Behind the Scenes with the Doc Team

by | Nov 19, 2021 | Catalog, Documentation, Kill Bill Internals, Kill Bill Resources | 0 comments

Kill Bill is a open-source subscription billing and payments platform. Fully extensible, you can build your business logic on top of it for a customized billing and payments solution.


In the past few months, we’ve added new guides to the Kill Bill documentation. We’re investing significant time and effort into our docs, and it gives us great pleasure to show off the results of all of this behind-the-scenes work. 

Here are links directly to the guides on docs.killbill.io:

We’ve also updated the Overdue System Guide. Keep reading for details!

New Catalog Examples with Guide

Although we already had several basic XML catalog examples, the Kill Bill documentation now has many more. We have supplemented our original 5 catalog examples with 11 more examples. You can see the list of all the catalog examples on GitHub.

TopicCatalog Example
Billing Modes
Plan Phases
Catalog with Multiple Plans
Billing Alignment Rules
Subscription Alignment Rules


To accompany the catalog examples, we’ve written a Catalog Examples Guide that explains how each example affects subscriptions and invoices in Kill Bill. It’s like the color commentary for your favorite sport. 😊

Here’s a screenshot from the Kill Bill documentation to show you what we mean: 

No Trial Phase & Monthly Evergreen Phase

Note: When you’re just getting started with the Kill Bill catalog, the best place to start is with the “Catalog” section in the Subscription Billing Manual. Then go through the new Catalog Examples Guide. After that, check out the Catalog API documentation.

Tip: We recently published a three-part blog post series on the subscription product catalog. 

Email Notification Plugin

This new Kill Bill documentation explains how to install, test, and use the Kill Bill email notification plugin. You can find the Email Notification Guide here.

Entitlement Plugin 

An entitlement plugin provides a way to intercept subscription operations, such as subscription creations or cancellations. The new Entitlement Plugin Guide explains how to implement the EntitlementPluginApi so that you can develop your own entitlement plugin(s). 

In your organization, you might find the need of an entitlement plugin if you need to: 

  • Change price information on the fly, such as right before the subscription is created. (Here’s a demo coupon plugin that highlights this functionality.)
  • Create state associated with the subscriptions (for example, adding custom fields to such subscriptions).
  • Dynamically create a (catalog) Plan and use the plan for the subscription calls. (In this case, this would also require a catalog plugin.)

Invoice Template 

This new Kill Bill guide consolidates invoice template information that was previously scattered across other manuals.

Kubernetes (K8) Deployment 

This new addition to the Kill Bill documentation explains how to get started with Kill Bill deployment in Kubernetes. A new support person who was getting started with Kill Bill wrote this, so we’re sure it has the details you need!

This guide uses Minikube to set up a local Kubernetes cluster and deploy Kill Bill to it. It also covers the steps to deploy Kill Bill to Kubernetes on DigitalOcean.

You can find the Kubernetes Deployment Guide in the “Operational” section of our documentation.

Managing Metrics with Datadog

This is a new document based on a blog post of the same name. Kill Bill provides over 1,300 metrics for a 360-degree view of your system’s behavior. 

Datadog is a low-cost option to monitor and display any of those metrics useful to your organization. This guide explains how to use Datadog with two types of Kill Bill implementations:  Amazon Web Services (AWS) for single-tier and multi-tier.  

Overdue System 

In the Overdue System Guide , we’ve added a section that provides more detail about the contents of the overdue.xml file. To accompany this guide, we’ve added several overdue.xml examples, which you can see here

One More Thing…

We would be remiss if I didn’t mention our ongoing video tutorials project. The Kill Bill YouTube channel now has a respectable number of videos! Keep this in mind as you onboard new Kill Bill users in your organization. 

If there’s a documentation topic you think we need to cover, please let us know. We’d love to hear about it.

See Also:

The Kill Bill Manuals: A Quick Tour