Minecraft anticheat guide
Swing Timer and Client Mod Signals in FairPlay
How FairPlay's SwingTimer and ClientModDetection checks observe swing timing and client signals, what legit setups resemble, and how to review them.
What do the swing timer and client mod checks observe?
SwingTimer looks at how the arm swing timing lines up with the actions around it, such as attacks and breaks. ClientModDetection looks for client plugin-channel signals that can point to a client mod. Its source notes describe it as a reporting check with no direct weight of its own. Together they inform a reviewer. Neither one is a verdict.
Treat both as context. A swing timer alert tells you about timing. A mod signal tells you what the client announced, which may or may not match what it does. Neither should be read alone. A swing timer alert on a player who also shows a mod signal deserves a fuller review than either signal on its own.
Which cheat behavior do they target?
Swing-timer cheats change animation timing so that actions happen faster than the animation would allow. Client mods can change the HUD, the input layer or the timing of actions, and some are built for that purpose. The mod signal helps a reviewer decide whether the client is one they should look at more closely.
Neither check identifies a specific cheat by name. They record a timing shape and a client announcement, and the reviewer must connect those to the behavior in front of them.
A useful way to think about the swing timer is as a timing question, not a client question. It asks whether the swing happened where a person would place it, relative to the actions around it. A mod signal asks a different question, which is what the client announced. Keep those two questions apart in your notes.
What legitimate setups can resemble these signals?
A wide range of legal setups can look similar. A fast client with unusual animation settings can change swing timing. Harmless tools can also announce plugin channels, which is how a mod signal can fire on a player who installed nothing unusual.
How should staff read these signals?
Read the swing alert and the mod signal separately first, then look for overlap with combat or movement alerts. The table gives the first step for each case.
| Signal | Question to ask | Next step |
|---|---|---|
| SwingTimer alert | Does the timing shape repeat across several fights? | Compare with ping and with the other combat checks |
| Client mod signal alone | Which channel did the client announce, and which client is it? | Ask what the player runs, if your policy allows it, and check your rules |
| Client mod signal plus combat alerts | Do the combat alerts happen in the same sessions as the signal? | Treat the signal as context for a full review, not as a result |
What is the review procedure?
Mod signals are easy to over-read because many harmless tools announce channels. A short, consistent procedure keeps the reviews fair.
What should you tune only in staging?
Keep both signals reporting-only at first. Confirm which mods and resource packs your players commonly use, and write your rules on them before you enable any action. Client mod detection depends on what the client and the wrapper layers support, so test on the protocol versions your players actually run.
Read the per-check reference before changing settings, and do not copy values from another server, since the mods your players use are specific to your community.
Publish a short list of allowed client mods and resource packs so players know the rules before a review starts. A clear list also makes a mod signal easier to classify, because staff are not guessing at policy during each case.
What have we not verified?
We have not measured which mods trigger the channel signal, how often it fires for legit players, or how the swing timer behaves across clients. This article describes what the two checks are named to observe. It does not claim that either signal identifies a cheat. Player privacy matters here too. Read the privacy article on this site before you log channel names, and decide how long those records should be kept.
FAQ
Is a mod signal a reason to ban?
Only if your published rules ban that specific mod. Check the rules page first, then review the player's conduct as you would for any other case.
Why does a player show a mod signal they say they never installed?
Resource packs and launchers can register channels without a mod being installed in the usual sense. Ask what they run, and check the client before deciding.
Can a swing timer alert come from a fast animation setting?
It can. Check the player's settings and compare the timing with ping before drawing a conclusion about the player.