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Kysely + Supabase

Supabase is an open-source Firebase alternative that provides a suite of tools for building applications. At the core, it is a managed PostgreSQL database vendor. They provide a CLI library called supabase that's at the heart of their ecosystem. It manages your database, migrates it and can generate TypeScript types from it. They also provide a JavaScript client library called @supabase/supabase-js that wraps a PostgREST API, and is pretty limited - doesn't even allow raw SQL. This is where Kysely comes in.

We provide a bridge library called kysely-supabase that allows you to translate supabase's generated TypeScript types into types compatible with Kysely.

Prerequisites​

  1. supabase CLI installed and a Supabase project set up.

  2. kysely installed.

  3. A PostgreSQL driver installed - e.g. pg or postgres. The latter requires kysely-postgres-js to be installed as well.

Installation​

npm i -D kysely-supabase

Usage​

Generate TypeScript types using supabase CLI​

npx supabase gen types typescript --local > path/to/supabase/generated/types/file

Translate Supabase types to Kysely types​

src/types.ts
import type { Database as SupabaseDatabase } from 'path/to/supabase/generated/types/file'
import type { KyselifyDatabase } from 'kysely-supabase'

export type Database = KyselifyDatabase<SupabaseDatabase>

Pass translated types to Kysely constructor​

src/db.ts
import { Kysely, PostgresDialect } from 'kysely'
import { Pool } from 'pg'
import type { Database } from './types'

export const db = new Kysely<Database>({
  //                         ^^^^^^^^
  dialect: new PostgresDialect({
    pool: new Pool({
      connectionString: process.env.DATABASE_URL,
    }),
  }),
})