Using Kysely

Kysely is a type-safe and autocompletion-friendly TypeScript SQL query builder. While Lucia doesn’t provide an adapter for Kysely itself, it does provide adapters for all database drivers supported by Kysely out of the box.

See the next section for setting up the dialects, and make sure to change the table names in type Database to match your database.

// db.ts
import { Kysely } from "kysely";

export const db = new Kysely<Database>({
	dialect
});

type Database = {
	user: UserTable;
	key: KeyTable;
	session: SessionTable;
};

type UserTable = {
	id: string;
};

type KeyTable = {
	id: string;
	user_id: string;
	hashed_password: string | null;
};

type SessionTable = {
	id: string;
	user_id: string;
	active_expires: bigint;
	idle_expires: bigint;
};

Dialects#

MySQL#

Install mysql2 and follow the adapter documentation to setup your database.

npm install mysql2

Create a new Pool from mysql/promise and use it to initialize both Kysely and Lucia.

// db.ts
import { createPool } from "mysql2/promise";
import { Kysely, MysqlDialect } from "kysely";

export const pool = createPool({
	// ...
});

const dialect = new MysqlDialect({
	pool: pool.pool // IMPORTANT NOT TO JUST PASS `pool`
});

export const db = new Kysely<Database>({
	dialect
});

// lucia.ts
import { lucia } from "lucia";
import { mysql2 } from "@lucia-auth/adapter-mysql";

import { pool } from "./db.js";

export const auth = lucia({
	adapter: mysql2(pool, tableNames)
});

PostgreSQL#

Install pg and follow the adapter documentation to setup your database.

npm install pg

Create a new Pool and use it to initialize both Kysely and Lucia.

// db.ts
import { Pool } from "pg";
import { Kysely, PostgresDialect } from "kysely";

export const pool = new Pool({
	// ...
});

const dialect = new PostgresDialect({
	pool
});

export const db = new Kysely<Database>({
	dialect
});

// lucia.ts
import { lucia } from "lucia";
import { pg } from "@lucia-auth/adapter-postgresql";

import { pool } from "./db.js";

export const auth = lucia({
	adapter: pg(pool, tableNames)
});

SQLite#

Install better-sqlite3 and follow the adapter documentation to setup your database.

npm install better-sqlite3

Create a new Database and use it to initialize both Kysely and Lucia.

// db.ts
import sqlite from "better-sqlite3";
import { Kysely, SqliteDialect } from "kysely";

export const sqliteDatabase = sqlite(/* ... */);

const dialect = new SqliteDialect({
	database: sqliteDatabase
});

export const db = new Kysely<Database>({
	dialect
});

// lucia.ts
import { lucia } from "lucia";
import { betterSqlite3 } from "@lucia-auth/adapter-sqlite";

import { sqliteDatabase } from "./db.js";

const auth = lucia({
	adapter: betterSqlite3(sqliteDatabase, tableNames)
	// ...
});