diff --git a/README.md b/README.md
index b0403a2..b16a0ef 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,7 @@ FLUSH PRIVILEGES;
 
 * Database initialization
 ```
-rails db:migrate
+RAILS_ENV=production rails db:migrate
 
 RAILS_ENV=production rails console
 ```
diff --git a/app/models/user.rb b/app/models/user.rb
index ab1be95..f9fe27c 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -3,4 +3,8 @@ class User < ApplicationRecord
   # Include default devise modules. Others available are:
   # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
   devise :recoverable, :rememberable, :validatable, :lockable, :timeoutable, :trackable, :registerable
+
+  def role
+
+  end
 end
diff --git a/db/migrate/20260427123300_create_domains_admins.rb b/db/migrate/20260427123300_create_domains_admins.rb
new file mode 100644
index 0000000..771739e
--- /dev/null
+++ b/db/migrate/20260427123300_create_domains_admins.rb
@@ -0,0 +1,8 @@
+class CreateDomainsAdmins < ActiveRecord::Migration[8.1]
+  def change
+    create_table :domains_admins, id: false do |t|
+      t.belongs_to :users
+      t.belongs_to :domains
+    end
+  end
+end
diff --git a/db/migrate/20260430151640_add_domain_red_to_credentials.rb b/db/migrate/20260430151640_add_domain_red_to_credentials.rb
new file mode 100644
index 0000000..734b84e
--- /dev/null
+++ b/db/migrate/20260430151640_add_domain_red_to_credentials.rb
@@ -0,0 +1,5 @@
+class AddDomainRedToCredentials < ActiveRecord::Migration[8.1]
+  def change
+    add_reference :credentials, :domain, null: false, foreign_key: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 2e731d5..d8892c7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,12 +10,14 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2024_05_21_090545) do
+ActiveRecord::Schema[8.1].define(version: 2026_04_30_151640) do
   create_table "credentials", charset: "latin1", collation: "latin1_swedish_ci", force: :cascade do |t|
     t.datetime "created_at", null: false
+    t.bigint "domain_id", null: false
     t.string "email"
     t.string "password"
     t.datetime "updated_at", null: false
+    t.index ["domain_id"], name: "index_credentials_on_domain_id"
   end
 
   create_table "domains", charset: "latin1", collation: "latin1_swedish_ci", force: :cascade do |t|
@@ -24,6 +26,13 @@ ActiveRecord::Schema[8.1].define(version: 2024_05_21_090545) do
     t.datetime "updated_at", null: false
   end
 
+  create_table "domains_admins", id: false, charset: "latin1", collation: "latin1_swedish_ci", force: :cascade do |t|
+    t.bigint "domains_id"
+    t.bigint "users_id"
+    t.index ["domains_id"], name: "index_domains_admins_on_domains_id"
+    t.index ["users_id"], name: "index_domains_admins_on_users_id"
+  end
+
   create_table "users", charset: "latin1", collation: "latin1_swedish_ci", force: :cascade do |t|
     t.integer "consumed_timestep"
     t.datetime "created_at", null: false
@@ -55,4 +64,6 @@ ActiveRecord::Schema[8.1].define(version: 2024_05_21_090545) do
     t.string "email"
     t.datetime "updated_at", null: false
   end
+
+  add_foreign_key "credentials", "domains"
 end