# Development Setup

Everything you build on Bkper starts with the CLI. It handles authentication, provides the `bkper-js` library for programmatic access, and manages the full app lifecycle.

## Prerequisites

- [Node.js](https://nodejs.org/) >= 22.19.0

## Install and authenticate

1. **Install the CLI**

   ```bash
   npm i -g bkper
   ```

2. **Authenticate**

   ```bash
   bkper auth login
   ```

   This opens your browser for Google OAuth authentication. Once complete, the CLI stores your credentials locally. All API calls — from the CLI, from scripts, and from `bkper-js` — use this token. To clean up later, run `bkper auth logout`, which revokes the stored refresh token when possible and clears local credentials.

3. **Verify**

   ```bash
   bkper book list
   ```

   You should see a list of your Bkper Books. If you do, you're ready to build.

## What you now have

After setup, you have:

- **CLI commands** — Manage books, accounts, transactions, and apps from the terminal. Run `bkper --help` for the full command list.
- **Auth provider for scripts** — Use `getOAuthToken()` from the `bkper` package in any Node.js script:

  ```ts
  import { Bkper } from 'bkper-js';
  import { getOAuthToken } from 'bkper';

  Bkper.setConfig({
      oauthTokenProvider: async () => getOAuthToken(),
  });
  ```

- **App development tools** — Initialize, develop, and deploy platform apps with `bkper app` commands.

## Optional: API key

For dedicated API quota and project-level usage tracking, you can configure your own API key. This is optional — the default shared quota (60 requests per minute) works for most use cases.

See [Direct API Usage](https://bkper.com/docs/build/scripts/rest-api.md#custom-api-key) for setup instructions.

## Next steps

- [Quick Wins](https://bkper.com/docs/build/getting-started/quick-wins.md) — The fastest ways to create value with Bkper programmatically
- [Your First App](https://bkper.com/docs/build/apps/first-app.md) — Build and deploy a platform app
- [CLI reference](https://bkper.com/docs/build/tools/cli.md) — Overview of CLI capabilities