AntiFly

Lightweight Paper + Fabric flight-control plugin by CevAPI.

Current release: 1.1.2

AntiFly is not a full anti-cheat - it focuses on flight/movement abuse with layered checks:

• server-side ground/support truth (never trusts client onGround)
• buffered air/hover/anti-kick suspicion + sustained-air detection
• disciplined setbacks to last known valid support
• Elytra checks that only flag what vanilla physics can't do (speed, instant vertical, stall)
• teleport-aware rebasing; /tp, pearls, chorus, portals never trigger setbacks
• Hunger Mode, a configurable food/health tax instead of hard blocks

Platforms

• Paper: 1.21.1-26.2 (Folia-supported)
• Fabric: 1.21.11 / 26.1.2 / 26.2

Install

• Paper: drop the jar into plugins/
• Fabric: drop the jar into mods/

Commands

Same set on Paper & Fabric. Requires op / antifly.admin on Paper, moderator-level on Fabric.

• /antifly enable|disable|status|help
• /antifly hungermode <on|off>
• /antifly set - lists every tunable key with its current value
• /antifly set <key> - read one value
• /antifly set <key> <value> - set one (applies instantly, auto-saves)
• /antifly alerts <off|game|console|both>
• /antifly debug <on|off>
• /antifly exempt <player> / /antifly unexempt <player>
• /antifly reset <player>
• /antifly disabledworlds <worldName> <true|false>

Tuning keys

All adjustable live via /antifly set. Defaults in brackets.

Movement

groundWalkMax (0.67) · groundMountedMax (0.75) · waterMax (0.55) · waterVerticalMax (0.7) · boatMaxHorizontal (0.85) · maxAirHorizontal (1.8) · maxAirVertical (1.0) · sustainedAirTicksLimit (150)

Elytra

Same keys on both platforms. On Fabric the rocket/no-rocket variants map to the single caps elytraMaxHorizontal (6.0) and elytraMaxUp (4.0); on Paper they're independent.

• elytraMaxHorizontal / elytraNoRocketSustainableHorizontal / elytraMaxRocketHorizontal
• elytraMaxUp / elytraMaxNoRocketUp / elytraMaxRocketUp
• elytraEnabled · elytraBoostGraceTicks · elytraStallTicks · elytraMovementBufferLimit

Hunger Mode

• hungerModeMaxBlocksPerSecond (200) · hungerModeHungerPerSecondAtMaxSpeed (10) · hungerModeRocketGraceTicks (80) · hungerModeAirborneMinimumBlocksPerSecond (20)
• hungerModeFlightDamageEnabled (true) · hungerModeFlightDamageAfterSeconds (20) · hungerModeFlightDamageAfterHungerSeconds (30) · hungerModeFlightDamagePerSecond (1)
• hungerModeElytraFoodEnabled (true) · hungerModeElytraFoodMultiplier (0.5) · hungerModeElytraSpeedThresholdBps (50) · hungerModeElytraNoRocketAfterSeconds (45) · hungerModeElytraDamageEnabled (true) · hungerModeRocketResetsDamage (true)

Hunger Mode

• /antifly hungermode on - replaces hard blocks with a food drain. Hovering always drains slowly, and client onGround spoofing can't bypass it.
• Drain scales quadratically with horizontal speed (cap 200 BPS = 10 food/s). Rocket boost = free for 80 ticks; gliding pays by its real speed (no unfair elytra tax).
• After 20s of continuous unsupported flight (not gliding), real health damage kicks in (generic damage, in full-heart chunks every 2s, every 4s while descending). Health damage always follows hunger: the timer only counts while hunger is actively draining, so the hunger phase comes first.
• Elytra is only punished when exploiting: flying over the speed threshold, hover-hacking, or gliding for a long time without any rocket (45s). Vanilla gliding (with rockets) is completely free - no food drain, no health damage. For elytra, health damage only starts after hunger has been actively draining for 30s.

Notes on Elytra

• Checks only block what vanilla can't do: sustained speed beyond ~6 b/t, instant climbs beyond ~4 b/t, and stall-hovering. Steep dives, pull-ups, rocket boosts and crashing into obstacles are all allowed.
• Repeated ground-flag spoofing can't refresh landing grace; sustained flat-air movement is blocked after 20 air ticks at 0.45 b/t.

Permissions (Paper)

• antifly.admin (default: op) · antifly.alerts (default: op)

Config

• Paper: plugins/AntiFly/config.yml · Fabric: config/antifly.json
• Disable AntiFly per world with disabledWorlds: [] on either platform
• Modrinth check (slug antiflight): /antifly status + startup warning when outdated