Extensions shouldn't mean downtime, and they shouldn't break on the next update. Caelestris is designed so mods snap in — and out — cleanly, backed by stable APIs that don't move under you.
Add a mod while the server is running. Pull it back out the same way. No restart, no downtime, no players kicked to a loading screen — capabilities that come and go on a live world instead of a maintenance window.
That's a genuinely hard thing to do well, and it's a defining goal of the Caelestris extension model: every mod loads in isolation and unloads cleanly, so removing one leaves the rest of your world untouched.
PlannedA server you can't extend safely isn't really extensible. Caelestris treats extension as a first-class concern: mods that load and unload on a live server, stable, versioned APIs so what you build keeps working, and clean isolation so one mod can never quietly take down another.
The principles behind the extension model.
Mods attach and detach while the world runs — iterate in minutes, not restart cycles.
Planned capabilityPulling a mod releases its resources and leaves everything else exactly as it was.
Planned capabilityExtension points are versioned and supported, so a mod written today survives tomorrow's update.
Planned capabilityEach mod runs behind clear boundaries — a fault in one doesn't cascade into the rest.
Built on the no-fallback modelReach for raw performance or rapid iteration — or both, side by side.
Compiled extensions that run at native speed, for the systems where every microsecond counts — physics, generation, custom protocols.
Lightweight, fast-to-write extensions for gameplay and content, where iteration speed matters more than raw throughput.
Hot-pluggable extension isn't bolted on later — it's what the current architecture is built to allow.
Every subsystem receives its dependencies rather than reaching for globals — the seam that lets new components slot in cleanly.
Core architecture todayThe server is a set of well-bounded subsystems that validate their dependencies and start or fail explicitly — the same discipline an extension plugs into.
Core architecture todayThe terrain pipeline is explicitly designed to accept modded content as a source of world material, alongside importers and procedural generators.
In the terrain design todayBehaviour is governed through a central configuration subsystem, so extensions can be switched on, tuned, and gated without code changes.
Core architecture todaySystems either run at full performance or fail loudly with diagnostics — so a misbehaving mod surfaces immediately instead of rotting quietly.
Core architecture todayA database abstraction spanning many backends means extensions store their state without binding your game to one vendor.
Core architecture todayThe dependency-injected subsystem architecture, configuration system, no-fallback discipline, and portable persistence exist in Caelestris today and are what make safe extension achievable. The plugin and mod loader, hot-plug lifecycle, and versioned extension APIs are on the roadmap — this page describes where that foundation is heading.
Caelestris Server is currently in development. Join our early look program and help shape an extension model built to last.
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