Adaptive Entity Prioritization (AEP)
by Will5Plays
Adaptive Entity Prioritization, shortened to AEP, is a Fabric server optimization that throttles mob AI, pathfinding and item merge checks only while the server is under load.
What it does
AEP watches the server's tick times and reduces work for entities when MSPT or TPS starts to drop. Throttled mobs tick only once in a few game ticks, and item entities skip some of their nearby-stack searches and physics checks. When the server is healthy, entities and item stacks behave normally, so the throttling is applied only during heavy periods.
The mod uses an adaptive throttling system rather than a blanket reduction, and it applies its logic at high mixin priority so it runs before the matching vanilla methods. Because the change takes effect as soon as lag is detected, it can reduce load immediately. AEP is compatible with Lithium, and it needs Fabric to run.
AEP is client and server, and only the server does work. Players can join without it, but the mod has to run on the server to do anything. It is published for 1.21.8 only, under the MIT License, and is not open source.
Key features
Adaptive mob throttling
Mob AI and pathfinding tick less often when the server strains, and resume full rate once tick times recover.
Item merge checks
Nearby item entities perform fewer merge searches while the server is under load, reducing physics work.
Lag-triggered activation
Throttling begins when high MSPT or falling TPS is detected, so the server does no reduction in quiet periods.
Early mixin hook
Throttling logic runs before the corresponding vanilla methods, so the reduction applies at the start of each affected call.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Busy survival servers
Servers with many mobs and dropped items can use the mod to limit tick spikes during peak play.
Farm-heavy worlds
Worlds with large mob farms and item collection setups can run the throttling only when the load rises.
Who it’s for: Server owners who run Fabric on 1.21.8 and see MSPT or TPS drops under heavy entity or item load. Players on single-player or client-only setups have no use for it.
How it compares
Prism Performance is a client-side only Fabric mod for 1.21 – 1.21.11 under the MIT License, and it is not open source. ItemStacker is server-side only, published for 1.21.11 under the MIT License, and not open source. Item Merge Begone is server-side only and open source under the MIT License, for 1.21.11, so it covers item merging alone where AEP also throttles mobs.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Adaptive Entity Prioritization (AEP) | Fabric | 1.21.8 | Client and server | 2025-11-30 |
| Prism Performance | Fabric | 1.21 – 1.21.11 | Client-side only | 2026-03-23 |
| ItemStacker | Fabric | 1.21.11 | Server-side only | 2026-06-06 |
| Item Merge Begone | Fabric | 1.21.11 | Server-side only | 2025-12-14 |
Questions
Does AEP need to be installed on the client?
Which loader and version does AEP support?
Does AEP work alongside Lithium?
In the catalog
Adaptive Entity Prioritization (AEP) is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 17,695 mods support Minecraft 1.21.8.
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What the author says
AEP is a lightweight, server-side performance optimization mod designed to automatically manage and reduce load caused by entity ticking and physics. Unlike blanket optimizations, AEP uses an adaptive throttling system. The mod only steps in to reduce work when the server needs it—primarily during periods of high…
Official listing
- Modrinth page
- modrinth.com/mod/aep
- Owner
- Will5Plays
- Published
- 2025-11-30
- Updated on Modrinth
- 2025-11-30
- Facts verified
- 2026-10-15