npm install @xenterprises/fastify-xauth-better better-auth @prisma/client

import Fastify from "fastify";
import xAuthBetter from "@xenterprises/fastify-xauth-better";
import { PrismaClient } from "@prisma/client";

const fastify = Fastify();
const prisma = new PrismaClient();

await fastify.register(xAuthBetter, {
  prisma,
  configs: [
    {
      name: "user",
      secret: process.env.AUTH_SECRET, // min 32 chars
      baseURL: "http://localhost:3000",
      basePath: "/api/auth",
      prefix: "/api",
    },
  ],
});

// Protected route — session validated automatically
fastify.get("/api/profile", async (request) => {
  return { user: request.user };
});

await fastify.listen({ port: 3000 });

await fastify.register(xAuthBetter, {
  prisma,
  configs: [
    {
      name: "admin",
      secret: process.env.ADMIN_SECRET,
      baseURL: "http://localhost:3000",
      basePath: "/api/auth/admin",
      prefix: "/api/admin",
      roles: ["superadmin", "admin"],
    },
    {
      name: "user",
      secret: process.env.USER_SECRET,
      baseURL: "http://localhost:3000",
      basePath: "/api/auth/user",
      prefix: "/api/user",
      roles: ["contractor", "homeowner"],
    },
  ],
});

const adminAuth = fastify.xauthbetter.get("admin");
const userAuth  = fastify.xauthbetter.get("user");

package: "@xenterprises/fastify-xauth-better"
type: fastify-plugin
use-when: Production auth with Better Auth — multi-instance, organizations, 2FA, magic links, audit logging, social OAuth
decorator: fastify.xauthbetter (get, default, configs, pruneAuditLogs)
request-decorators: request.user, request.auth, request.organization
requires: Prisma client with Better Auth schema, secret ≥ 32 chars per config
env: DATABASE_URL, NODE_ENV, GOOGLE_CLIENT_ID/SECRET, GITHUB_CLIENT_ID/SECRET (optional)
multi-instance: each configs[] entry gets its own auth instance, route prefix, and cookie namespace