diff --git a/.gitignore b/.gitignore
index daeb788019..e604323d64 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 .gradle/
 *-merged.jar
+*-mapped.jar
 *.DS_Store
 build/
 .idea/
diff --git a/build.gradle b/build.gradle
index 78bb78370f..9ffa3b70e9 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,9 +10,13 @@ buildscript {
 		classpath "net.fabricmc:weave:+"
 		classpath "commons-io:commons-io:1.4"
 		classpath "com.google.guava:guava:19.0"
+		classpath 'de.undercouch:gradle-download-task:3.4.3'
+		classpath 'net.fabricmc:tiny-remapper:+'
 	}
 }
 
+apply plugin: 'de.undercouch.download'
+
 def minecraft_version = "18w43c"
 def pomfVersion = "${minecraft_version}"
 
@@ -22,6 +26,15 @@ if (ENV.BUILD_NUMBER) {
 	pomfVersion = pomfVersion + "." + "${System.getenv().BUILD_NUMBER}"
 }
 
+def mappingsDir = file("mappings")
+def cacheFilesMinecraft = file(".gradle/minecraft")
+def mergedFile = file("${minecraft_version}-merged.jar")
+def mappedFile = file("${minecraft_version}-mapped.jar")
+def versionFile = new File(cacheFilesMinecraft, "${minecraft_version}.json")
+def clientJar = new File(cacheFilesMinecraft, "${minecraft_version}-client.jar")
+def serverJar = new File(cacheFilesMinecraft, "${minecraft_version}-server.jar")
+def libraries = new File(cacheFilesMinecraft, "${minecraft_version}-libraries")
+
 import groovy.json.JsonSlurper
 import org.apache.commons.io.FileUtils
 import com.google.common.hash.HashCode
@@ -30,12 +43,17 @@ import com.google.common.io.Files
 import net.fabricmc.weave.merge.JarMerger
 import net.fabricmc.weave.CommandTinyify
 import net.fabricmc.weave.CommandFindMappingErrors
+import net.fabricmc.tinyremapper.OutputConsumerPath
+import net.fabricmc.tinyremapper.TinyRemapper
+import net.fabricmc.tinyremapper.TinyUtils
 import groovy.util.XmlSlurper
+import groovy.io.FileType
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.zip.GZIPOutputStream;
 import java.io.File;
+import java.nio.file.Paths;
 
 boolean validateChecksum(File file, String checksum) {
 	if (file != null) {
@@ -49,25 +67,65 @@ boolean validateChecksum(File file, String checksum) {
 	return false
 }
 
-task download << {
-	def cacheFiles = new File(".gradle/minecraft")
-	if (!cacheFiles.exists()) cacheFiles.mkdirs()
+task downloadVersionsManifest {
+	//inputs.property "mc_ver", minecraft_version
+	inputs.property "currenttime", new Date()
+	def manifestFile = new File(cacheFilesMinecraft, "version_manifest.json")
+	outputs.file(manifestFile)
+	doLast {
+		logger.lifecycle(":downloading minecraft versions manifest")
+		FileUtils.copyURLToFile(new URL("https://launchermeta.mojang.com/mc/game/version_manifest.json"), manifestFile)
+	}
+}
 
-	def manifestFile = new File(cacheFiles, "version_manifest.json")
+def getManifestVersion(File manifestFile, String minecraft_version) {
+	def manifest = manifestFile.exists() ? new JsonSlurper().parseText(FileUtils.readFileToString(manifestFile)) : null
+	return manifest != null ? manifest.versions.stream().filter({it.id.equals(minecraft_version)}).findFirst() : java.util.Optional.empty()
+}
 
-	logger.lifecycle(":downloading minecraft json")
-	FileUtils.copyURLToFile(new URL("https://launchermeta.mojang.com/mc/game/version_manifest.json"), manifestFile)
+task downloadWantedVersionManifest(dependsOn: downloadVersionsManifest) {
+	def manifestFile = downloadVersionsManifest.outputs.files.singleFile
+	def manifestVersion = getManifestVersion(manifestFile, minecraft_version)
 
-	def manifest = new JsonSlurper().parseText(FileUtils.readFileToString(manifestFile))
-	def manifestVersion = manifest.versions.stream().filter({ it.id.equals(minecraft_version) }).findFirst()
-	if (manifestVersion.isPresent()) {
+	//have to grab the release time as there's a current timestamp on each element?!
+	inputs.property "releaseTime", manifestVersion.isPresent() ? manifestVersion.get().releaseTime : -1
 
-		def versionFile = new File(cacheFiles, "${minecraft_version}.json")
-		FileUtils.copyURLToFile(new URL(manifestVersion.get().url), versionFile)
+	outputs.file versionFile
+
+	doLast {
+		manifestVersion = getManifestVersion(manifestFile, minecraft_version) //nb need to re-read here in case it didn't exist before
+		if (manifestVersion.isPresent() || versionFile.exists()) {
+
+			if (manifestVersion.isPresent()) {
+				FileUtils.copyURLToFile(new URL(manifestVersion.get().url), versionFile)
+			}
+		} else {
+			throw new RuntimeException("No version data for Minecraft version ${minecraft_version}")
+		}
+	}
+
+}
+
+task downloadMcJars(dependsOn: downloadWantedVersionManifest) {
+
+	inputs.files versionFile
+
+	outputs.files(clientJar, serverJar)
+
+	outputs.upToDateWhen {
+		def version = new JsonSlurper().parseText(FileUtils.readFileToString(versionFile))
+		return clientJar.exists() && serverJar.exists() && validateChecksum(clientJar, version.downloads.client.sha1) && validateChecksum(serverJar, version.downloads.server.sha1)
+	}
+
+	doLast {
+		if (!versionFile.exists()) {
+			throw new RuntimeException("Can't download the jars without the ${versionFile.name} file!")
+		}
+
+		//reload in case it changed
 		def version = new JsonSlurper().parseText(FileUtils.readFileToString(versionFile))
 
-		def clientJar = new File(cacheFiles, "${minecraft_version}-client.jar")
-		def serverJar = new File(cacheFiles, "${minecraft_version}-server.jar")
+		logger.lifecycle(":downloading minecraft jars")
 
 		if (!clientJar.exists() || !validateChecksum(clientJar, version.downloads.client.sha1)) {
 			logger.lifecycle(":downloading minecraft client")
@@ -78,20 +136,17 @@ task download << {
 			logger.lifecycle(":downloading minecraft server")
 			FileUtils.copyURLToFile(new URL(version.downloads.server.url), serverJar)
 		}
-
-	} else {
-		throw new RuntimeException("No version data for Minecraft version ${minecraft_version}")
 	}
 }
 
-task mergeJars << {
-	def mergedFile = new File("${minecraft_version}-merged.jar")
+task mergeJars(dependsOn: downloadMcJars) {
+	inputs.files downloadMcJars.outputs.files.files
+	outputs.file(mergedFile)
 
-	if (!mergedFile.exists()) {
-		def cacheFiles = new File(".gradle/minecraft")
-
-		def client = new FileInputStream(new File(cacheFiles, "${minecraft_version}-client.jar"))
-		def server = new FileInputStream(new File(cacheFiles, "${minecraft_version}-server.jar"))
+	doLast {
+		logger.lifecycle(":merging jars")
+		def client = new FileInputStream(inputs.files.files.find {it.name.endsWith("-client.jar")})
+		def server = new FileInputStream(inputs.files.files.find {it.name.endsWith("-server.jar")})
 		def merged = new FileOutputStream(mergedFile)
 
 		def jarMerger = new JarMerger(client, server, merged)
@@ -104,90 +159,176 @@ task mergeJars << {
 	}
 
 }
-tasks.mergeJars.dependsOn "download"
 
-task setupPomf << {
+task setupPomf(dependsOn: mergeJars) {
 
 }
-tasks.setupPomf.dependsOn "mergeJars"
 
-task pomf << {
-	def cacheFiles = new File(".gradle/enigma")
-	if (!cacheFiles.exists()) cacheFiles.mkdirs()
+task pomf(dependsOn: setupPomf) {
+	doLast {
+		def cacheFilesEnigma = new File(".gradle/enigma")
+		if (!cacheFilesEnigma.exists()) {
+			cacheFilesEnigma.mkdirs()
+		}
 
-	def mavenMetadata = new File(cacheFiles, "maven-metadata.xml")
+		def mavenMetadata = new File(cacheFilesEnigma, "maven-metadata.xml")
+		def localEnigmaVersion = mavenMetadata.exists() ? new XmlSlurper().parseText(FileUtils.readFileToString(mavenMetadata)).versioning.release : ""
 
-	logger.lifecycle(":downloading enigma metadata")
-	FileUtils.copyURLToFile(new URL("http://maven.modmuss50.me/cuchaz/enigma/maven-metadata.xml"), mavenMetadata)
+		logger.lifecycle(":downloading enigma metadata")
+		FileUtils.copyURLToFile(new URL("http://maven.modmuss50.me/cuchaz/enigma/maven-metadata.xml"), mavenMetadata)
 
-	def metadata = new XmlSlurper().parseText(FileUtils.readFileToString(mavenMetadata))
-	def enigmaVersion = metadata.versioning.release
+		def metadata = new XmlSlurper().parseText(FileUtils.readFileToString(mavenMetadata))
+		def enigmaVersion = metadata.versioning.release
 
-	def enigma = new File(cacheFiles, "${enigmaVersion}.jar")
+		def enigma = new File(cacheFilesEnigma, "${enigmaVersion}.jar")
 
-	logger.lifecycle(":downloading enigma")
-	FileUtils.copyURLToFile(new URL("http://maven.modmuss50.me/cuchaz/enigma/${enigmaVersion}/enigma-${enigmaVersion}-all.jar"), enigma)
+		if (localEnigmaVersion != enigmaVersion || !enigma.exists()) {
+			logger.lifecycle(":downloading enigma")
+			FileUtils.copyURLToFile(new URL("http://maven.modmuss50.me/cuchaz/enigma/${enigmaVersion}/enigma-${enigmaVersion}-all.jar"), enigma)
+		} else {
+			logger.lifecycle(":skipping enigma download")
+		}
 
-	logger.lifecycle(":launching enigma ${enigmaVersion}")
-	ant.java(jar: enigma.getAbsolutePath(), fork: true, spawn: true) {
-		arg(value: new File("${minecraft_version}-merged.jar").getAbsolutePath())
-		arg(value: new File("mappings/").getAbsolutePath())
+		logger.lifecycle(":launching enigma")
+		ant.java(jar: enigma.getAbsolutePath(), fork: true, spawn: true) {
+			arg(value: mergedFile.getAbsolutePath())
+			arg(value: mappingsDir.getAbsolutePath())
+		}
 	}
 }
-tasks.pomf.dependsOn "setupPomf"
 
 task build(type: Zip) {
-	from "mappings/"
+	from mappingsDir
 	include "**/*"
 	archiveName "pomf-enigma-${pomfVersion}.zip"
 	destinationDir(file("build/libs"))
 }
 
-task checkMappings << {
-	logger.lifecycle(":checking mappings")
+task checkMappings {
+	inputs.dir mappingsDir
+	doLast {
+		logger.lifecycle(":checking mappings")
 
-	String[] args = [
-		new File("${minecraft_version}-merged.jar").getAbsolutePath(),
-		new File("mappings").getAbsolutePath()
-	]
+		String[] args = [
+			mergedFile.getAbsolutePath(),
+			mappingsDir.getAbsolutePath()
+		]
 
-	new CommandFindMappingErrors().run(args)
+		new CommandFindMappingErrors().run(args)
+	}
 }
 
-task buildTiny << {
-	logger.lifecycle(":generating tiny mappings")
-
-	String[] args = [
-		new File("${minecraft_version}-merged.jar").getAbsolutePath(),
-		new File("mappings").getAbsolutePath(),
-		"mappings.tiny",
-		"mojang",
-		"pomf"
-	]
-
-	new CommandTinyify().run(args)
-
-	logger.lifecycle(":compressing tiny mappings")
+task buildTiny(dependsOn: "mergeJars") {
+	inputs.dir mappingsDir
 	def libs = new File("build/libs/")
-	if (!libs.exists()) libs.mkdirs()
-
-	def buffer = new byte[1024]
+	if (!libs.exists()) {
+		libs.mkdirs()
+	}
 	def outputFile = new File(libs, "pomf-tiny-${pomfVersion}.gz")
-	def fileOutputStream = new FileOutputStream(outputFile)
-	def outputStream = new GZIPOutputStream(fileOutputStream)
-	def inputFile = new File("mappings.tiny")
-	def fileInputStream = new FileInputStream(inputFile)
+	outputs.file(outputFile)
+	doLast {
+		logger.lifecycle(":generating tiny mappings")
 
-	def length
-	while ((length = fileInputStream.read(buffer)) > 0) {
-		outputStream.write(buffer, 0, length)
+		String[] args = [
+			mergedFile.getAbsolutePath(),
+			mappingsDir.getAbsolutePath(),
+			"mappings.tiny",
+			"mojang",
+			"pomf"
+		]
+
+		new CommandTinyify().run(args)
+
+		logger.lifecycle(":compressing tiny mappings")
+
+		def buffer = new byte[1024]
+		def fileOutputStream = new FileOutputStream(outputFile)
+		def outputStream = new GZIPOutputStream(fileOutputStream)
+		def inputFile = new File("mappings.tiny")
+		def fileInputStream = new FileInputStream(inputFile)
+
+		def length
+		while ((length = fileInputStream.read(buffer)) > 0) {
+			outputStream.write(buffer, 0, length)
+		}
+
+		fileInputStream.close()
+		outputStream.finish()
+		outputStream.close()
+		inputFile.delete()
+	}
+}
+
+tasks.build.dependsOn "buildTiny"
+
+task downloadMcLibs(dependsOn: downloadWantedVersionManifest) {
+	inputs.files versionFile
+
+	outputs.file(libraries)
+
+	outputs.upToDateWhen {
+		return true
 	}
 
-	fileInputStream.close()
-	outputStream.finish()
-	outputStream.close()
-	inputFile.delete()
+	doLast {
+		if (!versionFile.exists()) {
+			throw new RuntimeException("Can't download the jars without the ${versionFile.name} file!")
+		}
+
+		def version = new JsonSlurper().parseText(FileUtils.readFileToString(versionFile))
+
+		logger.lifecycle(":downloading minecraft libraries")
+
+		if (!libraries.exists()) {
+			libraries.mkdirs()
+		}
+
+		version.libraries.each {
+			def downloadUrl = it.downloads.artifact.url
+
+			download {
+				src downloadUrl
+				dest new File(libraries, downloadUrl.substring(downloadUrl.lastIndexOf("/") + 1))
+				overwrite false
+			}
+		}
+	}
 }
 
-tasks.buildTiny.dependsOn "mergeJars"
-tasks.build.dependsOn "buildTiny"
+task mapJar(dependsOn: [downloadMcLibs, build]) {
+	inputs.files downloadMcLibs.outputs.files.files
+	outputs.file(mappedFile)
+
+	doLast {
+		logger.lifecycle(":mapping minecraft")
+
+		if (mappedFile.exists()) {
+			mappedFile.delete()
+		}
+
+		def tinyInput = new File("build/libs/pomf-tiny-${pomfVersion}.gz").toPath()
+
+		def remapper = TinyRemapper.newRemapper()
+			.withMappings(TinyUtils.createTinyMappingProvider(tinyInput, "mojang", "pomf"))
+			.build()
+      
+		try {
+
+			def outputConsumer = new OutputConsumerPath(mappedFile.toPath())
+
+			outputConsumer.addNonClassFiles(mergedFile.toPath())
+			remapper.read(mergedFile.toPath())
+
+			libraries.eachFileRecurse(FileType.FILES) {file ->
+				remapper.read(file.toPath())
+			}
+
+			remapper.apply(mergedFile.toPath(), outputConsumer)
+			outputConsumer.finish()
+			remapper.finish()
+		} catch (Exception e) {
+			remapper.finish();
+			throw new RuntimeException("Failed to remap jar", e);
+		}
+	}
+}
\ No newline at end of file