Simple OAuth for Plug apps.

Setup

# mix.exs
{:amur, "~> 0.2.2"}

Quickstart with mix amur.gen

Run the generator from your project root to scaffold the controller, mount the router, and write the config block automatically:

mix amur.gen

It inspects your mix.exs to detect the app name, derives the web module (AppWeb when a Phoenix-style lib/<app>_web layout is present, otherwise App), and writes the boilerplate for you — no prompts. It defaults to the github provider.

Options:

mix amur.gen --provider google

Manual setup

# config/runtime.exs
config :amur,
  base_url: "http://localhost:4000",
  providers: [
    github: [
      client_id: System.fetch_env!("GITHUB_CLIENT_ID"),
      client_secret: System.fetch_env!("GITHUB_CLIENT_SECRET")
    ]
  ],
  on_success: &MyAppWeb.AuthController.on_success/2,
  on_failure: &MyAppWeb.AuthController.on_failure/2

# router.ex
forward "/auth", Amur.Router

Mount Amur.Router under /auth in your router with forward "/auth", Amur.Router. In Phoenix, place the forward inside your browser pipeline so session and flash helpers are available if your callbacks use them, and use alias: false on the scope that contains the forward so Phoenix does not rewrite the module name. It works with both Phoenix.Router and Plug.Router. It exposes:

• GET /auth/:provider - start the OAuth flow
• GET /auth/:provider/callback- handle the provider callback
• GET /auth/logout - clear Amur's stored session params

Logout helper

Amur.logout/1 clears Amur's stored OAuth session params from the conn. Use it in your own logout handler, or rely on the built-in GET /auth/logout endpoint.

on_success payload

on_success/2 receives a map with two keys:

• :user - the normalized user map (provider-specific fields plus :provider)
• :token - the OAuth token returned by the strategy

Pattern-match only what you need. If you don't need the token, ignore it:

def on_success(conn, %{user: user}) do
  conn
  |> put_flash(:info, "Logged in as #{user[:email]}")
  |> redirect(to: "/")
end

If you need it (e.g. to call the provider's API on behalf of the user), bind it:

def on_success(conn, %{user: user, token: token}) do
  conn
  |> put_session(:access_token, token["access_token"])
  |> redirect(to: "/")
end