Product analytics 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 } from "drizzle-orm";
import {
  index,
  json,
  mysqlTable,
  text,
  timestamp,
  varchar,
} from "drizzle-orm/mysql-core";
// Better Auth owns identity; we only reference its `user` table by id.
import { user } from "./auth-schema";

export const trackedApps = mysqlTable(
  "tracked_apps",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    ownerId: varchar("owner_id", { length: 255 }).notNull().references(() => user.id, { onDelete: "cascade" }),
    name: text("name").notNull(),
    apiKey: varchar("api_key", { length: 255 }).notNull().unique(),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [index("idx_app_owner").on(t.ownerId)],
);

// Append-only event stream; the analytical workhorse.
export const events = mysqlTable(
  "events",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    appId: varchar("app_id", { length: 36 }).notNull().references(() => trackedApps.id, { onDelete: "cascade" }),
    name: text("name").notNull(),
    anonymousId: text("anonymous_id"),
    properties: json("properties"),
    occurredAt: timestamp("occurred_at").notNull(),
  },
  (t) => [index("idx_event_app_time").on(t.appId, t.occurredAt)],
);

export const sessions = mysqlTable(
  "sessions",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    appId: varchar("app_id", { length: 36 }).notNull().references(() => trackedApps.id, { onDelete: "cascade" }),
    anonymousId: text("anonymous_id").notNull(),
    startedAt: timestamp("started_at").notNull(),
    endedAt: timestamp("ended_at"),
  },
  (t) => [index("idx_session_app").on(t.appId)],
);

export const funnels = mysqlTable("funnels", {
  id: varchar("id", { length: 36 }).primaryKey(),
  appId: varchar("app_id", { length: 36 }).notNull().references(() => trackedApps.id, { onDelete: "cascade" }),
  name: text("name").notNull(),
  steps: json("steps"),
  createdAt: timestamp("created_at").notNull().defaultNow(),
});

export const trackedAppsRelations = relations(trackedApps, ({ one, many }) => ({
  owner: one(user, { fields: [trackedApps.ownerId], references: [user.id] }),
  events: many(events),
  sessions: many(sessions),
  funnels: many(funnels),
}));
export const eventsRelations = relations(events, ({ one }) => ({
  app: one(trackedApps, { fields: [events.appId], references: [trackedApps.id] }),
}));
export const sessionsRelations = relations(sessions, ({ one }) => ({
  app: one(trackedApps, { fields: [sessions.appId], references: [trackedApps.id] }),
}));
export const funnelsRelations = relations(funnels, ({ one }) => ({
  app: one(trackedApps, { fields: [funnels.appId], references: [trackedApps.id] }),
}));

// === 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 });