Deploy and Host Kill Bill on Railway

Kill Bill is Open-source billing and payments infrastructure for teams that need control - https://killbill.io/.

About Hosting Kill Bill

KillBill is a Java based billing platform that requires three moving parts: a MariaDB (or MySQL) database pre-seeded with two schemas (killbill and kaui), the KillBill application server (a Jetty-based Java app), and optionally KAUI (the Ruby on Rails admin UI). The app server is heavyweight. It runs Flyway migrations on first boot and loads an OSGi plugin container, so cold start takes 2–4 minutes. It's memory-hungry (1–2 GB minimum for the JVM). You need persistent storage for the database, internal networking between all three services, and a public HTTP endpoint for KAUI.

Common Use Cases

SaaS subscription billing - recurring plans, trials, upgrades/downgrades, proration
Usage-based billing - metered pricing (API calls, GB stored, minutes used)
Marketplace / multi-tenant billing - billing on behalf of multiple vendors from one platform
Invoicing & dunning - automatic invoice generation, failed payment retries, overdue notices
Tax & compliance - pluggable tax engines
Freemium monetisation - free tier with automatic conversion to paid on limit breach

Dependencies for Kill Bill Hosting

Runtime

Java 11+ (JVM — KillBill runs on Jetty)
MySQL 5.7+ or MariaDB 10+ (pre-seeded schemas via Flyway)
Ruby 2.x / JRuby (KAUI admin UI)

Networking

Internal private network between all three services
Public HTTPS endpoint for KAUI
Optional public endpoint for the KillBill API

Storage

Persistent volume for the database (data survives restarts)
No persistent disk needed for the app containers themselves

Compute

KillBill JVM: minimum 1–2 GB RAM, 1 vCPU
KAUI: ~512 MB RAM
MariaDB: ~512 MB RAM
Total minimum: ~2.5–3 GB RAM across all three

Credentials

DB root password (shared across all three services)
KillBill API key + secret (default: bob / lazar — change in production)
KAUI admin login (default: admin / password — change in production)

Deployment Dependencies

None

Why Deploy Kill Bill on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying Kill Bill on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.