diff --git a/lib/pleroma/ecto_enums.ex b/lib/pleroma/ecto_enums.ex
index f198cccb7..cd8606ae6 100644
--- a/lib/pleroma/ecto_enums.ex
+++ b/lib/pleroma/ecto_enums.ex
@@ -9,7 +9,8 @@ defenum(Pleroma.UserRelationship.Type,
   mute: 2,
   reblog_mute: 3,
   notification_mute: 4,
-  inverse_subscription: 5
+  inverse_subscription: 5,
+  membership: 6
 )
 
 defenum(Pleroma.FollowingRelationship.State,
diff --git a/lib/pleroma/group.ex b/lib/pleroma/group.ex
index 6cc208f15..732791ec2 100644
--- a/lib/pleroma/group.ex
+++ b/lib/pleroma/group.ex
@@ -10,7 +10,7 @@ defmodule Pleroma.Group do
   alias Pleroma.User
   alias Pleroma.Repo
   alias Pleroma.Web
-  alias Pleroma.EctoType.ActivityPub.ObjectValidators
+  alias Pleroma.UserRelationship
 
   @moduledoc """
   Groups contain all the additional information about a group that's not stored
@@ -29,7 +29,8 @@ defmodule Pleroma.Group do
     belongs_to(:user, User, type: FlakeId.Ecto.CompatType)
     belongs_to(:owner, User, type: FlakeId.Ecto.CompatType, foreign_key: :owner_id)
 
-    field(:members, {:array, ObjectValidators.ObjectID})
+    has_many(:members, through: [:user, :group_members])
+
     field(:name, :string)
     field(:description, :string)
     field(:members_collection, :string)
@@ -71,4 +72,24 @@ defmodule Pleroma.Group do
     |> cast(params, [:user_id, :owner_id, :name, :description, :members_collection])
     |> validate_required([:user_id, :owner_id, :members_collection])
   end
+
+  def is_member?(%{user_id: user_id}, member) do
+    UserRelationship.membership_exists?(%User{id: user_id}, member)
+  end
+
+  def members(group) do
+    Repo.preload(group, :members).members
+  end
+
+  def add_member(%{user_id: user_id} = group, member) do
+    with {:ok, _relationship} <- UserRelationship.create_membership(%User{id: user_id}, member) do
+      {:ok, group}
+    end
+  end
+
+  def remove_member(%{user_id: user_id} = group, member) do
+    with {:ok, _relationship} <- UserRelationship.delete_membership(%User{id: user_id}, member) do
+      {:ok, group}
+    end
+  end
 end
diff --git a/lib/pleroma/user.ex b/lib/pleroma/user.ex
index 3da658950..1e5c87403 100644
--- a/lib/pleroma/user.ex
+++ b/lib/pleroma/user.ex
@@ -58,6 +58,10 @@ defmodule Pleroma.User do
   # AP ID user relationships (blocks, mutes etc.)
   # Format: [rel_type: [outgoing_rel: :outgoing_rel_target, incoming_rel: :incoming_rel_source]]
   @user_relationships_config [
+    membership: [
+      group_memberships: :group_members,
+      user_memberships: :joined_groups
+    ],
     block: [
       blocker_blocks: :blocked_users,
       blockee_blocks: :blocker_users
diff --git a/test/pleroma/group_test.exs b/test/pleroma/group_test.exs
index f73abd237..e4c6cfd92 100644
--- a/test/pleroma/group_test.exs
+++ b/test/pleroma/group_test.exs
@@ -33,4 +33,23 @@ defmodule Pleroma.GroupTest do
     Repo.delete(group.user)
     refute Repo.get(Group, group.id)
   end
+
+  test "group members can be seen and added" do
+    user = insert(:user)
+    other_user = insert(:user)
+    third_user = insert(:user)
+
+    {:ok, group} = Group.create(%{owner_id: user.id, name: "cofe", description: "corndog"})
+
+    assert [] == Group.members(group)
+
+    {:ok, group} = Group.add_member(group, other_user)
+    assert [other_user] == Group.members(group)
+
+    assert Group.is_member?(group, other_user)
+    refute Group.is_member?(group, third_user)
+
+    {:ok, group} = Group.remove_member(group, other_user)
+    refute Group.is_member?(group, other_user)
+  end
 end