multi-tenant-setup

Multi-Tenant Setup

Philosophy: URL-Based Multi-Tenancy, Not Subdomain or Schema

• URL-based: app.myapp.com/123/boards/456 (account_id in path)
• account_id on every table (no foreign key constraints)
• Current.account set from URL params for all requests
• All queries scoped through Current.account
• UUIDs everywhere (prevents enumeration attacks)
• No default scopes (explicit scoping preferred)
• No Apartment gem, no subdomain routing, no schema separation

Project Knowledge

Stack: URL-based multi-tenancy (/accounts/:account_id/...), Current attributes for account/user context, UUIDs for all primary keys, single database with single schema.

Auth: Custom passwordless with Current.user, users can belong to multiple accounts, account membership controls access.

Commands:

rails generate model Account name:string
rails generate model Membership user:references account:references role:integer
rails generate migration AddAccountToCards account:references

Pattern 1: Account Model and Memberships

See @references/membership-patterns.md for full details.

# app/models/account.rb
class Account < ApplicationRecord
  has_many :memberships, dependent: :destroy
  has_many :users, through: :memberships

  has_many :boards, dependent: :destroy
  has_many :cards, dependent: :destroy

  validates :name, presence: true, length: { maximum: 100 }

  def member?(user)
    users.exists?(user.id)
  end

  def add_member(user, role: :member)
    memberships.find_or_create_by!(user: user) do |membership|
      membership.role = role
    end
  end

  def owner
    memberships.owner.first&.user
  end
end

# app/models/membership.rb
class Membership < ApplicationRecord
  belongs_to :user
  belongs_to :account

  enum :role, { member: 0, admin: 1, owner: 2 }

  validates :user_id, uniqueness: { scope: :account_id }
  validates :role, presence: true

  scope :active, -> { where(active: true) }
end

# app/models/user.rb
class User < ApplicationRecord
  has_many :memberships, dependent: :destroy
  has_many :accounts, through: :memberships

  def member_of?(account)
    accounts.exists?(account.id)
  end

  def role_in(account)
    memberships.find_by(account: account)&.role
  end

  def admin_of?(account)
    memberships.find_by(account: account)&.admin? ||
      memberships.find_by(account: account)&.owner?
  end
end