These are all the mandatory fields that a Bloop project needs.

bloop-config-minimal-example.json

{
    "version" : "1.0.0",
    "project" : {
        "name" : "frontend",
        "directory" : "/Users/jvican/Code/bloop/frontend",
        "sources" : [
            "/Users/jvican/Code/bloop/frontend/src/main/scala-2.12",
            "/Users/jvican/Code/bloop/frontend/src/main/scala",
            "/Users/jvican/Code/bloop/frontend/src/main/java",
            "/Users/jvican/Code/bloop/frontend/target/scala-2.12/src_managed/main"
        ],
        "dependencies" : [
            "backend",
            "jsonConfig212"
        ],
        "classpath" : [
            "/Users/jvican/Code/bloop/.bloop/backend/scala-2.12/classes",
            "/Users/jvican/Code/bloop/.bloop/jsonConfig212/scala-2.12/classes",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scalameta/lsp4s_2.12/0.1.0/lsp4s_2.12-0.1.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-jawn_2.12/0.9.3/circe-jawn_2.12-0.9.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc_2.12/1.2.1%2B76-109107b0/zinc_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lihaoyi/pprint_2.12/0.5.3/pprint_2.12-0.5.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/get-coursier/coursier-cache_2.12/1.1.0-M3/coursier-cache_2.12-1.1.0-M3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-generic_2.12/0.9.0/circe-generic_2.12-0.9.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/zaxxer/nuprocess/1.2.4/nuprocess-1.2.4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-relation_2.12/1.2.1/util-relation_2.12-1.2.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/typesafe/ssl-config-core_2.12/0.2.2/ssl-config-core_2.12-0.2.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/jline/jline/2.14.4/jline-2.14.4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/beachape/enumeratum_2.12/1.5.12/enumeratum_2.12-1.5.12.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/typelevel/cats-kernel_2.12/1.0.1/cats-kernel_2.12-1.0.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lmax/disruptor/3.3.6/disruptor-3.3.6.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/librarymanagement-core_2.12/1.2.0/librarymanagement-core_2.12-1.2.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-logging_2.12/1.2.1/util-logging_2.12-1.2.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/apache/logging/log4j/log4j-core/2.8.1/log4j-core-2.8.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/gigahorse-core_2.12/0.3.0/gigahorse-core_2.12-0.3.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lihaoyi/fastparse-utils_2.12/1.0.0/fastparse-utils_2.12-1.0.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lihaoyi/sourcecode_2.12/0.1.4/sourcecode_2.12-0.1.4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/bsp_2.12/1.0.0-M4/bsp_2.12-1.0.0-M4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lihaoyi/fansi_2.12/0.2.5/fansi_2.12-0.2.5.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-classpath_2.12/1.2.1%2B76-109107b0/zinc-classpath_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/sjson-new-core_2.12/0.8.2/sjson-new-core_2.12-0.8.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/case-app-annotations_2.12/1.2.0-faster-compile-time/case-app-annotations_2.12-1.2.0-faster-compile-time.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/github/soc/directories/10/directories-10.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-numbers_2.12/0.9.3/circe-numbers_2.12-0.9.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/google/j2objc/j2objc-annotations/1.1/j2objc-annotations-1.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/shaded-scalajson_2.12/1.0.0-M4/shaded-scalajson_2.12-1.0.0-M4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/sbinary_2.12/0.4.4/sbinary_2.12-0.4.4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/typelevel/machinist_2.12/0.6.2/machinist_2.12-0.6.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/sjson-new-scalajson_2.12/0.8.2/sjson-new-scalajson_2.12-0.8.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-core_2.12/1.2.1%2B76-109107b0/zinc-core_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/squareup/okio/okio/1.12.0/okio-1.12.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/thesamet/scalapb/lenses_2.12/0.8.0-RC1/lenses_2.12-0.8.0-RC1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/github/wumpz/diffutils/2.2/diffutils-2.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/typesafe/config/1.2.0/config-1.2.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-persist_2.12/1.2.1%2B76-109107b0/zinc-persist_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/gigahorse-okhttp_2.12/0.3.0/gigahorse-okhttp_2.12-0.3.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/jctools/jctools-core/2.0.1/jctools-core-2.0.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/google/errorprone/error_prone_annotations/2.0.18/error_prone_annotations-2.0.18.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/compiler-interface/1.2.1%2B76-109107b0/compiler-interface-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/.sbt/boot/scala-2.12.6/lib/scala-compiler.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/beachape/enumeratum-circe_2.12/1.5.15/enumeratum-circe_2.12-1.5.15.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/google/protobuf/protobuf-java/3.5.1/protobuf-java-3.5.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix-reactive_2.12/2.3.3/monix-reactive_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/google/guava/guava/23.0/guava-23.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/net/java/dev/jna/jna-platform/4.5.0/jna-platform-4.5.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/test-interface/1.0/test-interface-1.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/reactivestreams/reactive-streams/1.0.0/reactive-streams-1.0.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/librarymanagement-ivy_2.12/1.0.0/librarymanagement-ivy_2.12-1.0.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix-execution_2.12/2.3.3/monix-execution_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-ivy-integration_2.12/1.2.1%2B76-109107b0/zinc-ivy-integration_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-interface/1.2.1/util-interface-1.2.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/get-coursier/coursier_2.12/1.1.0-M3/coursier_2.12-1.1.0-M3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/eclipse/jgit/org.eclipse.jgit/4.4.1.201607150455-r/org.eclipse.jgit-4.4.1.201607150455-r.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-cache_2.12/1.2.0/util-cache_2.12-1.2.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/beachape/enumeratum-macros_2.12/1.5.9/enumeratum-macros_2.12-1.5.9.jar",
            "/Users/jvican/.sbt/boot/scala-2.12.6/lib/scala-reflect.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-parser_2.12/0.9.3/circe-parser_2.12-0.9.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/compiler-bridge_2.12/1.2.1%2B76-109107b0/compiler-bridge_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/.sbt/boot/scala-2.12.6/lib/scala-library.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/nailgun-server/0c8b937b/nailgun-server-0c8b937b.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/typelevel/cats-core_2.12/1.0.1/cats-core_2.12-1.0.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/squareup/okhttp3/okhttp-urlconnection/3.7.0/okhttp-urlconnection-3.7.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-control_2.12/1.2.1/util-control_2.12-1.2.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/modules/scala-xml_2.12/1.0.6/scala-xml_2.12-1.0.6.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-compile-core_2.12/1.2.1%2B76-109107b0/zinc-compile-core_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/typelevel/cats-macros_2.12/1.0.1/cats-macros_2.12-1.0.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/launcher-interface/1.0.0/launcher-interface-1.0.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/codehaus/mojo/animal-sniffer-annotations/1.14/animal-sniffer-annotations-1.14.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/case-app-util_2.12/1.2.0-faster-compile-time/case-app-util_2.12-1.2.0-faster-compile-time.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/jcraft/jsch/0.1.54/jsch-0.1.54.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/me/vican/jorge/directory-watcher/0.5.2-eade9dbe/directory-watcher-0.5.2-eade9dbe.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-apiinfo_2.12/1.2.1%2B76-109107b0/zinc-apiinfo_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/thesamet/scalapb/scalapb-runtime_2.12/0.8.0-RC1/scalapb-runtime_2.12-0.8.0-RC1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/chuusai/shapeless_2.12/2.3.3/shapeless_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scalaz/scalaz-core_2.12/7.2.20/scalaz-core_2.12-7.2.20.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/apache/logging/log4j/log4j-api/2.8.1/log4j-api-2.8.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-derivation_2.12/0.9.0-M3/circe-derivation_2.12-0.9.0-M3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/get-coursier/coursier-scalaz-interop_2.12/1.1.0-M3/coursier-scalaz-interop_2.12-1.1.0-M3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/eed3si9n/sjson-new-murmurhash_2.12/0.8.2/sjson-new-murmurhash_2.12-0.8.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/google/code/findbugs/jsr305/1.3.9/jsr305-1.3.9.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix-types_2.12/2.3.3/monix-types_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/io_2.12/1.2.0/io_2.12-1.2.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/case-app_2.12/1.2.0-faster-compile-time/case-app_2.12-1.2.0-faster-compile-time.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/typesafe/scala-logging/scala-logging_2.12/3.7.2/scala-logging_2.12-3.7.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-core_2.12/0.9.3/circe-core_2.12-0.9.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/typelevel/macro-compat_2.12/1.1.1/macro-compat_2.12-1.1.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/util-position_2.12/1.2.0/util-position_2.12-1.2.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/squareup/okhttp3/okhttp/3.7.0/okhttp-3.7.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/codehaus/groovy/groovy/2.4.0/groovy-2.4.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scalaz/scalaz-concurrent_2.12/7.2.20/scalaz-concurrent_2.12-7.2.20.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/test-agent/1.0.4/test-agent-1.0.4.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/qos/logback/logback-core/1.2.3/logback-core-1.2.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scalameta/jsonrpc_2.12/0.1.0/jsonrpc_2.12-0.1.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/spire-math/jawn-parser_2.12/0.11.1/jawn-parser_2.12-0.11.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-sbt/ivy/ivy/2.3.0-sbt-a3314352b638afbf0dca19f127e8263ed6f898bd/ivy-2.3.0-sbt-a3314352b638afbf0dca19f127e8263ed6f898bd.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/circe/circe-generic-extras_2.12/0.9.0/circe-generic-extras_2.12-0.9.0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/modules/scala-parser-combinators_2.12/1.0.5/scala-parser-combinators_2.12-1.0.5.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/net/java/dev/jna/jna/4.5.1/jna-4.5.1.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/ch/epfl/scala/zinc-classfile_2.12/1.2.1%2B76-109107b0/zinc-classfile_2.12-1.2.1%2B76-109107b0.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/swoval/apple-file-events/1.3.2/apple-file-events-1.3.2.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scalaz/scalaz-effect_2.12/7.2.20/scalaz-effect_2.12-7.2.20.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix_2.12/2.3.3/monix_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/io/monix/monix-eval_2.12/2.3.3/monix-eval_2.12-2.3.3.jar",
            "/Users/jvican/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/com/lihaoyi/fastparse_2.12/1.0.0/fastparse_2.12-1.0.0.jar"
        ],
        "out" : "/Users/jvican/Code/bloop/.bloop/frontend",
        "classesDir" : "/Users/jvican/Code/bloop/.bloop/frontend/scala-2.12/classes"
    }
}