diff --git a/examples/simple.exs b/examples/simple.exs
new file mode 100644
index 00000000..53290aae
--- /dev/null
+++ b/examples/simple.exs
@@ -0,0 +1,9 @@
+Mix.install([{:ex_webrtc, path: "./"}])
+
+alias ExWebRTC.PeerConnection
+
+{:ok, pc} = PeerConnection.start_link()
+
+{:ok, offer} = PeerConnection.create_offer(pc)
+
+IO.inspect(offer.sdp, label: :OFFER)
diff --git a/lib/ex_webrtc.ex b/lib/ex_webrtc.ex
deleted file mode 100644
index 47d72228..00000000
--- a/lib/ex_webrtc.ex
+++ /dev/null
@@ -1,3 +0,0 @@
-defmodule ExWebRTC do
-  @moduledoc false
-end
diff --git a/lib/ex_webrtc/peer_connection.ex b/lib/ex_webrtc/peer_connection.ex
new file mode 100644
index 00000000..adf9a4ca
--- /dev/null
+++ b/lib/ex_webrtc/peer_connection.ex
@@ -0,0 +1,99 @@
+defmodule ExWebRTC.PeerConnection do
+  @moduledoc false
+
+  use GenServer
+
+  alias ExWebRTC.SessionDescription
+
+  @type peer_connection() :: GenServer.server()
+
+  @type bundle_policy() ::
+    :balanced
+    | :max_compat
+    | :max_bundle
+
+  @type configuration() :: [
+    bundle_policy: bundle_policy(),
+    certificates: term(),
+    ice_candidate_pool_size: term(),
+    ice_servers: term(),
+    ice_transport_policy: term(),
+    peer_identity: term(),
+    rtcp_mux_policy: term()
+  ]
+
+  @type offer_options() :: [ice_restart: boolean()]
+  @type answer_options() :: []
+
+  #### API ####
+
+  def start_link(configuration \\ []) do
+    GenServer.start_link(__MODULE__, configuration)
+  end
+
+  def start(configuration \\ []) do
+    GenServer.start(__MODULE__, configuration)
+  end
+
+  @spec create_offer(peer_connection(), offer_options()) :: {:ok, SessionDescription.t()} | {:error, :TODO}  # TODO reason
+  def create_offer(peer_connection, options \\ []) do
+    GenServer.call(peer_connection, {:create_offer, options})
+  end
+
+  @spec create_answer(peer_connection(), answer_options()) :: {:ok, SessionDescription.t()} | {:error, :TODO}  # TODO reasons
+  def create_answer(peer_connection, options \\ []) do
+    GenServer.call(peer_connection, {:create_answer, options})
+  end
+
+  @spec set_local_description(peer_connection(), SessionDescription.t()) :: :ok | {:error, :TODO}  # TODO resons
+  def set_local_description(peer_connection, description) do
+    GenServer.call(peer_connection, {:set_local_description, description})
+  end
+
+  @spec set_remote_description(peer_connection(), SessionDescription.t()) :: :ok | {:error, :TODO}  # TODO resons
+  def set_remote_description(peer_connection, description) do
+    GenServer.call(peer_connection, {:set_remote_description, description})
+  end
+
+  #### CALLBACKS ####
+
+  @impl true
+  def init(config) do
+    _bundle_policy = Keyword.get(config, :bundle_policy, :balanced)
+    {:ok, %{}}
+  end
+
+  @impl true
+  def handle_call({:create_offer, options}, _from, state) do
+    _ice_restart = Keyword.get(options, :ice_restart, false)
+
+    sdp = 
+      %{ExSDP.new() | timing: %ExSDP.Timing{start_time: 0, stop_time: 0}}
+      |> ExSDP.add_attribute({:ice_options, "trickle"})
+
+    # identity?
+
+    # for each RTPTransceiver add "m=" section
+
+    desc = %SessionDescription{type: :offer, sdp: to_string(sdp)}
+    {:reply, {:ok, desc}, state}
+  end
+
+  @impl true
+  def handle_call({:create_answer, _options}, _from, state) do
+    sdp = ExSDP.new()
+
+    desc = %SessionDescription{type: :answer, sdp: to_string(sdp)}
+    {:reply, {:ok, desc}, state}
+  end
+
+  @impl true
+  def handle_call({:set_local_description, _desc}, _from, state) do
+    {:reply, :ok, state}
+  end
+
+  @impl true
+  def handle_call({:set_remote_description, _desc}, _from, state) do
+    {:reply, :ok, state}
+  end
+end
diff --git a/lib/ex_webrtc/session_description.ex b/lib/ex_webrtc/session_description.ex
new file mode 100644
index 00000000..b63da7f7
--- /dev/null
+++ b/lib/ex_webrtc/session_description.ex
@@ -0,0 +1,17 @@
+defmodule ExWebRTC.SessionDescription do
+  @moduledoc false
+
+  @type description_type() ::
+    :answer
+    | :offer
+    | :pranswer
+    | :rollback
+
+  @type t() :: %__MODULE__{
+    type: description_type(),
+    sdp: String.t()
+  }
+
+  @enforce_keys [:type, :sdp]
+  defstruct @enforce_keys
+end
diff --git a/mix.exs b/mix.exs
index 6ca2efa2..974952b8 100644
--- a/mix.exs
+++ b/mix.exs
@@ -48,7 +48,10 @@ defmodule ExWebRTC.MixProject do
       {:excoveralls, "~> 0.14", only: [:dev, :test], runtime: false},
       {:ex_doc, "~> 0.30", only: :dev, runtime: false},
       {:credo, "~> 1.7", only: [:dev, :test], runtime: false},
-      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false}
+      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false},
+
+      {:ex_sdp, "~> 0.11"},
+      {:ex_ice, "~> 0.1"}
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index 02a27f39..51dc4eb8 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,10 +1,14 @@
 %{
+  "bunch": {:hex, :bunch, "1.6.0", "4775f8cdf5e801c06beed3913b0bd53fceec9d63380cdcccbda6be125a6cfd54", [:mix], [], "hexpm", "ef4e9abf83f0299d599daed3764d19e8eac5d27a5237e5e4d5e2c129cfeb9a22"},
   "bunt": {:hex, :bunt, "0.2.1", "e2d4792f7bc0ced7583ab54922808919518d0e57ee162901a16a1b6664ef3b14", [:mix], [], "hexpm", "a330bfb4245239787b15005e66ae6845c9cd524a288f0d141c148b02603777a5"},
   "credo": {:hex, :credo, "1.7.0", "6119bee47272e85995598ee04f2ebbed3e947678dee048d10b5feca139435f75", [:mix], [{:bunt, "~> 0.2.1", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "6839fcf63d1f0d1c0f450abc8564a57c43d644077ab96f2934563e68b8a769d7"},
   "dialyxir": {:hex, :dialyxir, "1.4.1", "a22ed1e7bd3a3e3f197b68d806ef66acb61ee8f57b3ac85fc5d57354c5482a93", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "84b795d6d7796297cca5a3118444b80c7d94f7ce247d49886e7c291e1ae49801"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.34", "b0fbb4fd333ee7e9babc07e9573796850759cd12796fcf2fec59cf0031cbaad9", [:mix], [], "hexpm", "cc0d7a6f2367e4504867b4ec38ceee24e89ee6bca9c7b94a6d940f54aba2e8d5"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
   "ex_doc": {:hex, :ex_doc, "0.30.6", "5f8b54854b240a2b55c9734c4b1d0dd7bdd41f71a095d42a70445c03cf05a281", [:mix], [{:earmark_parser, "~> 1.4.31", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "bd48f2ddacf4e482c727f9293d9498e0881597eae6ddc3d9562bd7923375109f"},
+  "ex_ice": {:hex, :ex_ice, "0.1.0", "2653c884872d8769cf9fc655c74002a63ed6c21be1b3c2badfa42bdc74de2355", [:mix], [{:ex_stun, "~> 0.1.0", [hex: :ex_stun, repo: "hexpm", optional: false]}], "hexpm", "e2539a321f87f31997ba974d532d00511e5828f2f113b550b1ef6aa799dd2ffe"},
+  "ex_sdp": {:hex, :ex_sdp, "0.11.0", "19e3af1d70b945381752db3139dfc22a19da1e9394036721449b7fb8c49fe039", [:mix], [{:bunch, "~> 1.3", [hex: :bunch, repo: "hexpm", optional: false]}, {:uuid, "~> 1.1", [hex: :uuid, repo: "hexpm", optional: false]}], "hexpm", "7a3fe42f4ec0c18de09b10464829c27482d81d9c50c21bdebdbcfe17d2046408"},
+  "ex_stun": {:hex, :ex_stun, "0.1.0", "252474bf4c8519fbf4bc0fbfc6a1b846a634b1478c65dbbfb4b6ab4e33c2a95a", [:mix], [], "hexpm", "629fc8be45b624a92522f81d85ba001877b1f0745889a2419bdb678790d7480c"},
   "excoveralls": {:hex, :excoveralls, "0.17.1", "83fa7906ef23aa7fc8ad7ee469c357a63b1b3d55dd701ff5b9ce1f72442b2874", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "95bc6fda953e84c60f14da4a198880336205464e75383ec0f570180567985ae0"},
   "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
   "jason": {:hex, :jason, "1.4.1", "af1504e35f629ddcdd6addb3513c3853991f694921b1b9368b0bd32beb9f1b63", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "fbb01ecdfd565b56261302f7e1fcc27c4fb8f32d56eab74db621fc154604a7a1"},
@@ -12,4 +16,5 @@
   "makeup_elixir": {:hex, :makeup_elixir, "0.16.1", "cc9e3ca312f1cfeccc572b37a09980287e243648108384b97ff2b76e505c3555", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "e127a341ad1b209bd80f7bd1620a15693a9908ed780c3b763bccf7d200c767c6"},
   "makeup_erlang": {:hex, :makeup_erlang, "0.1.2", "ad87296a092a46e03b7e9b0be7631ddcf64c790fa68a9ef5323b6cbb36affc72", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "f3f5a1ca93ce6e092d92b6d9c049bcda58a3b617a8d888f8e7231c85630e8108"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.3.1", "2c54013ecf170e249e9291ed0a62e5832f70a476c61da16f6aac6dca0189f2af", [:mix], [], "hexpm", "2682e3c0b2eb58d90c6375fc0cc30bc7be06f365bf72608804fb9cffa5e1b167"},
+  "uuid": {:hex, :uuid, "1.1.8", "e22fc04499de0de3ed1116b770c7737779f226ceefa0badb3592e64d5cfb4eb9", [:mix], [], "hexpm", "c790593b4c3b601f5dc2378baae7efaf5b3d73c4c6456ba85759905be792f2ac"},
 }