diff --git a/build.sbt b/build.sbt
index 1199e135b..bba828f2a 100644
--- a/build.sbt
+++ b/build.sbt
@@ -176,6 +176,7 @@ def mimaSettingsSince(versions: Seq[String]): Seq[Def.Setting[_]] = Def settings
     exclude[DirectMissingMethodProblem]("sbt.PluginData.apply"),
     exclude[DirectMissingMethodProblem]("sbt.PluginData.copy"),
     exclude[DirectMissingMethodProblem]("sbt.PluginData.this"),
+    exclude[IncompatibleResultTypeProblem]("sbt.PluginData.copy$default$10")
   ),
 )
 
diff --git a/main/src/main/scala/sbt/EvaluateTask.scala b/main/src/main/scala/sbt/EvaluateTask.scala
index 29749cfde..eea3b357a 100644
--- a/main/src/main/scala/sbt/EvaluateTask.scala
+++ b/main/src/main/scala/sbt/EvaluateTask.scala
@@ -148,18 +148,20 @@ final case class PluginData(
     resolvers: Option[Vector[Resolver]],
     report: Option[UpdateReport],
     scalacOptions: Seq[String],
+    javacOptions: Seq[String],
     unmanagedSourceDirectories: Seq[File],
     unmanagedSources: Seq[File],
     managedSourceDirectories: Seq[File],
     managedSources: Seq[File],
+    classDirectory: Option[File],
     buildTarget: Option[BuildTargetIdentifier]
 ) {
   val classpath: Seq[Attributed[File]] = definitionClasspath ++ dependencyClasspath
 }
 
 object PluginData {
-  private[sbt] def apply(dependencyClasspath: Def.Classpath): PluginData =
-    PluginData(dependencyClasspath, Nil, None, None, Nil, Nil, Nil, Nil, Nil, None)
+  private[sbt] def apply(depClasspath: Def.Classpath): PluginData =
+    PluginData(depClasspath, Nil, None, None, Nil, Nil, Nil, Nil, Nil, Nil, None, None)
 }
 
 object EvaluateTask {
diff --git a/main/src/main/scala/sbt/Keys.scala b/main/src/main/scala/sbt/Keys.scala
index 0fb3c3bdc..3720a3693 100644
--- a/main/src/main/scala/sbt/Keys.scala
+++ b/main/src/main/scala/sbt/Keys.scala
@@ -419,19 +419,21 @@ object Keys {
   val bspBuildTargetOutputPathsItem = taskKey[OutputPathsItem]("").withRank(DTask)
   val bspBuildTargetCompile = inputKey[Unit]("").withRank(DTask)
   val bspBuildTargetCompileItem = taskKey[Int]("").withRank(DTask)
-  val bspBuildTargetTest = inputKey[Unit]("Corresponds to buildTarget/test request").withRank(DTask)
-  val bspBuildTargetRun = inputKey[Unit]("Corresponds to buildTarget/run request").withRank(DTask)
-  val bspBuildTargetCleanCache = inputKey[Unit]("Corresponds to buildTarget/cleanCache request").withRank(DTask)
+  val bspBuildTargetTest = inputKey[Unit]("Implementation of buildTarget/test").withRank(DTask)
+  val bspBuildTargetRun = inputKey[Unit]("Implementation of buildTarget/run").withRank(DTask)
+  val bspBuildTargetCleanCache = inputKey[Unit]("Implementation of buildTarget/cleanCache").withRank(DTask)
   val bspBuildTargetScalacOptions = inputKey[Unit]("").withRank(DTask)
   val bspBuildTargetScalacOptionsItem = taskKey[ScalacOptionsItem]("").withRank(DTask)
+  val bspBuildTargetJavacOptions = inputKey[Unit]("Implementation of buildTarget/javacOptions").withRank(DTask)
+  val bspBuildTargetJavacOptionsItem = taskKey[JavacOptionsItem]("Item of buildTarget/javacOptions").withRank(DTask)
 
-  val bspBuildTargetJVMRunEnvironment = inputKey[Unit]("Corresponds to the buildTarget/jvmRunEnvironment request").withRank(DTask)
-  val bspBuildTargetJVMTestEnvironment = inputKey[Unit]("Corresponds to the buildTarget/jvmTestEnvironment request").withRank(DTask)
+  val bspBuildTargetJVMRunEnvironment = inputKey[Unit]("Implementation of buildTarget/jvmRunEnvironment").withRank(DTask)
+  val bspBuildTargetJVMTestEnvironment = inputKey[Unit]("Implementation of buildTarget/jvmTestEnvironment").withRank(DTask)
   val bspBuildTargetJvmEnvironmentItem = taskKey[JvmEnvironmentItem]("Computes JVM environment item").withRank(DTask)
 
-  val bspScalaTestClasses = inputKey[Unit]("Corresponds to buildTarget/scalaTestClasses request").withRank(DTask)
+  val bspScalaTestClasses = inputKey[Unit]("Implementation of buildTarget/scalaTestClasses").withRank(DTask)
   val bspScalaTestClassesItem = taskKey[Seq[ScalaTestClassesItem]]("").withRank(DTask)
-  val bspScalaMainClasses = inputKey[Unit]("Corresponds to buildTarget/scalaMainClasses request").withRank(DTask)
+  val bspScalaMainClasses = inputKey[Unit]("Implementation of buildTarget/scalaMainClasses").withRank(DTask)
   val bspScalaMainClassesItem = taskKey[ScalaMainClassesItem]("").withRank(DTask)
   val bspReporter = taskKey[BuildServerReporter]("").withRank(DTask)
 
diff --git a/main/src/main/scala/sbt/internal/Load.scala b/main/src/main/scala/sbt/internal/Load.scala
index 3a3da3810..b00e0a911 100755
--- a/main/src/main/scala/sbt/internal/Load.scala
+++ b/main/src/main/scala/sbt/internal/Load.scala
@@ -1176,21 +1176,25 @@ private[sbt] object Load {
         val prod = (Configurations.Runtime / exportedProducts).value
         val cp = (Configurations.Runtime / fullClasspath).value
         val opts = (Configurations.Compile / scalacOptions).value
+        val javaOpts = (Configurations.Compile / javacOptions).value
         val unmanagedSrcDirs = (Configurations.Compile / unmanagedSourceDirectories).value
         val unmanagedSrcs = (Configurations.Compile / unmanagedSources).value
         val managedSrcDirs = (Configurations.Compile / managedSourceDirectories).value
         val managedSrcs = (Configurations.Compile / managedSources).value
         val buildTarget = (Configurations.Compile / bspTargetIdentifier).value
+        val clsDir = (Configurations.Compile / classDirectory).value
         PluginData(
           removeEntries(cp, prod),
           prod,
           Some(fullResolvers.value.toVector),
           Some(update.value),
           opts,
+          javaOpts,
           unmanagedSrcDirs,
           unmanagedSrcs,
           managedSrcDirs,
           managedSrcs,
+          Some(clsDir),
           Some(buildTarget)
         )
       },
@@ -1244,11 +1248,7 @@ private[sbt] object Load {
   }
 
   def noPlugins(dir: File, config: LoadBuildConfiguration): LoadedPlugins =
-    loadPluginDefinition(
-      dir,
-      config,
-      PluginData(config.globalPluginClasspath, Nil, None, None, Nil, Nil, Nil, Nil, Nil, None)
-    )
+    loadPluginDefinition(dir, config, PluginData(config.globalPluginClasspath))
 
   def buildPlugins(dir: File, s: State, config: LoadBuildConfiguration): LoadedPlugins =
     loadPluginDefinition(dir, config, buildPluginDefinition(dir, s, config))
@@ -1444,6 +1444,8 @@ final case class LoadBuildConfiguration(
           Nil,
           Nil,
           Nil,
+          Nil,
+          None,
           None
         )
       case None => PluginData(globalPluginClasspath)
diff --git a/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala b/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
index e54a0139b..2d89185d5 100644
--- a/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
+++ b/main/src/main/scala/sbt/internal/server/BuildServerProtocol.scala
@@ -201,24 +201,12 @@ object BuildServerProtocol {
     }.evaluated,
     bspBuildTargetCleanCache / aggregate := false,
     bspBuildTargetScalacOptions := bspInputTask { (state, _, workspace, filter) =>
-      val builds = workspace.builds
       Def.task {
         val items = bspBuildTargetScalacOptionsItem.result.all(filter).value
         val appProvider = appConfiguration.value.provider()
         val sbtJars = appProvider.mainClasspath()
-        val buildItems = builds.map {
-          build =>
-            val plugins: LoadedPlugins = build._2.unit.plugins
-            val scalacOptions = plugins.pluginData.scalacOptions
-            val pluginClassPath = plugins.classpath
-            val classpath = (pluginClassPath ++ sbtJars).map(_.toURI).toVector
-            val item = ScalacOptionsItem(
-              build._1,
-              scalacOptions.toVector,
-              classpath,
-              new File(build._2.localBase, "project/target").toURI
-            )
-            Value(item)
+        val buildItems = workspace.builds.map {
+          case (targetId, build) => Value(scalacOptionsBuildItem(sbtJars, targetId, build))
         }
         val successfulItems = anyOrThrow(items ++ buildItems)
         val result = ScalacOptionsResult(successfulItems.toVector)
@@ -226,6 +214,20 @@ object BuildServerProtocol {
       }
     }.evaluated,
     bspBuildTargetScalacOptions / aggregate := false,
+    bspBuildTargetJavacOptions := bspInputTask { (state, _, workspace, filter) =>
+      Def.task {
+        val items = bspBuildTargetJavacOptionsItem.result.all(filter).value
+        val appProvider = appConfiguration.value.provider()
+        val sbtJars = appProvider.mainClasspath()
+        val buildItems = workspace.builds.map {
+          case (targetId, build) => Value(javacOptionsBuildItem(sbtJars, targetId, build))
+        }
+        val successfulItems = anyOrThrow(items ++ buildItems)
+        val result = JavacOptionsResult(successfulItems.toVector)
+        state.respondEvent(result)
+      }
+    }.evaluated,
+    bspBuildTargetJavacOptions / aggregate := false,
     bspScalaTestClasses := bspInputTask { (state, _, workspace, filter) =>
       workspace.warnIfBuildsNonEmpty(Method.ScalaTestClasses, state.log)
       Def.task {
@@ -286,7 +288,20 @@ object BuildServerProtocol {
     },
     bspBuildTargetCompileItem := bspCompileTask.value,
     bspBuildTargetRun := bspRunTask.evaluated,
-    bspBuildTargetScalacOptionsItem := scalacOptionsTask.value,
+    bspBuildTargetScalacOptionsItem := {
+      val target = Keys.bspTargetIdentifier.value
+      val scalacOptions = Keys.scalacOptions.value.toVector
+      val classDirectory = Keys.classDirectory.value
+      val classpath = classpathTask.value
+      ScalacOptionsItem(target, scalacOptions, classpath, classDirectory.toURI)
+    },
+    bspBuildTargetJavacOptionsItem := {
+      val target = Keys.bspTargetIdentifier.value
+      val javacOptions = Keys.javacOptions.value.toVector
+      val classDirectory = Keys.classDirectory.value
+      val classpath = classpathTask.value
+      JavacOptionsItem(target, javacOptions, classpath, classDirectory.toURI)
+    },
     bspBuildTargetJVMRunEnvironment := bspInputTask { (state, _, _, filter) =>
       Def.task {
         val items = bspBuildTargetJvmEnvironmentItem.result.all(filter).value
@@ -328,7 +343,7 @@ object BuildServerProtocol {
       }
     }
   )
-  private object Method {
+  private[sbt] object Method {
     final val Initialize = "build/initialize"
     final val BuildTargets = "workspace/buildTargets"
     final val Reload = "workspace/reload"
@@ -665,6 +680,34 @@ object BuildServerProtocol {
     )
   }
 
+  private def scalacOptionsBuildItem(
+      sbtJars: Seq[File],
+      targetId: BuildTargetIdentifier,
+      build: LoadedBuildUnit
+  ): ScalacOptionsItem = {
+    val plugins: LoadedPlugins = build.unit.plugins
+    val scalacOptions = plugins.pluginData.scalacOptions.toVector
+    val pluginClassPath = plugins.classpath
+    val classpath = (pluginClassPath ++ sbtJars).map(_.toURI).toVector
+    val classDirectory = plugins.pluginData.classDirectory.map(_.toURI)
+    val item = ScalacOptionsItem(targetId, scalacOptions, classpath, classDirectory)
+    item
+  }
+
+  private def javacOptionsBuildItem(
+      sbtJars: Seq[File],
+      targetId: BuildTargetIdentifier,
+      build: LoadedBuildUnit
+  ): JavacOptionsItem = {
+    val plugins: LoadedPlugins = build.unit.plugins
+    val javacOptions = plugins.pluginData.javacOptions.toVector
+    val pluginClassPath = plugins.classpath
+    val classpath = (pluginClassPath ++ sbtJars).map(_.toURI).toVector
+    val classDirectory = plugins.pluginData.classDirectory.map(_.toURI)
+    val item = JavacOptionsItem(targetId, javacOptions, classpath, classDirectory)
+    item
+  }
+
   private def bspInputTask[T](
       taskImpl: (
           State,
@@ -697,26 +740,17 @@ object BuildServerProtocol {
     )
   }
 
-  private def scalacOptionsTask: Def.Initialize[Task[ScalacOptionsItem]] = Def.taskDyn {
-    val target = Keys.bspTargetIdentifier.value
-    val scalacOptions = Keys.scalacOptions.value
-    val classDirectory = Keys.classDirectory.value
+  private lazy val classpathTask: Def.Initialize[Task[Vector[URI]]] = Def.taskDyn {
     val externalDependencyClasspath = Keys.externalDependencyClasspath.value
-
     val internalDependencyClasspath = for {
       (ref, configs) <- bspInternalDependencyConfigurations.value
       config <- configs
     } yield ref / config / Keys.classDirectory
-
     Def.task {
       val classpath = internalDependencyClasspath.join.value.distinct ++
         externalDependencyClasspath.map(_.data)
-      ScalacOptionsItem(
-        target,
-        scalacOptions.toVector,
-        classpath.map(_.toURI).toVector,
-        classDirectory.toURI
-      )
+
+      classpath.map(_.toURI).toVector
     }
   }
 
diff --git a/main/src/test/scala/PluginCommandTest.scala b/main/src/test/scala/PluginCommandTest.scala
index b0fa5662b..d49950a6b 100644
--- a/main/src/test/scala/PluginCommandTest.scala
+++ b/main/src/test/scala/PluginCommandTest.scala
@@ -115,7 +115,7 @@ object FakeState {
       Nil
     )
 
-    val pluginData = PluginData(Nil, Nil, None, None, Nil, Nil, Nil, Nil, Nil, None)
+    val pluginData = PluginData(Nil, Nil, None, None, Nil, Nil, Nil, Nil, Nil, Nil, None, None)
     val builds: DetectedModules[BuildDef] = new DetectedModules[BuildDef](Nil)
 
     val detectedAutoPlugins: Seq[DetectedAutoPlugin] =
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsItem.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsItem.scala
new file mode 100644
index 000000000..30157dfb5
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsItem.scala
@@ -0,0 +1,57 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp
+/**
+ * @param options Additional arguments to the compiler.
+                  For example, -deprecation.
+ * @param classpath The dependency classpath for this target, must be
+                    identical to what is passed as arguments to
+                    the -classpath flag in the command line interface
+                    of scalac.
+ * @param classDirectory The output directory for classfiles produced by this target
+ */
+final class JavacOptionsItem private (
+  val target: sbt.internal.bsp.BuildTargetIdentifier,
+  val options: Vector[String],
+  val classpath: Vector[java.net.URI],
+  val classDirectory: Option[java.net.URI]) extends Serializable {
+  
+  
+  
+  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
+    case x: JavacOptionsItem => (this.target == x.target) && (this.options == x.options) && (this.classpath == x.classpath) && (this.classDirectory == x.classDirectory)
+    case _ => false
+  })
+  override def hashCode: Int = {
+    37 * (37 * (37 * (37 * (37 * (17 + "sbt.internal.bsp.JavacOptionsItem".##) + target.##) + options.##) + classpath.##) + classDirectory.##)
+  }
+  override def toString: String = {
+    "JavacOptionsItem(" + target + ", " + options + ", " + classpath + ", " + classDirectory + ")"
+  }
+  private[this] def copy(target: sbt.internal.bsp.BuildTargetIdentifier = target, options: Vector[String] = options, classpath: Vector[java.net.URI] = classpath, classDirectory: Option[java.net.URI] = classDirectory): JavacOptionsItem = {
+    new JavacOptionsItem(target, options, classpath, classDirectory)
+  }
+  def withTarget(target: sbt.internal.bsp.BuildTargetIdentifier): JavacOptionsItem = {
+    copy(target = target)
+  }
+  def withOptions(options: Vector[String]): JavacOptionsItem = {
+    copy(options = options)
+  }
+  def withClasspath(classpath: Vector[java.net.URI]): JavacOptionsItem = {
+    copy(classpath = classpath)
+  }
+  def withClassDirectory(classDirectory: Option[java.net.URI]): JavacOptionsItem = {
+    copy(classDirectory = classDirectory)
+  }
+  def withClassDirectory(classDirectory: java.net.URI): JavacOptionsItem = {
+    copy(classDirectory = Option(classDirectory))
+  }
+}
+object JavacOptionsItem {
+  
+  def apply(target: sbt.internal.bsp.BuildTargetIdentifier, options: Vector[String], classpath: Vector[java.net.URI], classDirectory: Option[java.net.URI]): JavacOptionsItem = new JavacOptionsItem(target, options, classpath, classDirectory)
+  def apply(target: sbt.internal.bsp.BuildTargetIdentifier, options: Vector[String], classpath: Vector[java.net.URI], classDirectory: java.net.URI): JavacOptionsItem = new JavacOptionsItem(target, options, classpath, Option(classDirectory))
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsParams.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsParams.scala
new file mode 100644
index 000000000..4cc1ebbe2
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsParams.scala
@@ -0,0 +1,37 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp
+/**
+ * Javac options
+ * The build target javac options request is sent from the client to the server
+ * to query for the list of compiler options necessary to compile in a given list of targets.
+ */
+final class JavacOptionsParams private (
+  val targets: Vector[sbt.internal.bsp.BuildTargetIdentifier]) extends Serializable {
+  
+  
+  
+  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
+    case x: JavacOptionsParams => (this.targets == x.targets)
+    case _ => false
+  })
+  override def hashCode: Int = {
+    37 * (37 * (17 + "sbt.internal.bsp.JavacOptionsParams".##) + targets.##)
+  }
+  override def toString: String = {
+    "JavacOptionsParams(" + targets + ")"
+  }
+  private[this] def copy(targets: Vector[sbt.internal.bsp.BuildTargetIdentifier] = targets): JavacOptionsParams = {
+    new JavacOptionsParams(targets)
+  }
+  def withTargets(targets: Vector[sbt.internal.bsp.BuildTargetIdentifier]): JavacOptionsParams = {
+    copy(targets = targets)
+  }
+}
+object JavacOptionsParams {
+  
+  def apply(targets: Vector[sbt.internal.bsp.BuildTargetIdentifier]): JavacOptionsParams = new JavacOptionsParams(targets)
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsResult.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsResult.scala
new file mode 100644
index 000000000..fb89063b4
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/JavacOptionsResult.scala
@@ -0,0 +1,32 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp
+final class JavacOptionsResult private (
+  val items: Vector[sbt.internal.bsp.JavacOptionsItem]) extends Serializable {
+  
+  
+  
+  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
+    case x: JavacOptionsResult => (this.items == x.items)
+    case _ => false
+  })
+  override def hashCode: Int = {
+    37 * (37 * (17 + "sbt.internal.bsp.JavacOptionsResult".##) + items.##)
+  }
+  override def toString: String = {
+    "JavacOptionsResult(" + items + ")"
+  }
+  private[this] def copy(items: Vector[sbt.internal.bsp.JavacOptionsItem] = items): JavacOptionsResult = {
+    new JavacOptionsResult(items)
+  }
+  def withItems(items: Vector[sbt.internal.bsp.JavacOptionsItem]): JavacOptionsResult = {
+    copy(items = items)
+  }
+}
+object JavacOptionsResult {
+  
+  def apply(items: Vector[sbt.internal.bsp.JavacOptionsItem]): JavacOptionsResult = new JavacOptionsResult(items)
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsItemFormats.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsItemFormats.scala
new file mode 100644
index 000000000..2605a99dc
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsItemFormats.scala
@@ -0,0 +1,33 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp.codec
+import _root_.sjsonnew.{ Unbuilder, Builder, JsonFormat, deserializationError }
+trait JavacOptionsItemFormats { self: sbt.internal.bsp.codec.BuildTargetIdentifierFormats with sjsonnew.BasicJsonProtocol =>
+implicit lazy val JavacOptionsItemFormat: JsonFormat[sbt.internal.bsp.JavacOptionsItem] = new JsonFormat[sbt.internal.bsp.JavacOptionsItem] {
+  override def read[J](__jsOpt: Option[J], unbuilder: Unbuilder[J]): sbt.internal.bsp.JavacOptionsItem = {
+    __jsOpt match {
+      case Some(__js) =>
+      unbuilder.beginObject(__js)
+      val target = unbuilder.readField[sbt.internal.bsp.BuildTargetIdentifier]("target")
+      val options = unbuilder.readField[Vector[String]]("options")
+      val classpath = unbuilder.readField[Vector[java.net.URI]]("classpath")
+      val classDirectory = unbuilder.readField[Option[java.net.URI]]("classDirectory")
+      unbuilder.endObject()
+      sbt.internal.bsp.JavacOptionsItem(target, options, classpath, classDirectory)
+      case None =>
+      deserializationError("Expected JsObject but found None")
+    }
+  }
+  override def write[J](obj: sbt.internal.bsp.JavacOptionsItem, builder: Builder[J]): Unit = {
+    builder.beginObject()
+    builder.addField("target", obj.target)
+    builder.addField("options", obj.options)
+    builder.addField("classpath", obj.classpath)
+    builder.addField("classDirectory", obj.classDirectory)
+    builder.endObject()
+  }
+}
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsParamsFormats.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsParamsFormats.scala
new file mode 100644
index 000000000..91bd41177
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsParamsFormats.scala
@@ -0,0 +1,27 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp.codec
+import _root_.sjsonnew.{ Unbuilder, Builder, JsonFormat, deserializationError }
+trait JavacOptionsParamsFormats { self: sbt.internal.bsp.codec.BuildTargetIdentifierFormats with sjsonnew.BasicJsonProtocol =>
+implicit lazy val JavacOptionsParamsFormat: JsonFormat[sbt.internal.bsp.JavacOptionsParams] = new JsonFormat[sbt.internal.bsp.JavacOptionsParams] {
+  override def read[J](__jsOpt: Option[J], unbuilder: Unbuilder[J]): sbt.internal.bsp.JavacOptionsParams = {
+    __jsOpt match {
+      case Some(__js) =>
+      unbuilder.beginObject(__js)
+      val targets = unbuilder.readField[Vector[sbt.internal.bsp.BuildTargetIdentifier]]("targets")
+      unbuilder.endObject()
+      sbt.internal.bsp.JavacOptionsParams(targets)
+      case None =>
+      deserializationError("Expected JsObject but found None")
+    }
+  }
+  override def write[J](obj: sbt.internal.bsp.JavacOptionsParams, builder: Builder[J]): Unit = {
+    builder.beginObject()
+    builder.addField("targets", obj.targets)
+    builder.endObject()
+  }
+}
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsResultFormats.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsResultFormats.scala
new file mode 100644
index 000000000..ee381306a
--- /dev/null
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JavacOptionsResultFormats.scala
@@ -0,0 +1,27 @@
+/**
+ * This code is generated using [[https://www.scala-sbt.org/contraband/ sbt-contraband]].
+ */
+
+// DO NOT EDIT MANUALLY
+package sbt.internal.bsp.codec
+import _root_.sjsonnew.{ Unbuilder, Builder, JsonFormat, deserializationError }
+trait JavacOptionsResultFormats { self: sbt.internal.bsp.codec.JavacOptionsItemFormats with sjsonnew.BasicJsonProtocol =>
+implicit lazy val JavacOptionsResultFormat: JsonFormat[sbt.internal.bsp.JavacOptionsResult] = new JsonFormat[sbt.internal.bsp.JavacOptionsResult] {
+  override def read[J](__jsOpt: Option[J], unbuilder: Unbuilder[J]): sbt.internal.bsp.JavacOptionsResult = {
+    __jsOpt match {
+      case Some(__js) =>
+      unbuilder.beginObject(__js)
+      val items = unbuilder.readField[Vector[sbt.internal.bsp.JavacOptionsItem]]("items")
+      unbuilder.endObject()
+      sbt.internal.bsp.JavacOptionsResult(items)
+      case None =>
+      deserializationError("Expected JsObject but found None")
+    }
+  }
+  override def write[J](obj: sbt.internal.bsp.JavacOptionsResult, builder: Builder[J]): Unit = {
+    builder.beginObject()
+    builder.addField("items", obj.items)
+    builder.endObject()
+  }
+}
+}
diff --git a/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JsonProtocol.scala b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JsonProtocol.scala
index 3a3ff0906..f6cae48d8 100644
--- a/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JsonProtocol.scala
+++ b/protocol/src/main/contraband-scala/sbt/internal/bsp/codec/JsonProtocol.scala
@@ -56,10 +56,13 @@ trait JsonProtocol extends sjsonnew.BasicJsonProtocol
   with sbt.internal.bsp.codec.RunParamsFormats
   with sbt.internal.bsp.codec.RunResultFormats
   with sbt.internal.bsp.codec.ScalaBuildTargetFormats
-  with sbt.internal.bsp.codec.SbtBuildTargetFormats
   with sbt.internal.bsp.codec.ScalacOptionsParamsFormats
   with sbt.internal.bsp.codec.ScalacOptionsItemFormats
   with sbt.internal.bsp.codec.ScalacOptionsResultFormats
+  with sbt.internal.bsp.codec.JavacOptionsParamsFormats
+  with sbt.internal.bsp.codec.JavacOptionsItemFormats
+  with sbt.internal.bsp.codec.JavacOptionsResultFormats
+  with sbt.internal.bsp.codec.SbtBuildTargetFormats
   with sbt.internal.bsp.codec.BspConnectionDetailsFormats
   with sbt.internal.bsp.codec.MetalsMetadataFormats
   with sbt.internal.bsp.codec.ScalaTestClassesItemFormats
diff --git a/protocol/src/main/contraband/bsp.contra b/protocol/src/main/contraband/bsp.contra
index 033143005..dd621786a 100644
--- a/protocol/src/main/contraband/bsp.contra
+++ b/protocol/src/main/contraband/bsp.contra
@@ -625,31 +625,6 @@ type ScalaBuildTarget {
   jars: [String]!
 }
 
-# sbt Extension
-
-## Contains sbt-specific metadata for providing editor support for sbt build files.
-## This metadata is embedded in the data: Option[Json] field of the BuildTarget definition
-## when the dataKind field contains "sbt".
-type SbtBuildTarget {
-  ## The sbt version. Useful to support version-dependent syntax.
-  sbtVersion: String!
-
-  ## A sequence of Scala imports that are automatically imported in the sbt build files.
-  autoImports: [String]!
-
-  ## The Scala build target describing the scala
-  ## version and scala jars used by this sbt version.
-  scalaBuildTarget: sbt.internal.bsp.ScalaBuildTarget!
-
-  ## An optional parent if the target has an sbt meta project.
-  parent: sbt.internal.bsp.BuildTargetIdentifier
-
-  ## The inverse of parent, list of targets that have this build target
-  ## defined as their parent. It can contain normal project targets or
-  ## sbt build targets if this target represents an sbt meta-meta build.
-  children: [sbt.internal.bsp.BuildTargetIdentifier]!
-}
-
 ## Scalac options
 ## The build target scalac options request is sent from the client to the server
 ## to query for the list of compiler options necessary to compile in a given list of targets.
@@ -678,6 +653,61 @@ type ScalacOptionsItem {
   classDirectory: java.net.URI
 }
 
+# Java Extension
+
+## Javac options
+## The build target javac options request is sent from the client to the server
+## to query for the list of compiler options necessary to compile in a given list of targets.
+type JavacOptionsParams {
+  targets: [sbt.internal.bsp.BuildTargetIdentifier]
+}
+
+type JavacOptionsResult {
+  items: [sbt.internal.bsp.JavacOptionsItem]
+}
+
+type JavacOptionsItem {
+  target: sbt.internal.bsp.BuildTargetIdentifier!
+
+  ## Additional arguments to the compiler.
+  ## For example, -deprecation.
+  options: [String]
+
+  ## The dependency classpath for this target, must be
+  ## identical to what is passed as arguments to
+  ## the -classpath flag in the command line interface
+  ## of scalac.
+  classpath: [java.net.URI]
+
+  ## The output directory for classfiles produced by this target
+  classDirectory: java.net.URI
+}
+
+# sbt Extension
+
+## Contains sbt-specific metadata for providing editor support for sbt build files.
+## This metadata is embedded in the data: Option[Json] field of the BuildTarget definition
+## when the dataKind field contains "sbt".
+type SbtBuildTarget {
+  ## The sbt version. Useful to support version-dependent syntax.
+  sbtVersion: String!
+
+  ## A sequence of Scala imports that are automatically imported in the sbt build files.
+  autoImports: [String]!
+
+  ## The Scala build target describing the scala
+  ## version and scala jars used by this sbt version.
+  scalaBuildTarget: sbt.internal.bsp.ScalaBuildTarget!
+
+  ## An optional parent if the target has an sbt meta project.
+  parent: sbt.internal.bsp.BuildTargetIdentifier
+
+  ## The inverse of parent, list of targets that have this build target
+  ## defined as their parent. It can contain normal project targets or
+  ## sbt build targets if this target represents an sbt meta-meta build.
+  children: [sbt.internal.bsp.BuildTargetIdentifier]!
+}
+
 ## https://build-server-protocol.github.io/docs/server-discovery.html
 type BspConnectionDetails {
   ## The name of the build tool
diff --git a/server-test/src/test/scala/testpkg/BuildServerTest.scala b/server-test/src/test/scala/testpkg/BuildServerTest.scala
index c694f1334..dc1486786 100644
--- a/server-test/src/test/scala/testpkg/BuildServerTest.scala
+++ b/server-test/src/test/scala/testpkg/BuildServerTest.scala
@@ -32,8 +32,7 @@ object BuildServerTest extends AbstractServerTest {
   private def nextId(): Int = idGen.getAndIncrement()
 
   test("build/initialize") { _ =>
-    val id = nextId()
-    initializeRequest(id)
+    val id = initializeRequest()
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"${id}"""") &&
       (s contains """"resourcesProvider":true""") &&
@@ -42,10 +41,7 @@ object BuildServerTest extends AbstractServerTest {
   }
 
   test("workspace/buildTargets") { _ =>
-    svr.sendJsonRpc(
-      s"""{ "jsonrpc": "2.0", "id": "${nextId()}", "method": "workspace/buildTargets", "params": {} }"""
-    )
-    assert(processing("workspace/buildTargets"))
+    sendRequest("workspace/buildTargets")
     val result = svr.waitFor[WorkspaceBuildTargetsResult](10.seconds)
     val utilTarget = result.targets.find(_.displayName.contains("util")).get
     assert(utilTarget.id.uri.toString.endsWith("#util/Compile"))
@@ -58,16 +54,14 @@ object BuildServerTest extends AbstractServerTest {
   test("buildTarget/sources") { _ =>
     val buildTarget = buildTargetUri("util", "Compile")
     val badBuildTarget = buildTargetUri("badBuildTarget", "Compile")
-    svr.sendJsonRpc(buildTargetSources(Seq(buildTarget, badBuildTarget)))
-    assert(processing("buildTarget/sources"))
+    buildTargetSources(Seq(buildTarget, badBuildTarget))
     val s = svr.waitFor[SourcesResult](10.seconds)
     val sources = s.items.head.sources.map(_.uri)
     assert(sources.contains(new File(svr.baseDirectory, "util/src/main/scala").toURI))
   }
   test("buildTarget/sources: base sources") { _ =>
     val buildTarget = buildTargetUri("buildserver", "Compile")
-    svr.sendJsonRpc(buildTargetSources(Seq(buildTarget)))
-    assert(processing("buildTarget/sources"))
+    buildTargetSources(Seq(buildTarget))
     val s = svr.waitFor[SourcesResult](10.seconds)
     val sources = s.items.head.sources
     val expectedSource = SourceItem(
@@ -80,8 +74,7 @@ object BuildServerTest extends AbstractServerTest {
 
   test("buildTarget/sources: sbt") { _ =>
     val x = new URI(s"${svr.baseDirectory.getAbsoluteFile.toURI}#buildserver-build")
-    svr.sendJsonRpc(buildTargetSources(Seq(x)))
-    assert(processing("buildTarget/sources"))
+    buildTargetSources(Seq(x))
     val s = svr.waitFor[SourcesResult](10.seconds)
     val sources = s.items.head.sources.map(_.uri).sorted
     val expectedSources = Vector(
@@ -99,17 +92,13 @@ object BuildServerTest extends AbstractServerTest {
 
   test("buildTarget/compile") { _ =>
     val buildTarget = buildTargetUri("util", "Compile")
-
-    compile(buildTarget, id = nextId())
-
-    assert(processing("buildTarget/compile"))
+    compile(buildTarget)
     val res = svr.waitFor[BspCompileResult](10.seconds)
     assert(res.statusCode == StatusCode.Success)
   }
 
   test("buildTarget/compile - reports compilation progress") { _ =>
     val buildTarget = buildTargetUri("runAndTest", "Compile")
-
     compile(buildTarget)
 
     // This doesn't always come back in 10s on CI.
@@ -271,18 +260,19 @@ object BuildServerTest extends AbstractServerTest {
     )
   }
 
-  test("buildTarget/scalacOptions") { _ =>
+  test("buildTarget/scalacOptions, buildTarget/javacOptions") { _ =>
     val buildTarget = buildTargetUri("util", "Compile")
     val badBuildTarget = buildTargetUri("badBuildTarget", "Compile")
-    val id = nextId()
-    svr.sendJsonRpc(
-      s"""{ "jsonrpc": "2.0", "id": "$id", "method": "buildTarget/scalacOptions", "params": {
-        |  "targets": [{ "uri": "$buildTarget" }, { "uri": "$badBuildTarget" }]
-        |} }""".stripMargin
-    )
-    assert(processing("buildTarget/scalacOptions"))
+    val id1 = scalacOptions(Seq(buildTarget, badBuildTarget))
+
     assert(svr.waitForString(10.seconds) { s =>
-      (s contains s""""id":"$id"""") &&
+      (s contains s""""id":"$id1"""") &&
+      (s contains "scala-library-2.13.11.jar")
+    })
+
+    val id2 = javacOptions(Seq(buildTarget, badBuildTarget))
+    assert(svr.waitForString(10.seconds) { s =>
+      (s contains s""""id":"$id2"""") &&
       (s contains "scala-library-2.13.11.jar")
     })
   }
@@ -306,7 +296,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/cleanCache"))
+    assertProcessing("buildTarget/cleanCache")
     val res = svr.waitFor[CleanCacheResult](10.seconds)
     assert(res.cleaned)
     assert(targetDir.list().isEmpty)
@@ -316,7 +306,7 @@ object BuildServerTest extends AbstractServerTest {
     svr.sendJsonRpc(
       s"""{ "jsonrpc": "2.0", "id": "${nextId()}", "method": "workspace/buildTargets", "params": {} }"""
     )
-    assert(processing("workspace/buildTargets"))
+    assertProcessing("workspace/buildTargets")
     val result = svr.waitFor[WorkspaceBuildTargetsResult](10.seconds)
     val allTargets = result.targets.map(_.id.uri)
 
@@ -327,7 +317,7 @@ object BuildServerTest extends AbstractServerTest {
          |  ]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/cleanCache"))
+    assertProcessing("buildTarget/cleanCache")
     val res = svr.waitFor[CleanCacheResult](10.seconds)
     assert(res.cleaned)
   }
@@ -337,7 +327,7 @@ object BuildServerTest extends AbstractServerTest {
     svr.sendJsonRpc(
       s"""{ "jsonrpc": "2.0", "id": "$id", "method": "workspace/reload"}"""
     )
-    assert(processing("workspace/reload"))
+    assertProcessing("workspace/reload")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"$id"""") &&
       (s contains """"result":null""")
@@ -355,9 +345,8 @@ object BuildServerTest extends AbstractServerTest {
         |)
         |""".stripMargin
     )
-    val id = nextId()
+    val id = reloadWorkspace()
     // reload
-    reloadWorkspace(id)
     assert(
       svr.waitForString(10.seconds) { s =>
         s.contains(s""""buildTarget":{"uri":"$metaBuildTarget"}""") &&
@@ -405,7 +394,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }, { "uri": "$badBuildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/scalaMainClasses"))
+    assertProcessing("buildTarget/scalaMainClasses")
     assert(svr.waitForString(30.seconds) { s =>
       (s contains s""""id":"$id"""") &&
       (s contains """"class":"main.Main"""")
@@ -422,7 +411,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "data": { "class": "main.Main" }
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/run"))
+    assertProcessing("buildTarget/run")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains "build/logMessage") &&
       (s contains """"message":"Hello World!"""")
@@ -443,7 +432,7 @@ object BuildServerTest extends AbstractServerTest {
           |  "params": { "targets": [{ "uri": "$buildTarget" }] }
           |}""".stripMargin
     )
-    assert(processing("buildTarget/jvmRunEnvironment"))
+    assertProcessing("buildTarget/jvmRunEnvironment")
     assert {
       svr.waitForString(10.seconds) { s =>
         (s contains s""""id":"$id"""") &&
@@ -465,7 +454,7 @@ object BuildServerTest extends AbstractServerTest {
           |  "params": { "targets": [{ "uri": "$buildTarget" }] }
           |}""".stripMargin
     )
-    assert(processing("buildTarget/jvmTestEnvironment"))
+    assertProcessing("buildTarget/jvmTestEnvironment")
     assert {
       svr.waitForString(10.seconds) { s =>
         (s contains s""""id":"$id"""") &&
@@ -487,7 +476,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }, { "uri": "$badBuildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/scalaTestClasses"))
+    assertProcessing("buildTarget/scalaTestClasses")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"$id"""") &&
       (s contains """"tests.FailingTest"""") &&
@@ -504,7 +493,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/test"))
+    assertProcessing("buildTarget/test")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"$id"""") &&
       (s contains """"statusCode":2""")
@@ -528,7 +517,7 @@ object BuildServerTest extends AbstractServerTest {
          |  }
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/test"))
+    assertProcessing("buildTarget/test")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"$id"""") &&
       (s contains """"statusCode":1""")
@@ -557,8 +546,7 @@ object BuildServerTest extends AbstractServerTest {
 
   test("buildTarget/compile: respond error") { _ =>
     val buildTarget = buildTargetUri("respondError", "Compile")
-    val id = nextId()
-    compile(buildTarget, id)
+    val id = compile(buildTarget)
     assert(svr.waitForString(10.seconds) { s =>
       s.contains(s""""id":"$id"""") &&
       s.contains(""""error"""") &&
@@ -576,7 +564,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }, { "uri": "$badBuildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/resources"))
+    assertProcessing("buildTarget/resources")
     assert(svr.waitForString(10.seconds) { s =>
       (s contains s""""id":"$id"""") && (s contains "util/src/main/resources/")
     })
@@ -590,7 +578,7 @@ object BuildServerTest extends AbstractServerTest {
          |  "targets": [{ "uri": "$buildTarget" }, { "uri": "$badBuildTarget" }]
          |} }""".stripMargin
     )
-    assert(processing("buildTarget/outputPaths"))
+    assertProcessing("buildTarget/outputPaths")
     val actualResult = svr.waitFor[OutputPathsResult](10.seconds)
     val expectedResult = OutputPathsResult(
       items = Vector(
@@ -608,7 +596,7 @@ object BuildServerTest extends AbstractServerTest {
     assert(actualResult == expectedResult)
   }
 
-  private def initializeRequest(id: Int): Unit = {
+  private def initializeRequest(): Int = {
     val params = InitializeBuildParams(
       "test client",
       "1.0.0",
@@ -617,35 +605,55 @@ object BuildServerTest extends AbstractServerTest {
       BuildClientCapabilities(Vector("scala")),
       None
     )
-    svr.sendJsonRpc(request(id, "build/initialize", params))
+    sendRequest("build/initialize", params)
   }
 
-  private def processing(method: String, debug: Boolean = false): Boolean = {
-    svr.waitForString(10.seconds) { msg =>
+  private def assertProcessing(method: String, debug: Boolean = false): Unit = {
+    assert(svr.waitForString(10.seconds) { msg =>
       if (debug) println(msg)
-      msg.contains("build/logMessage") &&
-      msg.contains(s""""message":"Processing $method"""")
-    }
+      msg.contains("build/logMessage") && msg.contains(s""""message":"Processing $method"""")
+    })
   }
 
-  private def reloadWorkspace(id: Int = nextId()): Unit =
-    svr.sendJsonRpc(s"""{ "jsonrpc": "2.0", "id": "$id", "method": "workspace/reload"}""")
+  private def reloadWorkspace(): Int =
+    sendRequest("workspace/reload")
 
-  private def compile(buildTarget: URI, id: Int = nextId()): Unit = {
+  private def compile(buildTarget: URI): Int = {
     val params =
       CompileParams(targets = Vector(BuildTargetIdentifier(buildTarget)), None, Vector.empty)
-    svr.sendJsonRpc(request(id, "buildTarget/compile", params))
+    sendRequest("buildTarget/compile", params)
   }
 
-  private def buildTargetSources(buildTargets: Seq[URI], id: Int = nextId()): String = {
+  private def scalacOptions(buildTargets: Seq[URI]): Int = {
     val targets = buildTargets.map(BuildTargetIdentifier.apply).toVector
-    request(id, "buildTarget/sources", SourcesParams(targets))
+    sendRequest("buildTarget/scalacOptions", ScalacOptionsParams(targets))
   }
 
-  private def request[T: JsonWriter](id: Int, method: String, params: T): String = {
-    val request = JsonRpcRequestMessage("2.0", id.toString, method, Converter.toJson(params).get)
-    val json = Converter.toJson(request).get
-    CompactPrinter(json)
+  private def javacOptions(buildTargets: Seq[URI]): Int = {
+    val targets = buildTargets.map(BuildTargetIdentifier.apply).toVector
+    sendRequest("buildTarget/scalacOptions", ScalacOptionsParams(targets))
+  }
+
+  private def buildTargetSources(buildTargets: Seq[URI]): Int = {
+    val targets = buildTargets.map(BuildTargetIdentifier.apply).toVector
+    sendRequest("buildTarget/sources", SourcesParams(targets))
+  }
+
+  private def sendRequest(method: String): Int = {
+    val id = nextId()
+    val msg = JsonRpcRequestMessage("2.0", id.toString, method, None)
+    val json = Converter.toJson(msg).get
+    svr.sendJsonRpc(CompactPrinter(json))
+    id
+  }
+
+  private def sendRequest[T: JsonWriter](method: String, params: T): Int = {
+    val id = nextId()
+    val msg = JsonRpcRequestMessage("2.0", id.toString, method, Converter.toJson(params).get)
+    val json = Converter.toJson(msg).get
+    svr.sendJsonRpc(CompactPrinter(json))
+    if (method != "build/initialize") assertProcessing(method)
+    id
   }
 
   private def buildTargetUri(project: String, config: String): URI =