diff --git a/lib/poa_agent/entity/ethereum/block.ex b/lib/poa_agent/entity/ethereum/block.ex
new file mode 100644
index 0000000..d986401
--- /dev/null
+++ b/lib/poa_agent/entity/ethereum/block.ex
@@ -0,0 +1,6 @@
+defmodule POAAgent.Entity.Ethereum.Block do
+  @type t :: %__MODULE__{
+  }
+  defstruct [
+  ]
+end
diff --git a/lib/poa_agent/entity/ethereum/history.ex b/lib/poa_agent/entity/ethereum/history.ex
new file mode 100644
index 0000000..c8621f0
--- /dev/null
+++ b/lib/poa_agent/entity/ethereum/history.ex
@@ -0,0 +1,3 @@
+defmodule POAAgent.Entity.Ethereum.History do
+  @type t :: [POAAgent.Entity.Ethereum.Block.t]
+end
diff --git a/lib/poa_agent/entity/ethereum/statistics.ex b/lib/poa_agent/entity/ethereum/statistics.ex
new file mode 100644
index 0000000..5044ad4
--- /dev/null
+++ b/lib/poa_agent/entity/ethereum/statistics.ex
@@ -0,0 +1,6 @@
+defmodule POAAgent.Entity.Ethereum.Statistics do
+  @type t :: %__MODULE__{
+  }
+  defstruct [
+  ]
+end
diff --git a/lib/poa_agent/entity/host/information.ex b/lib/poa_agent/entity/host/information.ex
new file mode 100644
index 0000000..0a738c1
--- /dev/null
+++ b/lib/poa_agent/entity/host/information.ex
@@ -0,0 +1,6 @@
+defmodule POAAgent.Entity.Host.Information do
+  @type t :: %__MODULE__{
+  }
+  defstruct [
+  ]
+end