diff --git a/crates/bindings-csharp/Codegen/Utils.cs b/crates/bindings-csharp/Codegen/Utils.cs
index 424fbb287b..134b9ed2fb 100644
--- a/crates/bindings-csharp/Codegen/Utils.cs
+++ b/crates/bindings-csharp/Codegen/Utils.cs
@@ -60,23 +60,23 @@ public static string GetTypeInfo(ITypeSymbol type)
             INamedTypeSymbol namedType
                 => type.SpecialType switch
                 {
-                    SpecialType.System_Boolean => "SpacetimeDB.SATS.BuiltinType.BoolTypeInfo",
-                    SpecialType.System_SByte => "SpacetimeDB.SATS.BuiltinType.I8TypeInfo",
-                    SpecialType.System_Byte => "SpacetimeDB.SATS.BuiltinType.U8TypeInfo",
-                    SpecialType.System_Int16 => "SpacetimeDB.SATS.BuiltinType.I16TypeInfo",
-                    SpecialType.System_UInt16 => "SpacetimeDB.SATS.BuiltinType.U16TypeInfo",
-                    SpecialType.System_Int32 => "SpacetimeDB.SATS.BuiltinType.I32TypeInfo",
-                    SpecialType.System_UInt32 => "SpacetimeDB.SATS.BuiltinType.U32TypeInfo",
-                    SpecialType.System_Int64 => "SpacetimeDB.SATS.BuiltinType.I64TypeInfo",
-                    SpecialType.System_UInt64 => "SpacetimeDB.SATS.BuiltinType.U64TypeInfo",
+                    SpecialType.System_Boolean => "SpacetimeDB.SATS.AlgebraicType.BoolTypeInfo",
+                    SpecialType.System_SByte => "SpacetimeDB.SATS.AlgebraicType.I8TypeInfo",
+                    SpecialType.System_Byte => "SpacetimeDB.SATS.AlgebraicType.U8TypeInfo",
+                    SpecialType.System_Int16 => "SpacetimeDB.SATS.AlgebraicType.I16TypeInfo",
+                    SpecialType.System_UInt16 => "SpacetimeDB.SATS.AlgebraicType.U16TypeInfo",
+                    SpecialType.System_Int32 => "SpacetimeDB.SATS.AlgebraicType.I32TypeInfo",
+                    SpecialType.System_UInt32 => "SpacetimeDB.SATS.AlgebraicType.U32TypeInfo",
+                    SpecialType.System_Int64 => "SpacetimeDB.SATS.AlgebraicType.I64TypeInfo",
+                    SpecialType.System_UInt64 => "SpacetimeDB.SATS.AlgebraicType.U64TypeInfo",
                     SpecialType.System_Single
-                        => "SpacetimeDB.SATS.BuiltinType.F32TypeInfo",
-                    SpecialType.System_Double => "SpacetimeDB.SATS.BuiltinType.F64TypeInfo",
-                    SpecialType.System_String => "SpacetimeDB.SATS.BuiltinType.StringTypeInfo",
+                        => "SpacetimeDB.SATS.AlgebraicType.F32TypeInfo",
+                    SpecialType.System_Double => "SpacetimeDB.SATS.AlgebraicType.F64TypeInfo",
+                    SpecialType.System_String => "SpacetimeDB.SATS.AlgebraicType.StringTypeInfo",
                     SpecialType.None when type.ToString() == "System.Int128"
-                        => "SpacetimeDB.SATS.BuiltinType.I128TypeInfo",
+                        => "SpacetimeDB.SATS.AlgebraicType.I128TypeInfo",
                     SpecialType.None when type.ToString() == "System.UInt128"
-                        => "SpacetimeDB.SATS.BuiltinType.U128TypeInfo",
+                        => "SpacetimeDB.SATS.AlgebraicType.U128TypeInfo",
                     SpecialType.None
                         when namedType.EnumUnderlyingType is not null
                             // check that enums also have [SpacetimeDB.Type]
@@ -88,12 +88,12 @@ when namedType.EnumUnderlyingType is not null
                                         a.AttributeClass?.ToDisplayString()
                                         == "SpacetimeDB.TypeAttribute"
                                 )
-                        => $"SpacetimeDB.SATS.BuiltinType.MakeEnum<{type}>()",
+                        => $"SpacetimeDB.SATS.AlgebraicType.MakeEnum<{type}>()",
                     SpecialType.None
                         => $"{type.OriginalDefinition.ToString() switch
                     {
-                        "System.Collections.Generic.List<T>" => "SpacetimeDB.SATS.BuiltinType.MakeList",
-                        "System.Collections.Generic.Dictionary<TKey, TValue>" => "SpacetimeDB.SATS.BuiltinType.MakeMap",
+                        "System.Collections.Generic.List<T>" => "SpacetimeDB.SATS.AlgebraicType.MakeList",
+                        "System.Collections.Generic.Dictionary<TKey, TValue>" => "SpacetimeDB.SATS.AlgebraicType.MakeMap",
                         // If we're here, then this is nullable value type like `int?`.
                         "System.Nullable<T>" => $"SpacetimeDB.SATS.SumType.MakeValueOption",
                         var name when name.StartsWith("System.") => throw new InvalidOperationException(
@@ -109,8 +109,8 @@ when namedType.EnumUnderlyingType is not null
             IArrayTypeSymbol arrayType
                 => arrayType.ElementType is INamedTypeSymbol namedType
                 && namedType.SpecialType == SpecialType.System_Byte
-                    ? "SpacetimeDB.SATS.BuiltinType.BytesTypeInfo"
-                    : $"SpacetimeDB.SATS.BuiltinType.MakeArray({GetTypeInfo(arrayType.ElementType)})",
+                    ? "SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo"
+                    : $"SpacetimeDB.SATS.AlgebraicType.MakeArray({GetTypeInfo(arrayType.ElementType)})",
             _ => throw new InvalidOperationException($"Unsupported type {type}")
         };
     }
diff --git a/crates/bindings-csharp/Runtime/AlgebraicType.cs b/crates/bindings-csharp/Runtime/AlgebraicType.cs
index e1cba56f09..e774e32027 100644
--- a/crates/bindings-csharp/Runtime/AlgebraicType.cs
+++ b/crates/bindings-csharp/Runtime/AlgebraicType.cs
@@ -193,8 +193,13 @@ public MapType(AlgebraicType key, AlgebraicType value)
     }
 
     [SpacetimeDB.Type]
-    public partial struct BuiltinType
+    public partial struct AlgebraicType
         : SpacetimeDB.TaggedEnum<(
+            AlgebraicTypeRef TypeRef,
+            SumType Sum,
+            ProductType Product,
+            AlgebraicType Array,
+            MapType Map,
             Unit Bool,
             Unit I8,
             Unit U8,
@@ -208,68 +213,81 @@ public partial struct BuiltinType
             Unit U128,
             Unit F32,
             Unit F64,
-            Unit String,
-            AlgebraicType Array,
-            MapType Map
+            Unit String
         )>
     {
+        public static implicit operator AlgebraicType(AlgebraicTypeRef typeRef)
+        {
+            return new AlgebraicType { TypeRef = typeRef };
+        }
+
+        public static implicit operator AlgebraicType(SumType sum)
+        {
+            return new AlgebraicType { Sum = sum };
+        }
+
+        public static implicit operator AlgebraicType(ProductType product)
+        {
+            return new AlgebraicType { Product = product };
+        }
+
         public static readonly TypeInfo<bool> BoolTypeInfo = new TypeInfo<bool>(
-            new BuiltinType { Bool = default },
+            new AlgebraicType { Bool = default },
             (reader) => reader.ReadBoolean(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<sbyte> I8TypeInfo = new TypeInfo<sbyte>(
-            new BuiltinType { I8 = default },
+            new AlgebraicType { I8 = default },
             (reader) => reader.ReadSByte(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<byte> U8TypeInfo = new TypeInfo<byte>(
-            new BuiltinType { U8 = default },
+            new AlgebraicType { U8 = default },
             (reader) => reader.ReadByte(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<short> I16TypeInfo = new TypeInfo<short>(
-            new BuiltinType { I16 = default },
+            new AlgebraicType { I16 = default },
             (reader) => reader.ReadInt16(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<ushort> U16TypeInfo = new TypeInfo<ushort>(
-            new BuiltinType { U16 = default },
+            new AlgebraicType { U16 = default },
             (reader) => reader.ReadUInt16(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<int> I32TypeInfo = new TypeInfo<int>(
-            new BuiltinType { I32 = default },
+            new AlgebraicType { I32 = default },
             (reader) => reader.ReadInt32(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<uint> U32TypeInfo = new TypeInfo<uint>(
-            new BuiltinType { U32 = default },
+            new AlgebraicType { U32 = default },
             (reader) => reader.ReadUInt32(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<long> I64TypeInfo = new TypeInfo<long>(
-            new BuiltinType { I64 = default },
+            new AlgebraicType { I64 = default },
             (reader) => reader.ReadInt64(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<ulong> U64TypeInfo = new TypeInfo<ulong>(
-            new BuiltinType { U64 = default },
+            new AlgebraicType { U64 = default },
             (reader) => reader.ReadUInt64(),
             (writer, value) => writer.Write(value)
         );
 
 #if NET7_0_OR_GREATER
         public static readonly TypeInfo<Int128> I128TypeInfo = new TypeInfo<Int128>(
-            new BuiltinType { I128 = default },
+            new AlgebraicType { I128 = default },
             (reader) => new Int128(reader.ReadUInt64(), reader.ReadUInt64()),
             (writer, value) =>
             {
@@ -279,7 +297,7 @@ MapType Map
         );
 
         public static readonly TypeInfo<UInt128> U128TypeInfo = new TypeInfo<UInt128>(
-            new BuiltinType { U128 = default },
+            new AlgebraicType { U128 = default },
             (reader) => new UInt128(reader.ReadUInt64(), reader.ReadUInt64()),
             (writer, value) =>
             {
@@ -290,19 +308,19 @@ MapType Map
 #endif
 
         public static readonly TypeInfo<float> F32TypeInfo = new TypeInfo<float>(
-            new BuiltinType { F32 = default },
+            new AlgebraicType { F32 = default },
             (reader) => reader.ReadSingle(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<double> F64TypeInfo = new TypeInfo<double>(
-            new BuiltinType { F64 = default },
+            new AlgebraicType { F64 = default },
             (reader) => reader.ReadDouble(),
             (writer, value) => writer.Write(value)
         );
 
         public static readonly TypeInfo<byte[]> BytesTypeInfo = new TypeInfo<byte[]>(
-            new BuiltinType { Array = U8TypeInfo.AlgebraicType },
+            new AlgebraicType { Array = U8TypeInfo.AlgebraicType },
             (reader) =>
             {
                 var length = reader.ReadInt32();
@@ -316,7 +334,7 @@ MapType Map
         );
 
         public static readonly TypeInfo<string> StringTypeInfo = new TypeInfo<string>(
-            new BuiltinType { String = default },
+            new AlgebraicType { String = default },
             (reader) => Encoding.UTF8.GetString(BytesTypeInfo.Read(reader)),
             (writer, value) => BytesTypeInfo.Write(writer, Encoding.UTF8.GetBytes(value))
         );
@@ -350,7 +368,7 @@ TypeInfo<T> elementTypeInfo
             where A : ICollection<T>
         {
             return new TypeInfo<A>(
-                new BuiltinType { Array = elementTypeInfo.AlgebraicType },
+                new AlgebraicType { Array = elementTypeInfo.AlgebraicType },
                 (reader) => create(ReadEnumerable(reader, elementTypeInfo.Read)),
                 (writer, array) => WriteEnumerable(writer, array, elementTypeInfo.Write)
             );
@@ -366,7 +384,7 @@ public static TypeInfo<Dictionary<K, V>> MakeMap<K, V>(TypeInfo<K> key, TypeInfo
             where K : notnull
         {
             return new TypeInfo<Dictionary<K, V>>(
-                new BuiltinType { Map = new MapType(key.AlgebraicType, value.AlgebraicType) },
+                new AlgebraicType { Map = new MapType(key.AlgebraicType, value.AlgebraicType) },
                 (reader) =>
                     ReadEnumerable(
                             reader,
@@ -422,36 +440,6 @@ public static TypeInfo<T> MakeEnum<T>()
         }
     }
 
-    [SpacetimeDB.Type]
-    public partial struct AlgebraicType
-        : SpacetimeDB.TaggedEnum<(
-            SumType Sum,
-            ProductType Product,
-            BuiltinType Builtin,
-            AlgebraicTypeRef TypeRef
-        )>
-    {
-        public static implicit operator AlgebraicType(SumType sum)
-        {
-            return new AlgebraicType { Sum = sum };
-        }
-
-        public static implicit operator AlgebraicType(ProductType product)
-        {
-            return new AlgebraicType { Product = product };
-        }
-
-        public static implicit operator AlgebraicType(BuiltinType builtin)
-        {
-            return new AlgebraicType { Builtin = builtin };
-        }
-
-        public static implicit operator AlgebraicType(AlgebraicTypeRef typeRef)
-        {
-            return new AlgebraicType { TypeRef = typeRef };
-        }
-    }
-
     [SpacetimeDB.Type]
     public partial struct AlgebraicTypeRef
     {
diff --git a/crates/bindings-csharp/Runtime/Runtime.cs b/crates/bindings-csharp/Runtime/Runtime.cs
index c434fbdcaa..3230712607 100644
--- a/crates/bindings-csharp/Runtime/Runtime.cs
+++ b/crates/bindings-csharp/Runtime/Runtime.cs
@@ -206,11 +206,11 @@ public override int GetHashCode() =>
                 // We need to set type info to inlined identity type as `generate` CLI currently can't recognise type references for built-ins.
                 new SpacetimeDB.SATS.ProductType
                 {
-                    { "__identity_bytes", SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.AlgebraicType }
+                    { "__identity_bytes", SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.AlgebraicType }
                 },
-                reader => new(SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.Read(reader)),
+                reader => new(SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.Read(reader)),
                 (writer, value) =>
-                    SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.Write(writer, value.bytes)
+                    SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.Write(writer, value.bytes)
             );
 
         public static SpacetimeDB.SATS.TypeInfo<Identity> GetSatsTypeInfo() => satsTypeInfo;
@@ -243,7 +243,7 @@ public override int GetHashCode() =>
                 // We need to set type info to inlined address type as `generate` CLI currently can't recognise type references for built-ins.
                 new SpacetimeDB.SATS.ProductType
                 {
-                  { "__address_bytes", SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.AlgebraicType }
+                  { "__address_bytes", SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.AlgebraicType }
                 },
                 // Concern: We use this "packed" representation (as Bytes)
                 //          in the caller_id field of reducer arguments,
@@ -252,9 +252,9 @@ public override int GetHashCode() =>
                 //          It's possible that these happen to be identical
                 //          because BSATN is minimally self-describing,
                 //          but that doesn't seem like something we should count on.
-                reader => new(SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.Read(reader)),
+                reader => new(SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.Read(reader)),
                 (writer, value) =>
-                    SpacetimeDB.SATS.BuiltinType.BytesTypeInfo.Write(writer, value.bytes)
+                    SpacetimeDB.SATS.AlgebraicType.BytesTypeInfo.Write(writer, value.bytes)
             );
 
         public static SpacetimeDB.SATS.TypeInfo<Address> GetSatsTypeInfo() => satsTypeInfo;