API documentation

Overview

FeatherMC is a fork of Paper. It does not publish its own API artifact. Its changes are inside the server: defaults, guards and internal work. The plugin-facing API is Paper's, unchanged.

• Compile against io.papermc.paper:paper-api for 26.3.
• Target Java 25.
• Test on Paper or FeatherMC. Behaviour your plugin can observe through the API is the same.

Project setup

Add Paper's Maven repository and the paper-api dependency, exactly as you would for Paper.

repositories {
    maven {
        url = uri("https://repo.papermc.io/repository/maven-public/")
    }
}

dependencies {
    compileOnly("io.papermc.paper:paper-api:26.3.build.+")
}

java {
    toolchain.languageVersion.set(JavaLanguageVersion.of(25))
}

repositories {
    maven {
        url = 'https://repo.papermc.io/repository/maven-public/'
    }
}

dependencies {
    compileOnly 'io.papermc.paper:paper-api:26.3.build.+'
}

java {
    toolchain.languageVersion = JavaLanguageVersion.of(25)
}

<repositories>
    <repository>
        <id>papermc</id>
        <url>https://repo.papermc.io/repository/maven-public/</url>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>io.papermc.paper</groupId>
        <artifactId>paper-api</artifactId>
        <version>[26.3.build,)</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

Plugin descriptor

Use plugin.yml or paper-plugin.yml with the same fields and api-version you would use for Paper 26.3. FeatherMC loads both formats through Paper's own plugin loader, so nothing in your descriptor needs to mention FeatherMC.

If your plugin declares that it depends on Paper, that check passes on FeatherMC, because the server keeps Paper's brand ID.

Detecting FeatherMC

Most plugins never need to know. If you want to show it in a debug command or enable something only on FeatherMC, check the brand name. The brand ID is deliberately still Paper's.

import io.papermc.paper.ServerBuildInfo;

public static boolean isFeatherMC() {
    return "FeatherMC".equals(ServerBuildInfo.buildInfo().brandName());
}

// Bukkit.getName()                      -> "FeatherMC"
// ServerBuildInfo.buildInfo().brandId() -> papermc:paper

Don't use this to work around Paper behaviour. If something behaves differently on FeatherMC than on Paper in a way your plugin can see, that is a FeatherMC bug and worth reporting.

Compatibility contract

FeatherMC keeps these the same as Paper on purpose, so tools and plugins built for Paper keep working:

What players can observe is also held constant. Redstone timing, mob behaviour, drops, physics and world generation must match Paper. The only exceptions are the opt-in guards documented below, and they are off unless an admin turns them on.

Config reference: feather.yml

FeatherMC's own options live in feather.yml in the server root, separate from Paper's config/ folder. The file is created with every option and its comment on first start. It is read once at startup, so restart to apply changes.

mass-destruction

Guards against mass-TNT "orbital strike" detonations.

mass-destruction:
  prevent-tnt-mass-detonation: false
  threshold: 100
  radius: 8.0

Changed Paper defaults

FeatherMC changes a small number of Paper's defaults. They only apply to keys that are not already in your config, so a server migrated from Paper keeps its existing values until you change them.

See the features page for why each default was chosen and when to change it.

Javadocs

There is no separate FeatherMC Javadoc, because there is no separate API. Use Paper's:

• Paper API Javadocs
• Paper developer guides
• Paper project setup

Found an API difference between Paper and FeatherMC? Open an issue on the FeatherMC repository with a small plugin that shows it.