Drizzle ORM adapter (@healthzkit/drizzle)

The @healthzkit/drizzle package provides a HealthAdapter for an existing Drizzle ORM database instance. Successful checks run a lightweight SQL probe (default SELECT 1) through Drizzle—execute for Postgres and MySQL, run for SQLite—and return ok with metadata.latencyMs plus any fields from an optional metadata hook; failures return fail with the caught error.

Install the adapter package and drizzle-orm (your app already has both if you use Drizzle):

pnpm add @healthzkit/drizzle drizzle-orm

Drivers stay in your app. This package does not list pg, mysql2, or SQLite clients as peer dependencies. The probe uses Drizzle’s public API on the db you pass in; driver packages remain in the package that created the instance.

Package entrypoints

• @healthzkit/drizzle — drizzleAdapter, extractClient, detectDriver, and option types.
• @healthzkit/drizzle/drizzle — drizzleAdapter only.
• @healthzkit/drizzle/extract — extractClient, detectDriver, and types.

Options

Option	Description
db	Your Drizzle instance (PgDatabase, MySqlDatabase, or BaseSQLiteDatabase). Required.
driver	Optional "pg", "mysql", or "sqlite" to override auto-detection from the session layout.
query	SQL for the probe. Default SELECT 1.
metadata	Optional (client) => Record<string, unknown> (sync or async). Uses db.session.client when available. Type client in your app with a second generic (see below).

Basic usage

Pass the same db your service uses for application queries:

import { createHealthKit } from "healthzkit";
import { drizzleAdapter } from "@healthzkit/drizzle";
import { db } from "./db.ts";

const kit = createHealthKit({
  checks: [
    {
      name: "database",
      type: ["readiness"],
      adapter: drizzleAdapter({ db }),
    },
  ],
});

Driver override

The adapter can infer the dialect from Drizzle’s session (query for Postgres, execute for MySQL, run / syncRun for SQLite). Set driver when you want an explicit probe path:

import { drizzleAdapter } from "@healthzkit/drizzle/drizzle";

const adapter = drizzleAdapter({
  db,
  driver: "mysql",
  query: "SELECT 1",
});

Typed metadata

The adapter does not import driver types. If you want a typed metadata callback, supply the client type from your application (where pg, mysql2, and so on are already installed):

import type { Pool } from "pg";
import { drizzleAdapter } from "@healthzkit/drizzle";

const adapter = drizzleAdapter<typeof db, Pool>({
  db,
  metadata: (client) => ({ totalCount: client.totalCount }),
});

Helpers

• detectDriver(db) — "pg" | "mysql" | "sqlite" | "unknown".
• extractClient(db) — underlying session.client as unknown.

Import from @healthzkit/drizzle or @healthzkit/drizzle/extract.

When to use this vs driver adapters

Situation	Suggestion
App already uses Drizzle for all DB access	@healthzkit/drizzle — pass db, no second connection
App already uses Prisma for all DB access	@healthzkit/prisma — pass your existing PrismaClient
Raw pg / mysql2 pool without ORM	@healthzkit/postgres, @healthzkit/mysql, or @healthzkit/sqlite

Scheduling

For busy databases, pair this adapter with a schedule on the check so readiness reads cached results (see Scheduling).