> ## Documentation Index
> Fetch the complete documentation index at: https://docs.smartbills.io/llms.txt
> Use this file to discover all available pages before exploring further.

# JavaScript SDK Overview

> Official JavaScript/TypeScript SDK for the Smartbills API, build expense management, bill processing, and vendor workflows into your applications.

## JavaScript / TypeScript SDK

The `@smartbills/sdk` package provides a fully typed TypeScript client for the Smartbills REST API. It handles authentication, pagination, file uploads, error mapping, and automatic retries so you can focus on building your integration.

## Features

* Full TypeScript type definitions for every request and response
* Automatic retry with exponential back-off on transient failures
* Structured error hierarchy with type guard helpers
* Multi-tenant support via `businessId` context
* Locale-aware responses (`en-CA`, `fr-CA`)
* ESM and CommonJS dual-module builds
* FormData-based file uploads and presigned S3 upload flow

## Quick start

```typescript theme={null}
import { SmartbillsClient } from '@smartbills/sdk';

const client = new SmartbillsClient({
  accessToken: 'YOUR_API_KEY',
  businessId: 123,
  locale: 'en-CA',
});

// List recent expenses
const { data: expenses, pagination } = await client.expenses.listBusiness({
  limit: 25,
  page: 1,
});
console.log(`Found ${pagination.count} expenses`);

// Create an expense report
const report = await client.expenseReports.create({
  name: 'Q1 Travel Expenses',
});

// Upload a receipt
const formData = new FormData();
formData.append('files', receiptFile);
const uploaded = await client.expenses.uploadBusiness(formData);
```

## Available services

The `SmartbillsClient` exposes the following service objects. Each service groups related API operations.

| Service         | Property                       | Description                                                              |
| --------------- | ------------------------------ | ------------------------------------------------------------------------ |
| Expenses        | `client.expenses`              | List, upload, update, split, export, and bulk-manage expenses            |
| Expense Reports | `client.expenseReports`        | Create, submit, approve, reject, and reimburse expense reports           |
| Report Expenses | `client.expenseReportExpenses` | Add, remove, and edit expenses within a report                           |
| Report Payments | `client.expenseReportPayments` | Reimburse and plan reimbursements for reports                            |
| Approbations    | `client.approbations`          | Manage approval workflows                                                |
| Bills           | `client.bills`                 | Full accounts-payable lifecycle (draft, approval, payment, cancellation) |
| Vendors         | `client.vendors`               | CRUD, batch operations, merge, CSV import                                |
| Employees       | `client.employees`             | Employee management within a business                                    |
| Businesses      | `client.businesses`            | Business entity management                                               |
| Categories      | `client.categories`            | Expense category management                                              |
| Receipts        | `client.receipts`              | Receipt processing and management                                        |

## Requirements

* **Node.js** 18 or later
* **TypeScript** 5.0 or later (optional but recommended)

## Next steps

* [Installation](/sdks/javascript/installation), install the package and configure your environment
* [Authentication](/sdks/javascript/authentication), set up credentials and multi-tenant context
* [Expenses](/sdks/javascript/expenses), full expense service reference
* [Error Handling](/sdks/javascript/error-handling), understand the error hierarchy and write resilient code