diff --git a/DepotDownloader/ConfigCache.cs b/DepotDownloader/ConfigCache.cs
new file mode 100644
index 00000000..7f73235f
--- /dev/null
+++ b/DepotDownloader/ConfigCache.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using ProtoBuf;
+using System.IO;
+using System.IO.Compression;
+using System.Net;
+
+namespace DepotDownloader
+{
+    [ProtoContract]
+    class ConfigCache
+    {
+        public const string CONFIG_FILENAME = "config.proto";
+        public static ConfigCache Instance = Load(CONFIG_FILENAME);
+
+        [ProtoContract]
+        class IPEndpointSurrogate
+        {
+            [ProtoMember(1)]
+            private byte[] address;
+            [ProtoMember(2)]
+            private int port;
+
+            public IPEndpointSurrogate()
+            {
+            }
+
+            public IPEndpointSurrogate(byte[] address, int port)
+            {
+                this.address = address;
+                this.port = port;
+            }
+
+            public static implicit operator IPEndPoint(IPEndpointSurrogate ip)
+            {
+                if (ip == null || ip.address == null)
+                    return null;
+
+                return new IPEndPoint(new IPAddress(ip.address), ip.port);
+            }
+
+            public static implicit operator IPEndpointSurrogate(IPEndPoint ip)
+            {
+                if (ip == null)
+                    return null;
+
+                return new IPEndpointSurrogate(ip.Address.GetAddressBytes(), ip.Port);
+            }
+        }
+
+        [ProtoMember(1)]
+        public byte[] CDRHash { get; set; }
+        [ProtoMember(2)]
+        public DateTime CDRCacheTime { get; set; }
+
+        [ProtoMember(3)]
+        public ServerList ConfigServers { get; set; }
+        [ProtoMember(4)]
+        public ServerList CSDSServers { get; set; }
+        [ProtoMember(5)]
+        public DateTime ServerCacheTime { get; set; }
+
+        public static ConfigCache Load(string filename)
+        {
+            ProtoBuf.Meta.RuntimeTypeModel.Default.Add(typeof(IPEndPoint), true).SetSurrogate(typeof(IPEndpointSurrogate));
+
+            if(!File.Exists(filename))
+                return new ConfigCache();
+
+            try
+            {
+                using (FileStream fs = File.Open(filename, FileMode.Open))
+                using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Decompress))
+                    return ProtoBuf.Serializer.Deserialize<ConfigCache>(ds);
+            }
+            catch (IOException)
+            {
+                File.Delete(filename);
+            }
+            catch (Exception e)
+            {
+                Console.WriteLine("Unable to load config cache: {0}", e.Message);
+            }
+
+            return new ConfigCache();
+        }
+
+        public void Save(string filename)
+        {
+            try
+            {
+                using (FileStream fs = File.Open(filename, FileMode.Create))
+                using (DeflateStream ds = new DeflateStream(fs, CompressionMode.Compress))
+                    ProtoBuf.Serializer.Serialize<ConfigCache>(ds, this);
+            }
+            catch (IOException)
+            {
+            }
+        }
+    }
+}