Last Login Method

On every successful sign-in, Kernia writes a browser-readable cookie naming the method that was used (email, google, github, passkey, …). Your sign-in page reads it on the next visit to surface a "Last used" badge on the right button. It can optionally persist the method on the user row.

Installation

Add the plugin to your server

Pass last_login_method() to your Kernia config.

auth.py

from kernia import KerniaOptions
from kernia.auth import init
from kernia.plugins.last_login_method import last_login_method

auth = init(KerniaOptions(
    database=adapter,
    secret=os.environ["KERNIA_SECRET"],
    base_url=os.environ["KERNIA_BASE_URL"],
    plugins=[last_login_method()],
))

Add the client plugin

Add the lastLoginMethod client plugin so the helpers can read the cookie:

auth-client.ts

import { createAuthClient } from "better-auth/client";
import { lastLoginMethodClient } from "better-auth/client/plugins";

export const authClient = createAuthClient({
  baseURL: "/api/auth",
  plugins: [lastLoginMethodClient()],
});

Usage

Read the last used method

const method = authClient.getLastUsedLoginMethod();   // "google" | "email" | null

Use the result to render a "Last used" badge on your sign-in page.

Check a specific method

if (authClient.isLastUsedLoginMethod("google")) {
  // highlight the "Continue with Google" button
}

Clear the stored method

authClient.clearLastUsedLoginMethod();

Options

Option	Type	Default	Description
`cookie_name`	`str`	`"better-auth.last_used_login_method"`	Cookie that stores the method. Must match the client `cookieName`.
`max_age`	`int`	`2592000` (30 days)	Cookie lifetime in seconds.
`store_in_database`	`bool`	`False`	Also persist the method on `user.lastLoginMethod`.
`custom_resolve_method`	`(ctx) -> str \| None`	`None`	Override how the method is derived from the request. Returning `None` falls back to the default resolver.

The default resolver recognises email sign-in/up, OAuth callbacks, SIWE, passkey, and magic-link paths.

Schema

By default the plugin only sets a cookie — no migration required. When store_in_database=True, it extends the user table:

Field	Type	Description
`lastLoginMethod`	`string` (nullable)	The method used on the most recent successful sign-in.

The cookie is intentionally not HTTP-only so your front-end can read it to highlight a button. It carries only a method name, never a token — never use it for authorization.

Last Login Method

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