SaaS on Nuxt 4, MySQL 8 and Clerk

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// ponytail: single module-level pool; the runtime + mysql2's pool handle concurrency,
// so no globalThis singleton dance needed.
const pool = mysql.createPool(process.env.DATABASE_URL!);

export const db = drizzle({ client: pool });

// Clerk on Nuxt 4 is a Nuxt MODULE: registering "@clerk/nuxt" auto-injects
// <ClerkProvider>, the Vue components (<SignIn/>, <UserButton/>), and a server plugin that
// attaches the Clerk Auth object to event.context.auth — no manual provider wiring.
// ponytail: Clerk is hosted — set NUXT_PUBLIC_CLERK_PUBLISHABLE_KEY (read client-side by the
// module) and NUXT_CLERK_SECRET_KEY (read server-side by clerkMiddleware) in the env; the
// module picks them up automatically, so nothing here references them.
// ponytail: Nuxt provides defineNuxtConfig as a global at runtime; import it explicitly from
// "nuxt/config" so this config type-checks under standalone tsc.
import { defineNuxtConfig } from "nuxt/config";

export default defineNuxtConfig({
  modules: ["@clerk/nuxt"],
});

// Clerk route protection as a Nitro server middleware — the Nuxt 4 analog of
// Next's clerkMiddleware proxy + auth.protect(). clerkMiddleware() wraps a handler that runs
// on every request with the Clerk Auth object on event.context.auth; here we guard the SaaS
// app surface and redirect signed-out users to the hosted sign-in.
// ponytail: Nuxt AUTO-IMPORTS the h3 helpers at runtime; we import getRequestURL + sendRedirect
// EXPLICITLY from h3 (Nitro's engine, a nuxt dep) so this type-checks under standalone tsc.
import { clerkMiddleware } from "@clerk/nuxt/server";
import { getRequestURL, sendRedirect, type H3Event } from "h3";

// ponytail: guard the SaaS app surface; widen the prefixes per app-type.
const PROTECTED_PREFIXES = ["/dashboard", "/settings"];

export default clerkMiddleware((event) => {
  // clerkMiddleware injects Clerk's Auth object on event.context.auth (see @clerk/nuxt module).
  const { isAuthenticated } = event.context.auth();
  // ponytail: @clerk/nuxt bundles its OWN h3 copy, so clerkMiddleware types `event` against that
  // copy; re-narrow to the top-level h3 H3Event (the SAME runtime object) so the explicitly
  // imported getRequestURL/sendRedirect type-check standalone — only the compiled d.ts differ.
  const h3Event = event as unknown as H3Event;
  const { pathname } = getRequestURL(h3Event);
  if (!isAuthenticated && PROTECTED_PREFIXES.some((prefix) => pathname.startsWith(prefix))) {
    return sendRedirect(h3Event, "/sign-in", 302);
  }
});

// === file: server/db/schema.ts ===
import { relations, sql } from "drizzle-orm";
import {
  bigint,
  check,
  index,
  int,
  mysqlTable,
  text,
  timestamp,
  unique,
  varchar,
} from "drizzle-orm/mysql-core";
// Better Auth owns identity; we only reference its `user` table by id. With Clerk
// the identity-sync mirror occupies this same ./auth-schema slot (src/db/auth-schema.ts).
import { user } from "./auth-schema";

export type MemberRole = "owner" | "admin" | "member";
export type SubscriptionStatus =
  | "trialing"
  | "active"
  | "past_due"
  | "canceled";

/** Tenant boundary: every billable/metered row hangs off an organization. */
export const organizations = mysqlTable(
  "organizations",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    slug: varchar("slug", { length: 255 }).notNull().unique(),
    name: text("name").notNull(),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [index("idx_org_slug").on(t.slug)],
);

/** org <-> user join with role. The composite unique is the membership identity. */
export const memberships = mysqlTable(
  "memberships",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    organizationId: varchar("organization_id", { length: 36 })
      .notNull()
      .references(() => organizations.id, { onDelete: "cascade" }),
    // Better Auth's user.id is text — match it as varchar(255).
    userId: varchar("user_id", { length: 255 })
      .notNull()
      .references(() => user.id, { onDelete: "cascade" }),
    role: varchar("role", { length: 32 }).$type<MemberRole>().notNull().default("member"),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [
    unique("memberships_org_user_unique").on(t.organizationId, t.userId),
    index("idx_membership_user").on(t.userId),
    check(
      "memberships_role_check",
      sql`${t.role} in ('owner','admin','member')`,
    ),
  ],
);

/** Catalog of billable plans (seed-managed). priceCents keeps money integer. */
export const plans = mysqlTable("plans", {
  id: varchar("id", { length: 36 }).primaryKey(),
  slug: varchar("slug", { length: 255 }).notNull().unique(), // free | pro | scale
  name: text("name").notNull(),
  priceCents: int("price_cents").notNull().default(0),
  // Monthly included credits; metering checks usage against this.
  monthlyCredits: bigint("monthly_credits", { mode: "number" })
    .notNull()
    .default(0),
});

/** One active subscription per org. Mirrors the billing provider's state. */
export const subscriptions = mysqlTable(
  "subscriptions",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    organizationId: varchar("organization_id", { length: 36 })
      .notNull()
      .references(() => organizations.id, { onDelete: "cascade" }),
    planId: varchar("plan_id", { length: 36 })
      .notNull()
      .references(() => plans.id),
    status: varchar("status", { length: 32 })
      .$type<SubscriptionStatus>()
      .notNull()
      .default("trialing"),
    // The generic billing-sync contract every webhook provider (Polar/Stripe/LemonSqueezy)
    // needs: the provider's subscription id as a UNIQUE idempotency key, plus the last
    // event timestamp as an out-of-order/staleness guard. The billing fragment maps a
    // provider's events onto these — it does NOT redeclare this table (compose, not duplicate).
    providerSubId: varchar("provider_sub_id", { length: 255 }).unique(),
    providerEventAt: timestamp("provider_event_at"),
    currentPeriodEnd: timestamp("current_period_end"),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [
    // One live subscription per org (the metering layer reads exactly one).
    unique("subscriptions_org_unique").on(t.organizationId),
    index("idx_sub_status").on(t.status),
    check(
      "subscriptions_status_check",
      sql`${t.status} in ('trialing','active','past_due','canceled')`,
    ),
  ],
);

/** Append-only credit/token meter. Roll up by org+window for quota + billing. */
export const apiUsage = mysqlTable(
  "api_usage",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    organizationId: varchar("organization_id", { length: 36 })
      .notNull()
      .references(() => organizations.id, { onDelete: "cascade" }),
    // Who/what spent — opaque key id, nullable for org-level system calls.
    apiKeyId: text("api_key_id"),
    creditsUsed: bigint("credits_used", { mode: "number" }).notNull(),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [
    // Drives the "credits used this period" rollup query.
    index("idx_usage_org_time").on(t.organizationId, t.createdAt),
  ],
);

export const organizationsRelations = relations(organizations, ({ many }) => ({
  memberships: many(memberships),
  subscriptions: many(subscriptions),
  usage: many(apiUsage),
}));

export const membershipsRelations = relations(memberships, ({ one }) => ({
  organization: one(organizations, {
    fields: [memberships.organizationId],
    references: [organizations.id],
  }),
  user: one(user, { fields: [memberships.userId], references: [user.id] }),
}));

export const subscriptionsRelations = relations(subscriptions, ({ one }) => ({
  organization: one(organizations, {
    fields: [subscriptions.organizationId],
    references: [organizations.id],
  }),
  plan: one(plans, {
    fields: [subscriptions.planId],
    references: [plans.id],
  }),
}));

export const apiUsageRelations = relations(apiUsage, ({ one }) => ({
  organization: one(organizations, {
    fields: [apiUsage.organizationId],
    references: [organizations.id],
  }),
}));

import { and, eq, isNull, lt, or } from "drizzle-orm";
import { subscriptions } from "~~/server/db/schema";

export type PolarSubscriptionEvent = {
  type: string;
  data: {
    id: string;
    status: string;
    currentPeriodEnd: string | null;
    modifiedAt: string;
    metadata: { organizationId: string; planId: string };
  };
};

const STATUS_MAP: Record<string, "trialing" | "active" | "past_due" | "canceled"> = {
  trialing: "trialing",
  active: "active",
  past_due: "past_due",
  unpaid: "past_due",
  canceled: "canceled",
  revoked: "canceled",
};

// Idempotent + CONCURRENCY-safe sync of a Polar subscription (MySQL). The staleness guard lives
// in the UPDATE's WHERE, so the row lock serializes concurrent retries. MySQL has no RETURNING —
// affectedRows tells us if a row advanced. The insert path catches the unique-key race (a
// concurrent delivery of the same NEW event) as an idempotent no-op, rethrowing every other error.
// Returns changed=true only on a real advance so callers can guard side effects (emails) against
// Polar's duplicate deliveries.
export async function recordPolarEvent(
  // ponytail: loosely typed Drizzle client so the emitted core stays portable.
  db: any,
  event: PolarSubscriptionEvent,
): Promise<{ changed: boolean }> {
  const sub = event.data;
  const status = STATUS_MAP[sub.status];
  if (!status) return { changed: false }; // unknown status — ignore, don't default
  const eventAt = new Date(sub.modifiedAt);
  const currentPeriodEnd = sub.currentPeriodEnd ? new Date(sub.currentPeriodEnd) : null;

  // Guarded UPDATE: applies only when our event is strictly newer than what's stored.
  // No TOCTOU — the comparison is in the WHERE, evaluated under the row lock.
  const updated = await db
    .update(subscriptions)
    .set({ status, currentPeriodEnd, providerEventAt: eventAt })
    .where(
      and(
        eq(subscriptions.providerSubId, sub.id),
        or(isNull(subscriptions.providerEventAt), lt(subscriptions.providerEventAt, eventAt)),
      ),
    );
  if (updated[0].affectedRows > 0) return { changed: true };

  // No row advanced: the row exists but our event is stale (guard rejected it), or it doesn't
  // exist yet. If it exists, this is a stale/duplicate delivery — ignore.
  const [existing] = await db
    .select({ id: subscriptions.id })
    .from(subscriptions)
    .where(eq(subscriptions.providerSubId, sub.id))
    .limit(1);
  if (existing) return { changed: false };

  // The row doesn't exist yet — insert it. A concurrent delivery of the SAME new subscription can
  // win the race between our SELECT and this INSERT; the unique key then rejects ours (ER_DUP_ENTRY)
  // — an idempotent no-op, NOT a change. Any other error is real: rethrow so the webhook fails loud
  // and Polar retries.
  try {
    await db.insert(subscriptions).values({
      id: crypto.randomUUID(),
      organizationId: sub.metadata.organizationId,
      planId: sub.metadata.planId,
      status,
      currentPeriodEnd,
      providerSubId: sub.id,
      providerEventAt: eventAt,
    });
    return { changed: true };
  } catch (err: any) {
    if ((err?.cause?.code ?? err?.code) === "ER_DUP_ENTRY") return { changed: false };
    throw err;
  }
}

// Polar webhook for Nuxt 4 (Nitro server route). Nitro invokes this
// handler on POST; it verifies the HMAC signature, then hands the event to the idempotent
// recordPolarEvent. Returns 200 even if non-critical work fails; only a signature failure
// is rejected.
// ponytail: Nuxt auto-imports these h3 helpers; import them explicitly so the module reads
// standalone (and type-checks against the installed h3).
import { defineEventHandler, readRawBody, getHeaders } from "h3";
import { validateEvent, WebhookVerificationError } from "@polar-sh/sdk/webhooks";
import { db } from "~~/server/lib/db";
import { recordPolarEvent, type PolarSubscriptionEvent } from "~~/server/lib/billing/record";

const SUBSCRIPTION_EVENTS = new Set([
  "subscription.created",
  "subscription.active",
  "subscription.updated",
  "subscription.canceled",
  "subscription.revoked",
  "subscription.uncanceled",
]);

export default defineEventHandler(async (event) => {
  const secret = process.env.POLAR_WEBHOOK_SECRET;
  if (!secret) {
    event.node.res.statusCode = 500;
    return { error: "Server misconfigured" };
  }

  const raw = (await readRawBody(event)) ?? "";
  const headers = getHeaders(event) as Record<string, string>;

  let payload: { type: string; data: unknown };
  try {
    payload = validateEvent(raw, headers, secret);
  } catch (error) {
    if (error instanceof WebhookVerificationError) {
      event.node.res.statusCode = 403;
      return { error: "Invalid signature" };
    }
    throw error;
  }

  if (SUBSCRIPTION_EVENTS.has(payload.type)) {
    await recordPolarEvent(db, payload as PolarSubscriptionEvent);
  }
  return { ok: true };
});

import { eq } from "drizzle-orm";
import { memberships, subscriptions, apiUsage } from "~~/server/db/schema";

// MySQL has NO row-level security. Tenant isolation is enforced HERE: route EVERY org-scoped
// read/write through forOrg(db, orgId). Fail-closed — a missing orgId throws rather than running
// unscoped. The global `plans` catalog is intentionally NOT scoped.
export function forOrg(db: any, orgId: string) {
  if (!orgId) throw new Error("forOrg: missing orgId — refusing to run an unscoped tenant query");
  const scoped = (table: any, orgCol: any) => ({
    select: () => db.select().from(table).where(eq(orgCol, orgId)),
    update: (values: Record<string, unknown>) => db.update(table).set(values).where(eq(orgCol, orgId)),
    delete: () => db.delete(table).where(eq(orgCol, orgId)),
  });
  return {
    memberships: scoped(memberships, memberships.organizationId),
    subscriptions: scoped(subscriptions, subscriptions.organizationId),
    apiUsage: scoped(apiUsage, apiUsage.organizationId),
  };
}

// === file: server/db/auth-schema.ts ===
import { mysqlTable, text, timestamp, varchar } from "drizzle-orm/mysql-core";

// Local mirror of Clerk identity — the FK target app-type schemas reference as user.
// id = Clerk's user id (varchar(255), matching the app-type user_id FKs), so existing
// user_id foreign keys resolve once the sync runs. This IS the auth-schema slot for Clerk cells.
export const user = mysqlTable("user", {
  id: varchar("id", { length: 255 }).primaryKey(), // = Clerk user id
  email: text("email"),
  firstName: text("first_name"),
  lastName: text("last_name"),
  imageUrl: text("image_url"),
  updatedAt: timestamp("updated_at"), // staleness key (Clerk updated_at)
  createdAt: timestamp("created_at").notNull().defaultNow(),
});

import { and, eq, isNull, lt, or } from "drizzle-orm";
import { user } from "~~/server/db/auth-schema";

export type ClerkUserEvent = {
  type: string;
  data: {
    id: string;
    email_addresses?: { email_address: string }[];
    first_name?: string | null;
    last_name?: string | null;
    image_url?: string | null;
    updated_at?: number;
  };
};

// Idempotent + concurrency-safe sync of a Clerk user into the local user table (MySQL).
// Keyed on id (= Clerk id, the PK); the staleness guard lives in the UPDATE WHERE. MySQL has no
// RETURNING — affectedRows tells us what happened. The insert path catches the unique-key race (a
// concurrent delivery of the same NEW user) as an idempotent no-op, rethrowing every other error.
// user.deleted removes the row.
export async function recordClerkEvent(
  // ponytail: loosely typed Drizzle client so the emitted core stays portable.
  db: any,
  event: ClerkUserEvent,
): Promise<{ changed: boolean }> {
  const d = event.data;
  if (event.type === "user.deleted") {
    const deleted = await db.delete(user).where(eq(user.id, d.id));
    return { changed: deleted[0].affectedRows > 0 };
  }

  const email = d.email_addresses?.[0]?.email_address ?? null;
  const eventAt = new Date(d.updated_at ?? 0);
  const fields = {
    email,
    firstName: d.first_name ?? null,
    lastName: d.last_name ?? null,
    imageUrl: d.image_url ?? null,
    updatedAt: eventAt,
  };

  const updated = await db
    .update(user)
    .set(fields)
    .where(and(eq(user.id, d.id), or(isNull(user.updatedAt), lt(user.updatedAt, eventAt))));
  if (updated[0].affectedRows > 0) return { changed: true };

  const [existing] = await db.select({ id: user.id }).from(user).where(eq(user.id, d.id)).limit(1);
  if (existing) return { changed: false };

  // The row doesn't exist yet — insert it. A concurrent delivery of the SAME new user can win the
  // race between our SELECT and this INSERT; the PK then rejects ours (ER_DUP_ENTRY) — an idempotent
  // no-op, NOT a change. Any other error is real: rethrow so the webhook fails loud and Clerk retries.
  try {
    await db.insert(user).values({ id: d.id, ...fields });
    return { changed: true };
  } catch (err: any) {
    if ((err?.cause?.code ?? err?.code) === "ER_DUP_ENTRY") return { changed: false };
    throw err;
  }
}

// Clerk identity webhook for Nuxt 4 (Nitro server route). The .post.ts
// suffix binds this handler to POST /api/webhooks/clerk. Clerk webhooks are svix: verify
// the signature, then hand the event to the idempotent recordClerkEvent.
// ponytail: Nuxt AUTO-IMPORTS the h3 helpers at runtime; we import defineEventHandler /
// readRawBody / getHeaders / createError EXPLICITLY from h3 (Nitro's engine, a nuxt dep) so
// this handler type-checks under standalone tsc — the one idiom trade for verifiability.
import { createError, defineEventHandler, getHeaders, readRawBody } from "h3";
import { Webhook } from "svix";
import { db } from "~~/server/lib/db";
import { recordClerkEvent, type ClerkUserEvent } from "~~/server/lib/identity/record";

const USER_EVENTS = new Set(["user.created", "user.updated", "user.deleted"]);

export default defineEventHandler(async (event) => {
  const secret = process.env.CLERK_WEBHOOK_SECRET;
  if (!secret) throw createError({ statusCode: 500, statusMessage: "Server misconfigured" });

  const raw = await readRawBody(event);
  if (!raw) throw createError({ statusCode: 400, statusMessage: "Missing body" });
  // getHeaders → Partial<Record<…, string | undefined>>; svix reads only the svix-* string
  // headers, so widen to the Record<string, string> its verify() signature expects.
  const headers = getHeaders(event) as Record<string, string>;

  let clerkEvent: ClerkUserEvent;
  try {
    clerkEvent = new Webhook(secret).verify(raw, headers) as ClerkUserEvent;
  } catch {
    throw createError({ statusCode: 403, statusMessage: "Invalid signature" });
  }

  if (USER_EVENTS.has(clerkEvent.type)) await recordClerkEvent(db, clerkEvent);
  return { ok: true };
});

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// Serverless: a small pool per short-lived instance — many instances × a big pool exhausts MySQL.
export const pool = mysql.createPool({ uri: process.env.DATABASE_URL!, connectionLimit: 2 });
export const db = drizzle({ client: pool });

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// Long-running process: a real, reused pool (mysql2 manages idle recycling).
export const pool = mysql.createPool({ uri: process.env.DATABASE_URL!, connectionLimit: 10 });
export const db = drizzle({ client: pool });

import { drizzle } from "drizzle-orm/planetscale-serverless";
import { Client } from "@planetscale/database";

// Edge/Workers have NO TCP sockets, so mysql2 cannot run here. PlanetScale's HTTP driver
// speaks MySQL over fetch — the client that works on Workers (the MySQL analog of Neon's HTTP driver).
const client = new Client({ url: process.env.DATABASE_URL! });
export const db = drizzle({ client });