Minecraft Forge 1.16 Mod that can call Slack APIs

build.gradle

buildscript {
    repositories {
        maven { url = 'https://files.minecraftforge.net/maven' }
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath group: 'net.minecraftforge.gradle', name: 'ForgeGradle', version: '3.+', changing: true
    }
}
apply plugin: 'net.minecraftforge.gradle'
// Only edit below this line, the above code adds and enables the necessary things for Forge to be setup.
apply plugin: 'eclipse'
apply plugin: 'maven-publish'

version = '1.0'
group = 'com.yourname.modid' // http://maven.apache.org/guides/mini/guide-naming-conventions.html
archivesBaseName = 'slack_1.16.4'

sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8' // Need this here so eclipse task generates correctly.

println('Java: ' + System.getProperty('java.version') + ' JVM: ' + System.getProperty('java.vm.version') + '(' + System.getProperty('java.vendor') + ') Arch: ' + System.getProperty('os.arch'))
minecraft {
    // The mappings can be changed at any time, and must be in the following format.
    // snapshot_YYYYMMDD   Snapshot are built nightly.
    // stable_#            Stables are built at the discretion of the MCP team.
    // Use non-default mappings at your own risk. they may not always work.
    // Simply re-run your setup task after changing the mappings to update your workspace.
    mappings channel: 'snapshot', version: '20201028-1.16.3'
    // makeObfSourceJar = false // an Srg named sources jar is made by default. uncomment this to disable.
    
    // accessTransformer = file('src/main/resources/META-INF/accesstransformer.cfg')

    // Default run configurations.
    // These can be tweaked, removed, or duplicated as needed.
    runs {
        client {
            workingDirectory project.file('run')

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'

            mods {
                examplemod {
                    source sourceSets.main
                }
            }
        }

        server {
            workingDirectory project.file('run')

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'

            mods {
                examplemod {
                    source sourceSets.main
                }
            }
        }

        data {
            workingDirectory project.file('run')

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'

            // Specify the modid for data generation, where to output the resulting resource, and where to look for existing resources.
            args '--mod', 'examplemod', '--all', '--output', file('src/generated/resources/'), '--existing', file('src/main/resources/')

            mods {
                examplemod {
                    source sourceSets.main
                }
            }
        }
    }
}

// Include resources generated by data generators.
sourceSets.main.resources { srcDir 'src/generated/resources' }

configurations {
    embed
    compile.extendsFrom(embed)
}
repositories {
    maven { url = 'https://files.minecraftforge.net/maven' }
    jcenter()
    mavenCentral()
}

dependencies {
    // Specify the version of Minecraft to use, If this is any group other then 'net.minecraft' it is assumed
    // that the dep is a ForgeGradle 'patcher' dependency. And it's patches will be applied.
    // The userdev artifact is a special name and will get all sorts of transformations applied to it.
    minecraft 'net.minecraftforge:forge:1.16.4-35.1.4'

    embed 'com.slack.api:slack-api-client:1.4.1'

    // You may put jars on which you depend on in ./libs or you may define them like so..
    // compile "some.group:artifact:version:classifier"
    // compile "some.group:artifact:version"

    // Real examples
    // compile 'com.mod-buildcraft:buildcraft:6.0.8:dev'  // adds buildcraft to the dev env
    // compile 'com.googlecode.efficient-java-matrix-library:ejml:0.24' // adds ejml to the dev env

    // The 'provided' configuration is for optional dependencies that exist at compile-time but might not at runtime.
    // provided 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // These dependencies get remapped to your current MCP mappings
    // deobf 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // For more info...
    // http://www.gradle.org/docs/current/userguide/artifact_dependencies_tutorial.html
    // http://www.gradle.org/docs/current/userguide/dependency_management.html

}

// Example for how to get properties into the manifest for reading by the runtime..
jar {
    from configurations.embed.collect { it.isDirectory() ? it : zipTree(it) }
    manifest {
        attributes([
            "Specification-Title": "slack_mod",
            "Specification-Vendor": "com.github.seratch.slack_mod",
            "Specification-Version": "1", // We are version 1 of ourselves
            "Implementation-Title": project.name,
            "Implementation-Version": "${version}",
            "Implementation-Vendor" :"examplemodsareus",
            "Implementation-Timestamp": new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
        ])
    }
}

// Example configuration to allow publishing using the maven-publish task
// This is the preferred method to reobfuscate your jar file
jar.finalizedBy('reobfJar') 
// However if you are in a multi-project build, dev time needs unobfed jar files, so you can delay the obfuscation until publishing by doing
//publish.dependsOn('reobfJar')

publishing {
    publications {
        mavenJava(MavenPublication) {
            artifact jar
        }
    }
    repositories {
        maven {
            url "file:///${project.projectDir}/mcmodsrepo"
        }
    }
}

mods.toml

# This is an example mods.toml file. It contains the data relating to the loading mods.
# There are several mandatory fields (#mandatory), and many more that are optional (#optional).
# The overall format is standard TOML format, v0.5.0.
# Note that there are a couple of TOML lists in this file.
# Find more information on toml format here:  https://github.com/toml-lang/toml
# The name of the mod loader type to load - for regular FML @Mod mods it should be javafml
modLoader="javafml" #mandatory
# A version range to match for said mod loader - for regular FML @Mod it will be the forge version
loaderVersion="[35,)" #mandatory This is typically bumped every Minecraft version by Forge. See our download page for lists of versions.
# The license for you mod. This is mandatory metadata and allows for easier comprehension of your redistributive properties.
# Review your options at https://choosealicense.com/. All rights reserved is the default copyright stance, and is thus the default here.
license="All rights reserved"
# A URL to refer people to when problems occur with this mod
issueTrackerURL="https://github.com/seratch/slack_mod/" #optional
# A list of mods - how many allowed here is determined by the individual mod loader
[[mods]] #mandatory
# The modid of the mod
modId="slack" #mandatory
# The version number of the mod - there's a few well known ${} variables useable here or just hardcode it
# ${file.jarVersion} will substitute the value of the Implementation-Version as read from the mod's JAR file metadata
# see the associated build.gradle script for how to populate this completely automatically during a build
version="${file.jarVersion}" #mandatory
 # A display name for the mod
displayName="Slack Mod" #mandatory
# A URL to query for updates for this mod. See the JSON update specification <here>
# updateJSONURL="http://myurl.me/" #optional
# A URL for the "homepage" for this mod, displayed in the mod UI
# displayURL="http://example.com/" #optional
# A file name (in the root of the mod JAR) containing a logo for display
# logoFile="examplemod.png" #optional
# A text field displayed in the mod UI
credits="Thanks for this example mod goes to Java" #optional
# A text field displayed in the mod UI
authors="Love, Cheese and small house plants" #optional
# The description text for the mod (multi line!) (#mandatory)
description='''
WIP
'''
# # A dependency - use the . to indicate dependency for a specific modid. Dependencies are optional.
# [[dependencies.examplemod]] #optional
#     # the modid of the dependency
#     modId="slack" #mandatory
#     # Does this dependency have to exist - if not, ordering below must be specified
#     mandatory=true #mandatory
#     # The version range of the dependency
#     versionRange="[35,)" #mandatory
#     # An ordering relationship for the dependency - BEFORE or AFTER required if the relationship is not mandatory
#     ordering="NONE"
#     # Side this dependency is applied on - BOTH, CLIENT or SERVER
#     side="BOTH"
# # Here's another dependency
# [[dependencies.examplemod]]
#     modId="minecraft"
#     mandatory=true
# # This version range declares a minimum of the current minecraft version up to but not including the next major version
#     versionRange="[1.16.4,1.17)"
#     ordering="NONE"
#     side="BOTH"

pack.mdmeta

{
    "pack": {
        "description": "slack mod resources",
        "pack_format": 6,
        "_comment": "A pack_format of 6 requires json lang files and some texture changes from 1.16.2. Note: we require v6 pack meta for all mods."
    }
}

SlackMod.java

package com.github.seratch.slack_mod;

import com.slack.api.Slack;
import com.slack.api.methods.response.chat.ChatPostMessageResponse;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.util.Optional;

// The value here should match an entry in the META-INF/mods.toml file
@Mod("slack")
public class SlackMod {
    private static final Logger LOGGER = LogManager.getLogger();
    private static final Slack SLACK = Slack.getInstance();

    public SlackMod() {
        MinecraftForge.EVENT_BUS.register(this);
    }

    final String botToken = System.getenv("SLACK_BOT_TOKEN");
    final String channel = Optional.ofNullable(System.getenv("SLACK_CHANNEL_ID")).orElse("#random");

    @SubscribeEvent
    public void onServerStarting(FMLServerStartingEvent event) {
        try {
            ChatPostMessageResponse response = SLACK.methods(botToken).chatPostMessage(r -> r
                    .channel(channel)
                    .text("Your Minecraft server started!"));
            LOGGER.info("Slack chat.postMessage API call result (ok: {}, error: {})",
                    response.isOk(), response.getError());
        } catch (Exception e) {
            LOGGER.error("Failed to call Slack chat.postMessage API", e);
        }
    }
}