contrib.fixers import ProxyFix
 
-from isso import db, migrate, wsgi
+local = Local()
+local_manager = LocalManager([local])
+
+from isso import db, migrate, wsgi, ext
 from isso.core import ThreadedMixin, uWSGIMixin, Config
-from isso.utils import parse, http, JSONRequest
+from isso.utils import parse, http, JSONRequest, origin
 from isso.views import comments
 
+from isso.ext.notifications import Stdout, SMTP
+
 logging.getLogger('werkzeug').setLevel(logging.ERROR)
 logging.basicConfig(
     level=logging.INFO,
@@ -72,20 +77,6 @@ logger = logging.getLogger("isso")
 class Isso(object):
 
     salt = b"Eech7co8Ohloopo9Ol6baimi"
-    urls = Map([
-        Rule('/new', methods=['POST'], endpoint=comments.new),
-
-        Rule('/id/<int:id>', methods=['GET', 'PUT', 'DELETE'], endpoint=comments.single),
-        Rule('/id/<int:id>/like', methods=['POST'], endpoint=comments.like),
-        Rule('/id/<int:id>/dislike', methods=['POST'], endpoint=comments.dislike),
-
-        Rule('/', methods=['GET'], endpoint=comments.fetch),
-        Rule('/count', methods=['GET'], endpoint=comments.count),
-        Rule('/delete/<string:auth>', endpoint=comments.delete),
-        Rule('/activate/<string:auth>', endpoint=comments.activate),
-
-        Rule('/check-ip', endpoint=comments.checkip)
-    ])
 
     def __init__(self, conf):
 
@@ -95,19 +86,30 @@ class Isso(object):
 
         super(Isso, self).__init__(conf)
 
+        subscribers = []
+        subscribers.append(Stdout(None))
+
+        if conf.get("general", "notify") == "smtp":
+            subscribers.append(SMTP(self))
+
+        self.signal = ext.Signal(*subscribers)
+
+        self.urls = Map()
+        self.api = comments.API(self)
+
     def sign(self, obj):
         return self.signer.dumps(obj)
 
     def unsign(self, obj, max_age=None):
         return self.signer.loads(obj, max_age=max_age or self.conf.getint('general', 'max-age'))
 
-    def markdown(self, text):
-        return misaka.html(text, extensions=misaka.EXT_STRIKETHROUGH
-            | misaka.EXT_SUPERSCRIPT | misaka.EXT_AUTOLINK
-            | misaka.HTML_SKIP_HTML  | misaka.HTML_SKIP_IMAGES | misaka.HTML_SAFELINK)
-
     def dispatch(self, request):
-        adapter = Isso.urls.bind_to_environ(request.environ)
+        local.request = request
+
+        local.host = wsgi.host(request.environ)
+        local.origin = origin(self.conf.getiter("general", "host"))(request.environ)
+
+        adapter = self.urls.bind_to_environ(request.environ)
 
         try:
             handler, values = adapter.match()
@@ -115,7 +117,7 @@ class Isso(object):
             return e
         else:
             try:
-                response = handler(self, request.environ, request, **values)
+                response = handler(request.environ, request, **values)
             except HTTPException as e:
                 return e
             except Exception:
@@ -125,7 +127,6 @@ class Isso(object):
                 return response
 
     def wsgi_app(self, environ, start_response):
-
         response = self.dispatch(JSONRequest(environ))
         return response(environ, start_response)
 
@@ -164,10 +165,11 @@ def make_app(conf=None):
             wsgi.SubURI(
                 wsgi.CORSMiddleware(
                     SharedDataMiddleware(
-                        ProfilerMiddleware(isso), {
-                            '/js': join(dirname(__file__), 'js/'),
-                            '/css': join(dirname(__file__), 'css/')}),
-                    list(isso.conf.getiter("general", "host")))))
+                        ProfilerMiddleware(
+                            local_manager.make_middleware(isso)), {
+                        '/js': join(dirname(__file__), 'js/'),
+                        '/css': join(dirname(__file__), 'css/')}),
+                    origin(isso.conf.getiter("general", "host")))))
 
     return app
 
diff --git a/isso/core.py b/isso/core.py
index 3157966..efa59d8 100644
--- a/isso/core.py
+++ b/isso/core.py
@@ -9,9 +9,6 @@ import binascii
 import threading
 import logging
 
-import socket
-import smtplib
-
 from configparser import ConfigParser
 
 try:
@@ -26,7 +23,6 @@ if PY2K:
 else:
     import _thread as thread
 
-from isso import notify
 from isso.utils import parse
 from isso.compat import text_type as str
 
@@ -35,6 +31,25 @@ from werkzeug.contrib.cache import NullCache, SimpleCache
 logger = logging.getLogger("isso")
 
 
+class Section:
+
+    def __init__(self, conf, section):
+        self.conf = conf
+        self.section = section
+
+    def get(self, key):
+        return self.conf.get(self.section, key)
+
+    def getint(self, key):
+        return self.conf.getint(self.section, key)
+
+    def getiter(self, key):
+        return self.conf.getiter(self.section, key)
+
+    def getboolean(self, key):
+        return self.conf.getboolean(self.section, key)
+
+
 class IssoParser(ConfigParser):
     """
     Extended :class:`ConfigParser` to parse human-readable timedeltas
@@ -81,6 +96,9 @@ class IssoParser(ConfigParser):
             if item:
                 yield item
 
+    def section(self, section):
+        return Section(self, section)
+
 
 class Config:
 
@@ -88,6 +106,7 @@ class Config:
         "[general]",
         "dbpath = /tmp/isso.db", "session-key = %r" % binascii.b2a_hex(os.urandom(24)),
         "host = http://localhost:8080/", "max-age = 15m",
+        "notify = ",
         "[moderation]",
         "enabled = false",
         "purge-after = 30d",
@@ -128,18 +147,6 @@ class Config:
         return rv
 
 
-def SMTP(conf):
-
-    try:
-        mailer = notify.SMTPMailer(conf)
-        logger.info("connected to SMTP server")
-    except (socket.error, smtplib.SMTPException):
-        logger.warn("unable to connect to SMTP server")
-        mailer = notify.NullMailer()
-
-    return mailer
-
-
 class Cache:
     """Wrapper around werkzeug's cache class, to make it compatible to
     uWSGI's cache framework.
@@ -188,20 +195,8 @@ class ThreadedMixin(Mixin):
         if conf.getboolean("moderation", "enabled"):
             self.purge(conf.getint("moderation", "purge-after"))
 
-        self.mailer = SMTP(conf)
         self.cache = Cache(SimpleCache(threshold=1024, default_timeout=3600))
 
-    @threaded
-    def notify(self, subject, body, retries=5):
-
-        for x in range(retries):
-            try:
-                self.mailer.sendmail(subject, body)
-            except Exception:
-                time.sleep(60)
-            else:
-                break
-
     @threaded
     def purge(self, delta):
         while True:
@@ -246,18 +241,7 @@ class uWSGIMixin(Mixin):
             def __exit__(self, exc_type, exc_val, exc_tb):
                 uwsgi.unlock()
 
-        def spooler(args):
-            try:
-                self.mailer.sendmail(args["subject"].decode('utf-8'), args["body"].decode('utf-8'))
-            except smtplib.SMTPConnectError:
-                return uwsgi.SPOOL_RETRY
-            else:
-                return uwsgi.SPOOL_OK
-
-        uwsgi.spooler = spooler
-
         self.lock = Lock()
-        self.mailer = SMTP(conf)
         self.cache = uWSGICache
 
         timedelta = conf.getint("moderation", "purge-after")
@@ -267,6 +251,3 @@ class uWSGIMixin(Mixin):
 
         # run purge once
         purge(1)
-
-    def notify(self, subject, body, retries=5):
-        uwsgi.spool({"subject": subject.encode('utf-8'), "body": body.encode('utf-8')})
diff --git a/isso/db/threads.py b/isso/db/threads.py
index 236ae2f..bb7067b 100644
--- a/isso/db/threads.py
+++ b/isso/db/threads.py
@@ -1,12 +1,12 @@
 # -*- encoding: utf-8 -*-
 
 
-class Thread(object):
-
-    def __init__(self, id, uri, title):
-        self.id = id
-        self.uri = uri
-        self.title = title
+def Thread(id, uri, title):
+    return {
+        "id": id,
+        "uri": uri,
+        "title": title
+    }
 
 
 class Threads(object):
@@ -27,3 +27,4 @@ class Threads(object):
 
     def new(self, uri, title):
         self.db.execute("INSERT INTO threads (uri, title) VALUES (?, ?)", (uri, title))
+        return self[uri]
diff --git a/isso/ext/__init__.py b/isso/ext/__init__.py
new file mode 100644
index 0000000..59a40e1
--- /dev/null
+++ b/isso/ext/__init__.py
@@ -0,0 +1,17 @@
+# -*- encoding: utf-8 -*-
+
+from collections import defaultdict
+
+
+class Signal(object):
+
+    def __init__(self, *subscriber):
+        self.subscriptions = defaultdict(list)
+
+        for sub in subscriber:
+            for signal, func in sub:
+                self.subscriptions[signal].append(func)
+
+    def __call__(self, origin, *args, **kwargs):
+        for subscriber in self.subscriptions[origin]:
+            subscriber(*args, **kwargs)
diff --git a/isso/ext/notifications.py b/isso/ext/notifications.py
new file mode 100644
index 0000000..49590d4
--- /dev/null
+++ b/isso/ext/notifications.py
@@ -0,0 +1,160 @@
+# -*- encoding: utf-8 -*-
+
+from __future__ import unicode_literals
+
+import time
+import json
+
+import socket
+import smtplib
+
+from email.header import Header
+from email.mime.text import MIMEText
+
+import logging
+logger = logging.getLogger("isso")
+
+try:
+    import uwsgi
+except ImportError:
+    uwsgi = None
+
+from isso.compat import PY2K
+from isso import local
+
+if PY2K:
+    from thread import start_new_thread
+else:
+    from _thread import start_new_thread
+
+
+class SMTP(object):
+
+    def __init__(self, isso):
+
+        self.isso = isso
+        self.conf = isso.conf.section("smtp")
+
+        # test SMTP connectivity
+        try:
+            with self:
+                logger.info("connected to SMTP server")
+        except (socket.error, smtplib.SMTPException):
+            logger.warn("unable to connect to SMTP server")
+
+        if uwsgi:
+            def spooler(args):
+                try:
+                    self._sendmail(args["subject"].decode("utf-8"),
+                                   args["body"].decode("utf-8"))
+                except smtplib.SMTPConnectError:
+                    return uwsgi.SPOOL_RETRY
+                else:
+                    return uwsgi.SPOOL_OK
+
+            uwsgi.spooler = spooler
+
+    def __enter__(self):
+        klass = (smtplib.SMTP_SSL if self.conf.getboolean('ssl') else smtplib.SMTP)
+        self.client = klass(host=self.conf.get('host'), port=self.conf.getint('port'))
+
+        if self.conf.get('username') and self.conf.get('password'):
+            self.client.login(self.conf.get('username'),
+                              self.conf.get('password'))
+
+        return self.client
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.client.quit()
+
+    def __iter__(self):
+        yield "comments.new:after-save", self.notify
+
+    def format(self, thread, comment):
+
+        permalink = local("origin") + thread["uri"] + "#isso-%i" % comment["id"]
+
+        rv = []
+        rv.append("%s schrieb:" % (comment["author"] or "Jemand"))
+        rv.append("")
+        rv.append(comment["text"])
+        rv.append("")
+
+        if comment["website"]:
+            rv.append("Webseite des Kommentators: %s" % comment["website"])
+
+        rv.append("IP Adresse: %s" % comment["remote_addr"])
+        rv.append("Link zum Kommentar: %s" % permalink)
+        rv.append("")
+
+        uri = local("host") + "/id/%i" % comment["id"]
+        key = self.isso.sign(comment["id"])
+
+        rv.append("---")
+        rv.append("Kommentar löschen: %s" % uri + "/delete/" + key)
+
+        if comment["mode"] == 2:
+            rv.append("Kommentar freischalten: %s" % uri + "/activate/" + key)
+
+        return u'\n'.join(rv)
+
+    def notify(self, thread, comment):
+
+        body = self.format(thread, comment)
+
+        if uwsgi:
+            uwsgi.spool({b"subject": thread["title"].encode("utf-8"),
+                         b"body": body.encode("utf-8")})
+        else:
+            start_new_thread(self._retry, (thread["title"], body))
+
+    def _sendmail(self, subject, body):
+
+        from_addr = self.conf.get("from")
+        to_addr = self.conf.get("to")
+
+        msg = MIMEText(body, 'plain', 'utf-8')
+        msg['From'] = "Ich schrei sonst! <%s>" % from_addr
+        msg['To'] = to_addr
+        msg['Subject'] = Header(subject, 'utf-8')
+
+        with self as con:
+            con.sendmail(from_addr, to_addr, msg.as_string())
+
+    def _retry(self, subject, body):
+        for x in range(5):
+            try:
+                self._sendmail(subject, body)
+            except smtplib.SMTPConnectError:
+                time.sleep(60)
+            else:
+                break
+
+
+class Stdout(object):
+
+    def __init__(self, conf):
+        pass
+
+    def __iter__(self):
+
+        yield "comments.new:new-thread", self._new_thread
+        yield "comments.new:finish", self._new_comment
+        yield "comments.edit", self._edit_comment
+        yield "comments.delete", self._delete_comment
+        yield "comments.activate", self._activate_comment
+
+    def _new_thread(self, thread):
+        logger.info("new thread %(id)s: %(title)s" % thread)
+
+    def _new_comment(self, thread, comment):
+        logger.info("comment created: %s", json.dumps(comment))
+
+    def _edit_comment(self, comment):
+        logger.info('comment %i edited: %s', comment["id"], json.dumps(comment))
+
+    def _delete_comment(self, id):
+        logger.info('comment %i deleted', id)
+
+    def _activate_comment(self, id):
+        logger.info("comment %s activated" % id)
diff --git a/isso/notify.py b/isso/notify.py
deleted file mode 100644
index a4b775e..0000000
--- a/isso/notify.py
+++ /dev/null
@@ -1,83 +0,0 @@
-# -*- encoding: utf-8 -*-
-
-from __future__ import unicode_literals
-
-from smtplib import SMTP, SMTP_SSL
-from email.header import Header
-from email.mime.text import MIMEText
-
-
-def format(comment, permalink, remote_addr, deletion_key, activation_key=None):
-
-    rv = []
-    rv.append("%s schrieb:" % (comment["author"] or "Jemand"))
-    rv.append("")
-    rv.append(comment["text"])
-    rv.append("")
-
-    if comment["website"]:
-        rv.append("Webseite des Kommentators: %s" % comment["website"])
-
-    rv.append("IP Adresse: %s" % remote_addr)
-    rv.append("Link zum Kommentar: %s" % permalink)
-
-    rv.append("")
-    rv.append("---")
-    rv.append("Kommentar löschen: %s" % deletion_key)
-
-    if activation_key:
-        rv.append("Kommentar freischalten: %s" % activation_key)
-
-    return u'\n'.join(rv)
-
-
-class Connection(object):
-    """
-    Establish connection to SMTP server, optional with authentication, and
-    close connection afterwards.
-    """
-
-    def __init__(self, conf):
-        self.conf = conf
-
-    def __enter__(self):
-        self.server = (SMTP_SSL if self.conf.getboolean('smtp', 'ssl') else SMTP)(
-            host=self.conf.get('smtp', 'host'), port=self.conf.getint('smtp', 'port'))
-
-        if self.conf.get('smtp', 'username') and self.conf.get('smtp', 'password'):
-            self.server.login(self.conf.get('smtp', 'username'),
-                              self.conf.get('smtp', 'password'))
-
-        return self.server
-
-    def __exit__(self, exc_type, exc_value, traceback):
-        self.server.quit()
-
-
-class SMTPMailer(object):
-
-    def __init__(self, conf):
-
-        self.conf = conf
-        self.from_addr = conf.get('smtp', 'from')
-        self.to_addr = conf.get('smtp', 'to')
-
-        # test SMTP connectivity
-        with Connection(self.conf):
-            pass
-
-    def sendmail(self, subject, body):
-
-        msg = MIMEText(body, 'plain', 'utf-8')
-        msg['From'] = "Ich schrei sonst! <%s>" % self.from_addr
-        msg['To'] = self.to_addr
-        msg['Subject'] = Header(subject, 'utf-8')
-
-        with Connection(self.conf) as con:
-            con.sendmail(self.from_addr, self.to_addr, msg.as_string())
-
-
-class NullMailer(object):
-
-    def sendmail(self, subject, body):
-        pass
diff --git a/isso/utils/__init__.py b/isso/utils/__init__.py
index de3be2b..4115bf1 100644
--- a/isso/utils/__init__.py
+++ b/isso/utils/__init__.py
@@ -14,6 +14,7 @@ from string import ascii_letters, digits
 from werkzeug.wrappers import Request
 from werkzeug.exceptions import BadRequest
 
+import misaka
 import ipaddress
 
 
@@ -103,3 +104,23 @@ class JSONRequest(Request):
             return json.loads(self.get_data(as_text=True))
         except ValueError:
             raise BadRequest('Unable to read JSON request')
+
+
+def markdown(text):
+    return misaka.html(text, extensions= misaka.EXT_STRIKETHROUGH
+        | misaka.EXT_SUPERSCRIPT | misaka.EXT_AUTOLINK
+        | misaka.HTML_SKIP_HTML  | misaka.HTML_SKIP_IMAGES | misaka.HTML_SAFELINK)
+
+
+def origin(hosts):
+
+    hosts = [x.rstrip("/") for x in hosts]
+
+    def func(environ):
+        for host in hosts:
+            if environ.get("HTTP_ORIGIN", None) == host:
+                return host
+        else:
+            return hosts[0]
+
+    return func
diff --git a/isso/crypto.py b/isso/utils/crypto.py
similarity index 100%
rename from isso/crypto.py
rename to isso/utils/crypto.py
diff --git a/isso/views/__init__.py b/isso/views/__init__.py
index 6031793..50cedfa 100644
--- a/isso/views/__init__.py
+++ b/isso/views/__init__.py
@@ -20,7 +20,7 @@ class requires:
         self.type = type
 
     def __call__(self, func):
-        def dec(app, env, req, *args, **kwargs):
+        def dec(cls, env, req, *args, **kwargs):
 
             if self.param not in req.args:
                 raise BadRequest("missing %s query" % self.param)
@@ -30,6 +30,6 @@ class requires:
             except TypeError:
                 raise BadRequest("invalid type for %s, expected %s" % (self.param, self.type))
 
-            return func(app, env, req, *args, **kwargs)
+            return func(cls, env, req, *args, **kwargs)
 
         return dec
diff --git a/isso/views/comments.py b/isso/views/comments.py
index 52a3f9c..4af9c8e 100644
--- a/isso/views/comments.py
+++ b/isso/views/comments.py
@@ -4,141 +4,186 @@ import cgi
 import json
 import time
 import hashlib
-import logging
 import functools
 
 from itsdangerous import SignatureExpired, BadSignature
 
 from werkzeug.http import dump_cookie
+from werkzeug.routing import Rule
 from werkzeug.wrappers import Response
 from werkzeug.exceptions import BadRequest, Forbidden, NotFound
 
 from isso.compat import text_type as str
 
-from isso import utils, notify, db
-from isso.utils import http, parse
+from isso import utils, local
+from isso.utils import http, parse, markdown
+from isso.utils.crypto import pbkdf2
 from isso.views import requires
-from isso.crypto import pbkdf2
 
-logger = logging.getLogger("isso")
 
-FIELDS = set(['id', 'parent', 'text', 'author', 'website', 'email', 'mode',
-              'created', 'modified', 'likes', 'dislikes', 'hash'])
+def md5(text):
+    return hashlib.md5(text.encode('utf-8')).hexdigest()
 
 
-@requires(str, 'uri')
-def new(app, environ, request, uri):
+class JSON(Response):
 
-    data = request.get_json()
+    def __init__(self, *args):
+        return super(JSON, self).__init__(*args, content_type='application/json')
 
-    for field in set(data.keys()) - set(['text', 'author', 'website', 'email', 'parent']):
-        data.pop(field)
 
-    if "text" not in data or data["text"] is None or len(data["text"]) < 3:
-        raise BadRequest("no text given")
+class API(object):
 
-    if "id" in data and not isinstance(data["id"], int):
-        raise BadRequest("parent id must be an integer")
+    FIELDS = set(['id', 'parent', 'text', 'author', 'website', 'email',
+                  'mode', 'created', 'modified', 'likes', 'dislikes', 'hash'])
 
-    if len(data.get("email") or "") > 254:
-        raise BadRequest("http://tools.ietf.org/html/rfc5321#section-4.5.3")
+    # comment fields, that can be submitted
+    ACCEPT = set(['text', 'author', 'website', 'email', 'parent'])
 
-    for field in ("author", "email"):
-        if data.get(field):
-            data[field] = cgi.escape(data[field])
+    VIEWS = [
+        ('fetch',   ('GET', '/')),
+        ('new',     ('POST', '/new')),
+        ('count',   ('GET', '/count')),
+        ('view',    ('GET', '/id/<int:id>')),
+        ('edit',    ('PUT', '/id/<int:id>')),
+        ('delete',  ('DELETE', '/id/<int:id>')),
+        ('delete',  ('GET', '/id/<int:id>/delete/<string:key>')),
+        ('like',    ('POST', '/id/<int:id>/like')),
+        ('dislike', ('POST', '/id/<int:id>/dislike')),
+        ('checkip', ('GET', '/check-ip'))
+    ]
 
-    data['mode'] = (app.conf.getboolean('moderation', 'enabled') and 2) or 1
-    data['remote_addr'] = utils.anonymize(str(request.remote_addr))
+    def __init__(self, isso):
 
-    with app.lock:
-        if uri not in app.db.threads:
-            for host in app.conf.getiter('general', 'host'):
-                with http.curl('GET', host, uri) as resp:
-                    if resp and resp.status == 200:
-                        title = parse.title(resp.read())
-                        break
-            else:
-                return Response('URI does not exist', 404)
+        self.isso = isso
+        self.cache = isso.cache
+        self.signal = isso.signal
 
-            app.db.threads.new(uri, title)
-            logger.info('new thread: %s -> %s', uri, title)
-        else:
-            title = app.db.threads[uri].title
+        self.conf = isso.conf.section("general")
+        self.moderated = isso.conf.getboolean("moderation", "enabled")
 
-    try:
-        with app.lock:
-            rv = app.db.comments.add(uri, data)
-    except db.IssoDBException:
-        raise Forbidden
+        self.threads = isso.db.threads
+        self.comments = isso.db.comments
 
-    host = list(app.conf.getiter('general', 'host'))[0].rstrip("/")
-    href = host + uri + "#isso-%i" % rv["id"]
+        for (view, (method, path)) in self.VIEWS:
+            isso.urls.add(
+                Rule(path, methods=[method], endpoint=getattr(self, view)))
 
-    deletion = host + environ["SCRIPT_NAME"] + "/delete/" + app.sign(str(rv["id"]))
-    activation = None
+    @classmethod
+    def verify(cls, comment):
 
-    if app.conf.getboolean('moderation', 'enabled'):
-        activation = host + environ["SCRIPT_NAME"] + "/activate/" + app.sign(str(rv["id"]))
+        if "text" not in comment:
+            return False, "text is missing"
 
-    app.notify(title, notify.format(rv, href, utils.anonymize(str(request.remote_addr)),
-                                    activation_key=activation, deletion_key=deletion))
+        if not isinstance(comment.get("parent"), (int, type(None))):
+            return False, "parent must be an integer or null"
 
-    # save checksum of text into cookie, so mallory can't modify/delete a comment, if
-    # he add a comment, then removed it but not the signed cookie.
-    checksum = hashlib.md5(rv["text"].encode('utf-8')).hexdigest()
+        for key in ("text", "author", "website", "email"):
+            if not isinstance(comment.get(key), (str, type(None))):
+                return False, "%s must be a string or null" % key
 
-    rv["text"] = app.markdown(rv["text"])
-    rv["hash"] = str(pbkdf2(rv['email'] or rv['remote_addr'], app.salt, 1000, 6))
+        if len(comment["text"]) < 3:
+            return False, "text is too short (minimum length: 3)"
 
-    app.cache.set('hash', (rv['email'] or rv['remote_addr']).encode('utf-8'), rv['hash'])
+        if len(comment.get("email") or "") > 254:
+            return False, "http://tools.ietf.org/html/rfc5321#section-4.5.3"
+
+        return True, ""
+
+    @requires(str, 'uri')
+    def new(self, environ, request, uri):
+
+        data = request.get_json()
 
-    for key in set(rv.keys()) - FIELDS:
-        rv.pop(key)
+        for field in set(data.keys()) - API.ACCEPT:
+            data.pop(field)
 
-    # success!
-    logger.info('comment created: %s', json.dumps(rv))
+        for key in ("author", "email", "website", "parent"):
+            data.setdefault(key, None)
 
-    cookie = functools.partial(dump_cookie,
-        value=app.sign([rv["id"], checksum]),
-        max_age=app.conf.getint('general', 'max-age'))
+        valid, reason = API.verify(data)
+        if not valid:
+            return BadRequest(reason)
+
+        for field in ("author", "email"):
+            if data.get(field) is not None:
+                data[field] = cgi.escape(data[field])
+
+        data['mode'] = 2 if self.moderated else 1
+        data['remote_addr'] = utils.anonymize(str(request.remote_addr))
+
+        with self.isso.lock:
+            if uri not in self.threads:
+                with http.curl('GET', local("origin"), uri) as resp:
+                    if resp and resp.status == 200:
+                        title = parse.title(resp.read())
+                    else:
+                        return NotFound('URI does not exist')
+
+                thread = self.threads.new(uri, title)
+                self.signal("comments.new:new-thread", thread)
+            else:
+                thread = self.threads[uri]
 
-    resp = Response(json.dumps(rv), 202 if rv["mode"] == 2 else 201, content_type='application/json')
-    resp.headers.add("Set-Cookie", cookie(str(rv["id"])))
-    resp.headers.add("X-Set-Cookie", cookie("isso-%i" % rv["id"]))
-    return resp
+        # notify extensions that the new comment is about to save
+        self.signal("comments.new:before-save", thread, data)
 
+        if data is None:
+            raise Forbidden
+
+        with self.isso.lock:
+            rv = self.comments.add(uri, data)
+
+        # notify extension, that the new comment has been successfully saved
+        self.signal("comments.new:after-save", thread, rv)
+
+        cookie = functools.partial(dump_cookie,
+            value=self.isso.sign([rv["id"], md5(rv["text"])]),
+            max_age=self.conf.getint('max-age'))
+
+        rv["text"] = markdown(rv["text"])
+        rv["hash"] = str(pbkdf2(rv['email'] or rv['remote_addr'], self.isso.salt, 1000, 6))
+
+        self.cache.set('hash', (rv['email'] or rv['remote_addr']).encode('utf-8'), rv['hash'])
+
+        for key in set(rv.keys()) - API.FIELDS:
+            rv.pop(key)
+
+        # success!
+        self.signal("comments.new:finish", thread, rv)
+
+        resp = JSON(json.dumps(rv), 202 if rv["mode"] == 2 else 201)
+        resp.headers.add("Set-Cookie", cookie(str(rv["id"])))
+        resp.headers.add("X-Set-Cookie", cookie("isso-%i" % rv["id"]))
+        return resp
 
-def single(app, environ, request, id):
+    def view(self, environ, request, id):
 
-    if request.method == 'GET':
-        rv = app.db.comments.get(id)
+        rv = self.comments.get(id)
         if rv is None:
             raise NotFound
 
-        for key in set(rv.keys()) - FIELDS:
+        for key in set(rv.keys()) - API.FIELDS:
             rv.pop(key)
 
         if request.args.get('plain', '0') == '0':
-            rv['text'] = app.markdown(rv['text'])
+            rv['text'] = markdown(rv['text'])
 
         return Response(json.dumps(rv), 200, content_type='application/json')
 
-    try:
-        rv = app.unsign(request.cookies.get(str(id), ''))
-    except (SignatureExpired, BadSignature):
+    def edit(self, environ, request, id):
+
         try:
-            rv = app.unsign(request.cookies.get('admin', ''))
+            rv = self.isso.unsign(request.cookies.get(str(id), ''))
         except (SignatureExpired, BadSignature):
             raise Forbidden
 
-    if rv[0] != id:
-        raise Forbidden
+        if rv[0] != id:
+            raise Forbidden
 
-    # verify checksum, mallory might skip cookie deletion when he deletes a comment
-    if rv[1] != hashlib.md5(app.db.comments.get(id)["text"].encode('utf-8')).hexdigest():
-        raise Forbidden
+        # verify checksum, mallory might skip cookie deletion when he deletes a comment
+        if rv[1] != md5(self.comments.get(id)["text"]):
+            raise Forbidden
 
-    if request.method == 'PUT':
         data = request.get_json()
 
         if "text" not in data or data["text"] is None or len(data["text"]) < 3:
@@ -149,123 +194,121 @@ def single(app, environ, request, id):
 
         data['modified'] = time.time()
 
-        with app.lock:
-            rv = app.db.comments.update(id, data)
+        with self.isso.lock:
+            rv = self.comments.update(id, data)
 
-        for key in set(rv.keys()) - FIELDS:
+        for key in set(rv.keys()) - API.FIELDS:
             rv.pop(key)
 
-        logger.info('comment %i edited: %s', id, json.dumps(rv))
-
-        checksum = hashlib.md5(rv["text"].encode('utf-8')).hexdigest()
-        rv["text"] = app.markdown(rv["text"])
+        self.signal("comments.edit", rv)
 
         cookie = functools.partial(dump_cookie,
-                value=app.sign([rv["id"], checksum]),
-                max_age=app.conf.getint('general', 'max-age'))
+                value=self.isso.sign([rv["id"], md5(rv["text"])]),
+                max_age=self.conf.getint('max-age'))
 
-        resp = Response(json.dumps(rv), 200, content_type='application/json')
+        rv["text"] = markdown(rv["text"])
+
+        resp = JSON(json.dumps(rv), 200)
         resp.headers.add("Set-Cookie", cookie(str(rv["id"])))
         resp.headers.add("X-Set-Cookie", cookie("isso-%i" % rv["id"]))
         return resp
 
-    if request.method == 'DELETE':
+    def delete(self, environ, request, id, key=None):
 
-        item = app.db.comments.get(id)
-        app.cache.delete('hash', (item['email'] or item['remote_addr']).encode('utf-8'))
+        try:
+            rv = self.isso.unsign(request.cookies.get(str(id), ""))
+        except (SignatureExpired, BadSignature):
+            try:
+                id = self.isso.unsign(key or "", max_age=2**32)
+            except (BadSignature, SignatureExpired):
+                raise Forbidden
+        else:
+            if rv[0] != id:
+                raise Forbidden
 
-        rv = app.db.comments.delete(id)
+            # verify checksum, mallory might skip cookie deletion when he deletes a comment
+            if rv[1] != md5(self.comments.get(id)["text"]):
+                raise Forbidden
+
+        item = self.comments.get(id)
+
+        if item is None:
+            raise NotFound
+
+        self.cache.delete('hash', (item['email'] or item['remote_addr']).encode('utf-8'))
+
+        rv = self.comments.delete(id)
         if rv:
-            for key in set(rv.keys()) - FIELDS:
+            for key in set(rv.keys()) - API.FIELDS:
                 rv.pop(key)
 
-        logger.info('comment %i deleted', id)
+        self.signal("comments.delete", id)
 
+        resp = JSON(json.dumps(rv), 200)
         cookie = functools.partial(dump_cookie, expires=0, max_age=0)
-
-        resp = Response(json.dumps(rv), 200, content_type='application/json')
         resp.headers.add("Set-Cookie", cookie(str(id)))
         resp.headers.add("X-Set-Cookie", cookie("isso-%i" % id))
         return resp
 
+    def activate(self, environ, request, _, key):
 
-@requires(str, 'uri')
-def fetch(app, environ, request, uri):
-
-    rv = list(app.db.comments.fetch(uri))
-    if not rv:
-        raise NotFound
-
-    for item in rv:
+        try:
+            id = self.isso.unsign(key, max_age=2**32)
+        except (BadSignature, SignatureExpired):
+            raise Forbidden
 
-        key = item['email'] or item['remote_addr']
-        val = app.cache.get('hash', key.encode('utf-8'))
+        with self.isso.lock:
+            self.comments.activate(id)
 
-        if val is None:
-            val = str(pbkdf2(key, app.salt, 1000, 6))
-            app.cache.set('hash', key.encode('utf-8'), val)
+        self.signal("comments.activate", id)
+        return Response("Yo", 200)
 
-        item['hash'] = val
+    @requires(str, 'uri')
+    def fetch(self, environ, request, uri):
 
-        for key in set(item.keys()) - FIELDS:
-            item.pop(key)
+        rv = list(self.comments.fetch(uri))
+        if not rv:
+            raise NotFound
 
-    if request.args.get('plain', '0') == '0':
         for item in rv:
-            item['text'] = app.markdown(item['text'])
-
-    return Response(json.dumps(rv), 200, content_type='application/json')
-
-
-def like(app, environ, request, id):
 
-    nv = app.db.comments.vote(True, id, utils.anonymize(str(request.remote_addr)))
-    return Response(json.dumps(nv), 200)
+            key = item['email'] or item['remote_addr']
+            val = self.cache.get('hash', key.encode('utf-8'))
 
+            if val is None:
+                val = str(pbkdf2(key, self.isso.salt, 1000, 6))
+                self.cache.set('hash', key.encode('utf-8'), val)
 
-def dislike(app, environ, request, id):
+            item['hash'] = val
 
-    nv = app.db.comments.vote(False, id, utils.anonymize(str(request.remote_addr)))
-    return Response(json.dumps(nv), 200)
-
-
-@requires(str, 'uri')
-def count(app, environ, request, uri):
-
-    rv = app.db.comments.count(uri)[0]
-
-    if rv == 0:
-        raise NotFound
-
-    return Response(json.dumps(rv), 200, content_type='application/json')
+            for key in set(item.keys()) - API.FIELDS:
+                item.pop(key)
 
+        if request.args.get('plain', '0') == '0':
+            for item in rv:
+                item['text'] = markdown(item['text'])
 
-def activate(app, environ, request, auth):
+        return JSON(json.dumps(rv), 200)
 
-    try:
-        id = app.unsign(auth, max_age=2**32)
-    except (BadSignature, SignatureExpired):
-        raise Forbidden
+    def like(self, environ, request, id):
 
-    with app.lock:
-        app.db.comments.activate(id)
+        nv = self.comments.vote(True, id, utils.anonymize(str(request.remote_addr)))
+        return Response(json.dumps(nv), 200)
 
-    logger.info("comment %s activated" % id)
-    return Response("Yo", 200)
+    def dislike(self, environ, request, id):
 
-def delete(app, environ, request, auth):
+        nv = self.comments.vote(False, id, utils.anonymize(str(request.remote_addr)))
+        return Response(json.dumps(nv), 200)
 
-    try:
-        id = app.unsign(auth, max_age=2**32)
-    except (BadSignature, SignatureExpired):
-        raise Forbidden
+    @requires(str, 'uri')
+    def count(self, environ, request, uri):
 
-    with app.lock:
-        app.db.comments.delete(id)
+        rv = self.comments.count(uri)[0]
 
-    logger.info("comment %s deleted" % id)
-    return Response("%s successfully removed" % id)
+        if rv == 0:
+            raise NotFound
 
+        return JSON(json.dumps(rv), 200)
 
-def checkip(app, env, req):
-    return Response(utils.anonymize(str(req.remote_addr)), 200)
+    def checkip(self, env, req):
+        return Response(utils.anonymize(str(req.remote_addr)), 200)
diff --git a/isso/wsgi.py b/isso/wsgi.py
index 4acd81f..891aaeb 100644
--- a/isso/wsgi.py
+++ b/isso/wsgi.py
@@ -1,8 +1,36 @@
 # -*- encoding: utf-8 -*-
 
+try:
+    from urllib import quote
+except ImportError:
+    from urllib.parse import quote
+
 from werkzeug.datastructures import Headers
 
 
+def host(environ):
+    """
+    Reconstruct host from environment. A modified version
+    of http://www.python.org/dev/peps/pep-0333/#url-reconstruction
+    """
+
+    url = environ['wsgi.url_scheme']+'://'
+
+    if environ.get('HTTP_HOST'):
+        url += environ['HTTP_HOST']
+    else:
+        url += environ['SERVER_NAME']
+
+        if environ['wsgi.url_scheme'] == 'https':
+            if environ['SERVER_PORT'] != '443':
+               url += ':' + environ['SERVER_PORT']
+        else:
+            if environ['SERVER_PORT'] != '80':
+               url += ':' + environ['SERVER_PORT']
+
+    return url + quote(environ.get('SCRIPT_NAME', ''))
+
+
 class SubURI(object):
 
     def __init__(self, app):
@@ -22,23 +50,15 @@ class SubURI(object):
 
 class CORSMiddleware(object):
 
-    def __init__(self, app, hosts):
+    def __init__(self, app, origin):
         self.app = app
-        self.hosts = hosts
+        self.origin = origin
 
     def __call__(self, environ, start_response):
 
         def add_cors_headers(status, headers, exc_info=None):
-
-            for host in self.hosts:
-                if environ.get("HTTP_ORIGIN", None) == host.rstrip("/"):
-                    origin = host.rstrip("/")
-                    break
-            else:
-                origin = host.rstrip("/")
-
             headers = Headers(headers)
-            headers.add("Access-Control-Allow-Origin", origin)
+            headers.add("Access-Control-Allow-Origin", self.origin(environ))
             headers.add("Access-Control-Allow-Headers", "Origin, Content-Type")
             headers.add("Access-Control-Allow-Credentials", "true")
             headers.add("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE")
diff --git a/specs/test_comments.py b/specs/test_comments.py
index 46dd625..bed2355 100644
--- a/specs/test_comments.py
+++ b/specs/test_comments.py
@@ -16,7 +16,7 @@ except ImportError:
 from werkzeug.test import Client
 from werkzeug.wrappers import Response
 
-from isso import Isso, notify, views, core
+from isso import Isso, core
 from isso.utils import http
 from isso.views import comments
 
@@ -250,7 +250,7 @@ class TestComments(unittest.TestCase):
 
         rv = loads(rv.data)
 
-        for key in comments.FIELDS:
+        for key in comments.API.FIELDS:
             rv.pop(key)
 
         assert not any(rv.keys())
diff --git a/specs/test_cors.py b/specs/test_cors.py
index b7a1e0c..fe11fc1 100644
--- a/specs/test_cors.py
+++ b/specs/test_cors.py
@@ -5,6 +5,7 @@ from werkzeug.test import Client
 from werkzeug.wrappers import Response
 
 from isso.wsgi import CORSMiddleware
+from isso.utils import origin
 
 
 def hello_world(environ, start_response):
@@ -14,11 +15,11 @@ def hello_world(environ, start_response):
 
 def test_simple_CORS():
 
-    app = CORSMiddleware(hello_world, hosts=[
+    app = CORSMiddleware(hello_world, origin=origin([
         "https://example.tld/",
         "http://example.tld/",
         "http://example.tld",
-    ])
+    ]))
 
     client = Client(app, Response)
 
@@ -30,19 +31,19 @@ def test_simple_CORS():
     assert rv.headers["Access-Control-Allow-Methods"] == "GET, POST, PUT, DELETE"
     assert rv.headers["Access-Control-Expose-Headers"] == "X-Set-Cookie"
 
-    a = client.get("/", headers={"ORIGIN": "http://example.tld/"})
+    a = client.get("/", headers={"ORIGIN": "http://example.tld"})
     assert a.headers["Access-Control-Allow-Origin"] == "http://example.tld"
 
     b = client.get("/", headers={"ORIGIN": "http://example.tld"})
-    assert a.headers["Access-Control-Allow-Origin"] == "http://example.tld"
+    assert b.headers["Access-Control-Allow-Origin"] == "http://example.tld"
 
-    c = client.get("/", headers={"ORIGIN": "http://foo.other/"})
-    assert a.headers["Access-Control-Allow-Origin"] == "http://example.tld"
+    c = client.get("/", headers={"ORIGIN": "http://foo.other"})
+    assert c.headers["Access-Control-Allow-Origin"] == "https://example.tld"
 
 
 def test_preflight_CORS():
 
-    app = CORSMiddleware(hello_world, hosts=["http://example.tld"])
+    app = CORSMiddleware(hello_world, origin=origin(["http://example.tld"]))
     client = Client(app, Response)
 
     rv = client.open(method="OPTIONS", path="/", headers={"ORIGIN": "http://example.tld"})
diff --git a/specs/test_vote.py b/specs/test_vote.py
index 36dfb6e..8feb97b 100644
--- a/specs/test_vote.py
+++ b/specs/test_vote.py
@@ -9,7 +9,7 @@ import unittest
 from werkzeug.test import Client
 from werkzeug.wrappers import Response
 
-from isso import Isso, notify, utils, core
+from isso import Isso, core
 from isso.utils import http
 
 class Dummy: