Better Auth Lark Plugin

A Lark billing plugin for Better Auth that automatically creates customers and subscribes them to free plans on signup.

Installation

npm i lark-billing
npm i @uselark/better-auth-lark

Setup

To use the Better Auth Lark plugin, you need to simply initialized the lark client and configure the plugin with options.

import LarkClient from "lark-billing";
import { lark } from "better-auth-lark";

const lark_client = new LarkClient({
  apiKey: "YOUR_API_KEY_FROM_ENV_VARS",
});

const plugin = lark({
    larkClient: lark_client,
    createCustomerOnSignUp: true,
    freePlanRateCardId: "FREE_PLAN_RATE_CARD_ID",
}),

Options

• larkClient: Initialize the Lark billing client with your private API key from env vars and pass it here.
• createCustomerOnSignUp: If false then the plugin doesn't do anything. If true then on customer sign up a lark subject will automatically be created with lark using their name, email, and external id being better auth user.id.
• freePlanRateCardId: You can optionally specify a rate card that you want all customers to get subscribed to on sign up. This rate card should have $0 fixed fees because otherwise users would have to go through a checkout flow to get subscribed and that isn't yet supported.

Learn more?

Visit docs.uselark.ai to learn more about lark billing integration. We provide frontend SDKs to fetch billing state and have simple APIs for subscription management.