Quickstart

Create a local development environment with npx gassma bootstrap, write a schema, generate a typed client, and start working with your spreadsheet.

note

If you want to use only the GAS script editor, add the library as described in Installation and see Using the GAS Editor.

Prerequisites

clasp must be installed and logged in.

$ npm install -g @google/clasp
$ clasp login

Also enable the Apps Script API on the Apps Script settings page.

1. Create a Project

$ npx gassma bootstrap my-app

An interactive prompt walks you through creating the Apps Script project, the build configuration, the schema file, and installing dependencies. Answering Yes to "Create a new spreadsheet as well?" creates a new spreadsheet along with a script bound to it.

The resulting directory looks like this:

my-app/
├── gassma/
│   └── schema.prisma
├── src/
│   └── index.ts
├── gassma.config.ts
├── esbuild.mjs
├── tsconfig.json
└── package.json

For the questions and the generated files in detail, see bootstrap.

2. Write the Schema

Define your models in gassma/schema.prisma. One model corresponds to one sheet.

generator client {
  provider = "prisma-client-js"
  output   = "./src/generated/gassma"
}

model User {
  id        Int      @id @default(autoincrement())
  name      String
  email     String   @unique
  age       Int
  createdAt DateTime @default(now())

  posts Post[]
}

model Post {
  id       Int    @id @default(autoincrement())
  title    String
  authorId Int

  author User @relation(fields: [authorId], references: [id], onDelete: Cascade)
}

The models and attributes you can write are covered in Schema.

3. Generate the Client

$ npx gassma generate

Type definitions and a client are generated into the directory specified by output. Settings such as relations and @default are already injected into the generated client.

During development, adding --watch regenerates automatically as the schema changes.

4. Create the Sheets in the Spreadsheet

Prepare the sheets and columns from your schema on the spreadsheet side.

$ npx gassma migrate dev --name init

This command does not access the spreadsheet directly. Push the generated gassma-migration.js and run it once in the Apps Script editor.

$ npm run push

Open the Apps Script editor (npm run open) and run the gassmaMigrate function once. This creates the sheets and their header rows.

caution

Right after migrate, use npm run push. npm run deploy rebuilds from scratch and may delete gassma-migration.js before pushing.

For the sync rules and --accept-data-loss, see migrate / db push.

5. Write Code

Import and use the generated client.

src/index.ts

import { GassmaClient } from "./generated/gassma/schemaClient";

const gassma = new GassmaClient();

export const main = () => {
  gassma.User.create({
    data: { name: "Alice", email: "[email protected]", age: 28 },
  });

  const users = gassma.User.findMany({
    where: { age: { gte: 20 } },
    orderBy: { name: "asc" },
    include: { posts: true },
  });

  console.log(users);
};

Exported functions become GAS global functions as-is (when you choose the export style in bootstrap).

6. Deploy and Run

$ npm run deploy

This builds and pushes to Apps Script. Open the editor with npm run open and run main.

What to Read Next

Page	Content
Basic	Client initialization and constructor options
Schema	How to write models, attributes, and relations
findMany	The core of reading: where, orderBy, pagination, and more
Relation Definition	Using relations with include and where
CLI Commands	Commands other than generate