diff --git a/lib/matrix_server.ex b/lib/matrix_server.ex
index 97d7bcc..4cc0a2f 100644
--- a/lib/matrix_server.ex
+++ b/lib/matrix_server.ex
@@ -2,6 +2,9 @@ defmodule MatrixServer do
   alias MatrixServer.EncodableMap
 
   @random_string_alphabet Enum.into(?a..?z, []) ++ Enum.into(?A..?Z, [])
+  @ipv6_regex ~r/^\[(?<ip>[^\]]+)\](?<port>:\d{1,5})?$/
+  @ipv4_regex ~r/^(?<hostname>[^:]+)(?<port>:\d{1,5})?$/
+  @dns_regex ~r/^[[:alnum:]-.]{1,255}$/
 
   @spec get_mxid(String.t()) :: String.t()
   def get_mxid(localpart) when is_binary(localpart) do
@@ -110,7 +113,8 @@ defmodule MatrixServer do
     %{object | signatures: new_sigs}
   end
 
-  @spec validate_change_simple(Ecto.Changeset.t(), atom(), (term() -> boolean())) :: Ecto.Changeset.t()
+  @spec validate_change_simple(Ecto.Changeset.t(), atom(), (term() -> boolean())) ::
+          Ecto.Changeset.t()
   def validate_change_simple(changeset, field, func) do
     augmented_func = fn _, val ->
       if func.(val), do: [], else: [{field, "invalid"}]
@@ -146,4 +150,35 @@ defmodule MatrixServer do
     |> String.replace("+", "-")
     |> String.replace("/", "_")
   end
+
+  @spec valid_domain?(String.t()) :: boolean()
+  def valid_domain?(domain) do
+    if String.starts_with?(domain, "[") do
+      # Parse as ipv6.
+      with %{"ip" => ip} <-
+             Regex.named_captures(@ipv6_regex, domain),
+           {:ok, _} <- :inet.parse_address(String.to_charlist(ip)) do
+        true
+      else
+        _ -> false
+      end
+    else
+      # Parse as ipv4 or dns name.
+      case Regex.named_captures(@ipv4_regex, domain) do
+        nil ->
+          false
+
+        %{"hostname" => hostname} ->
+          # Try to parse as ipv4.
+          case String.to_charlist(hostname) |> :inet.parse_address() do
+            {:ok, _} ->
+              true
+
+            {:error, _} ->
+              # Try to parse as dns name.
+              Regex.match?(@dns_regex, hostname)
+          end
+      end
+    end
+  end
 end
diff --git a/lib/matrix_server/identifier.ex b/lib/matrix_server/identifier.ex
deleted file mode 100644
index c1fa23d..0000000
--- a/lib/matrix_server/identifier.ex
+++ /dev/null
@@ -1,173 +0,0 @@
-defmodule MatrixServer.Identifier do
-  use Ecto.Type
-
-  alias MatrixServer.Identifier
-
-  defstruct [:type, :localpart, :domain]
-
-  def type(), do: :string
-
-  def cast(id) when is_binary(id) do
-    with %Identifier{} = identifier <- parse(id) do
-      {:ok, identifier}
-    end
-  end
-
-  def cast(_), do: :error
-
-  defp parse(id) do
-    {sigil, id} = String.split_at(id, 1)
-
-    case get_type(sigil) do
-      {:ok, :event} ->
-        parse_event(id)
-
-      {:ok, type} when type in [:user, :room, :group, :alias] ->
-        case String.split(id, ":", parts: 2) do
-          [localpart, domain] ->
-            case type do
-              :user -> parse_user(localpart, domain)
-              :room -> parse_room(localpart, domain)
-              :group -> parse_group(localpart, domain)
-              :alias -> parse_alias(localpart, domain)
-            end
-
-          _ ->
-            :error
-        end
-
-      :error ->
-        :error
-    end
-  end
-
-  defp get_type("@"), do: {:ok, :user}
-  defp get_type("!"), do: {:ok, :room}
-  defp get_type("$"), do: {:ok, :event}
-  defp get_type("+"), do: {:ok, :group}
-  defp get_type("#"), do: {:ok, :alias}
-  defp get_type(_), do: :error
-
-  @user_regex ~r/^[a-z0-9._=\-\/]+$/
-  defp parse_user(localpart, domain) do
-    if String.length(localpart) + String.length(domain) + 2 <= 255 and
-         Regex.match?(@user_regex, localpart) and
-         valid_domain?(domain) do
-      %Identifier{type: :user, localpart: localpart, domain: domain}
-    else
-      :error
-    end
-  end
-
-  defp parse_room(localpart, domain) do
-    if valid_domain?(domain) do
-      %Identifier{type: :room, localpart: localpart, domain: domain}
-    else
-      :error
-    end
-  end
-
-  @event_regex ~r/^[[:alnum:]-_]+$/
-  defp parse_event(localpart) do
-    if Regex.match?(@event_regex, localpart) do
-      %Identifier{type: :event, localpart: localpart}
-    else
-      :error
-    end
-  end
-
-  @group_regex ~r/^[[:lower:][:digit:]._=\-\/]+$/
-  defp parse_group(localpart, domain) do
-    if String.length(localpart) + String.length(domain) + 2 <= 255 and
-         Regex.match?(@group_regex, localpart) and
-         valid_domain?(domain) do
-      %Identifier{type: :group, localpart: localpart, domain: domain}
-    else
-      :error
-    end
-  end
-
-  defp parse_alias(localpart, domain) do
-    if String.length(localpart) + String.length(domain) + 2 <= 255 and valid_domain?(domain) do
-      %Identifier{type: :alias, localpart: localpart, domain: domain}
-    else
-      :error
-    end
-  end
-
-  def load(id) when is_binary(id) do
-    {:ok, parse_unvalidated(id)}
-  end
-
-  def load(_), do: :error
-
-  defp parse_unvalidated(id) do
-    {sigil, id} = String.split_at(id, 1)
-
-    case get_type(sigil) do
-      {:ok, :event} ->
-        %Identifier{type: :event, localpart: id}
-
-      {:ok, type} ->
-        [localpart, domain] = String.split(id, ":", parts: 2)
-
-        identifier = %Identifier{localpart: localpart, domain: domain}
-
-        case type do
-          :user -> %Identifier{identifier | type: :user}
-          :room -> %Identifier{identifier | type: :room}
-          :group -> %Identifier{identifier | type: :group}
-          :alias -> %Identifier{identifier | type: :alias}
-        end
-    end
-  end
-
-  def dump(%Identifier{type: :event, localpart: localpart}) do
-    {:ok, "$" <> localpart}
-  end
-
-  def dump(%Identifier{type: type, localpart: localpart, domain: domain}) do
-    {:ok, type_to_sigil(type) <> localpart <> ":" <> domain}
-  end
-
-  def dump(_), do: :error
-
-  defp type_to_sigil(:user), do: "@"
-  defp type_to_sigil(:room), do: "!"
-  defp type_to_sigil(:event), do: "$"
-  defp type_to_sigil(:group), do: "+"
-  defp type_to_sigil(:alias), do: "#"
-
-  @ipv6_regex ~r/^\[(?<ip>[^\]]+)\](?<port>:\d{1,5})?$/
-  @ipv4_regex ~r/^(?<hostname>[^:]+)(?<port>:\d{1,5})?$/
-  @dns_regex ~r/^[[:alnum:]-.]{1,255}$/
-  defp valid_domain?(domain) do
-    if String.starts_with?(domain, "[") do
-      # Parse as ipv6.
-      with %{"ip" => ip} <-
-             Regex.named_captures(@ipv6_regex, domain),
-           {:ok, _} <- :inet.parse_address(String.to_charlist(ip)) do
-        true
-      else
-        _ -> false
-      end
-    else
-      # Parse as ipv4 or dns name.
-      case Regex.named_captures(@ipv4_regex, domain) do
-        nil ->
-          false
-
-        %{"hostname" => hostname} ->
-          # Try to parse as ipv4.
-          case String.to_charlist(hostname) |> :inet.parse_address() do
-            {:ok, _} ->
-              true
-
-            {:error, _} ->
-              # Try to parse as dns name.
-              Regex.match?(@dns_regex, hostname)
-          end
-      end
-    end
-  end
-end
diff --git a/lib/matrix_server/room_server.ex b/lib/matrix_server/room_server.ex
index 25a7cd6..97fccaa 100644
--- a/lib/matrix_server/room_server.ex
+++ b/lib/matrix_server/room_server.ex
@@ -43,7 +43,11 @@ defmodule MatrixServer.RoomServer do
     end
   end
 
-  @spec create_room(pid(), MatrixServer.Account.t(), MatrixServerWeb.Client.Request.CreateRoom.t()) :: {:ok, String.t()} | {:error, atom()}
+  @spec create_room(
+          pid(),
+          MatrixServer.Account.t(),
+          MatrixServerWeb.Client.Request.CreateRoom.t()
+        ) :: {:ok, String.t()} | {:error, atom()}
   def create_room(pid, account, input) do
     GenServer.call(pid, {:create_room, account, input})
   end
diff --git a/lib/matrix_server/schema/account.ex b/lib/matrix_server/schema/account.ex
index a62fa93..dc69b6e 100644
--- a/lib/matrix_server/schema/account.ex
+++ b/lib/matrix_server/schema/account.ex
@@ -8,8 +8,8 @@ defmodule MatrixServer.Account do
   alias Ecto.Multi
 
   @type t :: %__MODULE__{
-    password_hash: String.t()
-  }
+          password_hash: String.t()
+        }
 
   @max_mxid_length 255
 
diff --git a/lib/matrix_server/schema/room.ex b/lib/matrix_server/schema/room.ex
index fbb898b..67d6370 100644
--- a/lib/matrix_server/schema/room.ex
+++ b/lib/matrix_server/schema/room.ex
@@ -8,10 +8,10 @@ defmodule MatrixServer.Room do
   alias MatrixServerWeb.Client.Request.CreateRoom
 
   @type t :: %__MODULE__{
-    visibility: :public | :private,
-    state: list(list(String.t())),
-    forward_extremities: list(String.t())
-  }
+          visibility: :public | :private,
+          state: list(list(String.t())),
+          forward_extremities: list(String.t())
+        }
 
   @primary_key {:id, :string, []}
   schema "rooms" do
diff --git a/lib/matrix_server/state_resolution/authorization.ex b/lib/matrix_server/state_resolution/authorization.ex
index d7f080d..61b7417 100644
--- a/lib/matrix_server/state_resolution/authorization.ex
+++ b/lib/matrix_server/state_resolution/authorization.ex
@@ -204,8 +204,8 @@ defmodule MatrixServer.StateResolution.Authorization do
   defp get_action_power_level(:invite, _), do: 50
   defp get_action_power_level(:ban, %{"ban" => pl}), do: pl
   defp get_action_power_level(:ban, _), do: 50
-  defp get_action_power_level(:redact, %{"redact" => pl}), do: pl
-  defp get_action_power_level(:redact, _), do: 50
+  # defp get_action_power_level(:redact, %{"redact" => pl}), do: pl
+  # defp get_action_power_level(:redact, _), do: 50
   defp get_action_power_level(:kick, %{"kick" => pl}), do: pl
   defp get_action_power_level(:kick, _), do: 50
 
diff --git a/lib/matrix_server/types/alias_id.ex b/lib/matrix_server/types/alias_id.ex
new file mode 100644
index 0000000..f738486
--- /dev/null
+++ b/lib/matrix_server/types/alias_id.ex
@@ -0,0 +1,43 @@
+defmodule MatrixServer.Types.AliasId do
+  use Ecto.Type
+
+  alias MatrixServer.Types.AliasId
+
+  defstruct [:localpart, :domain]
+
+  defimpl String.Chars, for: AliasId do
+    def to_string(%AliasId{localpart: localpart, domain: domain}) do
+      "#" <> localpart <> ":" <> domain
+    end
+  end
+
+  def type(), do: :string
+
+  def cast(s) when is_binary(s) do
+    with "#" <> rest <- s,
+         [localpart, domain] <- String.split(rest, ":", parts: 2) do
+      if String.length(localpart) + String.length(domain) + 2 <= 255 and
+           MatrixServer.valid_domain?(domain) do
+        %AliasId{localpart: localpart, domain: domain}
+      else
+        :error
+      end
+    else
+      _ -> :error
+    end
+  end
+
+  def cast(_), do: :error
+
+  def load(s) when is_binary(s) do
+    "@" <> rest = s
+    [localpart, domain] = String.split(rest, ":", parts: 2)
+
+    %AliasId{localpart: localpart, domain: domain}
+  end
+
+  def load(_), do: :error
+
+  def dump(%AliasId{} = alias_id), do: to_string(alias_id)
+  def dump(_), do: :error
+end
diff --git a/lib/matrix_server/types/event_id.ex b/lib/matrix_server/types/event_id.ex
new file mode 100644
index 0000000..47fe242
--- /dev/null
+++ b/lib/matrix_server/types/event_id.ex
@@ -0,0 +1,42 @@
+defmodule MatrixServer.Types.EventId do
+  use Ecto.Type
+
+  alias MatrixServer.Types.EventId
+
+  defstruct [:id]
+
+  @id_regex ~r/^[[:alnum:]-_]+$/
+
+  defimpl String.Chars, for: EventId do
+    def to_string(%EventId{id: id}) do
+      "$" <> id
+    end
+  end
+
+  def type(), do: :string
+
+  def cast(s) when is_binary(s) do
+    with "$" <> id <- s do
+      if Regex.match?(@id_regex, id) do
+        %EventId{id: id}
+      else
+        :error
+      end
+    else
+      _ -> :error
+    end
+  end
+
+  def cast(_), do: :error
+
+  def load(s) when is_binary(s) do
+    "$" <> rest = s
+
+    %EventId{id: rest}
+  end
+
+  def load(_), do: :error
+
+  def dump(%EventId{} = event_id), do: to_string(event_id)
+  def dump(_), do: :error
+end
diff --git a/lib/matrix_server/types/group_id.ex b/lib/matrix_server/types/group_id.ex
new file mode 100644
index 0000000..d73d8dc
--- /dev/null
+++ b/lib/matrix_server/types/group_id.ex
@@ -0,0 +1,46 @@
+defmodule MatrixServer.Types.GroupId do
+  use Ecto.Type
+
+  alias MatrixServer.Types.GroupId
+
+  defstruct [:localpart, :domain]
+
+  @localpart_regex ~r/^[[:lower:][:digit:]._=\-\/]+$/
+
+  defimpl String.Chars, for: GroupId do
+    def to_string(%GroupId{localpart: localpart, domain: domain}) do
+      "+" <> localpart <> ":" <> domain
+    end
+  end
+
+  def type(), do: :string
+
+  def cast(s) when is_binary(s) do
+    with "+" <> rest <- s,
+         [localpart, domain] <- String.split(rest, ":", parts: 2) do
+      if String.length(localpart) + String.length(domain) + 2 <= 255 and
+           Regex.match?(@localpart_regex, localpart) and
+           MatrixServer.valid_domain?(domain) do
+        %GroupId{localpart: localpart, domain: domain}
+      else
+        :error
+      end
+    else
+      _ -> :error
+    end
+  end
+
+  def cast(_), do: :error
+
+  def load(s) when is_binary(s) do
+    "@" <> rest = s
+    [localpart, domain] = String.split(rest, ":", parts: 2)
+
+    %GroupId{localpart: localpart, domain: domain}
+  end
+
+  def load(_), do: :error
+
+  def dump(%GroupId{} = group_id), do: to_string(group_id)
+  def dump(_), do: :error
+end
diff --git a/lib/matrix_server/types/room_id.ex b/lib/matrix_server/types/room_id.ex
new file mode 100644
index 0000000..0e7cf00
--- /dev/null
+++ b/lib/matrix_server/types/room_id.ex
@@ -0,0 +1,42 @@
+defmodule MatrixServer.Types.RoomId do
+  use Ecto.Type
+
+  alias MatrixServer.Types.RoomId
+
+  defstruct [:localpart, :domain]
+
+  defimpl String.Chars, for: RoomId do
+    def to_string(%RoomId{localpart: localpart, domain: domain}) do
+      "!" <> localpart <> ":" <> domain
+    end
+  end
+
+  def type(), do: :string
+
+  def cast(s) when is_binary(s) do
+    with "!" <> rest <- s,
+         [localpart, domain] <- String.split(rest, ":", parts: 2) do
+      if MatrixServer.valid_domain?(domain) do
+        %RoomId{localpart: localpart, domain: domain}
+      else
+        :error
+      end
+    else
+      _ -> :error
+    end
+  end
+
+  def cast(_), do: :error
+
+  def load(s) when is_binary(s) do
+    "!" <> rest = s
+    [localpart, domain] = String.split(rest, ":", parts: 2)
+
+    %RoomId{localpart: localpart, domain: domain}
+  end
+
+  def load(_), do: :error
+
+  def dump(%RoomId{} = room_id), do: to_string(room_id)
+  def dump(_), do: :error
+end
diff --git a/lib/matrix_server/types/user_id.ex b/lib/matrix_server/types/user_id.ex
new file mode 100644
index 0000000..585f05e
--- /dev/null
+++ b/lib/matrix_server/types/user_id.ex
@@ -0,0 +1,45 @@
+defmodule MatrixServer.Types.UserId do
+  use Ecto.Type
+
+  alias MatrixServer.Types.UserId
+
+  defstruct [:localpart, :domain]
+
+  @localpart_regex ~r/^[a-z0-9._=\-\/]+$/
+
+  defimpl String.Chars, for: UserId do
+    def to_string(%UserId{localpart: localpart, domain: domain}) do
+      "@" <> localpart <> ":" <> domain
+    end
+  end
+
+  def type(), do: :string
+
+  def cast(s) when is_binary(s) do
+    with "@" <> rest <- s,
+         [localpart, domain] <- String.split(rest, ":", parts: 2) do
+      if String.length(localpart) + String.length(domain) + 2 <= 255 and
+           Regex.match?(@localpart_regex, localpart) and MatrixServer.valid_domain?(domain) do
+        %UserId{localpart: localpart, domain: domain}
+      else
+        :error
+      end
+    else
+      _ -> :error
+    end
+  end
+
+  def cast(_), do: :error
+
+  def load(s) when is_binary(s) do
+    "@" <> rest = s
+    [localpart, domain] = String.split(rest, ":", parts: 2)
+
+    %UserId{localpart: localpart, domain: domain}
+  end
+
+  def load(_), do: :error
+
+  def dump(%UserId{} = user_id), do: to_string(user_id)
+  def dump(_), do: :error
+end
diff --git a/lib/matrix_server_web/client/request/create_room.ex b/lib/matrix_server_web/client/request/create_room.ex
index d37d129..4f260c3 100644
--- a/lib/matrix_server_web/client/request/create_room.ex
+++ b/lib/matrix_server_web/client/request/create_room.ex
@@ -6,14 +6,14 @@ defmodule MatrixServerWeb.Client.Request.CreateRoom do
   alias Ecto.Changeset
 
   @type t :: %__MODULE__{
-    visibility: String.t(),
-    room_alias_name: String.t(),
-    name: String.t(),
-    topic: String.t(),
-    invite: list(String.t()),
-    room_version: String.t(),
-    preset: String.t()
-  }
+          visibility: String.t(),
+          room_alias_name: String.t(),
+          name: String.t(),
+          topic: String.t(),
+          invite: list(String.t()),
+          room_version: String.t(),
+          preset: String.t()
+        }
 
   @primary_key false
   embedded_schema do
diff --git a/lib/matrix_server_web/federation/controllers/query_controller.ex b/lib/matrix_server_web/federation/controllers/query_controller.ex
index 829c3cd..84b9754 100644
--- a/lib/matrix_server_web/federation/controllers/query_controller.ex
+++ b/lib/matrix_server_web/federation/controllers/query_controller.ex
@@ -5,7 +5,8 @@ defmodule MatrixServerWeb.Federation.QueryController do
   import MatrixServerWeb.Error
   import Ecto.Query
 
-  alias MatrixServer.{Repo, Account, Identifier}
+  alias MatrixServer.{Repo, Account}
+  alias MatrixServer.Types.UserId
 
   defmodule ProfileRequest do
     use Ecto.Schema
@@ -14,7 +15,7 @@ defmodule MatrixServerWeb.Federation.QueryController do
 
     @primary_key false
     embedded_schema do
-      field :user_id, Identifier
+      field :user_id, UserId
       field :field, :string
     end
 
@@ -31,8 +32,7 @@ defmodule MatrixServerWeb.Federation.QueryController do
   end
 
   def profile(conn, params) do
-    with {:ok,
-          %ProfileRequest{user_id: %Identifier{type: :user, localpart: localpart, domain: domain}}} <-
+    with {:ok, %ProfileRequest{user_id: %UserId{localpart: localpart, domain: domain}}} <-
            ProfileRequest.validate(params) do
       if domain == MatrixServer.server_name() do
         case Repo.one(from a in Account, where: a.localpart == ^localpart) do
diff --git a/mix.exs b/mix.exs
index 3493cca..7b7aad7 100644
--- a/mix.exs
+++ b/mix.exs
@@ -11,7 +11,10 @@ defmodule MatrixServer.MixProject do
       start_permanent: Mix.env() == :prod,
       aliases: aliases(),
       deps: deps(),
-      dialyzer: [plt_add_deps: :app_tree]
+      dialyzer: [
+        plt_add_deps: :app_tree,
+        flags: [:error_handling, :race_conditions, :underspecs, :unknown, :unmatched_returns]
+      ]
     ]
   end