Agent Skills: Better Auth Integrations

Better Auth Integrations

Goals

• Mount the Better Auth handler at /api/auth/* (or a custom base path).
• Use framework helpers where available.
• Ensure cookies and headers flow correctly in SSR and server actions.

Quick start

1. Create an auth instance (see better-auth-core).
2. Add a catch-all route for /api/auth/*.
3. Use a framework helper (or auth.handler) to return a Response.

Next.js App Router

import { auth } from "@/lib/auth";
import { toNextJsHandler } from "better-auth/next-js";

export const { GET, POST } = toNextJsHandler(auth);

Next.js Pages Router

import { auth } from "@/lib/auth";
import { toNodeHandler } from "better-auth/node";

export const config = { api: { bodyParser: false } };
export default toNodeHandler(auth.handler);

Cookie handling in Next.js server actions

Use the nextCookies plugin so server actions set cookies correctly.

import { betterAuth } from "better-auth";
import { nextCookies } from "better-auth/next-js";

export const auth = betterAuth({
  // ...config
  plugins: [nextCookies()],
});

Guardrails

• Keep the base path consistent between server and client.
• Prefer framework helpers when available.
• Avoid running custom body parsers before the auth handler.

References

• toolchains/platforms/auth/better-auth/better-auth-integrations/references/nextjs.md
• toolchains/platforms/auth/better-auth/better-auth-integrations/references/frameworks.md