diff --git a/pysitemap/__init__.py b/pysitemap/__init__.py
new file mode 100644
index 0000000..bd13691
--- /dev/null
+++ b/pysitemap/__init__.py
@@ -0,0 +1 @@
+from pysitemap.crawler import Crawler
\ No newline at end of file
diff --git a/pysitemap/crawler.py b/pysitemap/crawler.py
index 228465a..378ad7a 100644
--- a/pysitemap/crawler.py
+++ b/pysitemap/crawler.py
@@ -3,25 +3,53 @@
 import time
 import asyncio
 from aiohttp import ClientSession
+from parsel import Selector
+from urllib.parse import urlparse, urlunparse
 
-class Knocker(object):
-    def __init__(self, urls=None, sleep_time=.5):
-        self.urls = urls or []
+
+class Crawler(object):
+    def __init__(self, url, sleep_time=.5):
+
+        self.urls = [url]
+        scheme, netloc, path, params, query, fragment = urlparse(url)
+        if not netloc:
+            netloc, path = path, netloc
+        url = urlunparse((scheme, netloc, "", params, "", fragment))
+        self.base_url = url
         self.sleep_time = float(sleep_time)
 
     async def fetch(self, url, session):
         async with session.get(url) as response:
             await asyncio.sleep(self.sleep_time)
-            status = response.status
-            date = response.headers.get("DATE")
-            print("{}:{} with status {}".format(date, response.url, status))
-            return url, status
+            return response.content
 
     async def bound_fetch(self, sem, url, session):
         # Getter function with semaphore.
         async with sem:
             await self.fetch(url, session)
 
+    def norm_link(self, url:str):
+        if url.startswith(self.base_url):
+            return url
+        elif url.startswith('//'):
+            return "{scheme}{url}".format(
+                scheme=self.base_url[:self.base_url.find(":")],
+                url=url
+            )
+        elif url.startswith("/"):
+            return self.base_url + url
+        return None
+
+    async def parse(self, content):
+        sel = Selector(content)
+        links = sel.xpath('//a/@href').getall()
+        normalized_links = []
+        for link in links:
+            link = self.norm_link(link)
+            if link:
+                normalized_links.append(link)
+        self.urls.extend(normalized_links)
+
     async def run(self):
         tasks = []
         # create instance of Semaphore
diff --git a/requirements.txt b/requirements.txt
index e5fc25b..320207f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
-lxml
-requests
+aiohttp
+asyncio
+parsel
\ No newline at end of file
diff --git a/run.py b/run.py
index 7997b13..c66b184 100644
--- a/run.py
+++ b/run.py
@@ -12,8 +12,9 @@ if __name__ == '__main__':
     logfile = 'errlog.log'  # path to logfile
     oformat = 'xml'  # output format
     outputfile = 'sitemap.xml'  # path to output file
+
     loop = asyncio.get_event_loop()
-    crawler = Crawler(url=url, logfile=logfile, oformat=oformat, outputfile=outputfile)
-    future = asyncio.ensure_future(crawler.crawl(echo=True))
+    crawler: Crawler = Crawler(url=url)
+    future = asyncio.ensure_future(crawler.run())
     loop.run_until_complete(future)
 
diff --git a/setup.py b/setup.py
index c6b0ecb..fa5dff1 100644
--- a/setup.py
+++ b/setup.py
@@ -3,6 +3,11 @@ from setuptools import find_packages, setup
 
 EXCLUDE_FROM_PACKAGES = ['tests',]
 
+def get_requirements():
+    requirements = []
+    with open('requirements.txt', 'r') as df:
+        requirements = df.readlines()
+    return [requirement.strip() for requirement in requirements]
 
 def get_version(major=0, minor=0, build=0):
     return '%s.%s.%s' % (major, minor, build)
@@ -28,11 +33,10 @@ setup(
         'License :: OSI Approved :: BSD License',
         'Operating System :: OS Independent',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.7',
         'Topic :: Software Development :: Libraries :: Python Modules',
     ],
-    install_requires=['lxml', 'requests'],
-    requires=['lxml', 'requests']
+    install_requires=get_requirements(),
+    requires=get_requirements()
 )
\ No newline at end of file