Inertia

Inertia is an open-source Minecraft anti-cheat foundation focused on version-neutral engine design.

The project is being built around behavior profiles, normalized movement and packet frames, world snapshots, collision models, and testable evidence handling.

Current scope

This repository does not claim full Minecraft 1.8 -> latest support yet.

The current implementation builds the foundation for that goal:

• lean module layout
• neutral version and profile API
• evidence and confidence accumulation
• false-positive context handling
• tests that run without a live server

Module layout

The current repo intentionally stays small:

• inertia-api - neutral public contracts
• inertia-core - core engine and evidence behavior
• inertia-testkit - scenario-oriented tests
• docs/ - project rules and research notes

Platform adapters, packet libraries, and plugin bootstrap code are intentionally deferred.

Design rules

Inertia models behavior, not server package names.

That means:

• no Bukkit or NMS in the core
• no v1_8_R3 style engine branching
• version differences belong in profiles
• the engine should be testable without booting a Minecraft server

Early focus

The first implementation pass covers:

• GameVersion, VersionRange, and grouped VersionProfile rules
• movement, world, collision, packet, and debug contracts
• evidence records and a default evidence accumulator
• false-positive context for teleports, velocity grace, latency spikes, and server-health drops
• required tests for evidence accumulation, decay, reductions, and trace output

The repository now also includes the first movement prediction skeleton:

• movement state tracking across frames
• basic horizontal and vertical sanity limits from version profiles
• teleport grace and velocity grace handling
• movement debug traces
• scenario-driven movement tests

This is still a foundation pass, not full vanilla movement parity.

Reference policy

Local reference projects may be inspected for category-level research only.

They are not part of Inertia and must not be copied into this repository.

See docs/reference-policy.md.

For the current engine boundaries and movement limits, see docs/architecture.md.