Ash Multi Account

Multi-account linking and switching for Phoenix apps using Ash and AshAuthentication. Let users add multiple accounts and switch between them without re-authenticating — similar to Google/Apple's account switcher UX.

Why?

AshAuthentication and AshAuthentication.Phoenix provide excellent single-user authentication — strategies, session management, and LiveView integration all work out of the box. But many apps need users to link and switch between multiple accounts: family accounts, work/personal separation, admin impersonation. That's a different problem entirely, requiring its own session management, security considerations (session fixation, authorization checks), and UI integration across both LiveView and controller-rendered pages.

Ash Multi Account picks up where AshAuthentication leaves off, adding multi-account linking and switching as a natural extension of the same Ash ecosystem.

Features

• Session-scoped account linking (primary user + linked accounts)
• Configurable active-user checks, display fields, and max linked accounts
• Self-link prevention and max-account enforcement
• Activate/deactivate linked accounts with status tracking
• Works with any AshAuthentication strategy (password, OAuth, magic links, etc.)
• Phoenix controller mixin with link/switch actions and session regeneration
• Works with both LiveView and controller-rendered pages:
  • LiveView hook resolves current_user and primary_user on every mount
  • LoadMultiAccount plug resolves the same assigns for controller pages
• Slot-based account switcher component — works identically in both contexts
• Router macros for link/switch routes
• Automatic return-to-origin after linking and switching (stays on current page)
• Session token plug for automatic token management

Built On

Ash Multi Account is an extension for the Ash Framework ecosystem.

Required — pulled in automatically as dependencies:

• Ash — resources, actions, and the DSL extension system (Spark)
• AshAuthentication — user authentication and session management
• Phoenix — controller mixin, router macros, plugs, and session management

Also needed (not pulled in transitively):

• AshAuthentication Phoenix — provides the auth controller (AshAuthentication.Phoenix.Controller) used for sign-in callbacks, and AshAuthentication.Phoenix.LiveSession for LiveView apps. Most Phoenix + AshAuthentication apps already have this.
• Phoenix LiveView — only needed if using the LiveView hook (AshMultiAccount.Phoenix.LiveHook) or account switcher component

Works with any Ash data layer (Postgres, SQLite, ETS, etc.) and any AshAuthentication strategy (password, OAuth, magic links, etc.).

Quick Look

Add two extensions to your resources — the transformer generates the full schema:

# User resource — add AshMultiAccount alongside AshAuthentication
defmodule MyApp.Accounts.User do
  use Ash.Resource,
    extensions: [AshAuthentication, AshMultiAccount]

  multi_account do
    linked_account_resource MyApp.Accounts.LinkedAccount
    active_check {:status, :active}
    display_fields [:name, :avatar_url]
    max_linked_accounts 5
  end
end

# LinkedAccount resource — attributes, relationships, and actions generated automatically
defmodule MyApp.Accounts.LinkedAccount do
  use Ash.Resource,
    extensions: [AshMultiAccount.LinkedAccount]

  multi_account do
    user_resource MyApp.Accounts.User
  end
end

The Phoenix integration provides plugs, controllers, router macros, and a LiveView hook — all resolving the same @current_user and @primary_user assigns. See the Getting Started guide for the full walkthrough.

Documentation

• Getting Started — step-by-step setup guide
• How It Works — architecture, data model, and flows
• Phoenix Integration — plug, controller, router, LiveView hook, components
• Customizing the Account Switcher — slot data, styling patterns, examples
• Testing — ETS test setup, testing flows and Phoenix integration
• DSL Reference — auto-generated from the Spark DSL schemas (run mix docs)

Demo App

A complete demo Phoenix app lives in example/demo/. It uses password authentication with ETS (no external dependencies — just mix setup && mix phx.server).

The demo includes two pages to demonstrate that multi-account works with both rendering approaches:

• LiveView Page (/) — uses AshMultiAccount.Phoenix.LiveHook to resolve assigns via on_mount
• Controller Page (/controller) — uses AshMultiAccount.Phoenix.LoadMultiAccount plug to resolve assigns in the router pipeline

Both pages show the same user data, account switcher, and multi-account status — proving the library works identically in both contexts. Switch between them using the tabs at the top of each page.

See the demo README for setup instructions and a walkthrough.

Installation

# mix.exs
{:ash_multi_account, "~> 0.1.0"}

The recommended way to get started is with the Igniter installer, which automates resource setup, domain registration, controller creation, and router configuration:

mix igniter.install ash_multi_account

See the Getting Started guide for manual setup or additional options.

License

MIT — see LICENSE.

AshMultiAccount is an independent project by Chris Cox, not affiliated with or maintained by the Ash Framework team. Built as a contribution back to the Phoenix and Ash community that has given me so much.