diff --git a/lib/zenohex.ex b/lib/zenohex.ex
index 902a0a9..3c97c97 100644
--- a/lib/zenohex.ex
+++ b/lib/zenohex.ex
@@ -1,13 +1,20 @@
 defmodule Zenohex do
   @moduledoc """
-  Documentation for `Zenohex`.
+  Documentation for `#{__MODULE__}`.
   """
 
-  @doc """
+  alias Zenohex.Nif
+  alias Zenohex.Session
 
+  @doc ~S"""
+  Open a zenoh Session.
+
+  ## Examples
+
+      iex> Zenohex.open!()
   """
-  @spec open :: NifZenoh.session()
-  def open do
-    NifZenoh.zenoh_open()
+  @spec open! :: Session.t()
+  def open!() do
+    Nif.zenoh_open()
   end
 end
diff --git a/lib/zenohex/nif.ex b/lib/zenohex/nif.ex
index c00c9c8..06c5c31 100644
--- a/lib/zenohex/nif.ex
+++ b/lib/zenohex/nif.ex
@@ -1,4 +1,6 @@
 defmodule Zenohex.Nif do
+  @moduledoc false
+
   use Rustler, otp_app: :zenohex, crate: "zenohex_nif"
 
   alias Zenohex.Publisher
diff --git a/lib/zenohex/publisher.ex b/lib/zenohex/publisher.ex
index bea740f..4da4212 100644
--- a/lib/zenohex/publisher.ex
+++ b/lib/zenohex/publisher.ex
@@ -1,21 +1,42 @@
 defmodule Zenohex.Publisher do
+  @moduledoc """
+  Documentation for `#{__MODULE__}`.
+  """
+
   alias Zenohex.Nif
 
   @type t :: reference()
-  @type congestion_control :: :drop | :block
-  @type priority ::
-          :real_time
-          | :interactive_high
-          | :interactive_low
-          | :data_high
-          | :data
-          | :data_low
-          | :background
 
   defmodule Options do
+    @moduledoc """
+    Documentation for `#{__MODULE__}`.
+    """
+
+    @type t :: %__MODULE__{congestion_control: congestion_control(), priority: priority()}
+    @type congestion_control :: :drop | :block
+    @type priority ::
+            :real_time
+            | :interactive_high
+            | :interactive_low
+            | :data_high
+            | :data
+            | :data_low
+            | :background
+
     defstruct congestion_control: :drop, priority: :data
   end
 
+  @doc ~S"""
+  Put data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> publisher = Zenohex.Session.declare_publisher!(session, "key/expression")
+      iex> :ok = Zenohex.Publisher.put!(publisher, "value")
+      iex> :ok = Zenohex.Publisher.put!(publisher, 0)
+      iex> :ok = Zenohex.Publisher.put!(publisher, 0.0)
+  """
   @spec put!(t(), binary()) :: :ok
   def put!(publisher, value) when is_binary(value) do
     Nif.publisher_put_binary(publisher, value)
@@ -31,17 +52,44 @@ defmodule Zenohex.Publisher do
     Nif.publisher_put_float(publisher, value)
   end
 
+  @doc ~S"""
+  Delete data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> publisher = Zenohex.Session.declare_publisher!(session, "key/expression")
+      iex> :ok = Zenohex.Publisher.delete!(publisher)
+  """
   @spec delete!(t()) :: :ok
   def delete!(publisher) do
     Nif.publisher_delete(publisher)
   end
 
-  @spec congestion_control!(t(), congestion_control()) :: t()
+  @doc ~S"""
+  Change the congestion_control to apply when routing the data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> publisher = Zenohex.Session.declare_publisher!(session, "key/expression")
+      iex> Zenohex.Publisher.congestion_control!(publisher, :drop)
+  """
+  @spec congestion_control!(t(), Options.congestion_control()) :: t()
   def congestion_control!(publisher, congestion_control) do
     Nif.publisher_congestion_control(publisher, congestion_control)
   end
 
-  @spec priority!(t(), priority()) :: t()
+  @doc ~S"""
+  Change the priority of the written data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> publisher = Zenohex.Session.declare_publisher!(session, "key/expression")
+      iex> Zenohex.Publisher.priority!(publisher, :real_time)
+  """
+  @spec priority!(t(), Options.priority()) :: t()
   def priority!(publisher, priority) do
     Nif.publisher_priority(publisher, priority)
   end
diff --git a/lib/zenohex/pull_subscriber.ex b/lib/zenohex/pull_subscriber.ex
index 0ae5c9a..3cb5130 100644
--- a/lib/zenohex/pull_subscriber.ex
+++ b/lib/zenohex/pull_subscriber.ex
@@ -1,15 +1,40 @@
 defmodule Zenohex.PullSubscriber do
+  @moduledoc """
+  Documentation for `#{__MODULE__}`.
+  """
+
   alias Zenohex.Nif
 
   @type t :: reference()
 
+  @doc """
+  Pull data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> subscriber = Zenohex.Session.declare_pull_subscriber!(session, "key/expression")
+      iex> Zenohex.PullSubscriber.pull!(subscriber)
+      :ok
+  """
   @spec pull!(t()) :: :ok
-  def pull!(pull_subscriber) do
+  def pull!(pull_subscriber) when is_reference(pull_subscriber) do
     Nif.pull_subscriber_pull(pull_subscriber)
   end
 
-  @spec recv_timeout!(t(), non_neg_integer()) :: integer() | float() | binary() | :timeout
-  def recv_timeout!(pull_subscriber, timeout_us) do
+  @doc """
+  Receive data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> subscriber = Zenohex.Session.declare_pull_subscriber!(session, "key/expression")
+      iex> Zenohex.PullSubscriber.recv_timeout!(subscriber, 1000)
+      :timeout
+  """
+  @spec recv_timeout!(t(), pos_integer()) :: integer() | float() | binary() | :timeout
+  def recv_timeout!(pull_subscriber, timeout_us)
+      when is_reference(pull_subscriber) and is_integer(timeout_us) and timeout_us > 0 do
     Nif.pull_subscriber_recv_timeout(pull_subscriber, timeout_us)
   end
 end
diff --git a/lib/zenohex/queryable.ex b/lib/zenohex/queryable.ex
index 6b449ef..0bda468 100644
--- a/lib/zenohex/queryable.ex
+++ b/lib/zenohex/queryable.ex
@@ -1,8 +1,17 @@
 defmodule Zenohex.Queryable do
+  @moduledoc """
+  Documentation for `#{__MODULE__}`.
+  """
+
   @type t :: reference()
-  @type complete :: boolean()
 
   defmodule Options do
+    @moduledoc """
+    Documentation for `#{__MODULE__}`.
+    """
+
+    @type t :: %__MODULE__{complete: complete()}
+    @type complete :: boolean()
     defstruct complete: false
   end
 end
diff --git a/lib/zenohex/session.ex b/lib/zenohex/session.ex
new file mode 100644
index 0000000..cc825c8
--- /dev/null
+++ b/lib/zenohex/session.ex
@@ -0,0 +1,128 @@
+defmodule Zenohex.Session do
+  @moduledoc """
+  Documentation for `#{__MODULE__}`.
+  """
+
+  alias Zenohex.Nif
+  alias Zenohex.Publisher
+  alias Zenohex.Subscriber
+  alias Zenohex.Queryable
+
+  @type t :: reference()
+
+  @doc ~S"""
+  Create a Publisher for the given key expression.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.declare_publisher!(session, "key/expression")
+  """
+  @spec declare_publisher!(t(), String.t(), Publisher.Options.t()) :: Publisher.t()
+  def declare_publisher!(session, key_expr, opts \\ %Publisher.Options{})
+      when is_reference(session) and is_binary(key_expr) and is_struct(opts, Publisher.Options) do
+    Nif.declare_publisher(session, key_expr, opts)
+  end
+
+  @doc ~S"""
+  Create a Subscriber for the given key expression.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.declare_subscriber!(session, "key/expression")
+  """
+  @spec declare_subscriber!(t(), String.t(), Subscriber.Options.t()) :: Subscriber.t()
+  def declare_subscriber!(session, key_expr, opts \\ %Subscriber.Options{})
+      when is_reference(session) and is_binary(key_expr) and is_struct(opts, Subscriber.Options) do
+    Nif.declare_subscriber(session, key_expr, opts)
+  end
+
+  @doc ~S"""
+  Create a PullSubscriber for the given key expression.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.declare_pull_subscriber!(session, "key/expression")
+  """
+  @spec declare_pull_subscriber!(t(), String.t(), Subscriber.Options.t()) :: Subscriber.t()
+  def declare_pull_subscriber!(session, key_expr, opts \\ %Subscriber.Options{})
+      when is_reference(session) and is_binary(key_expr) and is_struct(opts, Subscriber.Options) do
+    Nif.declare_pull_subscriber(session, key_expr, opts)
+  end
+
+  @doc ~S"""
+  Create a Quaryable for the given key expression.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.declare_queryable!(session, "key/expression")
+  """
+  @spec declare_queryable!(t(), String.t(), Queryable.Options.t()) :: Queryable.t()
+  def declare_queryable!(session, key_expr, opts \\ %Queryable.Options{})
+      when is_reference(session) and is_binary(key_expr) and is_struct(opts, Queryable.Options) do
+    Nif.declare_queryable(session, key_expr, opts)
+  end
+
+  @doc ~S"""
+  Put data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> :ok = Zenohex.Session.put!(session, "key/expression", "value")
+      iex> :ok = Zenohex.Session.put!(session, "key/expression", 0)
+      iex> :ok = Zenohex.Session.put!(session, "key/expression", 0.0)
+  """
+  @spec put!(t(), String.t(), binary()) :: :ok
+  def put!(session, key_expr, value)
+      when is_reference(session) and is_binary(key_expr) and is_binary(value) do
+    Nif.session_put_binary(session, key_expr, value)
+  end
+
+  @spec put!(t(), String.t(), integer()) :: :ok
+  def put!(session, key_expr, value)
+      when is_reference(session) and is_binary(key_expr) and is_integer(value) do
+    Nif.session_put_integer(session, key_expr, value)
+  end
+
+  @spec put!(t(), String.t(), float()) :: :ok
+  def put!(session, key_expr, value)
+      when is_reference(session) and is_binary(key_expr) and is_float(value) do
+    Nif.session_put_float(session, key_expr, value)
+  end
+
+  @doc ~S"""
+  Query data from the matching queryables in the system.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.get_timeout!(session, "key/**", 1000)
+      :timeout
+  """
+  @spec get_timeout!(t(), String.t(), pos_integer()) ::
+          binary() | integer() | float() | :timeout
+  # FIXME 返り値がリストになるケースがあるはずなので、 Nif を含めて見直し修正すること
+  def get_timeout!(session, selector, timeout_us)
+      when is_reference(session) and is_binary(selector) and is_integer(timeout_us) and
+             timeout_us > 0 do
+    Nif.session_get_timeout(session, selector, timeout_us)
+  end
+
+  @doc ~S"""
+  Delete data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> Zenohex.Session.delete!(session, "key/expression")
+      :ok
+  """
+  @spec delete!(t(), String.t()) :: :ok
+  def delete!(session, key_expr) when is_reference(session) and is_binary(key_expr) do
+    Nif.session_delete(session, key_expr)
+  end
+end
diff --git a/lib/zenohex/subscriber.ex b/lib/zenohex/subscriber.ex
index 45aab7c..3c9fe57 100644
--- a/lib/zenohex/subscriber.ex
+++ b/lib/zenohex/subscriber.ex
@@ -1,15 +1,35 @@
 defmodule Zenohex.Subscriber do
+  @moduledoc """
+  Documentation for `#{__MODULE__}`.
+  """
+
   alias Zenohex.Nif
 
-  @type t :: reference()
-  @type reliability :: :best_effort | :reliable
+  @opaque t :: reference()
 
   defmodule Options do
+    @moduledoc """
+    Documentation for `#{__MODULE__}`.
+    """
+
+    @type t :: %__MODULE__{reliability: reliability()}
+    @type reliability :: :best_effort | :reliable
     defstruct reliability: :best_effort
   end
 
-  @spec recv_timeout!(t(), non_neg_integer()) :: integer() | float() | binary() | :timeout
-  def recv_timeout!(subscriber, timeout_us) do
+  @doc """
+  Receive data.
+
+  ## Examples
+
+      iex> session = Zenohex.open!()
+      iex> subscriber = Zenohex.Session.declare_subscriber!(session, "key/expression")
+      iex> Zenohex.Subscriber.recv_timeout!(subscriber, 1000)
+      :timeout
+  """
+  @spec recv_timeout!(t(), pos_integer()) :: integer() | float() | binary() | :timeout
+  def recv_timeout!(subscriber, timeout_us)
+      when is_reference(subscriber) and is_integer(timeout_us) and timeout_us > 0 do
     Nif.subscriber_recv_timeout(subscriber, timeout_us)
   end
 end
diff --git a/test/zenohex/nif_test.exs b/test/zenohex/nif_test.exs
index 36b6069..908b3da 100644
--- a/test/zenohex/nif_test.exs
+++ b/test/zenohex/nif_test.exs
@@ -1,5 +1,5 @@
 defmodule Zenohex.NifTest do
-  use ExUnit.Case
+  use ExUnit.Case, async: true
 
   alias Zenohex.Nif
 
diff --git a/test/zenohex/publisher_test.exs b/test/zenohex/publisher_test.exs
new file mode 100644
index 0000000..87eee73
--- /dev/null
+++ b/test/zenohex/publisher_test.exs
@@ -0,0 +1,4 @@
+defmodule Zenohex.PublisherTest do
+  use ExUnit.Case, async: true
+  doctest Zenohex.Publisher
+end
diff --git a/test/zenohex/pull_subscriber_test.exs b/test/zenohex/pull_subscriber_test.exs
new file mode 100644
index 0000000..8272d6b
--- /dev/null
+++ b/test/zenohex/pull_subscriber_test.exs
@@ -0,0 +1,4 @@
+defmodule Zenohex.PullSubscriberTest do
+  use ExUnit.Case, async: true
+  doctest Zenohex.PullSubscriber
+end
diff --git a/test/zenohex/session_test.exs b/test/zenohex/session_test.exs
new file mode 100644
index 0000000..d00c612
--- /dev/null
+++ b/test/zenohex/session_test.exs
@@ -0,0 +1,4 @@
+defmodule Zenohex.SessionTest do
+  use ExUnit.Case, async: true
+  doctest Zenohex.Session
+end
diff --git a/test/zenohex/subscriber_test.exs b/test/zenohex/subscriber_test.exs
new file mode 100644
index 0000000..4d055a8
--- /dev/null
+++ b/test/zenohex/subscriber_test.exs
@@ -0,0 +1,4 @@
+defmodule Zenohex.SubscriberTest do
+  use ExUnit.Case, async: true
+  doctest Zenohex.Subscriber
+end
diff --git a/test/zenohex_test.exs b/test/zenohex_test.exs
index 720da75..cb93faa 100644
--- a/test/zenohex_test.exs
+++ b/test/zenohex_test.exs
@@ -1,4 +1,17 @@
 defmodule ZenohexTest do
-  use ExUnit.Case
+  use ExUnit.Case, async: true
   doctest Zenohex
+
+  test "pub/sub" do
+    session = Zenohex.open!()
+    publisher = Zenohex.Session.declare_publisher!(session, "pub/sub")
+    subscriber = Zenohex.Session.declare_subscriber!(session, "pub/sub")
+
+    for i <- 1..100 do
+      :ok = Zenohex.Publisher.put!(publisher, "Hello Zenoh Dragon #{i}")
+
+      assert Zenohex.Subscriber.recv_timeout!(subscriber, 1000) ==
+               "Hello Zenoh Dragon #{i}"
+    end
+  end
 end