diff --git a/.gitignore b/.gitignore
index f8b73e7..5adf2aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -138,3 +138,6 @@ dmypy.json
 # Cython debug symbols
 cython_debug/
 
+icygov.yaml
+pyrightconfig.json
+data/
diff --git a/.isort.cfg b/.isort.cfg
new file mode 100644
index 0000000..73017e5
--- /dev/null
+++ b/.isort.cfg
@@ -0,0 +1,3 @@
+[settings]
+multi_line_output=4
+src_paths=backend
diff --git a/__init__.py b/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/config.py b/config.py
new file mode 100644
index 0000000..8f6a5ba
--- /dev/null
+++ b/config.py
@@ -0,0 +1,20 @@
+from os import environ
+from pathlib import Path
+
+from yaml import load
+
+try:
+    from yaml import CLoader as Loader
+except ImportError:
+    from yaml import Loader
+
+_CONFPATH = environ.get('ICYGOV_CONFIG')
+if not _CONFPATH:
+    raise FileNotFoundError('ICYGOV_CONFIG must be an environment variable!')
+
+_PATH_CONF = Path(_CONFPATH)
+if not _PATH_CONF.exists():
+    raise FileNotFoundError(_CONFPATH)
+
+with _PATH_CONF.open() as fd:
+    CONFIG = load(stream=fd, Loader=Loader)
diff --git a/icygov-sample.yaml b/icygov-sample.yaml
new file mode 100644
index 0000000..dcf015a
--- /dev/null
+++ b/icygov-sample.yaml
@@ -0,0 +1 @@
+path_datadir: /etc/icygov/data
diff --git a/ip_collector/__init__.py b/ip_collector/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/ip_collector/dl_amazon.py b/ip_collector/dl_amazon.py
new file mode 100644
index 0000000..a99c8b8
--- /dev/null
+++ b/ip_collector/dl_amazon.py
@@ -0,0 +1,89 @@
+__doc__ = 'Downloader for amazon IP ranges'
+
+from functools import lru_cache
+from ipaddress import IPv4Address, IPv4Network, IPv6Address, IPv6Network
+from json import loads
+from pathlib import Path
+from tempfile import mkstemp
+from typing import Optional
+from urllib.request import urlopen
+
+from ..config import CONFIG
+from .typing import Ip4DictType, Ip6DictType
+
+# https://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html
+
+URL = 'https://ip-ranges.amazonaws.com/ip-ranges.json'
+_SEP = '||'
+_PATH_MY_DATA_V4 = Path(CONFIG['path_datadir'], 'amazon-ipv4.txt')
+_PATH_MY_DATA_V6 = Path(CONFIG['path_datadir'], 'amazon-ipv6.txt')
+_IP4_DICT: Ip4DictType = {}
+_IP6_DICT: Ip6DictType = {}
+
+if not _PATH_MY_DATA_V4.is_file():
+    _PATH_MY_DATA_V4.touch()
+if not _PATH_MY_DATA_V6.is_file():
+    _PATH_MY_DATA_V6.touch()
+
+
+@lru_cache(maxsize=50)
+def _amazon_match_v4(address: IPv4Address) -> Optional[str]:
+    'Try to match an IPv4 address, return data if it matches.'
+    for network, description in _IP4_DICT.items():
+        if address in network:
+            return f'{address} in {network}: {description}'
+
+
+@lru_cache(maxsize=50)
+def _amazon_match_v6(address: IPv6Address) -> Optional[str]:
+    'Try to match an IPv6 address, return data if it matches.'
+    for network, description in _IP6_DICT.items():
+        if address in network:
+            return f'{address} in {network}: {description}'
+
+
+def _amazon_load():
+    'Load data from files'
+    global _IP4_DICT, _IP6_DICT
+    my_ip4dict: Ip4DictType = {}
+    my_ip6dict: Ip6DictType = {}
+    with _PATH_MY_DATA_V4.open('r') as fd:
+        for line in fd:
+            line = line.strip()
+            if not line:
+                continue
+            address, description = line.split(_SEP)
+            my_ip4dict[IPv4Network(address=address)] = description
+    with _PATH_MY_DATA_V6.open('r') as fd:
+        for line in fd:
+            line = line.strip()
+            if not line:
+                continue
+            address, description = line.split(_SEP)
+            my_ip6dict[IPv6Network(address=address)] = description
+    _IP4_DICT = my_ip4dict
+    _IP6_DICT = my_ip6dict
+
+
+def _amazon_download():
+    'Download, parse and save files.'
+    with urlopen(url=URL) as fd:
+        data = loads(s=fd.read())
+    my_tmp_fd_v4, my_tmp_path_v4 = mkstemp()
+    with open(my_tmp_fd_v4, 'w') as fd:
+        for ip4_items in data['prefixes']:
+            fd.write(
+                f'{ip4_items["ip_prefix"]}{_SEP}'
+                f'Amazon: {ip4_items["service"]} '
+                f'{ip4_items["network_border_group"]}\n')
+    my_tmp_fd_v6, my_tmp_path_v6 = mkstemp()
+    Path(_PATH_MY_DATA_V4).write_text(Path(my_tmp_path_v4).read_text())
+    Path(my_tmp_path_v4).unlink()
+    with open(my_tmp_fd_v4, 'w') as fd:
+        for ip6_items in data['ipv6_prefixes']:
+            fd.write(
+                f'{ip6_items["ipv6_prefix"]}{_SEP}'
+                f'Amazon: {ip6_items["service"]} '
+                f'{ip6_items["network_border_group"]}\n')
+    Path(_PATH_MY_DATA_V6).write_text(Path(my_tmp_path_v6).read_text())
+    Path(my_tmp_path_v6).unlink()
diff --git a/ip_collector/reader.py b/ip_collector/reader.py
new file mode 100644
index 0000000..335b7a0
--- /dev/null
+++ b/ip_collector/reader.py
@@ -0,0 +1,35 @@
+from functools import lru_cache
+from ipaddress import IPv4Address, IPv6Address
+from typing import Optional, Union
+
+from .dl_amazon import (
+    _amazon_download, _amazon_load, _amazon_match_v4, _amazon_match_v6)
+
+
+@lru_cache(maxsize=50)
+def _match_v4(address: IPv4Address) -> Optional[str]:
+    return _amazon_match_v4(address=address)
+
+
+@lru_cache(maxsize=50)
+def _match_v6(address: IPv6Address) -> Optional[str]:
+    return _amazon_match_v6(address=address)
+
+
+def match(address: Union[IPv4Address, IPv6Address]) -> Optional[str]:
+    if type(address) is IPv4Address:
+        return _match_v4(address=address)
+    return _match_v6(address=address)
+
+
+def redownload_ranges():
+    'Redownload the ranges from all available providers.'
+    _amazon_download()
+
+
+def load():
+    'Load values from file.'
+    _amazon_load()
+
+
+load()
diff --git a/ip_collector/typing.py b/ip_collector/typing.py
new file mode 100644
index 0000000..88bf891
--- /dev/null
+++ b/ip_collector/typing.py
@@ -0,0 +1,5 @@
+from ipaddress import IPv4Network, IPv6Network
+from typing import Dict
+
+Ip4DictType = Dict[IPv4Network, str]
+Ip6DictType = Dict[IPv6Network, str]
diff --git a/main.py b/main.py
index 628da84..e163b2a 100755
--- a/main.py
+++ b/main.py
@@ -1,11 +1,50 @@
 #!/usr/bin/env python3
-from time import sleep
+
+from ipaddress import IPv4Network, ip_address
+
+from flask.app import Flask
+from flask.globals import request
+from flask.helpers import make_response
+from flask.wrappers import Response
+
+from .ip_collector.reader import redownload_ranges, match
+
+app = Flask(import_name="icy_governor")
+BASE_PATH = '/icy-governor'
 
 
-def main():
-    while True:
-        sleep(10)
+@app.route(rule=f'{BASE_PATH}/reload-ranges/', methods=['GET'])
+def reload_ranges() -> Response:
+    redownload_ranges()
+    response = make_response('', 200)
+    return response
+
+
+@app.route(rule=f'{BASE_PATH}/listener-add/', methods=['POST'])
+def listener_add() -> Response:
+    app.logger.debug('Add data received: %s', request.form)
+    response = make_response('alrighty', 200)
+    ip = request.form.get('ip')
+    if not ip:
+        response.headers['Icecast-Auth-Message'] = 'IP not specified'
+        return response
+    ip_addr = ip_address(address=ip)
+    result = match(address=ip_addr)
+    app.logger.debug('IP is: %s, result: %r', ip_addr, result)
+    if result:
+        response.headers['Icecast-Auth-Message'] = result
+    else:
+        response.headers['Icecast-Auth-User'] = 1
+    # response.headers['icecast-auth-timelimit'] = 10
+    return response
+
+
+@app.route(rule=f'{BASE_PATH}/listener-remove/', methods=['POST'])
+def listener_remove() -> Response:
+    app.logger.debug('Remove data received: %s', request.form)
+    response = make_response('alrighty', 200)
+    return response
 
 
 if __name__ == '__main__':
-    main()
+    app.run()