diff --git a/ZeroLevel.UnitTests/TrieTests.cs b/ZeroLevel.UnitTests/TrieTests.cs
new file mode 100644
index 0000000..b191a91
--- /dev/null
+++ b/ZeroLevel.UnitTests/TrieTests.cs
@@ -0,0 +1,93 @@
+using Xunit;
+using ZeroLevel.Services.Semantic;
+using ZeroLevel.Services.Serialization;
+
+namespace ZeroLevel.UnitTests
+{
+    public class TrieTests
+    {
+        [Fact]
+        public void MainTest()
+        {
+            // Arrange            
+            var tree = new Trie();
+            // Act
+            tree.Append("коллекция");
+            tree.Append("коллектор");
+            tree.Append("колл-центр");
+            tree.Append("коллектив");
+            tree.Append("коллегия");
+            tree.Append("метро");
+            tree.Append("метрополитен");
+            tree.Append("метрополит");
+            // Assert
+            Assert.True(tree.Key("коллекция") == 1);
+            Assert.True(tree.Key("коллектор") == 2);
+            Assert.True(tree.Key("колл-центр") == 3);
+            Assert.True(tree.Key("коллектив") == 4);
+            Assert.True(tree.Key("коллегия") == 5);
+            Assert.True(tree.Key("метро") == 6);
+            Assert.True(tree.Key("метрополитен") == 7);
+            Assert.True(tree.Key("метрополит") == 8);
+
+            Assert.True(tree.Key("колл") == null);
+            Assert.True(tree.Key("центр") == null);
+
+            Assert.True(tree.Contains("коллекция"));
+            Assert.True(tree.Contains("коллектор"));
+            Assert.True(tree.Contains("колл-центр"));
+            Assert.True(tree.Contains("коллектив"));
+            Assert.True(tree.Contains("коллегия"));
+            Assert.True(tree.Contains("метро"));
+            Assert.True(tree.Contains("метрополитен"));
+            Assert.True(tree.Contains("метрополит"));
+
+            Assert.False(tree.Contains("колл"));
+            Assert.False(tree.Contains("коллег"));
+        }
+
+        [Fact]
+        public void SerializationTest()
+        {
+            // Arrange            
+            var tree_original = new Trie();
+            // Act
+            tree_original.Append("коллекция");
+            tree_original.Append("коллектор");
+            tree_original.Append("колл-центр");
+            tree_original.Append("коллектив");
+            tree_original.Append("коллегия");
+            tree_original.Append("метро");
+            tree_original.Append("метрополитен");
+            tree_original.Append("метрополит");
+
+            var data = MessageSerializer.Serialize(tree_original);
+            var tree = MessageSerializer.Deserialize<Trie>(data);
+
+            // Assert
+            Assert.True(tree.Key("коллекция") == 1);
+            Assert.True(tree.Key("коллектор") == 2);
+            Assert.True(tree.Key("колл-центр") == 3);
+            Assert.True(tree.Key("коллектив") == 4);
+            Assert.True(tree.Key("коллегия") == 5);
+            Assert.True(tree.Key("метро") == 6);
+            Assert.True(tree.Key("метрополитен") == 7);
+            Assert.True(tree.Key("метрополит") == 8);
+
+            Assert.True(tree.Key("колл") == null);
+            Assert.True(tree.Key("центр") == null);
+
+            Assert.True(tree.Contains("коллекция"));
+            Assert.True(tree.Contains("коллектор"));
+            Assert.True(tree.Contains("колл-центр"));
+            Assert.True(tree.Contains("коллектив"));
+            Assert.True(tree.Contains("коллегия"));
+            Assert.True(tree.Contains("метро"));
+            Assert.True(tree.Contains("метрополитен"));
+            Assert.True(tree.Contains("метрополит"));
+
+            Assert.False(tree.Contains("колл"));
+            Assert.False(tree.Contains("коллег"));
+        }
+    }
+}
diff --git a/ZeroLevel/Services/Semantic/Trie.cs b/ZeroLevel/Services/Semantic/Trie.cs
new file mode 100644
index 0000000..c6b9d45
--- /dev/null
+++ b/ZeroLevel/Services/Semantic/Trie.cs
@@ -0,0 +1,189 @@
+using System.Collections.Generic;
+using ZeroLevel.Services.Serialization;
+
+namespace ZeroLevel.Services.Semantic
+{
+    public class Trie
+        : IBinarySerializable
+    {
+        private class TrieNode
+            : IBinarySerializable
+        {
+            public char Key;
+            public uint? Value;
+            public List<TrieNode> Children;
+
+            public void Deserialize(IBinaryReader reader)
+            {
+                this.Key = reader.ReadChar();
+                if (reader.ReadBoolean())
+                {
+                    this.Value = reader.ReadUInt32();
+                }
+                else
+                {
+                    this.Value = null;
+                }
+                this.Children = reader.ReadCollection<TrieNode>();
+            }
+
+            public void Serialize(IBinaryWriter writer)
+            {
+                writer.WriteChar(this.Key);
+                if (this.Value.HasValue)
+                {
+                    writer.WriteBoolean(true);
+                    writer.WriteUInt32(this.Value.Value);
+                }
+                else
+                {
+                    writer.WriteBoolean(false);
+                }
+                if (this.Children == null)
+                {
+                    writer.WriteInt32(0);
+                }
+                else
+                {
+                    writer.WriteCollection<TrieNode>(this.Children);
+                }
+            }
+
+            internal void Append(string word, ref uint word_index, int index)
+            {
+                if (word.Length == index + 1)
+                {
+                    if (!this.Value.HasValue)
+                    {
+                        this.Value = ++word_index;
+                    }
+                }
+                else
+                {
+                    if (this.Children == null)
+                    {
+                        this.Children = new List<TrieNode>();
+                    }
+                    bool found = false;
+                    for (int i = 0; i < Children.Count; i++)
+                    {
+                        if (Children[i].Key == word[index])
+                        {
+                            Children[i].Append(word, ref word_index, index + 1);
+                            found = true;
+                        }
+                    }
+                    if (!found)
+                    {
+                        var tn = new TrieNode { Key = word[index] };
+                        Children.Add(tn);
+                        tn.Append(word, ref word_index, index + 1);
+                    }
+                }
+            }
+
+            internal uint? GetKey(string word, int index)
+            {
+                if (word.Length == index + 1)
+                {
+                    return this.Value;
+                }
+                else
+                {
+                    if (this.Children == null)
+                    {
+                        this.Children = new List<TrieNode>();
+                    }
+                    for (int i = 0; i < Children.Count; i++)
+                    {
+                        if (Children[i].Key == word[index])
+                        {
+                            return Children[i].GetKey(word, index + 1);
+                        }
+                    }
+                }
+                return null;
+            }
+        }
+
+        private List<TrieNode> _roots;
+        private uint _word_index = 0;
+
+        public Trie()
+        {
+            _roots = new List<TrieNode>();
+        }
+
+        public void Append(string word)
+        {
+            if (word.Length == 0) return;
+            bool found = false;
+            for (int i = 0; i < _roots.Count; i++)
+            {
+                if (_roots[i].Key == word[0])
+                {
+                    _roots[i].Append(word, ref _word_index, 1);
+                    found = true;
+                }
+            }
+            if (!found)
+            {
+                var tn = new TrieNode { Key = word[0] };
+                _roots.Add(tn);
+                tn.Append(word, ref _word_index, 1);
+            }
+        }
+
+        public uint? Key(string word)
+        {
+            if (word?.Length == 0) return null;
+            for (int i = 0; i < _roots.Count; i++)
+            {
+                if (_roots[i].Key == word[0])
+                {
+                    if (word.Length == 1)
+                    {
+                        return _roots[i].Value;
+                    }
+                    else
+                    {
+                        return _roots[i].GetKey(word, 1);
+                    }
+                }
+            }
+            return null;
+        }
+
+        public bool Contains(string word)
+        {
+            if (word?.Length == 0) return false;
+            for (int i = 0; i < _roots.Count; i++)
+            {
+                if (_roots[i].Key == word[0])
+                {
+                    if (word.Length == 1)
+                    {
+                        return _roots[i].Value.HasValue;
+                    }
+                    else
+                    {
+                        return _roots[i].GetKey(word, 1).HasValue;
+                    }
+                }
+            }
+            return false;
+        }
+
+        public void Serialize(IBinaryWriter writer)
+        {
+            writer.WriteUInt32(this._word_index);
+            writer.WriteCollection<TrieNode>(this._roots);
+        }
+
+        public void Deserialize(IBinaryReader reader)
+        {
+            this._word_index = reader.ReadUInt32();
+            this._roots = reader.ReadCollection<TrieNode>();
+        }
+    }
+}
diff --git a/ZeroLevel/Services/Serialization/IBinaryReader.cs b/ZeroLevel/Services/Serialization/IBinaryReader.cs
index ca2cf76..8235d38 100644
--- a/ZeroLevel/Services/Serialization/IBinaryReader.cs
+++ b/ZeroLevel/Services/Serialization/IBinaryReader.cs
@@ -8,6 +8,8 @@ namespace ZeroLevel.Services.Serialization
     {
         bool ReadBoolean();
 
+        char ReadChar();
+
         byte ReadByte();
 
         byte[] ReadBytes();
diff --git a/ZeroLevel/Services/Serialization/IBinaryWriter.cs b/ZeroLevel/Services/Serialization/IBinaryWriter.cs
index 714d228..8d2609c 100644
--- a/ZeroLevel/Services/Serialization/IBinaryWriter.cs
+++ b/ZeroLevel/Services/Serialization/IBinaryWriter.cs
@@ -10,6 +10,8 @@ namespace ZeroLevel.Services.Serialization
     {
         void WriteBoolean(bool val);
 
+        void WriteChar(char val);
+
         void WriteByte(byte val);
 
         void WriteBytes(byte[] val);
diff --git a/ZeroLevel/Services/Serialization/MemoryStreamReader.cs b/ZeroLevel/Services/Serialization/MemoryStreamReader.cs
index c2e2f33..65de261 100644
--- a/ZeroLevel/Services/Serialization/MemoryStreamReader.cs
+++ b/ZeroLevel/Services/Serialization/MemoryStreamReader.cs
@@ -55,6 +55,14 @@ namespace ZeroLevel.Services.Serialization
             return (byte)_stream.ReadByte();
         }
 
+        public char ReadChar()
+        {
+            if (CheckOutOfRange(_stream, 1))
+                throw new OutOfMemoryException("Array index out of bounds");
+            var buffer = ReadBuffer(2);
+            return BitConverter.ToChar(buffer, 0);
+        }
+
         /// <summary>
         /// Reading bytes
         /// </summary>
diff --git a/ZeroLevel/Services/Serialization/MemoryStreamWriter.cs b/ZeroLevel/Services/Serialization/MemoryStreamWriter.cs
index 6809d59..cc78595 100644
--- a/ZeroLevel/Services/Serialization/MemoryStreamWriter.cs
+++ b/ZeroLevel/Services/Serialization/MemoryStreamWriter.cs
@@ -45,6 +45,14 @@ namespace ZeroLevel.Services.Serialization
             _stream.WriteByte(val);
         }
 
+        /// <summary>
+        /// Write char (2 bytes)
+        /// </summary>
+        public void WriteChar(char val)
+        {
+            _stream.Write(BitConverter.GetBytes(val), 0, 2);
+        }
+
         /// <summary>
         /// Write array bytes
         /// </summary>
diff --git a/ZeroLevel/ZeroLevel.csproj b/ZeroLevel/ZeroLevel.csproj
index 5f09a63..4cc8295 100644
--- a/ZeroLevel/ZeroLevel.csproj
+++ b/ZeroLevel/ZeroLevel.csproj
@@ -5,16 +5,17 @@
     <Description>Infrastructure layer library</Description>
     <Authors>ogoun</Authors>
     <Company>ogoun</Company>
-    <AssemblyVersion>3.0.0.5</AssemblyVersion>
-    <PackageReleaseNotes>Fixes</PackageReleaseNotes>
+    <AssemblyVersion>3.0.0.6</AssemblyVersion>
+    <PackageReleaseNotes>Added char serialization
+Added prefix tree (Trie)</PackageReleaseNotes>
     <PackageProjectUrl>https://github.com/ogoun/Zero/wiki</PackageProjectUrl>
     <Copyright>Copyright Ogoun 2019</Copyright>
     <PackageLicenseUrl>https://opensource.org/licenses/MIT</PackageLicenseUrl>
     <PackageIconUrl>https://raw.githubusercontent.com/ogoun/Zero/master/zero.png</PackageIconUrl>
     <RepositoryUrl>https://github.com/ogoun/Zero</RepositoryUrl>
     <RepositoryType>GitHub</RepositoryType>
-    <Version>3.0.5</Version>
-    <FileVersion>3.0.0.5</FileVersion>
+    <Version>3.0.6</Version>
+    <FileVersion>3.0.0.6</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">