MSP-first ticketing • SLA-driven • Multi-company

Ticketing built around SLAs, designed for supporting multiple clients.

Casilium is a self-hosted, open-source support system for MSPs and service providers. Track requests by Organisation → Site → Contact, with business-hours-aware SLA targets, notifications, and email replies.

Run it in minutes View on GitHub
Self-hosted: free Docker Compose supported Mobile-friendly web UI
At-a-glance dashboard
SLA compliance

Built for on-call reality: overdue, due soon, and SLA health in one place.

Overdue
7
Due today
3
Average resolution
hours
2.7h
Designed to be kept private
Self-host behind a VPN or IP allowlist: your clients, your data, your control.
Production-hardened by daily MSP use.
Multi-company SLA + business hours Email replies Client reporting

Everything you need for client support, without SaaS lock-in

Casilium is opinionated in the right places: built for MSP workflows where visibility per client matters.

Client hierarchy

Organise work as Companies → Sites → Employees → Tickets, and view every request per company or contact.

SLA-first design

Response and resolution targets calculated using business hours — so Friday 4pm doesn’t mean weekend spam.

Smart notifications

Alerts as tickets approach due, and when overdue — ideal for queues and on-call rotations.

Reply by email

Keep conversations moving: notifications and updates can be handled via email without living in a portal.

Client reports

Executive summaries and monthly reporting to support reviews, invoicing, and “what did we do?” conversations.

Mobile-friendly web UI

No dedicated app required — use it on your phone when you’re on-site or on-call.

What Casilium is (and isn’t)

Casilium is deliberately narrow in scope. It exists to do one job properly and does not attempt to grow beyond it.

What Casilium is
  • A focused, open-source system for tracking support cases
  • Designed around organisations, sites, contacts, and tickets
  • Built with SLA and business-hours awareness at its core
  • Intended for ongoing, retainer-based support work
  • Self-hosted, transparent, and free from vendor lock-in
  • Designed to remain predictable, stable, and maintainable
What Casilium isn’t
  • A billing or invoicing platform
  • A time-tracking or project management system
  • An asset management or monitoring platform
  • A remote access or automation tool
  • An all-in-one PSA platform

Casilium records support activity and outcomes. It does not attempt to manage billing, time sheets, or operational tooling.

Casilium tracks support cases, that’s its only job. Its scope is intentional and not expected to expand beyond that purpose.

Run it locally, behind a VPN, or on a VPS

Casilium is self-hosted by design. Keep it private with IP allowlisting or a VPN, or choose managed hosting if you’d rather not maintain the infrastructure.

Designed for straightforward deployment
Docker Compose makes it simple to bring up an environment quickly for evaluation or production.
$ git clone https://github.com/casilium/casilium
$ cd casilium
$ docker compose up --build
Next: create an Organisation, Site, Contact, set Business Hours + SLA, then raise your first ticket.
Why it’s different for MSPs
  • Built for many client companies
    Not a single-company help desk with “organisations” bolted on afterwards.
  • Business-hours-aware SLA maths
    Due dates and reminders behave correctly across weekends and multiple business hours profiles.
  • Self-hosted control
    Keep it private, limit by IP, and integrate public CSAT via token/UUID links.
Open source
Browse the code

Fork it, run it, and customise it to match your workflow. Contributions welcome.

Frequently asked questions

Clear answers to common questions about Casilium’s scope and design choices.

Casilium exists to track client support cases properly. It records requests, responses, outcomes, and SLA commitments across multiple organisations. That’s its job — and it stays focused on doing that well.

No. Casilium does not handle billing or invoicing, and it never will. Tickets may be marked as chargeable for reporting purposes, but billing and accounts are intentionally left to other systems.

No. Casilium is not a project tracker and does not include time tracking. It is designed for retainer-based support work, where outcomes and responsiveness matter more than recording individual minutes.

No. Casilium is designed to work alongside existing RMM, asset management, and remote access tools. It does not attempt to replace them.

No. Casilium is intentionally scoped. It will continue to evolve within its purpose — tracking support cases — but it is not intended to become an all-in-one PSA platform.

Yes. Casilium is open source and can be self-hosted without restriction. Optional paid hosting and support are available for organisations that want them.

Pricing that matches how you want to run it

Casilium is open source and free to self-host. If you’d prefer, I can host a dedicated instance for you on a managed VPS.

Self-hosted

Run it on your own infrastructure
Free
£0
Forever. No feature restrictions.
  • Full functionality (SLA, notifications, email replies, reporting)
  • Docker Compose quick start
  • Keep it private (VPN / IP allowlisting)
  • You control updates, backups, and access
  • Your data belongs to you
Self-hosted installations are provided without support.
Get it on GitHub

Managed VPS

Dedicated hosted instance, deployed via Docker from:
Managed
£65/mo
A straightforward hosted option — no per-user pricing.
  • Dedicated VPS (no shared instance)
  • Single-tenant deployment (your own database and services)
  • Daily backups included
  • Updates and basic maintenance
  • Unlimited users, clients, and tickets
Optional paid support is available, but hosting does not require a support contract.
Enquire about hosting
Is Casilium multi-tenant?
Casilium is designed to support multiple client organisations in one system. Managed hosting is single-tenant: each customer gets a dedicated instance.
Do I need a mobile app?
No. Casilium is a responsive web application designed to work well on mobile browsers.
Can I keep it private?
Yes — run it behind a VPN or restrict access by IP. Casilium is designed to be kept private if you prefer.

Security-minded by design

Casilium is typically deployed privately. Many teams keep it behind a VPN or IP allowlist and expose only what’s necessary.

Reduce public exposure
Keep the ticketing UI private and integrate public CSAT via UUID tokens if required.
IP allowlisting & VPN friendly
Deploy behind a reverse proxy with strict network controls.
Strong defaults, clear boundaries
Practical security choices made from real operational experience.
Open source, no surprises

Read the code, run it locally, and decide how you want to deploy. If you choose the managed VPS option, you still keep a clear separation of concerns.

Explore the repository Compare options

Ready to try Casilium?

Self-host for free, or enquire about a managed VPS deployment.

Run it from GitHub Ask about hosting
Laminas
Framework components
Why Laminas & Mezzio?

Casilium has evolved alongside this ecosystem for nearly two decades. Its earliest versions date back to around 2007, progressing through Zend Framework, Zend Expressive, Laminas, and now Mezzio.

Laminas provides the underlying components, while Mezzio supplies a PSR-based, middleware-first application structure. This stack has been used in production continuously for around 19 years, with contributions back to the components along the way.

Mezzio
PSR-based application framework