better-auth-integration

Install @dodopayments/better-auth, dodopayments, and better-auth, then register the dodopayments plugin with checkout() in its use array. Map product slugs to Dodo product IDs and call authClient.dodopayments.checkoutSession from the browser to start checkout.

Set createCustomerOnSignUp: true in the dodopayments plugin options so a Dodo customer is created automatically when a user signs up. Use getCustomerParams to attach metadata such as the Better Auth user ID, and avoid calling client.customers.create() separately.

Each endpoint only exists if its feature is registered in the plugin's use array. Enabling only portal() means checkout, usage, and webhook routes do not exist; add checkout(), usage(), and webhooks() to register their routes.

Register webhooks({ webhookKey, onPayload }) in the plugin and point the Dodo dashboard at /api/auth/dodopayments/webhooks. The plugin verifies the Standard Webhooks signature itself; do not create a second route or custom verifier.

Yes, use authClient.dodopayments methods from the dodopaymentsClient plugin, which send the Better Auth session cookie automatically. Do not pass request headers to these browser methods, and use Better Auth's server API separately for server-side handling.