Leveraging Python for Xero API: Automating Financial Processes

Introduction

Welcome everyone to another article in our series, Leveraging Python for API(s). In this installment, we will explore how to use Python to interact with the Xero API for invoice management. This guide covers the basics of making API calls to Xero with Python, demonstrating through a real-world case study how this approach can streamline your invoice management processes.

Imagine you are a business owner using Xero for accounting. You need to update specific details on many invoices regularly. Manually making these updates through Xero's UI is time-consuming and tedious. Python and the Xero API can automate this task, saving you time and reducing errors.

In this guide, you will learn how to set up your environment, authenticate with the Xero API, fetch invoices, and update them. We will also cover error handling and best practices for structuring your code.

By the end of this guide, you'll have a solid understanding of how to use Python to interact with the Xero API and apply this knowledge to your own business needs. Let's dive in and start automating your invoice management!

Xero API Overview

The Xero API is a RESTful web service that uses OAuth 2.0 for authentication and authorization. It allows third-party applications to interact with the Xero platform, enabling various tasks such as querying data, posting transactions, and more…

Key Endpoints:

• Invoices: 
   
  • Endpoint: /api.xro/2.0/Invoices
     
  • Methods: GET, POST, PUT
     
  • Description: Allows for the retrieval, creation, and updating of invoices within Xero. This is essential for managing your accounts receivable and ensuring accurate financial records.
     
  • Ref: https://developer.xero.com/documentation/api/accounting/invoices
     
• Contacts:
   
  • Endpoint: /api.xro/2.0/Contacts
     
  • Methods: GET, POST, PUT
     
  • Description: Enables access to contact information, facilitating the management of customer and supplier details. This is crucial for maintaining up-to-date and accurate contact lists.
     
  • Ref: https://developer.xero.com/documentation/api/accounting/contacts
     
• Payments:
   
  • Endpoint: /api.xro/2.0/Payments
     
  • Methods: GET, POST, PUT
     
  • Description: Provides functionality to handle payments against invoices, helping you keep track of incoming and outgoing payments, and ensuring your financial transactions are accurately recorded.
     
  • Ref: https://developer.xero.com/documentation/api/accounting/payments

Setting Up the Environment

First, set up your development environment with the necessary packages.

NOTE: in order to follow the guide eazily, you should have your system installed python and pyenv first.

Now , after all the process are done, you can now access the new shell with command:

Authenticating with the Xero API

To make API calls, you'll need to authenticate with Xero using OAuth 2.0. Follow the steps in the Xero OAuth Documentation to obtain your access tokens.

Or you can copy the code below to quickly obtain your new access token, the explaination for each step also available in the code.

NOTE: you will need to get your Xero’s client id and client secret first, which can be obtained in this app management page.
Go to this link, click on your app (your app must be the Custom Connection type, not other type of app, follow this link for more information), then click on the Configuration section, then you can see your Client ID. For Client Secret, you will need to create one, by simply click on Create.
For more information about those credentials, please follow this link.
Note that you should not share your credentials to any one, because with that credentials they can have full access to your Xero site.

Fetching Invoices

Use the Invoice API to fetch invoice(s) from your Xero account.

To do this, you’ll need to know the id of the invoice that you want to get, or skip it if you want to get all the invoice. In my case, I want to fetch an specific invoice, so that I need that invoice’s id.

After running this code, in success, you can see that the following content is printed into your shell (the below is my invoice with ID fee88eea-f2aa-4a71-a372-33d6d83d3c45):

Updating Invoices

The way you make the request to update an invoice is nearly similar to the way you fetch them, except that you’ll need to prepare the invoice with the data that you want to update, then use the POST method to update them in Xero.

Here is how you can do that in python. In this case, I want to update the InvoiceNumber of the invoice to My InvoiceNumber, and this is how I do that with python:

After the API call is completed, then now you can see that the invoice is updated with the InvoiceNumber as My InvoiceNumber

Now that you know how to update an invoice using the Xero API, you can explore updating other fields within the invoice as well. The Xero API provides comprehensive functionality to manage various aspects of your invoices. For more detailed information on how to make these updates, please refer to the official Xero API documentation on invoices.

Conclusion

Congratulations! You now know how to make API calls to Xero using Python, which can greatly improve your efficiency in managing invoices. This knowledge can be extended to integrate other functionalities of Xero into your applications.