AntiPopup

AntiPopup is a standalone Paper plugin that hides Minecraft's unsafe-server login popup. This mrfdev fork is a deliberately narrow build for Paper 26.2 and its future Paper update line with Java 25 bytecode.

Player guide: AntiPopup on docs.1moreblock.com

What Is Special About This Fork

• One Paper plugin and one deployable JAR; Velocity, BungeeCord, Spigot server, Folia, and historical Minecraft build targets are gone.
• Compiles against the Paper API and contains no legacy command or chat- messaging surface.
• Contains no CraftBukkit/NMS implementation and no exact-version NMS switch. PacketEvents performs the protocol work, which removes the most brittle part of a Paper patch or minor-version update.
• Uses stable, pinned dependencies plus a Gradle lockfile. Snapshot dependencies and unused BoostedYAML, FoliaLib, ViaVersion hook, and compatibility modules are gone.
• Treats deprecation and removal warnings as build errors and verifies the final JAR's target bytecode, descriptor, main class, and legacy exclusions.
• Runs after ordinary packet listeners and leaves packets already cancelled by another listener untouched.
• Beginning with build 006, contains no commands, permissions, configuration, reload path, setup behavior, or persistent plugin state.

Server-Specific Direction After Build 005

Build 005 was confirmed on the 1MoreBlock server: the blue popup stayed hidden on join and ordinary player chat continued to work. Its exact JAR is retained internally as the known-good rollback artifact.

Starting with build 006, this fork is intentionally a server-specific tool that performs one operation and nothing else. It sets the modern Paper join packet's secure-chat flag so the native 26.2 client does not show the popup. The following historical upstream scope is deliberately removed moving forward:

• Proxy and protocol-translation integrations, load-order metadata, and networking-platform targets such as Velocity and BungeeCord.
• Spigot, Folia, legacy NMS modules, old Minecraft releases, and old-client packet formats.
• Old Java targets; this fork emits Java 25 bytecode and build 006 has passed its server smoke test on the installed Java 26.0.1 runtime.
• Commands, help, info, permissions, configuration, reload, diagnostics, chat-report features, metrics, console filtering, and server-properties setup.

PacketEvents remains embedded solely as the Paper packet transport needed for the one join-packet mutation. Its upstream spigot adapter name is an internal Bukkit/Paper implementation detail, not a supported Spigot server target. AntiPopup itself now owns only five classes. The standalone JAR remains about 4.5 MiB because PacketEvents' full reflection-driven injector and protocol library stays embedded; its generic internals are not supported old-client or proxy paths, and aggressively pruning them would risk breaking login injection.

Release Lines

• Build 006 — current 1MB modern: the certified popup-only Paper 26.2 build documented by this README. It has no commands, configuration, reload, setup, chat-report modification, metrics, Log4j filter, legacy-client path, proxy integration, or persistent state.
• Build 003 — archived full legacy: the feature-complete Paper-only 26.2 fallback. It retains /antipopup commands, configuration and reload, the popup toggle, server.properties setup/restart handling, chat-report blocking, the status marker, chat-session cancellation, disguised-chat conversion, optional bStats, the Log4j [Not Secure] filter, legacy SERVER_DATA handling, and translator soft-dependency metadata.

Build 003 is published for users who discover that build 006 deliberately removed behavior they still require. It is archived and unsupported, includes the features later rejected for the 1MB server, and will not receive future Paper updates. Never install builds 003 and 006 at the same time. Downloads and checksums are available from the GitHub releases page.

Compatibility

Component	Certified build
Server	Paper 26.2
Paper API	26.2.build.56-alpha
Java bytecode	Java 25 (class version 69)
Runtime	Paper 26.2-60-main@1cb58fb on Java 26.0.1 smoke-tested
Plugin version	14.0.0-006
Artifact	1MB-AntiPopup-v14.0.0-006-j25-26.2.jar

No proxy or companion plugin is required. The embedded PacketEvents Paper/Bukkit adapter retains spigot in its upstream artifact and class names; that is an implementation detail, not a supported Spigot server target.

What It Does

• For an uncancelled modern JOIN_GAME packet, sets enforcesSecureChat=true so the native 26.2 client does not show the popup.
• Nothing else. Suppression is always enabled while the plugin is installed.

AntiPopup has no rewards, costs, cooldowns, progression, player data, database, PlaceholderAPI placeholders, commands, permissions, or configuration.

Build and Test

JDK 25 is the configured Gradle toolchain:

./gradlew clean build --warning-mode all

The build runs strict compilation and verifyArtifact, then writes only the shaded, deployable plugin to:

build/libs/1MB-AntiPopup-v14.0.0-006-j25-26.2.jar

pluginVersion and the required three-digit pluginBuild live in gradle.properties. Future artifacts keep the pattern 1MB-AntiPopup-v<version>-<build>-j<java>-<paper>.jar.

PacketEvents 2.13.0 is relocated inside the JAR. The matching Adventure NBT 5.2.0 implementation is bundled while Paper supplies Adventure's API, keeping Paper and PacketEvents on one compatible component type system. PacketEvents' bundled bStats implementation is excluded, and its hard-coded metrics bootstrap is linked to inert local compatibility shims.

The strict build runs its artifact checks. An isolated runtime test verifies startup, plugin listing, and clean disable on Paper 26.2 build 60 with Java 26.0.1. Build 006 also passed its native 26.2 client join and ordinary-chat test; every later candidate must repeat that test.

Future Paper Updates

No project can guarantee compatibility with an unreleased Paper API. This fork instead removes the known exact-version/NMS failure point and keeps a repeatable certification path. For 26.2.1 or 26.3, make another disposable branch, update paperApiVersion and paperTarget in gradle.properties, refresh the lockfile, run the strict build, and complete an isolated server and client-login test before merging.

The complete checklist is in Maintaining Paper compatibility.

The embedded PacketEvents injector emits Java 26's final-field-mutation warning while it attaches to Paper's network channels. It works on Java 26.0.1; a server can explicitly authorize that access with --enable-final-field-mutation=ALL-UNNAMED. Re-test this boundary when moving to a later JDK or PacketEvents release.

Documentation

• Player guide
• Installation and updates
• Integrations
• Maintaining Paper compatibility
• Troubleshooting

Persistence and Privacy

AntiPopup has no configuration or persistent plugin state. PacketEvents update checks are disabled and no metrics service is started.

The isolated test does not replace a real-client login test. The production native 26.2 client completed the build 006 certification steps in docs/maintenance.md; protocol translators and older clients remain out of scope for the modern release.

Source, Support, and License

• Fork: mrfdev/AntiPopup
• Issues: mrfdev/AntiPopup issues
• Upstream: KaspianDev/AntiPopup

AntiPopup is distributed under the GNU General Public License v3.0. See LICENSE.