Snappy loves Supabase


For seeding data into your Supabase project, we recommend selecting public and auth schemas only. If you experience any issues with any of the paths, reach out to us on Discord (opens in a new tab).

Generate data for your Supabase local development stack

Supabase makes it easy to set up a local development environment linked to your Supabase project. Seed can improve your local development by seeding your local database with data, making coding and testing more efficient and accurate.

In this short guide we'll focus on how to integate @snaplet/seed with your Supabase project.

1. Setup your supabase project

Once you have a working supabase project with a local development stack (opens in a new tab) setup.

Running npx supabase start should spin up the database and give you the URL to access postgres database.

Started supabase local development setup.
DB URL: postgresql://postgres:postgres@

Make sure that you have the migrations applied in your local database with your differents app tables on it. If you don't refer to Supabase docs (opens in a new tab) to run your migrations.

2. Set up Seed

2.1. To interface with your postgres database we'll need to install an adapter for @snaplet/seed you can use either node-postgres or postgres

npm install -D postgres

2.2. Initialise @snaplet/seed in your your root project.

>_ terminal

npx @snaplet/seed init

2.3. The init command will create a seed.config.ts file in which you can specify the database connection details and exclude part of the database schema you don't want to alter with @snaplet/seed

import { SeedPostgres } from "@snaplet/seed/adapter-postgres";
import { defineConfig } from "@snaplet/seed/config";
import postgres from "postgres";
export default defineConfig({
adapter: () => {
const client = postgres("postgresql://postgres:postgres@");
return new SeedPostgres(client);
select: [
// We don't alter any extensions tables that might be owned by extensions
// We want to alter all the tables under public schema
// We also want to alter some of the tables under the auth schema

Once you save the edited file, the init command will continue and create a seed.ts example file in your project folder. You are now ready to seed your database.

4. Keep Seed Client in sync with your database

Whenever your database structure changes (e.g after a new migration is applied), @snaplet/seed will need be regenerated to reflect the new structure. To do this, run the following command:

>_ terminal

npx @snaplet/seed sync

4. (optional) Hook into Supabase seeding workflow

You can hook into Supabase seeding workflow (opens in a new tab) using the dryRun option for client creation in the seed.ts file:

import { createSeedClient } from "@snaplet/seed";
const seed = await createSeedClient({ dryRun: true });

This option will turn on the dry run mode, which will log the SQL queries that would be executed to the console, without actually executing them.

You can then put those queries into the sql seed script expected by supabase:

npx tsx seed.ts > supabase/seed.sql

Then, running npx supabase db reset should apply the seed script to your local database.

Going futher

For a full example of a project using @snaplet/seed with Supabase including:

  • seeding data
  • seeding with e2e tests
  • seeding with supabase created user pool

check out the example project (opens in a new tab)