diff --git a/Pf2eDataScrapper/Pf2eDataScrapper.csproj b/Pf2eDataScrapper/Pf2eDataScrapper.csproj
index 2150e37..af748c0 100644
--- a/Pf2eDataScrapper/Pf2eDataScrapper.csproj
+++ b/Pf2eDataScrapper/Pf2eDataScrapper.csproj
@@ -7,4 +7,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+  </ItemGroup>
+
 </Project>
diff --git a/Pf2eDataScrapper/Program.cs b/Pf2eDataScrapper/Program.cs
index 3751555..3ed0e5d 100644
--- a/Pf2eDataScrapper/Program.cs
+++ b/Pf2eDataScrapper/Program.cs
@@ -1,2 +1,3 @@
 // See https://aka.ms/new-console-template for more information
 Console.WriteLine("Hello, World!");
+
diff --git a/Pf2eDataScrapper/SchemaBuilder/AbstractSchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/AbstractSchemaType.cs
new file mode 100644
index 0000000..5b92be2
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/AbstractSchemaType.cs
@@ -0,0 +1,142 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal abstract class AbstractSchemaType
+    {
+        /// <summary>
+        /// If the value is nullable.
+        /// </summary>
+        public bool IsNullable = false;
+
+        /// <summary>
+        /// Mark the value as nullable.
+        /// </summary>
+        /// <returns>This object</returns>
+        public AbstractSchemaType MarkNullable()
+        {
+            IsNullable = true;
+            return this;
+        }
+
+        /// <summary>
+        /// Check if type is compatible with current type.
+        /// </summary>
+        /// <param name="value">Value to be checked</param>
+        /// <returns>True if value is compatible with current type</returns>
+        public abstract bool IsCompatibleValue(object value);
+
+        /// <summary>
+        /// Adapt to new value. 
+        /// If value is compatible with current type, `this` will be returned. 
+        /// If value is not compatible, new type will be created.
+        /// </summary>
+        /// <param name="value">Value to be checked</param>
+        /// <returns>Compatible type</returns>
+        public virtual AbstractSchemaType Adapt(object value)
+        {
+            if (IsCompatibleValue(value))
+            {
+                return this;
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Add new possible value.
+        /// </summary>
+        /// <param name="value">New value</param>
+        public abstract void AddValue(object value);
+
+        /// <summary>
+        /// String representation of type.
+        /// </summary>
+        /// <returns></returns>
+        public abstract string GetTypeName();
+
+        public override abstract string ToString();
+
+
+
+        /// <summary>
+        /// Tabulation characters.
+        /// </summary>
+        public const string TAB = "    ";
+
+        /// <summary>
+        /// Limit of elements in list or dictionary to be displayed.
+        /// </summary>
+        public const int ElementLimit = 20;
+
+        /// <summary>
+        /// Indent text.
+        /// </summary>
+        /// <param name="text">Text to be indented</param>
+        /// <returns>Indented text</returns>
+        public static string Indent(string text)
+        {
+            return text.Replace("\n", "\n" + TAB);
+        }
+
+        /// <summary>
+        /// Get string representation of value type.
+        /// </summary>
+        /// <param name="value">Value to be checked</param>
+        /// <returns>String representation of value type</returns>
+        public static string ResolveType(object value)
+        {
+            if (value == null)
+            {
+                return "null";
+            }
+            if (value is string)
+            {
+                return "string";
+            }
+            if (value is bool)
+            {
+                return "bool";
+            }
+            if (value is int)
+            {
+                return "int";
+            }
+            if (value is double)
+            {
+                return "double";
+            }
+            if (value is List<object>)
+            {
+                return "List<object>";
+            }
+            if (value is Dictionary<string, object>)
+            {
+                return "Dictionary<string, object>";
+            }
+            return "object";
+        }
+
+        /// <summary>
+        /// Create new type from value.
+        /// </summary>
+        /// <param name="value">Value to be checked</param>
+        /// <returns></returns>
+        public static AbstractSchemaType CreateFromValue(object value)
+        {
+
+            switch (ResolveType(value))
+            {
+                //case "null": return new NullSchemaType();
+
+                default: throw new NotImplementedException();
+            }
+        }
+    }
+}
diff --git a/Pf2eDataScrapper/SchemaBuilder/ArraySchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/ArraySchemaType.cs
new file mode 100644
index 0000000..af91b17
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/ArraySchemaType.cs
@@ -0,0 +1,98 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal class ArraySchemaType : AbstractSchemaType
+    {
+        public int MinCount = int.MaxValue;
+
+        public int MaxCount = int.MinValue;
+
+        protected AbstractSchemaType ElementType = new EmptySchemaType();
+
+        protected List<object> Values = [];
+
+
+        public override void AddValue(object value)
+        {
+            MinCount = Math.Min(MinCount, Values.Count);
+            MaxCount = Math.Max(MaxCount, Values.Count);
+
+            foreach (var item in Values)
+            {
+                ElementType.AddValue(item);
+            }
+        }
+
+        public override string GetTypeName()
+        {
+            throw new NotImplementedException();
+        }
+
+        public override bool IsCompatibleValue(object value)
+        {
+            var type = ResolveType(value);
+
+            if (type == "none")
+            {
+                return true;
+            }
+
+            if (type == "array")
+            {
+                return false;
+            }
+
+            foreach (var item in Values)
+            {
+                if (!ElementType.IsCompatibleValue(item))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        public override AbstractSchemaType Adapt(object value)
+        {
+            if (value is not Array)
+            {
+                throw new Exception("Value is not an array");
+            }
+
+            var array = (object[])value;
+
+            if ((ResolveType(value) == "none") && (ElementType is EmptySchemaType))
+            {
+                ElementType = CreateFromValue(array[0]);
+            }
+
+            if (IsCompatibleValue(value))
+            {
+                foreach (var item in array)
+                {
+                    ElementType.Adapt(item);
+                }
+
+                return this;
+            }
+
+            return new MixedSchemaType(this);
+        }
+
+        public override string ToString()
+        {
+            List<string> rows = [ GetTypeName() ];
+
+            rows.Add($"Length: min={MinCount} max={MaxCount}");
+            rows.Add("Value type:" + Indent(ElementType.GetTypeName()));
+            
+            return string.Join("\n" + TAB, rows);
+        }
+    }
+}
diff --git a/Pf2eDataScrapper/SchemaBuilder/EmptySchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/EmptySchemaType.cs
new file mode 100644
index 0000000..9e6676d
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/EmptySchemaType.cs
@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal class EmptySchemaType : AbstractSchemaType
+    {
+        public override AbstractSchemaType Adapt(object value)
+        {
+            if (IsCompatibleValue(value))
+            {
+                return this;
+            }
+
+            return CreateFromValue(value).MarkNullable();
+        }
+
+        public override void AddValue(object value)
+        {
+        }
+
+        public override string GetTypeName()
+        {
+            return "empty[] -> null";
+        }
+
+        public override bool IsCompatibleValue(object value)
+        {
+            return ResolveType(value) == "null";
+        }
+
+        public override string ToString()
+        {
+            return "null";
+        }
+    }
+}
diff --git a/Pf2eDataScrapper/SchemaBuilder/MixedSchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/MixedSchemaType.cs
new file mode 100644
index 0000000..4c75c4d
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/MixedSchemaType.cs
@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal class MixedSchemaType : AbstractSchemaType
+    {
+        public List<AbstractSchemaType> Types = [];
+
+        public MixedSchemaType(AbstractSchemaType baseType) 
+        {
+            Types.Add(baseType);
+        }
+
+        public AbstractSchemaType AddType(object value)
+        {
+            var newType = CreateFromValue(value);
+
+            Types.Add(newType);
+
+            return newType;
+        }
+
+        public AbstractSchemaType? GetCompatibleType(object value)
+        {
+            foreach (var type in Types)
+            {
+                if (type.IsCompatibleValue(value))
+                {
+                    return type;
+                }
+            }
+            return null;
+        }   
+
+        public override AbstractSchemaType Adapt(object value)
+        {
+            var type = GetCompatibleType(value);
+
+            if (type == null)
+            {
+                AddType(value);
+            }
+
+            return this;
+        }
+
+        public override void AddValue(object value)
+        {
+            GetCompatibleType(value)?.AddValue(value);
+        }
+
+        public override string GetTypeName()
+        {
+            List<string> typeNames = Types.Select(t => t.GetTypeName()).ToList();
+
+            return string.Join("|", typeNames);
+        }
+
+        public override bool IsCompatibleValue(object value) => true;
+
+        /// <summary>
+        /// String representation of type.
+        /// </summary>
+        /// <returns></returns>
+        public override string ToString()
+        {
+            List<string> result = ["mixed"];
+
+            foreach (var type in Types)
+            {
+                result.Add(Indent(type?.ToString() ?? ""));
+            }
+
+            return string.Join("\n" + TAB, result);
+        }
+    }
+}
diff --git a/Pf2eDataScrapper/SchemaBuilder/ObjectSchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/ObjectSchemaType.cs
new file mode 100644
index 0000000..6ac95b2
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/ObjectSchemaType.cs
@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal class ObjectSchemaType : AbstractSchemaType
+    {
+        protected bool IsFresh = true;
+
+        public Dictionary<string, AbstractSchemaType> Fields = [];
+
+        public override void AddValue(object value)
+        {
+            if (value == null)
+            {
+                MarkNullable();
+                return;
+            }
+
+            var dict = (Dictionary<string, object>)value;
+
+            if (dict.Keys.Count == 0)
+            {
+                MarkNullable();
+                return;
+            }
+
+            foreach (var field in Fields)
+            {
+                if (!dict.ContainsKey(field.Key))
+                {
+                    field.Value.MarkNullable();
+                }
+            }
+
+            foreach (var field in dict)
+            {
+                Fields[field.Key].AddValue(field.Value);
+            }
+        }
+
+        public override string GetTypeName()
+        {
+            throw new NotImplementedException();
+        }
+
+        public override bool IsCompatibleValue(object value)
+        {
+            return (ResolveType(value) == "object") || (ResolveType(value) == "null");
+        }
+
+        public override AbstractSchemaType Adapt(object value)
+        {
+            if (!IsCompatibleValue(value))
+            {
+                return new MixedSchemaType(this);
+            }
+
+            Dictionary<string, object> dict = (Dictionary<string, object>)value;
+
+            foreach (var field in Fields)
+            {
+                if (!dict.ContainsKey(field.Key))
+                {
+                    field.Value.MarkNullable();
+                }
+            }
+
+            foreach (var field in dict) {
+                if (!Fields.ContainsKey(field.Key))
+                {
+                    Fields[field.Key] = CreateFromValue(field.Value);
+
+                    if (!IsFresh)
+                    {
+                        Fields[field.Key].MarkNullable();
+                    }
+                }
+            }
+
+            IsFresh = false;
+            return this;
+        }
+
+        public override string ToString()
+        {
+            List<string> rows = ["object"];
+
+            foreach (var field in Fields)
+            {
+                string s = field.Key;
+
+                if (field.Value.IsNullable)
+                {
+                    s = $"[{s}]";
+                }
+
+                s += " : " + Indent(field.Value.ToString());
+
+                rows.Add(Indent($"{field.Key}: {field.Value}"));
+            }
+
+            return string.Join("\n", rows);
+        }
+    }
+
+}
diff --git a/Pf2eDataScrapper/SchemaBuilder/StaticSchemaType.cs b/Pf2eDataScrapper/SchemaBuilder/StaticSchemaType.cs
new file mode 100644
index 0000000..b8a39c3
--- /dev/null
+++ b/Pf2eDataScrapper/SchemaBuilder/StaticSchemaType.cs
@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Pf2eDataScrapper.SchemaBuilder
+{
+    internal class StaticSchemaType(string type) : AbstractSchemaType
+    {
+        protected string Type = type;
+
+        protected Dictionary<object, int> Values = [];
+
+        public override void AddValue(object value)
+        {
+            Values.TryAdd(value, 0);
+
+            Values[value]++;
+        }
+
+        public override string GetTypeName()
+        {
+            return Type;
+        }
+
+        public override bool IsCompatibleValue(object value)
+        {
+            return ResolveType(value) == Type;
+        }
+
+        public override string ToString()
+        {
+            string result = Type;
+            int count = Values.Count;
+
+            result += $" (different values: {count})";
+
+            if ((count <= ElementLimit) && (count > 0))
+            {
+                result += "\n";
+                foreach (var value in Values)
+                {
+                    result += $"{TAB}{value.Key} (x{value.Value})\n";
+                }
+            }
+
+            return result.Trim();
+        }
+    }
+}