diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -23,6 +23,7 @@
     * Node.js version 5.0.0 or newer is required.
     * Install dependencies with `npm install`
     * Install babel presets: `npm install babel-preset-es2015 babel-preset-es2016`
+* Initialize database: `mix amnesia.create -db KolabChat.Database --disk`
 * Start Phoenix endpoint with `mix phoenix.server`
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.
diff --git a/config/config.exs b/config/config.exs
--- a/config/config.exs
+++ b/config/config.exs
@@ -7,7 +7,6 @@
 
 # General application configuration
 config :kolab_chat,
-  ecto_repos: [KolabChat.Repo],
   salts: [session_signing: "M7HpCp6W",
           session_encryption: nil]
 
diff --git a/config/dev.exs b/config/dev.exs
--- a/config/dev.exs
+++ b/config/dev.exs
@@ -32,12 +32,3 @@
 # Set a higher stacktrace during development. Avoid configuring such
 # in production as building large stacktraces may be expensive.
 config :phoenix, :stacktrace_depth, 20
-
-# Configure your database
-config :kolab_chat, KolabChat.Repo,
-  adapter: Ecto.Adapters.MySQL,
-  username: "root",
-  password: "12345",
-  database: "kolab_chat_dev",
-  hostname: "localhost",
-  pool_size: 10
diff --git a/config/test.exs b/config/test.exs
--- a/config/test.exs
+++ b/config/test.exs
@@ -8,12 +8,3 @@
 
 # Print only warnings and errors during test
 config :logger, level: :warn
-
-# Configure your database
-config :kolab_chat, KolabChat.Repo,
-  adapter: Ecto.Adapters.MySQL,
-  username: "root",
-  password: "12345",
-  database: "kolab_chat_test",
-  hostname: "localhost",
-  pool: Ecto.Adapters.SQL.Sandbox
diff --git a/lib/kolab_chat.ex b/lib/kolab_chat.ex
--- a/lib/kolab_chat.ex
+++ b/lib/kolab_chat.ex
@@ -8,8 +8,6 @@
 
     # Define workers and child supervisors to be supervised
     children = [
-      # Start the Ecto repository
-      supervisor(KolabChat.Repo, []),
       # Start the endpoint when the application starts
       supervisor(KolabChat.Endpoint, []),
       # Start phoenix presence module
diff --git a/lib/kolab_chat/database.ex b/lib/kolab_chat/database.ex
new file mode 100644
--- /dev/null
+++ b/lib/kolab_chat/database.ex
@@ -0,0 +1,19 @@
+use Amnesia
+
+defdatabase KolabChat.Database do
+
+  deftable User, [{:id, autoincrement}, :username, :fullname], type: :ordered_set, index: [:username] do
+
+    # Find a user by username
+    def find(username) do
+      Amnesia.transaction do
+        case User.read_at(username, :username) do
+          nil -> nil
+          users -> Enum.at(users, 0)
+        end
+      end
+    end
+
+  end
+
+end
diff --git a/lib/kolab_chat/repo.ex b/lib/kolab_chat/repo.ex
deleted file mode 100644
--- a/lib/kolab_chat/repo.ex
+++ /dev/null
@@ -1,3 +0,0 @@
-defmodule KolabChat.Repo do
-  use Ecto.Repo, otp_app: :kolab_chat
-end
diff --git a/mix.exs b/mix.exs
--- a/mix.exs
+++ b/mix.exs
@@ -19,7 +19,7 @@
   def application do
     [mod: {KolabChat, []},
      applications: [:phoenix, :phoenix_pubsub, :phoenix_html, :cowboy, :logger, :gettext,
-                    :phoenix_ecto, :mariaex]]
+                    :amnesia]]
   end
 
   # Specifies which paths to compile per environment.
@@ -32,11 +32,10 @@
   defp deps do
     [{:phoenix, "~> 1.2.1"},
      {:phoenix_pubsub, "~> 1.0"},
-     {:phoenix_ecto, "~> 3.0"},
-     {:mariaex, "~> 0.7.9", override: true},
      {:phoenix_html, "~> 2.6"},
      {:phoenix_live_reload, "~> 1.0", only: :dev},
      {:gettext, "~> 0.11"},
+     {:amnesia, "~> 0.2.0"},
      {:cowboy, "~> 1.0"}]
   end
 
@@ -47,8 +46,6 @@
   #
   # See the documentation for `Mix` for more info on aliases.
   defp aliases do
-    ["ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
-     "ecto.reset": ["ecto.drop", "ecto.setup"],
-     "test": ["ecto.create --quiet", "ecto.migrate", "test"]]
+    []
   end
 end
diff --git a/mix.lock b/mix.lock
--- a/mix.lock
+++ b/mix.lock
@@ -1,19 +1,14 @@
-%{"connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], []},
+%{"amnesia": {:hex, :amnesia, "0.2.5", "3202e0b01e380671274caea32fbe78bbd1989e1215215f41a2d97583e5c7d163", [:mix], [{:exquisite, "~> 0.1.6", [hex: :exquisite, optional: false]}]},
   "cowboy": {:hex, :cowboy, "1.0.4", "a324a8df9f2316c833a470d918aaf73ae894278b8aa6226ce7a9bf699388f878", [:rebar, :make], [{:cowlib, "~> 1.0.0", [hex: :cowlib, optional: false]}, {:ranch, "~> 1.0", [hex: :ranch, optional: false]}]},
   "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [:make], []},
-  "db_connection": {:hex, :db_connection, "1.0.0", "63c03e520d54886a66104d34e32397ba960db6e74b596ce221592c07d6a40d8d", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, optional: true]}]},
-  "decimal": {:hex, :decimal, "1.3.1", "157b3cedb2bfcb5359372a7766dd7a41091ad34578296e951f58a946fcab49c6", [:mix], []},
-  "ecto": {:hex, :ecto, "2.0.6", "9dcbf819c2a77f67a66b83739b7fcc00b71aaf6c100016db4f798930fa4cfd47", [:mix], [{:db_connection, "~> 1.0", [hex: :db_connection, optional: true]}, {:decimal, "~> 1.1.2 or ~> 1.2", [hex: :decimal, optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, optional: true]}, {:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, optional: false]}, {:postgrex, "~> 0.12.0", [hex: :postgrex, optional: true]}, {:sbroker, "~> 1.0-beta", [hex: :sbroker, optional: true]}]},
+  "exquisite": {:hex, :exquisite, "0.1.7", "4106503e976f409246731b168cd76eb54262bd04f4facc5cba82c2f53982aaf0", [:mix], []},
   "fs": {:hex, :fs, "0.9.2", "ed17036c26c3f70ac49781ed9220a50c36775c6ca2cf8182d123b6566e49ec59", [:rebar], []},
   "gettext": {:hex, :gettext, "0.13.0", "daafbddc5cda12738bb93b01d84105fe75b916a302f1c50ab9fb066b95ec9db4", [:mix], []},
-  "mariaex": {:hex, :mariaex, "0.7.9", "52f837cf1b0717f95a0e62624bb99707329cba599885cf3bd2fdecc0172a98ad", [:mix], [{:db_connection, "~> 1.0.0-rc", [hex: :db_connection, optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, optional: false]}]},
   "mime": {:hex, :mime, "1.0.1", "05c393850524767d13a53627df71beeebb016205eb43bfbd92d14d24ec7a1b51", [:mix], []},
   "phoenix": {:hex, :phoenix, "1.2.1", "6dc592249ab73c67575769765b66ad164ad25d83defa3492dc6ae269bd2a68ab", [:mix], [{:cowboy, "~> 1.0", [hex: :cowboy, optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, optional: false]}, {:plug, "~> 1.1", [hex: :plug, optional: false]}, {:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: false]}]},
-  "phoenix_ecto": {:hex, :phoenix_ecto, "3.0.1", "42eb486ef732cf209d0a353e791806721f33ff40beab0a86f02070a5649ed00a", [:mix], [{:ecto, "~> 2.0", [hex: :ecto, optional: false]}, {:phoenix_html, "~> 2.6", [hex: :phoenix_html, optional: true]}, {:plug, "~> 1.0", [hex: :plug, optional: false]}]},
-  "phoenix_html": {:hex, :phoenix_html, "2.8.0", "777598a4b6609ad6ab8b180f7b25c9af2904644e488922bb9b9b03ce988d20b1", [:mix], [{:plug, "~> 1.0", [hex: :plug, optional: false]}]},
+  "phoenix_html": {:hex, :phoenix_html, "2.9.2", "371160b30cf4e10443b015efce6f03e1f19aae98ff6487620477b13a5b2ef660", [:mix], [{:plug, "~> 1.0", [hex: :plug, optional: false]}]},
   "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.0.6", "4490d588c4f60248b1c5f1f0dc0a7271e1aed4bddbd8b1542630f7bf6bc7b012", [:mix], [{:fs, "~> 0.9.1", [hex: :fs, optional: false]}, {:phoenix, "~> 1.0 or ~> 1.2-rc", [hex: :phoenix, optional: false]}]},
   "phoenix_pubsub": {:hex, :phoenix_pubsub, "1.0.1", "c10ddf6237007c804bf2b8f3c4d5b99009b42eca3a0dfac04ea2d8001186056a", [:mix], []},
   "plug": {:hex, :plug, "1.3.0", "6e2b01afc5db3fd011ca4a16efd9cb424528c157c30a44a0186bcc92c7b2e8f3", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1", [hex: :cowboy, optional: true]}, {:mime, "~> 1.0", [hex: :mime, optional: false]}]},
   "poison": {:hex, :poison, "2.2.0", "4763b69a8a77bd77d26f477d196428b741261a761257ff1cf92753a0d4d24a63", [:mix], []},
-  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [:rebar], []},
   "ranch": {:hex, :ranch, "1.2.1", "a6fb992c10f2187b46ffd17ce398ddf8a54f691b81768f9ef5f461ea7e28c762", [:make], []}}
diff --git a/web/channels/user_socket.ex b/web/channels/user_socket.ex
--- a/web/channels/user_socket.ex
+++ b/web/channels/user_socket.ex
@@ -1,8 +1,7 @@
 defmodule KolabChat.UserSocket do
   use Phoenix.Socket
 
-  alias KolabChat.Repo
-  alias KolabChat.User
+  alias KolabChat.Database
 
   ## Channels
   channel "room:*", KolabChat.RoomChannel
@@ -21,7 +20,7 @@
   def connect(%{"token" => token}, socket) do
     case Phoenix.Token.verify(socket, "user", token, max_age: 86400) do
       {:ok, user_id} ->
-        socket = assign(socket, :user, Repo.get!(User, user_id))
+        socket = assign(socket, :user, Database.User.read!(user_id))
         {:ok, socket}
       {:error, _} ->
         :error
diff --git a/web/controllers/auth_controller.ex b/web/controllers/auth_controller.ex
--- a/web/controllers/auth_controller.ex
+++ b/web/controllers/auth_controller.ex
@@ -1,6 +1,11 @@
 defmodule KolabChat.AuthController do
   use KolabChat.Web, :controller
 
+  # FIXME: is there a better place to put these
+  #        Both are required for using Amnesia.transaction
+  require Amnesia
+  require Amnesia.Helper
+
   @doc """
   Handler for the default logon form
   """
@@ -13,13 +18,12 @@
         |> put_flash(:error, gettext("Invalid username!"))
         |> redirect(to: "/")
       true ->
-        changeset = User.changeset(%User{}, %{username: user})
-        signin(conn, changeset)
+        signin(conn, user)
     end
   end
 
-  defp signin(conn, changeset) do
-    case insert_or_update_user(changeset) do
+  defp signin(conn, username) do
+    case insert_or_update_user(username) do
       {:ok, user} ->
         conn
         |> put_flash(:info, gettext("Signed in!"))
@@ -32,10 +36,13 @@
     end
   end
 
-  defp insert_or_update_user(changeset) do
-    case Repo.get_by(User, username: changeset.changes.username) do
+  defp insert_or_update_user(username) do
+    case Database.User.find(username) do
       nil ->
-        Repo.insert(changeset)
+        user = Amnesia.transaction do
+          Database.User.write!(%Database.User{username: username})
+        end
+        {:ok, user}
       user ->
         {:ok, user}
     end
diff --git a/web/controllers/plugs/set_user.ex b/web/controllers/plugs/set_user.ex
--- a/web/controllers/plugs/set_user.ex
+++ b/web/controllers/plugs/set_user.ex
@@ -1,8 +1,7 @@
 defmodule KolabChat.Plugs.SetUser do
   import Plug.Conn
 
-  alias KolabChat.Repo
-  alias KolabChat.User
+  use KolabChat.Database
 
   def init(params), do: params
 
@@ -10,7 +9,7 @@
   def call(%{"params": %{"token" => token}} = conn, _params) do
     case Phoenix.Token.verify(conn, "user", token, max_age: 86400) do
       {:ok, user_id} ->
-        assign(conn, :user, Repo.get!(User, user_id))
+        assign(conn, :user, get_user_by_id(user_id))
       _ ->
         assign(conn, :user, nil)
     end
@@ -21,10 +20,17 @@
     user_id = get_session(conn, :user_id)
 
     cond do
-      user = user_id && Repo.get(User, user_id) ->
+      user = user_id && get_user_by_id(user_id) ->
         assign(conn, :user, user)
       true ->
         assign(conn, :user, nil)
     end
   end
+
+  def get_user_by_id(user_id) do
+    require Amnesia.Helper # FIXME: this is required by Amnesia.transaction, where to put it best?
+    Amnesia.transaction do
+      Database.User.read(user_id)
+    end
+  end
 end
diff --git a/web/models/user.ex b/web/models/user.ex
deleted file mode 100644
--- a/web/models/user.ex
+++ /dev/null
@@ -1,13 +0,0 @@
-defmodule KolabChat.User do
-  use KolabChat.Web, :model
-
-  schema "users" do
-    field :username, :string
-  end
-
-  def changeset(struct, params \\ %{}) do
-    struct
-    |> cast(params, [:username])
-    |> validate_required([:username])
-  end
-end
diff --git a/web/web.ex b/web/web.ex
--- a/web/web.ex
+++ b/web/web.ex
@@ -16,25 +16,11 @@
   below.
   """
 
-  def model do
-    quote do
-      use Ecto.Schema
-
-      import Ecto
-      import Ecto.Changeset
-      import Ecto.Query
-    end
-  end
-
   def controller do
     quote do
       use Phoenix.Controller
 
-      alias KolabChat.Repo
-      alias KolabChat.User
-
-      import Ecto
-      import Ecto.Query
+      alias KolabChat.Database
 
       import KolabChat.Router.Helpers
       import KolabChat.Gettext
@@ -67,9 +53,6 @@
     quote do
       use Phoenix.Channel
 
-      alias KolabChat.Repo
-      import Ecto
-      import Ecto.Query
       import KolabChat.Gettext
     end
   end