diff --git a/src/it/java/io/weaviate/containers/Container.java b/src/it/java/io/weaviate/containers/Container.java
index 2c4218a9f..ee8859a18 100644
--- a/src/it/java/io/weaviate/containers/Container.java
+++ b/src/it/java/io/weaviate/containers/Container.java
@@ -10,7 +10,7 @@
 import org.testcontainers.containers.Network;
 import org.testcontainers.lifecycle.Startable;
 
-import io.weaviate.client6.WeaviateClient;
+import io.weaviate.client6.v1.api.WeaviateClient;
 import lombok.RequiredArgsConstructor;
 
 public class Container {
diff --git a/src/it/java/io/weaviate/containers/Weaviate.java b/src/it/java/io/weaviate/containers/Weaviate.java
index d6251c028..c70342fd1 100644
--- a/src/it/java/io/weaviate/containers/Weaviate.java
+++ b/src/it/java/io/weaviate/containers/Weaviate.java
@@ -9,8 +9,8 @@
 
 import org.testcontainers.weaviate.WeaviateContainer;
 
-import io.weaviate.client6.Config;
-import io.weaviate.client6.WeaviateClient;
+import io.weaviate.client6.v1.api.Config;
+import io.weaviate.client6.v1.api.WeaviateClient;
 
 public class Weaviate extends WeaviateContainer {
   private WeaviateClient clientInstance;
diff --git a/src/it/java/io/weaviate/integration/AggregationITest.java b/src/it/java/io/weaviate/integration/AggregationITest.java
index 29bc7b43c..7c7597c0c 100644
--- a/src/it/java/io/weaviate/integration/AggregationITest.java
+++ b/src/it/java/io/weaviate/integration/AggregationITest.java
@@ -12,7 +12,8 @@
 import org.junit.Test;
 
 import io.weaviate.ConcurrentTest;
-import io.weaviate.client6.WeaviateClient;
+import io.weaviate.client6.v1.api.WeaviateClient;
+import io.weaviate.client6.v1.api.collections.Property;
 import io.weaviate.client6.v1.api.collections.Vectors;
 import io.weaviate.client6.v1.api.collections.aggregate.AggregateResponseGroup;
 import io.weaviate.client6.v1.api.collections.aggregate.AggregateResponseGrouped;
@@ -20,9 +21,8 @@
 import io.weaviate.client6.v1.api.collections.aggregate.GroupBy;
 import io.weaviate.client6.v1.api.collections.aggregate.GroupedBy;
 import io.weaviate.client6.v1.api.collections.aggregate.IntegerAggregation;
-import io.weaviate.client6.v1.collections.Property;
-import io.weaviate.client6.v1.collections.VectorIndex;
-import io.weaviate.client6.v1.collections.Vectorizer;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
 import io.weaviate.containers.Container;
 
 public class AggregationITest extends ConcurrentTest {
@@ -36,7 +36,7 @@ public static void beforeAll() throws IOException {
             .properties(
                 Property.text("category"),
                 Property.integer("price"))
-            .vectors(io.weaviate.client6.v1.collections.Vectors.of(new VectorIndex<>(Vectorizer.none()))));
+            .vector(Hnsw.of(new NoneVectorizer())));
 
     var things = client.collections.use(COLLECTION);
     for (var category : List.of("Shoes", "Hat", "Jacket")) {
diff --git a/src/it/java/io/weaviate/integration/CollectionsITest.java b/src/it/java/io/weaviate/integration/CollectionsITest.java
index 59083c44b..0b5b94fbe 100644
--- a/src/it/java/io/weaviate/integration/CollectionsITest.java
+++ b/src/it/java/io/weaviate/integration/CollectionsITest.java
@@ -7,15 +7,12 @@
 import org.junit.Test;
 
 import io.weaviate.ConcurrentTest;
-import io.weaviate.client6.WeaviateClient;
-import io.weaviate.client6.v1.collections.Collection;
-import io.weaviate.client6.v1.collections.NoneVectorizer;
-import io.weaviate.client6.v1.collections.Property;
-import io.weaviate.client6.v1.collections.VectorIndex;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexType;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-import io.weaviate.client6.v1.collections.Vectorizer;
-import io.weaviate.client6.v1.collections.Vectors;
+import io.weaviate.client6.v1.api.WeaviateClient;
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.api.collections.VectorIndex;
+import io.weaviate.client6.v1.api.collections.WeaviateCollection;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
 import io.weaviate.containers.Container;
 
 public class CollectionsITest extends ConcurrentTest {
@@ -27,18 +24,19 @@ public void testCreateGetDelete() throws IOException {
     client.collections.create(collectionName,
         col -> col
             .properties(Property.text("username"), Property.integer("age"))
-            .vector(new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.none())));
+            .vector(Hnsw.of(new NoneVectorizer())));
 
     var thingsCollection = client.collections.getConfig(collectionName);
 
     Assertions.assertThat(thingsCollection).get()
         .hasFieldOrPropertyWithValue("name", collectionName)
-        .extracting(Collection::vectors).extracting(Vectors::getDefault)
-        .as("default vector").satisfies(defaultVector -> {
+        .extracting(WeaviateCollection::vectors, InstanceOfAssertFactories.map(String.class, VectorIndex.class))
+        .as("default vector").extractingByKey("default")
+        .satisfies(defaultVector -> {
           Assertions.assertThat(defaultVector).extracting(VectorIndex::vectorizer)
               .as("has none vectorizer").isInstanceOf(NoneVectorizer.class);
-          Assertions.assertThat(defaultVector).extracting(VectorIndex::configuration)
-              .as("has hnsw index").returns(IndexType.HNSW, IndexingStrategy::type);
+          Assertions.assertThat(defaultVector).extracting(VectorIndex::config)
+              .isInstanceOf(Hnsw.class);
         });
 
     client.collections.delete(collectionName);
diff --git a/src/it/java/io/weaviate/integration/DataITest.java b/src/it/java/io/weaviate/integration/DataITest.java
index 5d2325200..1f29861aa 100644
--- a/src/it/java/io/weaviate/integration/DataITest.java
+++ b/src/it/java/io/weaviate/integration/DataITest.java
@@ -9,16 +9,15 @@
 import org.junit.Test;
 
 import io.weaviate.ConcurrentTest;
-import io.weaviate.client6.WeaviateClient;
+import io.weaviate.client6.v1.api.WeaviateClient;
+import io.weaviate.client6.v1.api.collections.Property;
 import io.weaviate.client6.v1.api.collections.Vectors;
-import io.weaviate.client6.v1.collections.Property;
-import io.weaviate.client6.v1.collections.VectorIndex;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-import io.weaviate.client6.v1.collections.Vectorizer;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
 import io.weaviate.containers.Container;
 
 public class DataITest extends ConcurrentTest {
-
   private static WeaviateClient client = Container.WEAVIATE.getClient();
   private static final String COLLECTION = unique("Artists");
   private static final String VECTOR_INDEX = "bring_your_own";
@@ -34,9 +33,10 @@ public void testCreateGetDelete() throws IOException {
     var id = randomUUID();
     Float[] vector = { 1f, 2f, 3f };
 
-    artists.data.insert(Map.of("name", "john doe"), metadata -> metadata
-        .id(id)
-        .vectors(Vectors.of(VECTOR_INDEX, vector)));
+    artists.data.insert(Map.of("name", "john doe"),
+        metadata -> metadata
+            .uuid(id)
+            .vectors(Vectors.of(VECTOR_INDEX, vector)));
 
     var object = artists.query.byId(id, query -> query
         .returnProperties("name")
@@ -45,11 +45,10 @@ public void testCreateGetDelete() throws IOException {
     Assertions.assertThat(object)
         .as("object exists after insert").get()
         .satisfies(obj -> {
-          Assertions.assertThat(obj.metadata().id())
+          Assertions.assertThat(obj.metadata().uuid())
               .as("object id").isEqualTo(id);
 
-          Assertions.assertThat(obj.metadata().vectors()).extracting(Vectors::getSingle)
-              .asInstanceOf(InstanceOfAssertFactories.OPTIONAL).as("has single vector").get()
+          Assertions.assertThat(obj.metadata().vectors()).extracting(v -> v.getSingle(VECTOR_INDEX))
               .asInstanceOf(InstanceOfAssertFactories.array(Float[].class)).containsExactly(vector);
 
           Assertions.assertThat(obj.properties())
@@ -77,11 +76,11 @@ public void testBlobData() throws IOException {
         "breed", "ragdoll",
         "img", ragdollPng));
 
-    var got = cats.query.byId(ragdoll.metadata().id(),
+    var got = cats.query.byId(ragdoll.metadata().uuid(),
         cat -> cat.returnProperties("img"));
 
     Assertions.assertThat(got).get()
-        .extracting(io.weaviate.client6.v1.api.collections.WeaviateObject::properties, InstanceOfAssertFactories.MAP)
+        .extracting(WeaviateObject::properties, InstanceOfAssertFactories.MAP)
         .extractingByKey("img").isEqualTo(ragdollPng);
   }
 
@@ -99,6 +98,6 @@ private static void createTestCollections() throws IOException {
                 Property.integer("age"))
             .references(
                 Property.reference("hasAwards", awardsGrammy, awardsOscar))
-            .vector(VECTOR_INDEX, new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.none())));
+            .vectors(named -> named.vector(VECTOR_INDEX, Hnsw.of(new NoneVectorizer()))));
   }
 }
diff --git a/src/it/java/io/weaviate/integration/ReferencesITest.java b/src/it/java/io/weaviate/integration/ReferencesITest.java
index 7feca750b..519319e64 100644
--- a/src/it/java/io/weaviate/integration/ReferencesITest.java
+++ b/src/it/java/io/weaviate/integration/ReferencesITest.java
@@ -1,6 +1,7 @@
 package io.weaviate.integration;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
@@ -9,15 +10,14 @@
 import org.junit.Test;
 
 import io.weaviate.ConcurrentTest;
-import io.weaviate.client6.WeaviateClient;
-import io.weaviate.client6.v1.api.collections.ObjectReference;
+import io.weaviate.client6.v1.api.WeaviateClient;
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.api.collections.ReferenceProperty;
 import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.api.collections.data.Reference;
 import io.weaviate.client6.v1.api.collections.query.MetadataField;
-import io.weaviate.client6.v1.api.collections.query.QueryMetadata;
 import io.weaviate.client6.v1.api.collections.query.QueryReference;
-import io.weaviate.client6.v1.collections.Property;
-import io.weaviate.client6.v1.collections.Reference;
-import io.weaviate.client6.v1.collections.ReferenceProperty;
 import io.weaviate.containers.Container;
 
 /**
@@ -75,7 +75,7 @@ public void testReferences() throws IOException {
         Map.of("name", "Alex"),
         opt -> opt
             .reference("hasAwards", Reference.uuids(
-                grammy_1.metadata().id(), oscar_1.metadata().id()))
+                grammy_1.metadata().uuid(), oscar_1.metadata().uuid()))
             .reference("hasAwards", Reference.objects(grammy_2, oscar_2)));
 
     // Act: add one more reference
@@ -92,7 +92,7 @@ public void testReferences() throws IOException {
         .extracting(ReferenceProperty::dataTypes, InstanceOfAssertFactories.list(String.class))
         .containsOnly(nsMovies);
 
-    var gotAlex = artists.query.byId(alex.metadata().id(),
+    var gotAlex = artists.query.byId(alex.metadata().uuid(),
         opt -> opt.returnReferences(
             QueryReference.multi("hasAwards", nsOscar,
                 ref -> ref.returnMetadata(MetadataField.ID)),
@@ -101,10 +101,13 @@ public void testReferences() throws IOException {
 
     Assertions.assertThat(gotAlex).get()
         .as("Artists: fetch by id including hasAwards references")
-        .extracting(WeaviateObject::references, InstanceOfAssertFactories.map(String.class, ObjectReference.class))
+
+        // Cast references to Map<String, List<WeaviateObject>>
+        .extracting(WeaviateObject::references, InstanceOfAssertFactories.map(String.class, List.class))
         .as("hasAwards object reference").extractingByKey("hasAwards")
-        .extracting(ObjectReference::objects, InstanceOfAssertFactories.list(WeaviateObject.class))
-        .extracting(object -> ((QueryMetadata) object.metadata()).id())
+        .asInstanceOf(InstanceOfAssertFactories.list(WeaviateObject.class))
+
+        .extracting(object -> ((ObjectMetadata) object.metadata()).uuid())
         .containsOnly(
             // INVESTIGATE: When references to 2+ collections are requested,
             // seems to Weaviate only return references to the first one in the list.
@@ -112,7 +115,7 @@ public void testReferences() throws IOException {
             // so the latter will not be in the response.
             //
             // grammy_1.metadata().id(), grammy_2.metadata().id(),
-            oscar_1.metadata().id(), oscar_2.metadata().id());
+            oscar_1.metadata().uuid(), oscar_2.metadata().uuid());
   }
 
   @Test
@@ -155,7 +158,7 @@ public void testNestedReferences() throws IOException {
             .reference("hasAwards", Reference.objects(grammy_1)));
 
     // Assert: fetch nested references
-    var gotAlex = artists.query.byId(alex.metadata().id(),
+    var gotAlex = artists.query.byId(alex.metadata().uuid(),
         opt -> opt.returnReferences(
             QueryReference.single("hasAwards",
                 ref -> ref
@@ -167,15 +170,20 @@ public void testNestedReferences() throws IOException {
 
     Assertions.assertThat(gotAlex).get()
         .as("Artists: fetch by id including nested references")
-        .extracting(WeaviateObject::references, InstanceOfAssertFactories.map(String.class, ObjectReference.class))
+
+        // Cast references to Map<String, List<WeaviateObject>>
+        .extracting(WeaviateObject::references, InstanceOfAssertFactories.map(String.class, List.class))
         .as("hasAwards object reference").extractingByKey("hasAwards")
-        .extracting(ObjectReference::objects, InstanceOfAssertFactories.list(WeaviateObject.class))
+        .asInstanceOf(InstanceOfAssertFactories.list(WeaviateObject.class))
+
         .hasSize(1).allSatisfy(award -> Assertions.assertThat(award)
-            .returns(grammy_1.metadata().id(), grammy -> ((QueryMetadata) grammy.metadata()).id())
-            .extracting(WeaviateObject::references,
-                InstanceOfAssertFactories.map(String.class, ObjectReference.class))
-            .extractingByKey("presentedBy")
-            .extracting(ObjectReference::objects, InstanceOfAssertFactories.list(WeaviateObject.class))
+            .returns(grammy_1.metadata().uuid(), grammy -> ((ObjectMetadata) grammy.metadata()).uuid())
+
+            // Cast references to Map<String, List<WeaviateObject>>
+            .extracting(WeaviateObject::references, InstanceOfAssertFactories.map(String.class, List.class))
+            .as("presentedBy object reference").extractingByKey("presentedBy")
+            .asInstanceOf(InstanceOfAssertFactories.list(WeaviateObject.class))
+
             .hasSize(1).extracting(WeaviateObject::properties)
             .allSatisfy(properties -> Assertions.assertThat(properties)
                 .asInstanceOf(InstanceOfAssertFactories.map(String.class, Object.class))
diff --git a/src/it/java/io/weaviate/integration/SearchITest.java b/src/it/java/io/weaviate/integration/SearchITest.java
index a7f8d6970..17679a5bc 100644
--- a/src/it/java/io/weaviate/integration/SearchITest.java
+++ b/src/it/java/io/weaviate/integration/SearchITest.java
@@ -15,17 +15,18 @@
 import org.junit.rules.TestRule;
 
 import io.weaviate.ConcurrentTest;
-import io.weaviate.client6.WeaviateClient;
+import io.weaviate.client6.v1.api.WeaviateClient;
+import io.weaviate.client6.v1.api.collections.Property;
 import io.weaviate.client6.v1.api.collections.Vectors;
 import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.api.collections.data.Reference;
 import io.weaviate.client6.v1.api.collections.query.GroupBy;
 import io.weaviate.client6.v1.api.collections.query.MetadataField;
 import io.weaviate.client6.v1.api.collections.query.QueryResponseGroup;
-import io.weaviate.client6.v1.collections.Property;
-import io.weaviate.client6.v1.collections.Reference;
-import io.weaviate.client6.v1.collections.VectorIndex;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-import io.weaviate.client6.v1.collections.Vectorizer;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.api.collections.vectorizers.Img2VecNeuralVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Text2VecContextionaryVectorizer;
 import io.weaviate.containers.Container;
 import io.weaviate.containers.Container.ContainerGroup;
 import io.weaviate.containers.Contextionary;
@@ -111,10 +112,10 @@ private static Map<String, Float[]> populateTest(int n) throws IOException {
       var object = things.data.insert(
           Map.of("category", CATEGORIES.get(i % CATEGORIES.size())),
           metadata -> metadata
-              .id(randomUUID())
+              .uuid(randomUUID())
               .vectors(Vectors.of(VECTOR_INDEX, vector)));
 
-      created.put(object.metadata().id(), vector);
+      created.put(object.metadata().uuid(), vector);
     }
 
     return created;
@@ -128,7 +129,7 @@ private static Map<String, Float[]> populateTest(int n) throws IOException {
   private static void createTestCollection() throws IOException {
     client.collections.create(COLLECTION, cfg -> cfg
         .properties(Property.text("category"))
-        .vector(VECTOR_INDEX, new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.none())));
+        .vector(VECTOR_INDEX, Hnsw.of(new NoneVectorizer())));
   }
 
   @Test
@@ -137,7 +138,7 @@ public void testNearText() throws IOException {
     client.collections.create(nsSongs,
         col -> col
             .properties(Property.text("title"))
-            .vector(new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.text2vecContextionary())));
+            .vector(Hnsw.of(Text2VecContextionaryVectorizer.of())));
 
     var songs = client.collections.use(nsSongs);
     var submarine = songs.data.insert(Map.of("title", "Yellow Submarine"));
@@ -148,7 +149,7 @@ public void testNearText() throws IOException {
         opt -> opt
             .distance(0.5f)
             .moveTo(.98f, to -> to.concepts("tropical"))
-            .moveAway(.4f, away -> away.uuids(submarine.metadata().id()))
+            .moveAway(.4f, away -> away.uuids(submarine.metadata().uuid()))
             .returnProperties("title"));
 
     Assertions.assertThat(result.objects()).hasSize(2)
@@ -159,7 +160,7 @@ public void testNearText() throws IOException {
 
   @Test
   public void testNearText_groupBy() throws IOException {
-    var vectorIndex = new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.text2vecContextionary());
+    var vectorIndex = Hnsw.of(Text2VecContextionaryVectorizer.of());
 
     var nsArtists = ns("Artists");
     client.collections.create(nsArtists,
@@ -190,8 +191,8 @@ public void testNearText_groupBy() throws IOException {
 
     Assertions.assertThat(result.groups()).hasSize(2)
         .containsOnlyKeys(
-            "weaviate://localhost/%s/%s".formatted(nsArtists, beatles.metadata().id()),
-            "weaviate://localhost/%s/%s".formatted(nsArtists, ccr.metadata().id()));
+            "weaviate://localhost/%s/%s".formatted(nsArtists, beatles.metadata().uuid()),
+            "weaviate://localhost/%s/%s".formatted(nsArtists, ccr.metadata().uuid()));
   }
 
   @Test
@@ -203,9 +204,8 @@ public void testNearImage() throws IOException {
             .properties(
                 Property.text("breed"),
                 Property.blob("img"))
-            .vector(new VectorIndex<>(
-                IndexingStrategy.hnsw(),
-                Vectorizer.img2VecNeuralVectorizer(
+            .vector(Hnsw.of(
+                Img2VecNeuralVectorizer.of(
                     i2v -> i2v.imageFields("img")))));
 
     var cats = client.collections.use(nsCats);
diff --git a/src/main/java/io/weaviate/client6/Config.java b/src/main/java/io/weaviate/client6/Config.java
deleted file mode 100644
index e749aa8c4..000000000
--- a/src/main/java/io/weaviate/client6/Config.java
+++ /dev/null
@@ -1,50 +0,0 @@
-package io.weaviate.client6;
-
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Map.Entry;
-
-import io.weaviate.client6.v1.internal.grpc.GrpcChannelOptions;
-
-public class Config implements GrpcChannelOptions {
-  private final String version = "v1";
-  private final String scheme;
-  private final String httpHost;
-  private final String grpcHost;
-  private final Collection<Entry<String, String>> headers = Collections.emptyList();
-
-  public Config(String scheme, String httpHost, String grpcHost) {
-    this.scheme = scheme;
-    this.httpHost = httpHost;
-    this.grpcHost = grpcHost;
-  }
-
-  public String baseUrl() {
-    return scheme + "://" + httpHost + "/" + version;
-  }
-
-  public String grpcAddress() {
-    if (grpcHost.contains(":")) {
-      return grpcHost;
-    }
-    // FIXME: use secure port (433) if scheme == https
-    return String.format("%s:80", grpcHost);
-  }
-
-  // GrpcChannelOptions -------------------------------------------------------
-
-  @Override
-  public String host() {
-    return grpcAddress();
-  }
-
-  @Override
-  public Collection<Entry<String, String>> headers() {
-    return headers;
-  }
-
-  @Override
-  public boolean useTls() {
-    return scheme.equals("https");
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/WeaviateClient.java b/src/main/java/io/weaviate/client6/WeaviateClient.java
deleted file mode 100644
index 484546a60..000000000
--- a/src/main/java/io/weaviate/client6/WeaviateClient.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package io.weaviate.client6;
-
-import java.io.Closeable;
-import java.io.IOException;
-
-import io.weaviate.client6.internal.GrpcClient;
-import io.weaviate.client6.internal.HttpClient;
-import io.weaviate.client6.v1.collections.CollectionsClient;
-import io.weaviate.client6.v1.internal.grpc.DefaultGrpcTransport;
-import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
-
-public class WeaviateClient implements Closeable {
-  private final HttpClient http;
-  private final GrpcClient grpc;
-
-  public final CollectionsClient collections;
-
-  private final GrpcTransport grpcTransport;
-
-  public WeaviateClient(Config config) {
-    this.http = new HttpClient();
-    this.grpc = new GrpcClient(config);
-
-    this.grpcTransport = new DefaultGrpcTransport(config);
-
-    this.collections = new CollectionsClient(config, http, grpc, grpcTransport);
-  }
-
-  @Override
-  public void close() throws IOException {
-    this.http.close();
-    this.grpc.close();
-
-    this.grpcTransport.close();
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/internal/DtoTypeAdapterFactory.java b/src/main/java/io/weaviate/client6/internal/DtoTypeAdapterFactory.java
deleted file mode 100644
index 812f6dddd..000000000
--- a/src/main/java/io/weaviate/client6/internal/DtoTypeAdapterFactory.java
+++ /dev/null
@@ -1,108 +0,0 @@
-package io.weaviate.client6.internal;
-
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
-
-import com.google.gson.Gson;
-import com.google.gson.TypeAdapter;
-import com.google.gson.TypeAdapterFactory;
-import com.google.gson.reflect.TypeToken;
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonWriter;
-
-/**
- * DtoTypeAdapterFactory de-/serializes objects using their registerred DTOs.
- *
- * <p>
- * DTO classes must implement {@link Dto}, which produces the original model.
- * Meanwhile, models do not need to be modified, to avoid leaking
- * de-/serialization details.
- *
- * <p>
- * Usage:
- *
- * <pre>{@code
- * public class HttpHanlder {
- *   static {
- *     DtoTypeAdapterFactory.register(
- *         MyDomainObject.class,
- *         MyDtoObject.class,
- *         domain -> new MyDtoObject(domain));
- *   }
- *   static final Gson gson = new GsonBuilder()
- *       .registerTypeAdapterFactory(new DtoTypeAdapterFactory())
- *       .create();
- * }
- * }</pre>
- */
-public class DtoTypeAdapterFactory implements TypeAdapterFactory {
-  private static boolean locked = false;
-  private static final Map<Class<?>, Pair<?, ?>> registry = new HashMap<>();
-
-  /**
-   * Register a model-DTO pair.
-   *
-   * <p>
-   * Only one DTO can be registerred per model.
-   * Subsequent registrations will be ignored.
-   */
-  public static <M, DTO extends Dto<M>> void register(Class<M> model, Class<DTO> dto,
-      ModelConverter<M, Dto<M>> convert) {
-    registry.putIfAbsent(model, new Pair<M, DTO>(dto, convert));
-  }
-
-  /**
-   * Get model-DTO pair for the provided model class. Returns null if no pair is
-   * registerred. In this case {@link #create} should also return null.
-   *
-   * <p>
-   * Conversion to {@code Pair<M, DTO>} is safe, as entries to {@link #registry}
-   * can only be added via {@link #register}, which is type-safe.
-   */
-  @SuppressWarnings("unchecked")
-  private static <M, DTO extends Dto<M>> Pair<M, DTO> getPair(TypeToken<? super M> type) {
-    var cls = type.getRawType();
-    if (!registry.containsKey(cls)) {
-      return null;
-    }
-    return (Pair<M, DTO>) registry.get(cls);
-  }
-
-  /** Dto produces a domain model. */
-  public interface Dto<M> {
-    M toModel();
-  }
-
-  /** ModelConverter converts domain model to a DTO. */
-  @FunctionalInterface
-  public interface ModelConverter<M, D extends Dto<?>> {
-    D toDTO(M model);
-  }
-
-  record Pair<M, DTO extends Dto<M>>(Class<DTO> dto, ModelConverter<M, Dto<M>> convert) {
-  }
-
-  @Override
-  public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
-    var pair = getPair(type);
-    if (pair == null) {
-      return null;
-    }
-    var delegate = gson.getDelegateAdapter(this, TypeToken.get(pair.dto));
-    return new TypeAdapter<T>() {
-
-      @Override
-      public T read(JsonReader in) throws IOException {
-        var dto = delegate.read(in);
-        return dto.toModel();
-      }
-
-      @Override
-      public void write(JsonWriter out, T value) throws IOException {
-        var dto = pair.convert.toDTO(value);
-        delegate.write(out, dto);
-      }
-    };
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/internal/GrpcClient.java b/src/main/java/io/weaviate/client6/internal/GrpcClient.java
deleted file mode 100644
index 8d36f84f5..000000000
--- a/src/main/java/io/weaviate/client6/internal/GrpcClient.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package io.weaviate.client6.internal;
-
-import java.io.Closeable;
-import java.io.IOException;
-
-import io.grpc.ManagedChannel;
-import io.grpc.ManagedChannelBuilder;
-import io.grpc.stub.MetadataUtils;
-import io.weaviate.client6.Config;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateGrpc;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateGrpc.WeaviateBlockingStub;
-
-public class GrpcClient implements Closeable {
-  private final ManagedChannel channel;
-  public final WeaviateBlockingStub grpc;
-
-  public GrpcClient(Config config) {
-    this.channel = buildChannel(config);
-    this.grpc = buildStub(channel);
-  }
-
-  @Override
-  public void close() throws IOException {
-    channel.shutdown();
-  }
-
-  private static ManagedChannel buildChannel(Config config) {
-    ManagedChannelBuilder<?> channelBuilder = ManagedChannelBuilder.forTarget(config.grpcAddress());
-    channelBuilder.usePlaintext();
-    return channelBuilder.build();
-  }
-
-  private static WeaviateBlockingStub buildStub(ManagedChannel channel) {
-    return WeaviateGrpc.newBlockingStub(channel)
-        .withInterceptors(MetadataUtils.newAttachHeadersInterceptor(new io.grpc.Metadata()));
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/internal/HttpClient.java b/src/main/java/io/weaviate/client6/internal/HttpClient.java
deleted file mode 100644
index 1d1122b37..000000000
--- a/src/main/java/io/weaviate/client6/internal/HttpClient.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package io.weaviate.client6.internal;
-
-import java.io.Closeable;
-import java.io.IOException;
-
-import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
-import org.apache.hc.client5.http.impl.classic.HttpClients;
-
-public class HttpClient implements Closeable {
-  // TODO: move somewhere
-  // public static final Gson GSON =
-
-  public final CloseableHttpClient http;
-
-  public HttpClient() {
-    http = HttpClients.createDefault();
-  }
-
-  @Override
-  public void close() throws IOException {
-    http.close();
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/api/Config.java b/src/main/java/io/weaviate/client6/v1/api/Config.java
new file mode 100644
index 000000000..2e7d9391d
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/Config.java
@@ -0,0 +1,68 @@
+package io.weaviate.client6.v1.api;
+
+import java.util.Collections;
+import java.util.Map;
+
+import io.weaviate.client6.v1.internal.grpc.GrpcChannelOptions;
+import io.weaviate.client6.v1.internal.rest.TransportOptions;
+
+public class Config {
+  private final String version = "v1";
+  private final String scheme;
+  private final String httpHost;
+  private final String grpcHost;
+  private final Map<String, String> headers = Collections.emptyMap();
+
+  public Config(String scheme, String httpHost, String grpcHost) {
+    this.scheme = scheme;
+    this.httpHost = httpHost;
+    this.grpcHost = grpcHost;
+  }
+
+  public String baseUrl() {
+    return scheme + "://" + httpHost + "/" + version;
+  }
+
+  public String grpcAddress() {
+    if (grpcHost.contains(":")) {
+      return grpcHost;
+    }
+    // FIXME: use secure port (433) if scheme == https
+    return String.format("%s:80", grpcHost);
+  }
+
+  public TransportOptions rest() {
+    return new TransportOptions() {
+
+      @Override
+      public String host() {
+        return baseUrl();
+      }
+
+      @Override
+      public Map<String, String> headers() {
+        return headers;
+      }
+
+    };
+  }
+
+  public GrpcChannelOptions grpc() {
+    return new GrpcChannelOptions() {
+      @Override
+      public String host() {
+        return grpcAddress();
+      }
+
+      @Override
+      public boolean useTls() {
+        return scheme.equals("https");
+      }
+
+      @Override
+      public Map<String, String> headers() {
+        return headers;
+      }
+    };
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/WeaviateClient.java b/src/main/java/io/weaviate/client6/v1/api/WeaviateClient.java
new file mode 100644
index 000000000..f2ceeff24
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/WeaviateClient.java
@@ -0,0 +1,38 @@
+package io.weaviate.client6.v1.api;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+import io.weaviate.client6.v1.api.collections.WeaviateCollectionsClient;
+import io.weaviate.client6.v1.internal.grpc.DefaultGrpcTransport;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.rest.DefaultRestTransport;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateClient implements Closeable {
+  /** Store this for {@link #async()} helper. */
+  private final Config config;
+
+  private final RestTransport restTransport;
+  private final GrpcTransport grpcTransport;
+
+  public final WeaviateCollectionsClient collections;
+
+  public WeaviateClient(Config config) {
+    this.config = config;
+    this.restTransport = new DefaultRestTransport(config.rest());
+    this.grpcTransport = new DefaultGrpcTransport(config.grpc());
+
+    this.collections = new WeaviateCollectionsClient(restTransport, grpcTransport);
+  }
+
+  public WeaviateClientAsync async() {
+    return new WeaviateClientAsync(config);
+  }
+
+  @Override
+  public void close() throws IOException {
+    this.restTransport.close();
+    this.grpcTransport.close();
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/WeaviateClientAsync.java b/src/main/java/io/weaviate/client6/v1/api/WeaviateClientAsync.java
new file mode 100644
index 000000000..a33927292
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/WeaviateClientAsync.java
@@ -0,0 +1,30 @@
+package io.weaviate.client6.v1.api;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+import io.weaviate.client6.v1.api.collections.WeaviateCollectionsClientAsync;
+import io.weaviate.client6.v1.internal.grpc.DefaultGrpcTransport;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.rest.DefaultRestTransport;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateClientAsync implements Closeable {
+  private final RestTransport restTransport;
+  private final GrpcTransport grpcTransport;
+
+  public final WeaviateCollectionsClientAsync collections;
+
+  public WeaviateClientAsync(Config config) {
+    this.restTransport = new DefaultRestTransport(config.rest());
+    this.grpcTransport = new DefaultGrpcTransport(config.grpc());
+
+    this.collections = new WeaviateCollectionsClientAsync(restTransport, grpcTransport);
+  }
+
+  @Override
+  public void close() throws IOException {
+    this.restTransport.close();
+    this.grpcTransport.close();
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandle.java b/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandle.java
new file mode 100644
index 000000000..47f569cc7
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandle.java
@@ -0,0 +1,27 @@
+package io.weaviate.client6.v1.api.collections;
+
+import io.weaviate.client6.v1.api.collections.aggregate.WeaviateAggregateClient;
+import io.weaviate.client6.v1.api.collections.config.WeaviateConfigClient;
+import io.weaviate.client6.v1.api.collections.data.WeaviateDataClient;
+import io.weaviate.client6.v1.api.collections.query.WeaviateQueryClient;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class CollectionHandle<T> {
+  public final WeaviateConfigClient config;
+  public final WeaviateDataClient<T> data;
+  public final WeaviateQueryClient<T> query;
+  public final WeaviateAggregateClient aggregate;
+
+  public CollectionHandle(
+      RestTransport restTransport,
+      GrpcTransport grpcTransport,
+      CollectionDescriptor<T> collectionDescriptor) {
+
+    this.config = new WeaviateConfigClient(collectionDescriptor, restTransport, grpcTransport);
+    this.data = new WeaviateDataClient<>(collectionDescriptor, restTransport);
+    this.query = new WeaviateQueryClient<>(collectionDescriptor, grpcTransport);
+    this.aggregate = new WeaviateAggregateClient(collectionDescriptor, grpcTransport);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandleAsync.java b/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandleAsync.java
new file mode 100644
index 000000000..95a3096c6
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/CollectionHandleAsync.java
@@ -0,0 +1,27 @@
+package io.weaviate.client6.v1.api.collections;
+
+import io.weaviate.client6.v1.api.collections.aggregate.WeaviateAggregateClientAsync;
+import io.weaviate.client6.v1.api.collections.config.WeaviateConfigClientAsync;
+import io.weaviate.client6.v1.api.collections.data.WeaviateDataClientAsync;
+import io.weaviate.client6.v1.api.collections.query.WeaviateQueryClientAsync;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class CollectionHandleAsync<T> {
+  public final WeaviateConfigClientAsync config;
+  public final WeaviateDataClientAsync<T> data;
+  public final WeaviateQueryClientAsync<T> query;
+  public final WeaviateAggregateClientAsync aggregate;
+
+  public CollectionHandleAsync(
+      RestTransport restTransport,
+      GrpcTransport grpcTransport,
+      CollectionDescriptor<T> collectionDescriptor) {
+
+    this.config = new WeaviateConfigClientAsync(collectionDescriptor, restTransport, grpcTransport);
+    this.data = new WeaviateDataClientAsync<>(collectionDescriptor, restTransport);
+    this.query = new WeaviateQueryClientAsync<>(collectionDescriptor, grpcTransport);
+    this.aggregate = new WeaviateAggregateClientAsync(collectionDescriptor, grpcTransport);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/CreateCollectionRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/CreateCollectionRequest.java
new file mode 100644
index 000000000..25fe319ef
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/CreateCollectionRequest.java
@@ -0,0 +1,18 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.util.Collections;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import io.weaviate.client6.v1.internal.json.JSON;
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record CreateCollectionRequest(WeaviateCollection collection) {
+  public static final Endpoint<CreateCollectionRequest, WeaviateCollection> _ENDPOINT = Endpoint.of(
+      request -> "POST",
+      request -> "/schema/",
+      (gson, request) -> JSON.serialize(request.collection),
+      request -> Collections.emptyMap(),
+      code -> code != HttpStatus.SC_SUCCESS,
+      (gson, response) -> JSON.deserialize(response, WeaviateCollection.class));
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/DataType.java b/src/main/java/io/weaviate/client6/v1/api/collections/DataType.java
new file mode 100644
index 000000000..c114f0ab5
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/DataType.java
@@ -0,0 +1,13 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.util.Set;
+
+import com.google.common.collect.ImmutableSet;
+
+public interface DataType {
+  public static final String TEXT = "text";
+  public static final String INT = "int";
+  public static final String BLOB = "blob";
+
+  public static final Set<String> KNOWN_TYPES = ImmutableSet.of(TEXT, INT, BLOB);
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/DeleteCollectionRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/DeleteCollectionRequest.java
new file mode 100644
index 000000000..e49b52317
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/DeleteCollectionRequest.java
@@ -0,0 +1,17 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.util.Collections;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record DeleteCollectionRequest(String collectionName) {
+  public static final Endpoint<DeleteCollectionRequest, Void> _ENDPOINT = Endpoint.of(
+      request -> "DELETE",
+      request -> "/schema/" + request.collectionName,
+      (gson, request) -> null,
+      request -> Collections.emptyMap(),
+      status -> status != HttpStatus.SC_SUCCESS,
+      (gson, resopnse) -> null);
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/GetConfigRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/GetConfigRequest.java
new file mode 100644
index 000000000..2027428ce
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/GetConfigRequest.java
@@ -0,0 +1,19 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.util.Collections;
+import java.util.Optional;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import io.weaviate.client6.v1.internal.json.JSON;
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record GetConfigRequest(String collectionName) {
+  public static final Endpoint<GetConfigRequest, Optional<WeaviateCollection>> _ENDPOINT = Endpoint.of(
+      request -> "GET",
+      request -> "/schema/" + request.collectionName,
+      (gson, request) -> null,
+      request -> Collections.emptyMap(),
+      code -> code != HttpStatus.SC_SUCCESS,
+      (gson, response) -> Optional.ofNullable(JSON.deserialize(response, WeaviateCollection.class)));
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/ObjectMetadata.java b/src/main/java/io/weaviate/client6/v1/api/collections/ObjectMetadata.java
index 4fc2d97cf..d0aa0a815 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/ObjectMetadata.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/ObjectMetadata.java
@@ -2,11 +2,18 @@
 
 import java.util.function.Function;
 
+import com.google.gson.annotations.SerializedName;
+
 import io.weaviate.client6.v1.internal.ObjectBuilder;
 
-public record ObjectMetadata(String id, Vectors vectors) {
+public record ObjectMetadata(
+    @SerializedName("id") String uuid,
+    @SerializedName("vectors") Vectors vectors,
+    @SerializedName("creationTimeUnix") Long createdAt,
+    @SerializedName("lastUpdateTImeUnix") Long lastUpdatedAt) implements WeaviateMetadata {
+
   public ObjectMetadata(Builder builder) {
-    this(builder.id, builder.vectors);
+    this(builder.id, builder.vectors, null, null);
   }
 
   public static ObjectMetadata of(Function<Builder, ObjectBuilder<ObjectMetadata>> fn) {
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/ObjectReference.java b/src/main/java/io/weaviate/client6/v1/api/collections/ObjectReference.java
index 6cc3395f9..b7f5f9128 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/ObjectReference.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/ObjectReference.java
@@ -2,5 +2,8 @@
 
 import java.util.List;
 
-public record ObjectReference(List<? extends WeaviateObject<?, ?>> objects) {
+import io.weaviate.client6.v1.api.collections.query.QueryMetadata;
+
+public record ObjectReference<T>(
+    List<WeaviateObject<T, ObjectReference<? extends Object>, QueryMetadata>> objects) {
 }
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Property.java b/src/main/java/io/weaviate/client6/v1/api/collections/Property.java
similarity index 67%
rename from src/main/java/io/weaviate/client6/v1/collections/Property.java
rename to src/main/java/io/weaviate/client6/v1/api/collections/Property.java
index bb9293abb..fb1e636b7 100644
--- a/src/main/java/io/weaviate/client6/v1/collections/Property.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/Property.java
@@ -1,4 +1,4 @@
-package io.weaviate.client6.v1.collections;
+package io.weaviate.client6.v1.api.collections;
 
 import java.util.Arrays;
 import java.util.List;
@@ -9,19 +9,23 @@ public record Property(
     @SerializedName("name") String name,
     @SerializedName("dataType") List<String> dataTypes) {
 
+  public Property(String name, String dataType) {
+    this(name, List.of(dataType));
+  }
+
   /** Add text property with default configuration. */
   public static Property text(String name) {
-    return new Property(name, AtomicDataType.TEXT);
+    return new Property(name, DataType.TEXT);
   }
 
   /** Add integer property with default configuration. */
   public static Property integer(String name) {
-    return new Property(name, AtomicDataType.INT);
+    return new Property(name, DataType.INT);
   }
 
   /** Add blob property with default configuration. */
   public static Property blob(String name) {
-    return new Property(name, AtomicDataType.BLOB);
+    return new Property(name, DataType.BLOB);
   }
 
   public static ReferenceProperty reference(String name, String... collections) {
@@ -31,13 +35,4 @@ public static ReferenceProperty reference(String name, String... collections) {
   public static ReferenceProperty reference(String name, List<String> collections) {
     return new ReferenceProperty(name, collections);
   }
-
-  public boolean isReference() {
-    return dataTypes.stream().noneMatch(t -> AtomicDataType.isAtomic(t));
-  }
-
-  private Property(String name, AtomicDataType type) {
-    this(name, List.of(type.name().toLowerCase()));
-  }
-
 }
diff --git a/src/main/java/io/weaviate/client6/v1/collections/ReferenceProperty.java b/src/main/java/io/weaviate/client6/v1/api/collections/ReferenceProperty.java
similarity index 62%
rename from src/main/java/io/weaviate/client6/v1/collections/ReferenceProperty.java
rename to src/main/java/io/weaviate/client6/v1/api/collections/ReferenceProperty.java
index 2b0c5b55a..3ed9b5aed 100644
--- a/src/main/java/io/weaviate/client6/v1/collections/ReferenceProperty.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/ReferenceProperty.java
@@ -1,4 +1,4 @@
-package io.weaviate.client6.v1.collections;
+package io.weaviate.client6.v1.api.collections;
 
 import java.util.List;
 
@@ -7,4 +7,8 @@
 public record ReferenceProperty(
     @SerializedName("name") String name,
     @SerializedName("dataType") List<String> dataTypes) {
+
+  public Property toProperty() {
+    return new Property(name, dataTypes);
+  }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/VectorIndex.java b/src/main/java/io/weaviate/client6/v1/api/collections/VectorIndex.java
new file mode 100644
index 000000000..05f535ad9
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/VectorIndex.java
@@ -0,0 +1,126 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.io.IOException;
+import java.util.EnumMap;
+import java.util.Map;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonParser;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.internal.Streams;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.api.collections.vectorindex.Flat;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.internal.json.JsonEnum;
+
+public interface VectorIndex {
+  static final String DEFAULT_VECTOR_NAME = "default";
+
+  public enum Kind implements JsonEnum<Kind> {
+    HNSW("hnsw"),
+    FLAT("flat"),
+    DYNAMIC("dynamic");
+
+    private static final Map<String, Kind> jsonValueMap = JsonEnum.collectNames(Kind.values());
+    private final String jsonValue;
+
+    private Kind(String jsonValue) {
+      this.jsonValue = jsonValue;
+    }
+
+    @Override
+    public String jsonValue() {
+      return this.jsonValue;
+    }
+
+    public static Kind valueOfJson(String jsonValue) {
+      return JsonEnum.valueOfJson(jsonValue, jsonValueMap, Kind.class);
+    }
+  }
+
+  VectorIndex.Kind _kind();
+
+  default String type() {
+    return _kind().jsonValue();
+  }
+
+  Vectorizer vectorizer();
+
+  Object config();
+
+  public static enum CustomTypeAdapterFactory implements TypeAdapterFactory {
+    INSTANCE;
+
+    private static final EnumMap<VectorIndex.Kind, TypeAdapter<? extends VectorIndex>> readAdapters = new EnumMap<>(
+        VectorIndex.Kind.class);
+
+    private final void addAdapter(Gson gson, VectorIndex.Kind kind, Class<? extends VectorIndex> cls) {
+      readAdapters.put(kind, (TypeAdapter<? extends VectorIndex>) gson.getDelegateAdapter(this, TypeToken.get(cls)));
+    }
+
+    private final void init(Gson gson) {
+      addAdapter(gson, VectorIndex.Kind.HNSW, Hnsw.class);
+      addAdapter(gson, VectorIndex.Kind.FLAT, Flat.class);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+      var rawType = type.getRawType();
+      if (!VectorIndex.class.isAssignableFrom(rawType)) {
+        return null;
+      }
+
+      if (readAdapters.isEmpty()) {
+        init(gson);
+      }
+
+      final var vectorizerAdapter = gson.getDelegateAdapter(this, TypeToken.get(Vectorizer.class));
+      final var writeAdapter = gson.getDelegateAdapter(this, TypeToken.get(rawType));
+      return (TypeAdapter<T>) new TypeAdapter<VectorIndex>() {
+
+        @Override
+        public void write(JsonWriter out, VectorIndex value) throws IOException {
+          out.beginObject();
+          out.name("vectorIndexType");
+          out.value(value._kind().jsonValue());
+
+          var config = writeAdapter.toJsonTree((T) value.config());
+          config.getAsJsonObject().remove("vectorizer");
+          out.name("vectorIndexConfig");
+          Streams.write(config, out);
+
+          out.name("vectorizer");
+          vectorizerAdapter.write(out, value.vectorizer());
+          out.endObject();
+        }
+
+        @Override
+        public VectorIndex read(JsonReader in) throws IOException {
+          var jsonObject = JsonParser.parseReader(in).getAsJsonObject();
+
+          VectorIndex.Kind kind;
+          var kindString = jsonObject.get("vectorIndexType").getAsString();
+          try {
+            kind = VectorIndex.Kind.valueOfJson(kindString);
+          } catch (IllegalArgumentException e) {
+            return null;
+          }
+
+          var adapter = readAdapters.get(kind);
+          if (adapter == null) {
+            return null;
+          }
+
+          var config = jsonObject.get("vectorIndexConfig").getAsJsonObject();
+          config.add("vectorizer", jsonObject.get("vectorizer"));
+          return adapter.fromJsonTree(config);
+        }
+      }.nullSafe();
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/Vectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/Vectorizer.java
new file mode 100644
index 000000000..7752cfb07
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/Vectorizer.java
@@ -0,0 +1,113 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.io.IOException;
+import java.util.EnumMap;
+import java.util.Map;
+
+import com.google.gson.Gson;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.api.collections.vectorizers.Img2VecNeuralVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Multi2VecClipVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Text2VecContextionaryVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Text2VecWeaviateVectorizer;
+import io.weaviate.client6.v1.internal.json.JsonEnum;
+
+public interface Vectorizer {
+  public enum Kind implements JsonEnum<Kind> {
+    NONE("none"),
+    IMG2VEC_NEURAL("img2vec-neural"),
+    TEXT2VEC_CONTEXTIONARY("text2vec-contextionary"),
+    TEXT2VEC_WEAVIATE("text2vec-weaviate"),
+    MULTI2VEC_CLIP("multi2vec-clip");
+
+    private static final Map<String, Kind> jsonValueMap = JsonEnum.collectNames(Kind.values());
+    private final String jsonValue;
+
+    private Kind(String jsonValue) {
+      this.jsonValue = jsonValue;
+    }
+
+    @Override
+    public String jsonValue() {
+      return this.jsonValue;
+    }
+
+    public static Kind valueOfJson(String jsonValue) {
+      return JsonEnum.valueOfJson(jsonValue, jsonValueMap, Kind.class);
+    }
+  }
+
+  Kind _kind();
+
+  Object _self();
+
+  public static enum CustomTypeAdapterFactory implements TypeAdapterFactory {
+    INSTANCE;
+
+    private static final EnumMap<Vectorizer.Kind, TypeAdapter<? extends Vectorizer>> readAdapters = new EnumMap<>(
+        Vectorizer.Kind.class);
+
+    private final void addAdapter(Gson gson, Vectorizer.Kind kind, Class<? extends Vectorizer> cls) {
+      readAdapters.put(kind, (TypeAdapter<? extends Vectorizer>) gson.getDelegateAdapter(this, TypeToken.get(cls)));
+    }
+
+    private final void init(Gson gson) {
+      addAdapter(gson, Vectorizer.Kind.NONE, NoneVectorizer.class);
+      addAdapter(gson, Vectorizer.Kind.IMG2VEC_NEURAL, Img2VecNeuralVectorizer.class);
+      addAdapter(gson, Vectorizer.Kind.MULTI2VEC_CLIP, Multi2VecClipVectorizer.class);
+      addAdapter(gson, Vectorizer.Kind.TEXT2VEC_WEAVIATE, Text2VecWeaviateVectorizer.class);
+      addAdapter(gson, Vectorizer.Kind.TEXT2VEC_CONTEXTIONARY, Text2VecContextionaryVectorizer.class);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+      final var rawType = type.getRawType();
+      if (!Vectorizer.class.isAssignableFrom(rawType)) {
+        return null;
+      }
+
+      if (readAdapters.isEmpty()) {
+        init(gson);
+      }
+
+      return (TypeAdapter<T>) new TypeAdapter<Vectorizer>() {
+
+        @Override
+        public void write(JsonWriter out, Vectorizer value) throws IOException {
+          var writeAdapter = readAdapters.get(value._kind());
+
+          out.beginObject();
+          out.name(value._kind().jsonValue());
+          ((TypeAdapter<T>) writeAdapter).write(out, (T) value._self());
+          out.endObject();
+        }
+
+        @Override
+        public Vectorizer read(JsonReader in) throws IOException {
+          in.beginObject();
+          var vectorizerName = in.nextName();
+          try {
+            var kind = Vectorizer.Kind.valueOfJson(vectorizerName);
+            var adapter = readAdapters.get(kind);
+            return adapter.read(in);
+          } catch (IllegalArgumentException e) {
+            return null;
+          } finally {
+            if (in.peek() == JsonToken.BEGIN_OBJECT) {
+              in.beginObject();
+            }
+            in.endObject();
+          }
+        }
+      }.nullSafe();
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/Vectors.java b/src/main/java/io/weaviate/client6/v1/api/collections/Vectors.java
index dcc4850d9..cfd647ce3 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/Vectors.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/Vectors.java
@@ -1,60 +1,76 @@
 package io.weaviate.client6.v1.api.collections;
 
+import java.io.IOException;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Optional;
 import java.util.function.Function;
 
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
 import io.weaviate.client6.v1.internal.ObjectBuilder;
 import lombok.ToString;
 
 /**
- * Vectors is an abstraction over named vectors.
- * It may contain both 1-dimensional and 2-dimensional vectors.
+ * Vectors is an abstraction over named vectors, which can store
+ * both 1-dimensional and 2-dimensional vectors.
  */
 @ToString
 public class Vectors {
-  // TODO: define this in collection.config.Vectors
-  private static final String DEFAULT = "default";
-
-  private final Float[] unnamedVector;
   private final Map<String, Object> namedVectors;
 
-  /**
-   * Pass legacy unnamed vector.
-   * Multi-vectors can only be passed as named vectors.
-   */
-  public static Vectors unnamed(Float[] vector) {
-    return new Vectors(vector);
+  public static Vectors of(Float[] vector) {
+    return new Vectors(VectorIndex.DEFAULT_VECTOR_NAME, vector);
   }
 
-  public static Vectors of(Float[] vector) {
-    return new Vectors(DEFAULT, vector);
+  public static Vectors of(String name, Float[] vector) {
+    return new Vectors(name, vector);
   }
 
   public static Vectors of(Float[][] vector) {
-    return new Vectors(DEFAULT, vector);
+    return new Vectors(VectorIndex.DEFAULT_VECTOR_NAME, vector);
   }
 
-  public static Vectors of(String name, Float[] vector) {
+  public static Vectors of(String name, Float[][] vector) {
     return new Vectors(name, vector);
   }
 
-  public static Vectors of(String name, Float[][] vector) {
-    return new Vectors(name, vector);
+  public static Vectors of(Function<Builder, ObjectBuilder<Vectors>> fn) {
+    return fn.apply(new Builder()).build();
   }
 
-  public static Vectors of(Map<String, ? extends Object> vectors) {
-    return new Vectors(vectors, null);
+  public Vectors(Builder builder) {
+    this.namedVectors = builder.namedVectors;
   }
 
-  public static Vectors of(Function<Builder, ObjectBuilder<Vectors>> fn) {
-    return fn.apply(new Builder()).build();
+  /*
+   * Create a single named vector.
+   * Intended to be used by factory methods, which can statically restrict
+   * vector's type to {@code Float[]} and {@code Float[][]}.
+   *
+   * @param name Vector name.
+   *
+   * @param vector {@code Float[]} or {@code Float[][]} vector.
+   *
+   */
+  private Vectors(String name, Object vector) {
+    this.namedVectors = Collections.singletonMap(name, vector);
+  }
+
+  private Vectors(Map<String, Object> namedVectors) {
+    this.namedVectors = namedVectors;
   }
 
-  public static class Builder {
-    private Map<String, Object> namedVectors = new HashMap<>();
+  public static class Builder implements ObjectBuilder<Vectors> {
+    private final Map<String, Object> namedVectors = new HashMap<>();
 
     public Builder vector(String name, Float[] vector) {
       this.namedVectors.put(name, vector);
@@ -66,8 +82,9 @@ public Builder vector(String name, Float[][] vector) {
       return this;
     }
 
+    @Override
     public Vectors build() {
-      return new Vectors(this.namedVectors, null);
+      return new Vectors(this);
     }
   }
 
@@ -76,12 +93,7 @@ public Float[] getSingle(String name) {
   }
 
   public Float[] getDefaultSingle() {
-    return getSingle(DEFAULT);
-  }
-
-  @SuppressWarnings("unchecked")
-  public Optional<Float[]> getSingle() {
-    return (Optional<Float[]>) getOnly();
+    return getSingle(VectorIndex.DEFAULT_VECTOR_NAME);
   }
 
   public Float[][] getMulti(String name) {
@@ -89,43 +101,51 @@ public Float[][] getMulti(String name) {
   }
 
   public Float[][] getDefaultMulti() {
-    return getMulti(DEFAULT);
-  }
-
-  @SuppressWarnings("unchecked")
-  public Optional<Float[][]> getMulti() {
-    return (Optional<Float[][]>) getOnly();
-  }
-
-  public Optional<Float[]> getUnnamed() {
-    return Optional.ofNullable(unnamedVector);
-  }
-
-  private Optional<?> getOnly() {
-    if (namedVectors == null || namedVectors.isEmpty() || namedVectors.size() > 1) {
-      return Optional.empty();
+    return getMulti(VectorIndex.DEFAULT_VECTOR_NAME);
+  }
+
+  public static enum CustomTypeAdapterFactory implements TypeAdapterFactory {
+    INSTANCE;
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+      if (type.getRawType() != Vectors.class) {
+        return null;
+      }
+      final var mapAdapter = gson.getDelegateAdapter(this, new TypeToken<Map<String, Object>>() {
+      });
+      final var float_1d = gson.getDelegateAdapter(this, TypeToken.get(Float[].class));
+      final var float_2d = gson.getDelegateAdapter(this, TypeToken.get(Float[][].class));
+      return (TypeAdapter<T>) new TypeAdapter<Vectors>() {
+
+        @Override
+        public void write(JsonWriter out, Vectors value) throws IOException {
+          mapAdapter.write(out, value.namedVectors);
+        }
+
+        @Override
+        public Vectors read(JsonReader in) throws IOException {
+          var vectorsMap = JsonParser.parseReader(in).getAsJsonObject().asMap();
+          var namedVectors = new HashMap<String, Object>();
+
+          for (var entry : vectorsMap.entrySet()) {
+            String vectorName = entry.getKey();
+            JsonElement el = entry.getValue();
+            if (el.isJsonArray()) {
+              JsonArray array = el.getAsJsonArray();
+              Object vector;
+              if (array.size() > 0 && array.get(0).isJsonArray()) {
+                vector = float_2d.fromJsonTree(array);
+              } else {
+                vector = float_1d.fromJsonTree(array);
+              }
+              namedVectors.put(vectorName, vector);
+            }
+          }
+          return new Vectors(namedVectors);
+        }
+      }.nullSafe();
     }
-    return Optional.ofNullable(namedVectors.values().iterator().next());
-  }
-
-  public Map<String, Object> getNamed() {
-    return Map.copyOf(namedVectors);
-  }
-
-  private Vectors(Map<String, ? extends Object> named) {
-    this(named, null);
-  }
-
-  private Vectors(Float[] unnamed) {
-    this(Collections.emptyMap(), unnamed);
-  }
-
-  private Vectors(String name, Object vector) {
-    this(Collections.singletonMap(name, vector));
-  }
-
-  private Vectors(Map<String, ? extends Object> named, Float[] unnamed) {
-    this.namedVectors = Map.copyOf(named);
-    this.unnamedVector = unnamed;
   }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollection.java b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollection.java
new file mode 100644
index 000000000..6dc8fa306
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollection.java
@@ -0,0 +1,167 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonParser;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.annotations.SerializedName;
+import com.google.gson.internal.Streams;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record WeaviateCollection(
+    @SerializedName("class") String name,
+    @SerializedName("description") String description,
+    @SerializedName("properties") List<Property> properties,
+    List<ReferenceProperty> references,
+    @SerializedName("vectorConfig") Map<String, VectorIndex> vectors) {
+
+  public static WeaviateCollection of(String collectionName) {
+    return of(collectionName, ObjectBuilder.identity());
+  }
+
+  public static WeaviateCollection of(String collectionName, Function<Builder, ObjectBuilder<WeaviateCollection>> fn) {
+    return fn.apply(new Builder(collectionName)).build();
+  }
+
+  public WeaviateCollection(Builder builder) {
+    this(
+        builder.collectionName,
+        builder.description,
+        builder.properties,
+        builder.references,
+        builder.vectors);
+  }
+
+  public static class Builder implements ObjectBuilder<WeaviateCollection> {
+    // Required parameters;
+    private final String collectionName;
+
+    private String description;
+    private List<Property> properties = new ArrayList<>();
+    private List<ReferenceProperty> references = new ArrayList<>();
+    private Map<String, VectorIndex> vectors = new HashMap<>();
+
+    public Builder(String collectionName) {
+      this.collectionName = collectionName;
+    }
+
+    public Builder description(String description) {
+      this.description = description;
+      return this;
+    }
+
+    public Builder properties(Property... properties) {
+      return properties(Arrays.asList(properties));
+    }
+
+    public Builder properties(List<Property> properties) {
+      this.properties = properties;
+      return this;
+    }
+
+    public Builder references(ReferenceProperty... references) {
+      return references(Arrays.asList(references));
+    }
+
+    public Builder references(List<ReferenceProperty> references) {
+      this.references = references;
+      return this;
+    }
+
+    public Builder vector(VectorIndex vector) {
+      this.vectors.put(VectorIndex.DEFAULT_VECTOR_NAME, vector);
+      return this;
+    }
+
+    public Builder vector(String name, VectorIndex vector) {
+      this.vectors.put(name, vector);
+      return this;
+    }
+
+    public Builder vectors(Function<VectorsBuilder, ObjectBuilder<Map<String, VectorIndex>>> fn) {
+      this.vectors = fn.apply(new VectorsBuilder()).build();
+      return this;
+    }
+
+    public static class VectorsBuilder implements ObjectBuilder<Map<String, VectorIndex>> {
+      private Map<String, VectorIndex> vectors = new HashMap<>();
+
+      public VectorsBuilder vector(String name, VectorIndex vector) {
+        vectors.put(name, vector);
+        return this;
+      }
+
+      @Override
+      public Map<String, VectorIndex> build() {
+        return this.vectors;
+      }
+    }
+
+    @Override
+    public WeaviateCollection build() {
+      return new WeaviateCollection(this);
+    }
+  }
+
+  public static enum CustomTypeAdapterFactory implements TypeAdapterFactory {
+    INSTANCE;
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+      if (type.getRawType() != WeaviateCollection.class) {
+        return null;
+      }
+
+      final var delegate = gson.getDelegateAdapter(this, (TypeToken<WeaviateCollection>) type);
+      return (TypeAdapter<T>) new TypeAdapter<WeaviateCollection>() {
+
+        @Override
+        public void write(JsonWriter out, WeaviateCollection value) throws IOException {
+          var jsonObject = delegate.toJsonTree(value).getAsJsonObject();
+
+          var references = jsonObject.remove("references").getAsJsonArray();
+          var properties = jsonObject.get("properties").getAsJsonArray();
+          properties.addAll(references);
+
+          Streams.write(jsonObject, out);
+        }
+
+        @Override
+        public WeaviateCollection read(JsonReader in) throws IOException {
+          var jsonObject = JsonParser.parseReader(in).getAsJsonObject();
+
+          var mixedProperties = jsonObject.get("properties").getAsJsonArray();
+          var references = new JsonArray();
+          var properties = new JsonArray();
+
+          for (var property : mixedProperties) {
+            var dataTypes = property.getAsJsonObject().get("dataType").getAsJsonArray();
+            if (dataTypes.size() == 1 && DataType.KNOWN_TYPES.contains(dataTypes.get(0).getAsString())) {
+              properties.add(property);
+            } else {
+              references.add(property);
+            }
+          }
+
+          jsonObject.add("properties", properties);
+          jsonObject.add("references", references);
+          return delegate.fromJsonTree(jsonObject);
+        }
+      }.nullSafe();
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClient.java
new file mode 100644
index 000000000..0937572bf
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClient.java
@@ -0,0 +1,47 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.Function;
+
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateCollectionsClient {
+  private final RestTransport restTransport;
+  private final GrpcTransport grpcTransport;
+
+  public WeaviateCollectionsClient(RestTransport restTransport, GrpcTransport grpcTransport) {
+    this.restTransport = restTransport;
+    this.grpcTransport = grpcTransport;
+  }
+
+  public CollectionHandle<Map<String, Object>> use(String collectionName) {
+    return new CollectionHandle<>(restTransport, grpcTransport, CollectionDescriptor.ofMap(collectionName));
+  }
+
+  public WeaviateCollection create(String name) throws IOException {
+    return create(WeaviateCollection.of(name));
+  }
+
+  public WeaviateCollection create(String name,
+      Function<WeaviateCollection.Builder, ObjectBuilder<WeaviateCollection>> fn) throws IOException {
+    return create(WeaviateCollection.of(name, fn));
+  }
+
+  public WeaviateCollection create(WeaviateCollection collection) throws IOException {
+    return this.restTransport.performRequest(new CreateCollectionRequest(collection),
+        CreateCollectionRequest._ENDPOINT);
+  }
+
+  public Optional<WeaviateCollection> getConfig(String name) throws IOException {
+    return this.restTransport.performRequest(new GetConfigRequest(name), GetConfigRequest._ENDPOINT);
+  }
+
+  public void delete(String name) throws IOException {
+    this.restTransport.performRequest(new DeleteCollectionRequest(name), DeleteCollectionRequest._ENDPOINT);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClientAsync.java b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClientAsync.java
new file mode 100644
index 000000000..14f900484
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateCollectionsClientAsync.java
@@ -0,0 +1,48 @@
+package io.weaviate.client6.v1.api.collections;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Function;
+
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateCollectionsClientAsync {
+  private final RestTransport restTransport;
+  private final GrpcTransport grpcTransport;
+
+  public WeaviateCollectionsClientAsync(RestTransport restTransport, GrpcTransport grpcTransport) {
+    this.restTransport = restTransport;
+    this.grpcTransport = grpcTransport;
+  }
+
+  public CollectionHandle<Map<String, Object>> use(String collectionName) {
+    return new CollectionHandle<>(restTransport, grpcTransport,
+        CollectionDescriptor.ofMap(collectionName));
+  }
+
+  public CompletableFuture<WeaviateCollection> create(String name) {
+    return create(WeaviateCollection.of(name));
+  }
+
+  public CompletableFuture<WeaviateCollection> create(String name,
+      Function<WeaviateCollection.Builder, ObjectBuilder<WeaviateCollection>> fn) {
+    return create(WeaviateCollection.of(name, fn));
+  }
+
+  public CompletableFuture<WeaviateCollection> create(WeaviateCollection collection) {
+    return this.restTransport.performRequestAsync(new CreateCollectionRequest(collection),
+        CreateCollectionRequest._ENDPOINT);
+  }
+
+  public CompletableFuture<Optional<WeaviateCollection>> getConfig(String name) {
+    return this.restTransport.performRequestAsync(new GetConfigRequest(name), GetConfigRequest._ENDPOINT);
+  }
+
+  public CompletableFuture<Void> delete(String name) {
+    return this.restTransport.performRequestAsync(new DeleteCollectionRequest(name), DeleteCollectionRequest._ENDPOINT);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateMetadata.java b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateMetadata.java
new file mode 100644
index 000000000..9121e33c3
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateMetadata.java
@@ -0,0 +1,7 @@
+package io.weaviate.client6.v1.api.collections;
+
+public interface WeaviateMetadata {
+  String uuid();
+
+  Vectors vectors();
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateObject.java b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateObject.java
index 7c58e7cc9..84367b67e 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateObject.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/WeaviateObject.java
@@ -1,10 +1,177 @@
 package io.weaviate.client6.v1.api.collections;
 
+import java.io.IOException;
+import java.lang.reflect.ParameterizedType;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
-public record WeaviateObject<T, M>(
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.internal.Streams;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record WeaviateObject<P, R, M extends WeaviateMetadata>(
     String collection,
-    T properties,
-    Map<String, ObjectReference> references,
+    P properties,
+    Map<String, List<R>> references,
     M metadata) {
+
+  public WeaviateObject(Builder<P, R, M> builder) {
+    this(builder.collection, builder.properties, builder.references, builder.metadata);
+  }
+
+  public static class Builder<P, R, M extends WeaviateMetadata> implements ObjectBuilder<WeaviateObject<P, R, M>> {
+    private String collection;
+    private P properties;
+    private Map<String, List<R>> references = new HashMap<>();
+    private M metadata;
+
+    public final Builder<P, R, M> collection(String collection) {
+      this.collection = collection;
+      return this;
+    }
+
+    public final Builder<P, R, M> properties(P properties) {
+      this.properties = properties;
+      return this;
+    }
+
+    /**
+     * Add a reference. Calls to {@link #reference} can be chained
+     * to add multiple references.
+     */
+    @SafeVarargs
+    public final Builder<P, R, M> reference(String property, R... references) {
+      for (var ref : references) {
+        addReference(property, ref);
+      }
+      return this;
+    }
+
+    private final void addReference(String property, R reference) {
+      if (!references.containsKey(property)) {
+        references.put(property, new ArrayList<>());
+      }
+      references.get(property).add(reference);
+    }
+
+    public Builder<P, R, M> references(Map<String, List<R>> references) {
+      this.references = references;
+      return this;
+    }
+
+    public Builder<P, R, M> metadata(M metadata) {
+      this.metadata = metadata;
+      return this;
+    }
+
+    @Override
+    public WeaviateObject<P, R, M> build() {
+      return new WeaviateObject<>(this);
+    }
+  }
+
+  public static enum CustomTypeAdapterFactory implements TypeAdapterFactory {
+    INSTANCE;
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
+      var type = typeToken.getType();
+      var rawType = typeToken.getRawType();
+      if (rawType != WeaviateObject.class ||
+          !(type instanceof ParameterizedType parameterized)
+          || parameterized.getActualTypeArguments().length < 3) {
+        return null;
+      }
+
+      var typeParams = parameterized.getActualTypeArguments();
+      final var propertiesType = typeParams[0];
+      final var referencesType = typeParams[1];
+      final var metadataType = typeParams[2];
+
+      final var propertiesAdapter = gson.getAdapter(TypeToken.get(propertiesType));
+      final var metadataAdapter = gson.getAdapter(TypeToken.get(metadataType));
+      final var referencesAdapter = gson.getAdapter(TypeToken.get(referencesType));
+
+      return (TypeAdapter<T>) new TypeAdapter<WeaviateObject<?, ?, ?>>() {
+
+        @Override
+        public void write(JsonWriter out, WeaviateObject<?, ?, ?> value) throws IOException {
+          out.beginObject();
+
+          out.name("class");
+          out.value(value.collection());
+
+          out.name("properties");
+          if (value.references().isEmpty()) {
+            ((TypeAdapter<Object>) propertiesAdapter).write(out, value.properties());
+          } else {
+            var properties = ((TypeAdapter<Object>) propertiesAdapter).toJsonTree(value.properties()).getAsJsonObject();
+            for (var refEntry : value.references().entrySet()) {
+              var beacons = new JsonArray();
+              for (var reference : (List<Object>) refEntry.getValue()) {
+                var beacon = ((TypeAdapter<Object>) referencesAdapter).toJsonTree(reference);
+                beacons.add(beacon);
+              }
+              properties.add(refEntry.getKey(), beacons);
+            }
+            Streams.write(properties, out);
+          }
+
+          // Flatten out metadata fields.
+          var metadata = ((TypeAdapter<Object>) metadataAdapter).toJsonTree(value.metadata);
+          for (var entry : metadata.getAsJsonObject().entrySet()) {
+            out.name(entry.getKey());
+            Streams.write(entry.getValue(), out);
+          }
+          out.endObject();
+        }
+
+        @Override
+        public WeaviateObject<?, ?, ?> read(JsonReader in) throws IOException {
+          var builder = new WeaviateObject.Builder<>();
+          var metadata = new ObjectMetadata.Builder();
+
+          var object = JsonParser.parseReader(in).getAsJsonObject();
+          builder.collection(object.get("class").getAsString());
+
+          var jsonProperties = object.get("properties").getAsJsonObject();
+          var trueProperties = new JsonObject();
+          for (var property : jsonProperties.entrySet()) {
+            var value = property.getValue();
+            if (!value.isJsonArray()) {
+              trueProperties.add(property.getKey(), value);
+              continue;
+            }
+            var array = value.getAsJsonArray();
+            var first = array.get(0);
+            if (first.isJsonObject() && first.getAsJsonObject().has("beacon")) {
+              for (var el : array) {
+                var beacon = ((TypeAdapter<Object>) referencesAdapter).fromJsonTree(el);
+                builder.reference(property.getKey(), beacon);
+              }
+            }
+          }
+
+          builder.properties(propertiesAdapter.fromJsonTree(trueProperties));
+
+          metadata.id(object.get("id").getAsString());
+          builder.metadata(metadata.build());
+
+          return builder.build();
+        }
+      };
+    }
+  }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/AbstractAggregateClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/AbstractAggregateClient.java
index dff37670e..c63c9ff9f 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/AbstractAggregateClient.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/AbstractAggregateClient.java
@@ -10,7 +10,7 @@
 import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
 import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
 
-public abstract class AbstractAggregateClient<ResponseT, GroupedResponseT> {
+abstract class AbstractAggregateClient<ResponseT, GroupedResponseT> {
   protected final CollectionDescriptor<?> collection;
   protected final GrpcTransport transport;
 
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/Aggregation.java b/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/Aggregation.java
index a95a359ea..1cea32828 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/Aggregation.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/aggregate/Aggregation.java
@@ -1,5 +1,6 @@
 package io.weaviate.client6.v1.api.collections.aggregate;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
@@ -36,7 +37,7 @@ public Builder(ObjectFilter objectFilter) {
       this.objectFilter = objectFilter;
     }
 
-    private List<PropertyAggregation> metrics;
+    private List<PropertyAggregation> metrics = new ArrayList<>();
     private Integer objectLimit;
     private boolean includeTotalCount = false;
 
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/config/AddPropertyRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/config/AddPropertyRequest.java
new file mode 100644
index 000000000..ec670a13c
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/config/AddPropertyRequest.java
@@ -0,0 +1,19 @@
+package io.weaviate.client6.v1.api.collections.config;
+
+import java.util.Collections;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.internal.json.JSON;
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record AddPropertyRequest(String collectionName, Property property) {
+  public static final Endpoint<AddPropertyRequest, Void> _ENDPOINT = Endpoint.of(
+      request -> "POST",
+      request -> "/schema/" + request.collectionName + "/properties",
+      (gson, request) -> JSON.serialize(request.property),
+      request -> Collections.emptyMap(),
+      code -> code != HttpStatus.SC_SUCCESS,
+      (gson, response) -> null);
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClient.java
new file mode 100644
index 000000000..0fa3cb860
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClient.java
@@ -0,0 +1,38 @@
+package io.weaviate.client6.v1.api.collections.config;
+
+import java.io.IOException;
+import java.util.Optional;
+
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.api.collections.WeaviateCollection;
+import io.weaviate.client6.v1.api.collections.WeaviateCollectionsClient;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateConfigClient {
+  private final RestTransport transport;
+  private final WeaviateCollectionsClient collectionsClient;
+
+  protected final CollectionDescriptor<?> collection;
+
+  public WeaviateConfigClient(CollectionDescriptor<?> collection, RestTransport restTransport,
+      GrpcTransport grpcTransport) {
+    this.transport = restTransport;
+    this.collectionsClient = new WeaviateCollectionsClient(restTransport, grpcTransport);
+
+    this.collection = collection;
+  }
+
+  public Optional<WeaviateCollection> get() throws IOException {
+    return collectionsClient.getConfig(collection.name());
+  }
+
+  public void addProperty(Property property) throws IOException {
+    this.transport.performRequest(new AddPropertyRequest(collection.name(), property), AddPropertyRequest._ENDPOINT);
+  }
+
+  public void addReference(String name, String... dataTypes) throws IOException {
+    this.addProperty(Property.reference(name, dataTypes).toProperty());
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClientAsync.java b/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClientAsync.java
new file mode 100644
index 000000000..54e586a2b
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/config/WeaviateConfigClientAsync.java
@@ -0,0 +1,40 @@
+package io.weaviate.client6.v1.api.collections.config;
+
+import java.io.IOException;
+import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
+
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.api.collections.WeaviateCollection;
+import io.weaviate.client6.v1.api.collections.WeaviateCollectionsClientAsync;
+import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateConfigClientAsync {
+  private final RestTransport transport;
+  private final WeaviateCollectionsClientAsync collectionsClient;
+
+  protected final CollectionDescriptor<?> collection;
+
+  public WeaviateConfigClientAsync(CollectionDescriptor<?> collection, RestTransport restTransport,
+      GrpcTransport grpcTransport) {
+    this.transport = restTransport;
+    this.collectionsClient = new WeaviateCollectionsClientAsync(restTransport, grpcTransport);
+
+    this.collection = collection;
+  }
+
+  public CompletableFuture<Optional<WeaviateCollection>> get() throws IOException {
+    return collectionsClient.getConfig(collection.name());
+  }
+
+  public CompletableFuture<Void> addProperty(Property property) throws IOException {
+    return this.transport.performRequestAsync(new AddPropertyRequest(collection.name(), property),
+        AddPropertyRequest._ENDPOINT);
+  }
+
+  public CompletableFuture<Void> addReference(String name, String... dataTypes) throws IOException {
+    return this.addProperty(Property.reference(name, dataTypes).toProperty());
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/DeleteObjectRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/DeleteObjectRequest.java
new file mode 100644
index 000000000..a425fc2a8
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/DeleteObjectRequest.java
@@ -0,0 +1,18 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import java.util.Collections;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record DeleteObjectRequest(String collectionName, String uuid) {
+
+  public static final Endpoint<DeleteObjectRequest, Void> _ENDPOINT = Endpoint.of(
+      request -> "DELETE",
+      request -> "/objects/" + request.collectionName + "/" + request.uuid,
+      (gson, request) -> null,
+      request -> Collections.emptyMap(),
+      code -> code != HttpStatus.SC_NO_CONTENT,
+      (gson, response) -> null);
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectRequest.java
new file mode 100644
index 000000000..6654c9c8d
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectRequest.java
@@ -0,0 +1,77 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import java.util.Collections;
+import java.util.function.Function;
+
+import org.apache.hc.core5.http.HttpStatus;
+
+import com.google.gson.reflect.TypeToken;
+
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
+import io.weaviate.client6.v1.api.collections.Vectors;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.json.JSON;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.Endpoint;
+
+public record InsertObjectRequest<T>(WeaviateObject<T, Reference, ObjectMetadata> object) {
+
+  @SuppressWarnings("unchecked")
+  public static final <T> Endpoint<InsertObjectRequest<T>, WeaviateObject<T, Object, ObjectMetadata>> endpoint(
+      CollectionDescriptor<T> descriptor) {
+    return Endpoint.of(
+        request -> "POST",
+        request -> "/objects/",
+        (gson, request) -> JSON.serialize(request.object, TypeToken.getParameterized(
+            WeaviateObject.class, descriptor.typeToken().getType(), Reference.class, ObjectMetadata.class)),
+        request -> Collections.emptyMap(),
+        code -> code != HttpStatus.SC_SUCCESS,
+        (gson, response) -> JSON.deserialize(response,
+            (TypeToken<WeaviateObject<T, Object, ObjectMetadata>>) TypeToken.getParameterized(
+                WeaviateObject.class, descriptor.typeToken().getType(), Object.class, ObjectMetadata.class)));
+  }
+
+  public static <T> InsertObjectRequest<T> of(String collectionName, T properties) {
+    return of(collectionName, properties, ObjectBuilder.identity());
+  }
+
+  public static <T> InsertObjectRequest<T> of(String collectionName, T properties,
+      Function<Builder<T>, ObjectBuilder<InsertObjectRequest<T>>> fn) {
+    return fn.apply(new Builder<T>(collectionName, properties)).build();
+  }
+
+  public InsertObjectRequest(Builder<T> builder) {
+    this(builder.object.build());
+  }
+
+  public static class Builder<T> implements ObjectBuilder<InsertObjectRequest<T>> {
+    private final WeaviateObject.Builder<T, Reference, ObjectMetadata> object = new WeaviateObject.Builder<>();
+    private final ObjectMetadata.Builder metadata = new ObjectMetadata.Builder();
+
+    public Builder(String collectionName, T properties) {
+      this.object.collection(collectionName).properties(properties);
+    }
+
+    public Builder<T> uuid(String uuid) {
+      this.metadata.id(uuid);
+      return this;
+    }
+
+    public Builder<T> vectors(Vectors vectors) {
+      this.metadata.vectors(vectors);
+      return this;
+    }
+
+    public Builder<T> reference(String property, Reference... references) {
+      this.object.reference(property, references);
+      return this;
+    }
+
+    @Override
+    public InsertObjectRequest<T> build() {
+      this.object.metadata(this.metadata.build());
+      return new InsertObjectRequest<>(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectResponse.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectResponse.java
new file mode 100644
index 000000000..c3eb95f2f
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/InsertObjectResponse.java
@@ -0,0 +1,14 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.Vectors;
+
+public record InsertObjectResponse<T>(
+    @SerializedName("class") String collectionName,
+    @SerializedName("properties") T properties,
+    @SerializedName("id") String uuid,
+    @SerializedName("vectors") Vectors vectors,
+    @SerializedName("creationTimeUnix") Long createdAt,
+    @SerializedName("lastUpdateTimeUnix") Long lastUpdatedAt) {
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/Reference.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/Reference.java
new file mode 100644
index 000000000..5cf0c6b68
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/Reference.java
@@ -0,0 +1,84 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+import com.google.gson.TypeAdapter;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+
+public record Reference(String collection, List<String> uuids) {
+
+  public Reference(String collection, String uuid) {
+    this(collection, List.of(uuid));
+  }
+
+  /**
+   * Create reference to objects by their UUIDs.
+   * <p>
+   * Weaviate will search each of the existing collections to identify
+   * the objects before inserting the references, so this may include
+   * some performance overhead.
+   */
+  public static Reference uuids(String... uuids) {
+    return new Reference(null, Arrays.asList(uuids));
+  }
+
+  /** Create references to {@link WeaviateObject}. */
+  public static Reference[] objects(WeaviateObject<?, ?, ?>... objects) {
+    return Arrays.stream(objects)
+        .map(o -> new Reference(o.collection(), o.metadata().uuid()))
+        .toArray(Reference[]::new);
+  }
+
+  /** Create references to objects in a collection by their UUIDs. */
+  public static Reference collection(String collection, String... uuids) {
+    return new Reference(collection, Arrays.asList(uuids));
+  }
+
+  public static final TypeAdapter<Reference> TYPE_ADAPTER = new TypeAdapter<Reference>() {
+
+    @Override
+    public void write(JsonWriter out, Reference value) throws IOException {
+      for (var uuid : value.uuids()) {
+        out.beginObject();
+        out.name("beacon");
+
+        var beacon = "weaviate://localhost";
+        if (value.collection() != null) {
+          beacon += "/" + value.collection();
+        }
+        beacon += "/" + uuid;
+
+        out.value(beacon);
+        out.endObject();
+      }
+    }
+
+    @Override
+    public Reference read(JsonReader in) throws IOException {
+      String collection = null;
+      String id = null;
+
+      in.beginObject();
+      in.nextName(); // expect "beacon"?
+      var beacon = in.nextString();
+      in.endObject();
+
+      beacon = beacon.replaceFirst("weaviate://localhost/", "");
+      if (beacon.contains("/")) {
+        var parts = beacon.split("/");
+        collection = parts[0];
+        id = parts[1];
+      } else {
+        id = beacon;
+      }
+
+      return new Reference(collection, id);
+    }
+
+  }.nullSafe();
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClient.java
new file mode 100644
index 000000000..b4466b72d
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClient.java
@@ -0,0 +1,39 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import java.io.IOException;
+import java.util.function.Function;
+
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateDataClient<T> {
+  private final RestTransport restTransport;
+  private final CollectionDescriptor<T> collectionDescriptor;
+
+  public WeaviateDataClient(CollectionDescriptor<T> collectionDescriptor, RestTransport restTransport) {
+    this.restTransport = restTransport;
+    this.collectionDescriptor = collectionDescriptor;
+  }
+
+  public WeaviateObject<T, Object, ObjectMetadata> insert(T properties) throws IOException {
+    return insert(InsertObjectRequest.of(collectionDescriptor.name(), properties));
+  }
+
+  public WeaviateObject<T, Object, ObjectMetadata> insert(T properties,
+      Function<InsertObjectRequest.Builder<T>, ObjectBuilder<InsertObjectRequest<T>>> fn)
+      throws IOException {
+    return insert(InsertObjectRequest.of(collectionDescriptor.name(), properties, fn));
+  }
+
+  public WeaviateObject<T, Object, ObjectMetadata> insert(InsertObjectRequest<T> request) throws IOException {
+    return this.restTransport.performRequest(request, InsertObjectRequest.endpoint(collectionDescriptor));
+  }
+
+  public void delete(String uuid) throws IOException {
+    this.restTransport.performRequest(new DeleteObjectRequest(collectionDescriptor.name(), uuid),
+        DeleteObjectRequest._ENDPOINT);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClientAsync.java b/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClientAsync.java
new file mode 100644
index 000000000..e0ac5ed74
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/data/WeaviateDataClientAsync.java
@@ -0,0 +1,41 @@
+package io.weaviate.client6.v1.api.collections.data;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Function;
+
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
+import io.weaviate.client6.v1.internal.rest.RestTransport;
+
+public class WeaviateDataClientAsync<T> {
+  private final RestTransport restTransport;
+  private final CollectionDescriptor<T> collectionDescriptor;
+
+  public WeaviateDataClientAsync(CollectionDescriptor<T> collectionDescriptor, RestTransport restTransport) {
+    this.restTransport = restTransport;
+    this.collectionDescriptor = collectionDescriptor;
+  }
+
+  public CompletableFuture<WeaviateObject<T, Object, ObjectMetadata>> insert(T properties) throws IOException {
+    return insert(InsertObjectRequest.of(collectionDescriptor.name(), properties));
+  }
+
+  public CompletableFuture<WeaviateObject<T, Object, ObjectMetadata>> insert(T properties,
+      Function<InsertObjectRequest.Builder<T>, ObjectBuilder<InsertObjectRequest<T>>> fn)
+      throws IOException {
+    return insert(InsertObjectRequest.of(collectionDescriptor.name(), properties, fn));
+  }
+
+  public CompletableFuture<WeaviateObject<T, Object, ObjectMetadata>> insert(InsertObjectRequest<T> request)
+      throws IOException {
+    return this.restTransport.performRequestAsync(request, InsertObjectRequest.endpoint(collectionDescriptor));
+  }
+
+  public CompletableFuture<Void> delete(String uuid) {
+    return this.restTransport.performRequestAsync(new DeleteObjectRequest(collectionDescriptor.name(), uuid),
+        DeleteObjectRequest._ENDPOINT);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/AbstractQueryClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/AbstractQueryClient.java
index 38a78ea5f..abdca72a3 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/AbstractQueryClient.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/AbstractQueryClient.java
@@ -8,7 +8,7 @@
 import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
 import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
 
-public abstract class AbstractQueryClient<PropertiesT, SingleT, ResponseT, GroupedResponseT> {
+abstract class AbstractQueryClient<PropertiesT, SingleT, ResponseT, GroupedResponseT> {
   protected final CollectionDescriptor<PropertiesT> collection;
   protected final GrpcTransport transport;
 
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/NearVector.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/NearVector.java
index d77cb4fe8..0a3b27c2a 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/NearVector.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/NearVector.java
@@ -2,9 +2,9 @@
 
 import java.util.function.Function;
 
-import io.weaviate.client6.internal.GRPC;
 import io.weaviate.client6.v1.api.collections.aggregate.ObjectFilter;
 import io.weaviate.client6.v1.internal.ObjectBuilder;
+import io.weaviate.client6.v1.internal.grpc.GRPC;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoAggregate;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBaseSearch;
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryMetadata.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryMetadata.java
index 54980688e..59cdee22a 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryMetadata.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryMetadata.java
@@ -1,9 +1,10 @@
 package io.weaviate.client6.v1.api.collections.query;
 
 import io.weaviate.client6.v1.api.collections.Vectors;
+import io.weaviate.client6.v1.api.collections.WeaviateMetadata;
 import io.weaviate.client6.v1.internal.ObjectBuilder;
 
-public record QueryMetadata(String id, Float distance, Float certainty, Vectors vectors) {
+public record QueryMetadata(String uuid, Float distance, Float certainty, Vectors vectors) implements WeaviateMetadata {
 
   private QueryMetadata(Builder builder) {
     this(builder.uuid, builder.distance, builder.certainty, builder.vectors);
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryObjectGrouped.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryObjectGrouped.java
index 9fdaed176..1000d6321 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryObjectGrouped.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryObjectGrouped.java
@@ -7,7 +7,8 @@ public record QueryObjectGrouped<T>(
     QueryMetadata metadata,
     String belongsToGroup) {
 
-  QueryObjectGrouped(WeaviateObject<T, QueryMetadata> object, String belongsToGroup) {
+  QueryObjectGrouped(WeaviateObject<T, Object, QueryMetadata> object,
+      String belongsToGroup) {
     this(object.properties(), object.metadata(), belongsToGroup);
   }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryReference.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryReference.java
index e3c3a3537..fdc8a1c01 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryReference.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryReference.java
@@ -3,7 +3,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.function.Consumer;
 import java.util.function.Function;
 
 import io.weaviate.client6.v1.internal.ObjectBuilder;
@@ -47,14 +46,6 @@ public static QueryReference multi(String property, String collection,
     return fn.apply(new Builder(collection, property)).build();
   }
 
-  public static QueryReference[] multi(String property, Consumer<Builder> fn, String... collections) {
-    return Arrays.stream(collections).map(collection -> {
-      var builder = new Builder(collection, property);
-      fn.accept(builder);
-      return new QueryReference(builder);
-    }).toArray(QueryReference[]::new);
-  }
-
   public static class Builder implements ObjectBuilder<QueryReference> {
     private final String property;
     private final String collection;
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryRequest.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryRequest.java
index 4b9dd3ea8..33c271cf5 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryRequest.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryRequest.java
@@ -9,10 +9,10 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import io.weaviate.client6.internal.GRPC;
-import io.weaviate.client6.v1.api.collections.ObjectReference;
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
 import io.weaviate.client6.v1.api.collections.Vectors;
 import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.internal.grpc.GRPC;
 import io.weaviate.client6.v1.internal.grpc.Rpc;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateGrpc.WeaviateBlockingStub;
 import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateGrpc.WeaviateFutureStub;
@@ -39,11 +39,11 @@ static <T> Rpc<QueryRequest, WeaviateProtoSearchGet.SearchRequest, QueryResponse
           return message.build();
         },
         reply -> {
-          List<WeaviateObject<T, QueryMetadata>> objects = reply.getResultsList().stream()
+          var objects = reply
+              .getResultsList()
+              .stream()
               .map(obj -> QueryRequest.unmarshalResultObject(
-                  obj.getProperties(),
-                  obj.getMetadata(),
-                  collection))
+                  obj.getProperties(), obj.getMetadata(), collection))
               .toList();
           return new QueryResponse<>(objects);
         },
@@ -82,7 +82,20 @@ static <T> Rpc<QueryRequest, WeaviateProtoSearchGet.SearchRequest, QueryResponse
         }, () -> rpc.method(), () -> rpc.methodAsync());
   }
 
-  private static <T> WeaviateObject<T, QueryMetadata> unmarshalResultObject(
+  private static <T> WeaviateObject<T, Object, QueryMetadata> unmarshalResultObject(
+      WeaviateProtoSearchGet.PropertiesResult propertiesResult,
+      WeaviateProtoSearchGet.MetadataResult metadataResult,
+      CollectionDescriptor<T> descriptor) {
+    var res = unmarshalReferences(propertiesResult, metadataResult, descriptor);
+    var metadata = new QueryMetadata.Builder()
+        .id(res.metadata().uuid())
+        .distance(metadataResult.getDistance())
+        .certainty(metadataResult.getCertainty())
+        .vectors(res.metadata().vectors());
+    return new WeaviateObject<>(descriptor.name(), res.properties(), res.references(), metadata.build());
+  }
+
+  private static <T> WeaviateObject<T, Object, ObjectMetadata> unmarshalReferences(
       WeaviateProtoSearchGet.PropertiesResult propertiesResult,
       WeaviateProtoSearchGet.MetadataResult metadataResult,
       CollectionDescriptor<T> descriptor) {
@@ -97,22 +110,31 @@ private static <T> WeaviateObject<T, QueryMetadata> unmarshalResultObject(
     // I.e. { "ref": A-1 } , { "ref": B-1 } => { "ref": [A-1, B-1] }
     var referenceProperties = propertiesResult.getRefPropsList()
         .stream().reduce(
-            new HashMap<String, ObjectReference>(),
+            new HashMap<String, List<Object>>(),
             (map, ref) -> {
               var refObjects = ref.getPropertiesList().stream()
-                  .map(property -> unmarshalResultObject(property, property.getMetadata(), descriptor))
+                  .map(property -> {
+                    var reference = unmarshalReferences(
+                        property, property.getMetadata(),
+                        // TODO: this should be possible to configure for ODM?
+                        CollectionDescriptor.ofMap(property.getTargetCollection()));
+                    return (Object) new WeaviateObject<>(
+                        reference.collection(),
+                        (Object) reference.properties(),
+                        reference.references(),
+                        reference.metadata());
+                  })
                   .toList();
 
               // Merge ObjectReferences by joining the underlying WeaviateObjects.
               map.merge(
                   ref.getPropName(),
-                  // TODO: check if this works
-                  new ObjectReference((List<WeaviateObject<T, QueryMetadata>>) refObjects),
+                  refObjects,
                   (left, right) -> {
                     var joined = Stream.concat(
-                        left.objects().stream(),
-                        right.objects().stream()).toList();
-                    return new ObjectReference(joined);
+                        left.stream(),
+                        right.stream()).toList();
+                    return joined;
                   });
               return map;
             },
@@ -121,33 +143,35 @@ private static <T> WeaviateObject<T, QueryMetadata> unmarshalResultObject(
               return left;
             });
 
-    // TODO: should we return without metdata (null)?
-    if (metadataResult == null) {
-      metadataResult = propertiesResult.getMetadata();
-    }
-
-    var metadata = new QueryMetadata.Builder()
-        .id(metadataResult.getId())
-        .distance(metadataResult.getDistance())
-        .certainty(metadataResult.getCertainty());
+    ObjectMetadata metadata = null;
+    if (metadataResult != null) {
+      var metadataBuilder = new ObjectMetadata.Builder()
+          .id(metadataResult.getId());
 
-    var vectors = new Vectors.Builder();
-    for (final var vector : metadataResult.getVectorsList()) {
-      var vectorName = vector.getName();
-      switch (vector.getType()) {
-        case VECTOR_TYPE_SINGLE_FP32:
-          vectors.vector(vectorName, GRPC.fromByteString(vector.getVectorBytes()));
-          break;
-        case VECTOR_TYPE_MULTI_FP32:
-          vectors.vector(vectorName, GRPC.fromByteStringMulti(vector.getVectorBytes()));
-          break;
-        default:
-          continue;
+      var vectors = new Vectors.Builder();
+      for (final var vector : metadataResult.getVectorsList()) {
+        var vectorName = vector.getName();
+        switch (vector.getType()) {
+          case VECTOR_TYPE_SINGLE_FP32:
+            vectors.vector(vectorName, GRPC.fromByteString(vector.getVectorBytes()));
+            break;
+          case VECTOR_TYPE_MULTI_FP32:
+            vectors.vector(vectorName, GRPC.fromByteStringMulti(vector.getVectorBytes()));
+            break;
+          default:
+            continue;
+        }
       }
+      metadataBuilder.vectors(vectors.build());
+      metadata = metadataBuilder.build();
     }
-    metadata.vectors(vectors.build());
 
-    return new WeaviateObject<>(descriptor.name(), properties.build(), referenceProperties, metadata.build());
+    var obj = new WeaviateObject.Builder<T, Object, ObjectMetadata>()
+        .collection(descriptor.name())
+        .properties(properties.build())
+        .references(referenceProperties)
+        .metadata(metadata);
+    return obj.build();
   }
 
   private static <T> void setProperty(String property, WeaviateProtoProperties.Value value,
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryResponse.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryResponse.java
index 552ccc594..b5d465f8c 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryResponse.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/QueryResponse.java
@@ -4,5 +4,6 @@
 
 import io.weaviate.client6.v1.api.collections.WeaviateObject;
 
-public record QueryResponse<T>(List<WeaviateObject<T, QueryMetadata>> objects) {
+public record QueryResponse<T>(
+    List<WeaviateObject<T, Object, QueryMetadata>> objects) {
 }
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateObjectUnmarshaler.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateObjectUnmarshaler.java
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClient.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClient.java
index c2494f503..1bd313e3b 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClient.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClient.java
@@ -8,14 +8,14 @@
 
 public class WeaviateQueryClient<T>
     extends
-    AbstractQueryClient<T, Optional<WeaviateObject<T, QueryMetadata>>, QueryResponse<T>, QueryResponseGrouped<T>> {
+    AbstractQueryClient<T, Optional<WeaviateObject<T, Object, QueryMetadata>>, QueryResponse<T>, QueryResponseGrouped<T>> {
 
   public WeaviateQueryClient(CollectionDescriptor<T> collection, GrpcTransport transport) {
     super(collection, transport);
   }
 
   @Override
-  protected Optional<WeaviateObject<T, QueryMetadata>> byId(ById byId) {
+  protected Optional<WeaviateObject<T, Object, QueryMetadata>> byId(ById byId) {
     var request = new QueryRequest(byId, null);
     var result = this.transport.performRequest(request, QueryRequest.rpc(collection));
     return optionalFirst(result.objects());
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClientAsync.java b/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClientAsync.java
index 5e5f0729f..50bc536cc 100644
--- a/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClientAsync.java
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/query/WeaviateQueryClientAsync.java
@@ -9,14 +9,15 @@
 
 public class WeaviateQueryClientAsync<T>
     extends
-    AbstractQueryClient<T, CompletableFuture<Optional<WeaviateObject<T, QueryMetadata>>>, CompletableFuture<QueryResponse<T>>, CompletableFuture<QueryResponseGrouped<T>>> {
+    AbstractQueryClient<T, CompletableFuture<Optional<WeaviateObject<T, Object, QueryMetadata>>>, CompletableFuture<QueryResponse<T>>, CompletableFuture<QueryResponseGrouped<T>>> {
 
   public WeaviateQueryClientAsync(CollectionDescriptor<T> collection, GrpcTransport transport) {
     super(collection, transport);
   }
 
   @Override
-  protected CompletableFuture<Optional<WeaviateObject<T, QueryMetadata>>> byId(ById byId) {
+  protected CompletableFuture<Optional<WeaviateObject<T, Object, QueryMetadata>>> byId(
+      ById byId) {
     var request = new QueryRequest(byId, null);
     var result = this.transport.performRequestAsync(request, QueryRequest.rpc(collection));
     return result.thenApply(r -> optionalFirst(r.objects()));
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/BaseVectorIndex.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/BaseVectorIndex.java
new file mode 100644
index 000000000..49ed116c2
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/BaseVectorIndex.java
@@ -0,0 +1,19 @@
+package io.weaviate.client6.v1.api.collections.vectorindex;
+
+import io.weaviate.client6.v1.api.collections.VectorIndex;
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import lombok.EqualsAndHashCode;
+
+@EqualsAndHashCode
+abstract class BaseVectorIndex implements VectorIndex {
+  protected final Vectorizer vectorizer;
+
+  @Override
+  public Vectorizer vectorizer() {
+    return this.vectorizer;
+  }
+
+  public BaseVectorIndex(Vectorizer vectorizer) {
+    this.vectorizer = vectorizer;
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Distance.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Distance.java
new file mode 100644
index 000000000..602e90693
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Distance.java
@@ -0,0 +1,16 @@
+package io.weaviate.client6.v1.api.collections.vectorindex;
+
+import com.google.gson.annotations.SerializedName;
+
+public enum Distance {
+  @SerializedName("cosine")
+  COSINE,
+  @SerializedName("dot")
+  DOT,
+  @SerializedName("l2-squared")
+  L2_SQUARED,
+  @SerializedName("hamming")
+  HAMMING,
+  @SerializedName("manhattan")
+  MANHATTAN;
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Flat.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Flat.java
new file mode 100644
index 000000000..90ca1990c
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Flat.java
@@ -0,0 +1,62 @@
+package io.weaviate.client6.v1.api.collections.vectorindex;
+
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.VectorIndex;
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@EqualsAndHashCode(callSuper = true)
+@ToString
+public class Flat extends BaseVectorIndex {
+  @SerializedName("vectorCacheMaxObjects")
+  Long vectorCacheMaxObjects;
+
+  @Override
+  public VectorIndex.Kind _kind() {
+    return VectorIndex.Kind.FLAT;
+  }
+
+  @Override
+  public Object config() {
+    return this;
+  }
+
+  public static Flat of(Vectorizer vectorizer) {
+    return of(vectorizer, ObjectBuilder.identity());
+  }
+
+  public static Flat of(Vectorizer vectorizer, Function<Builder, ObjectBuilder<Flat>> fn) {
+    return fn.apply(new Builder(vectorizer)).build();
+  }
+
+  public Flat(Builder builder) {
+    super(builder.vectorizer);
+    this.vectorCacheMaxObjects = builder.vectorCacheMaxObjects;
+  }
+
+  public static class Builder implements ObjectBuilder<Flat> {
+    // Required parameters.
+    private final Vectorizer vectorizer;
+
+    private Long vectorCacheMaxObjects;
+
+    protected Builder(Vectorizer vectorizer) {
+      this.vectorizer = vectorizer;
+    }
+
+    public Builder vectorCacheMaxObjects(long vectorCacheMaxObjects) {
+      this.vectorCacheMaxObjects = vectorCacheMaxObjects;
+      return this;
+    }
+
+    @Override
+    public Flat build() {
+      return new Flat(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Hnsw.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Hnsw.java
new file mode 100644
index 000000000..4538ad9b4
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorindex/Hnsw.java
@@ -0,0 +1,175 @@
+package io.weaviate.client6.v1.api.collections.vectorindex;
+
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.VectorIndex;
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+@EqualsAndHashCode(callSuper = true)
+@ToString
+public class Hnsw extends BaseVectorIndex {
+  @SerializedName("distance")
+  private final Distance distance;
+  @SerializedName("ef")
+  private final Integer ef;
+  @SerializedName("efConstruction")
+  private final Integer efConstruction;
+  @SerializedName("maxConnections")
+  private final Integer maxConnections;
+  @SerializedName("vectorCacheMaxObjects")
+  private final Long vectorCacheMaxObjects;
+  @SerializedName("cleanupIntervalSeconds")
+  private final Integer cleanupIntervalSeconds;
+  @SerializedName("filterStrategy")
+  private final FilterStrategy filterStrategy;
+
+  @SerializedName("dynamicEfMin")
+  private final Integer dynamicEfMin;
+  @SerializedName("dynamicEfMax")
+  private final Integer dynamicEfMax;
+  @SerializedName("dynamicEfFactor")
+  private final Integer dynamicEfFactor;
+  @SerializedName("flatSearchCutoff")
+  private final Integer flatSearchCutoff;
+  @SerializedName("skip")
+  Boolean skipVectorization;
+
+  @Override
+  public VectorIndex.Kind _kind() {
+    return VectorIndex.Kind.HNSW;
+  }
+
+  @Override
+  public Object config() {
+    return this;
+  }
+
+  @Override
+  public Vectorizer vectorizer() {
+    return this.vectorizer;
+  }
+
+  public static Hnsw of(Vectorizer vectorizer) {
+    return of(vectorizer, ObjectBuilder.identity());
+  }
+
+  public static Hnsw of(Vectorizer vectorizer, Function<Builder, ObjectBuilder<Hnsw>> fn) {
+    return fn.apply(new Builder(vectorizer)).build();
+  }
+
+  public Hnsw(Builder builder) {
+    super(builder.vectorizer);
+    this.distance = builder.distance;
+    this.ef = builder.ef;
+    this.efConstruction = builder.efConstruction;
+    this.maxConnections = builder.maxConnections;
+    this.vectorCacheMaxObjects = builder.vectorCacheMaxObjects;
+    this.cleanupIntervalSeconds = builder.cleanupIntervalSeconds;
+    this.filterStrategy = builder.filterStrategy;
+    this.dynamicEfMin = builder.dynamicEfMin;
+    this.dynamicEfMax = builder.dynamicEfMax;
+    this.dynamicEfFactor = builder.dynamicEfFactor;
+    this.flatSearchCutoff = builder.flatSearchCutoff;
+    this.skipVectorization = builder.skipVectorization;
+  }
+
+  public static class Builder implements ObjectBuilder<Hnsw> {
+    // Required parameters.
+    private final Vectorizer vectorizer;
+
+    private Distance distance;
+    private Integer ef;
+    private Integer efConstruction;
+    private Integer maxConnections;
+    private Long vectorCacheMaxObjects;
+    private Integer cleanupIntervalSeconds;
+    private FilterStrategy filterStrategy;
+
+    private Integer dynamicEfMin;
+    private Integer dynamicEfMax;
+    private Integer dynamicEfFactor;
+    private Integer flatSearchCutoff;
+    private Boolean skipVectorization;
+
+    public Builder(Vectorizer vectorizer) {
+      this.vectorizer = vectorizer;
+    }
+
+    public Builder distance(Distance distance) {
+      this.distance = distance;
+      return this;
+    }
+
+    public Builder ef(int ef) {
+      this.ef = ef;
+      return this;
+    }
+
+    public final Builder efConstruction(int efConstruction) {
+      this.efConstruction = efConstruction;
+      return this;
+    }
+
+    public final Builder maxConnections(int maxConnections) {
+      this.maxConnections = maxConnections;
+      return this;
+    }
+
+    public final Builder vectorCacheMaxObjects(long vectorCacheMaxObjects) {
+      this.vectorCacheMaxObjects = vectorCacheMaxObjects;
+      return this;
+    }
+
+    public final Builder cleanupIntervalSeconds(int cleanupIntervalSeconds) {
+      this.cleanupIntervalSeconds = cleanupIntervalSeconds;
+      return this;
+    }
+
+    public final Builder filterStrategy(FilterStrategy filterStrategy) {
+      this.filterStrategy = filterStrategy;
+      return this;
+    }
+
+    public final Builder dynamicEfMin(int dynamicEfMin) {
+      this.dynamicEfMin = dynamicEfMin;
+      return this;
+    }
+
+    public final Builder dynamicEfMax(int dynamicEfMax) {
+      this.dynamicEfMax = dynamicEfMax;
+      return this;
+    }
+
+    public final Builder dynamicEfFactor(int dynamicEfFactor) {
+      this.dynamicEfFactor = dynamicEfFactor;
+      return this;
+    }
+
+    public final Builder flatSearchCutoff(int flatSearchCutoff) {
+      this.flatSearchCutoff = flatSearchCutoff;
+      return this;
+    }
+
+    public final Builder skipVectorization(boolean skip) {
+      this.skipVectorization = skip;
+      return this;
+    }
+
+    @Override
+    public Hnsw build() {
+      return new Hnsw(this);
+    }
+  }
+
+  public enum FilterStrategy {
+    @SerializedName("sweeping")
+    SWEEPING,
+    @SerializedName("acorn")
+    ACORN;
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Img2VecNeuralVectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Img2VecNeuralVectorizer.java
new file mode 100644
index 000000000..2d9ff6beb
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Img2VecNeuralVectorizer.java
@@ -0,0 +1,55 @@
+package io.weaviate.client6.v1.api.collections.vectorizers;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record Img2VecNeuralVectorizer(
+    @SerializedName("imageFields") List<String> imageFields) implements Vectorizer {
+
+  @Override
+  public Vectorizer.Kind _kind() {
+    return Vectorizer.Kind.IMG2VEC_NEURAL;
+  }
+
+  @Override
+  public Object _self() {
+    return this;
+  }
+
+  public static Img2VecNeuralVectorizer of() {
+    return of(ObjectBuilder.identity());
+  }
+
+  public static Img2VecNeuralVectorizer of(Function<Builder, ObjectBuilder<Img2VecNeuralVectorizer>> fn) {
+    return fn.apply(new Builder()).build();
+  }
+
+  public Img2VecNeuralVectorizer(Builder builder) {
+    this(builder.imageFields);
+  }
+
+  public static class Builder implements ObjectBuilder<Img2VecNeuralVectorizer> {
+    private List<String> imageFields = new ArrayList<>();
+
+    public Builder imageFields(List<String> fields) {
+      this.imageFields = fields;
+      return this;
+    }
+
+    public Builder imageFields(String... fields) {
+      return imageFields(Arrays.asList(fields));
+    }
+
+    @Override
+    public Img2VecNeuralVectorizer build() {
+      return new Img2VecNeuralVectorizer(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Multi2VecClipVectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Multi2VecClipVectorizer.java
new file mode 100644
index 000000000..945984cc4
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Multi2VecClipVectorizer.java
@@ -0,0 +1,104 @@
+package io.weaviate.client6.v1.api.collections.vectorizers;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record Multi2VecClipVectorizer(
+    @SerializedName("vectorizeClassName") boolean vectorizeCollectionName,
+    @SerializedName("inferenceUrl") String inferenceUrl,
+    @SerializedName("imageFields") List<String> imageFields,
+    @SerializedName("textFields") List<String> textFields,
+    @SerializedName("weights") Weights weights) implements Vectorizer {
+
+  private static record Weights(
+      @SerializedName("imageWeights") List<Float> imageWeights,
+      @SerializedName("textWeights") List<Float> textWeights) {
+  }
+
+  @Override
+  public Vectorizer.Kind _kind() {
+    return Vectorizer.Kind.MULTI2VEC_CLIP;
+  }
+
+  @Override
+  public Object _self() {
+    return this;
+  }
+
+  public static Multi2VecClipVectorizer of() {
+    return of(ObjectBuilder.identity());
+  }
+
+  public static Multi2VecClipVectorizer of(Function<Builder, ObjectBuilder<Multi2VecClipVectorizer>> fn) {
+    return fn.apply(new Builder()).build();
+  }
+
+  public Multi2VecClipVectorizer(Builder builder) {
+    this(
+        builder.vectorizeCollectionName,
+        builder.inferenceUrl,
+        builder.imageFields.keySet().stream().toList(),
+        builder.textFields.keySet().stream().toList(),
+        new Weights(
+            builder.imageFields.values().stream().toList(),
+            builder.textFields.values().stream().toList()));
+  }
+
+  public static class Builder implements ObjectBuilder<Multi2VecClipVectorizer> {
+    private boolean vectorizeCollectionName = false;
+    private String inferenceUrl;
+    private Map<String, Float> imageFields = new HashMap<>();
+    private Map<String, Float> textFields = new HashMap<>();
+
+    public Builder inferenceUrl(String inferenceUrl) {
+      this.inferenceUrl = inferenceUrl;
+      return this;
+    }
+
+    public Builder imageFields(List<String> fields) {
+      fields.forEach(field -> imageFields.put(field, null));
+      return this;
+    }
+
+    public Builder imageFields(String... fields) {
+      return imageFields(Arrays.asList(fields));
+    }
+
+    public Builder imageField(String field, float weight) {
+      imageFields.put(field, weight);
+      return this;
+    }
+
+    public Builder textFields(List<String> fields) {
+      fields.forEach(field -> textFields.put(field, null));
+      return this;
+    }
+
+    public Builder textFields(String... fields) {
+      return textFields(Arrays.asList(fields));
+    }
+
+    public Builder textField(String field, float weight) {
+      textFields.put(field, weight);
+      return this;
+    }
+
+    public Builder vectorizeCollectionName(boolean enable) {
+      this.vectorizeCollectionName = enable;
+      return this;
+    }
+
+    @Override
+    public Multi2VecClipVectorizer build() {
+      return new Multi2VecClipVectorizer(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/NoneVectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/NoneVectorizer.java
new file mode 100644
index 000000000..6449ba89b
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/NoneVectorizer.java
@@ -0,0 +1,45 @@
+package io.weaviate.client6.v1.api.collections.vectorizers;
+
+import java.io.IOException;
+
+import com.google.gson.TypeAdapter;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+
+public record NoneVectorizer() implements Vectorizer {
+  @Override
+  public Kind _kind() {
+    return Vectorizer.Kind.NONE;
+  }
+
+  @Override
+  public Object _self() {
+    return this;
+  }
+
+  public static final TypeAdapter<NoneVectorizer> TYPE_ADAPTER = new TypeAdapter<NoneVectorizer>() {
+
+    @Override
+    public void write(JsonWriter out, NoneVectorizer value) throws IOException {
+      out.beginObject();
+      out.name(value._kind().jsonValue());
+      out.beginObject();
+      out.endObject();
+      out.endObject();
+    }
+
+    @Override
+    public NoneVectorizer read(JsonReader in) throws IOException {
+      // NoneVectorizer expects no parameters, so we just skip to the closing bracket.
+      in.beginObject();
+      while (in.peek() != JsonToken.END_OBJECT) {
+        in.skipValue();
+      }
+      in.endObject();
+      return new NoneVectorizer();
+    }
+  }.nullSafe();
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecContextionaryVectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecContextionaryVectorizer.java
new file mode 100644
index 000000000..7bbfc6c9c
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecContextionaryVectorizer.java
@@ -0,0 +1,48 @@
+package io.weaviate.client6.v1.api.collections.vectorizers;
+
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record Text2VecContextionaryVectorizer(
+    @SerializedName("vectorizeClassName") boolean vectorizeCollectionName) implements Vectorizer {
+
+  @Override
+  public Vectorizer.Kind _kind() {
+    return Vectorizer.Kind.TEXT2VEC_CONTEXTIONARY;
+  }
+
+  @Override
+  public Object _self() {
+    return this;
+  }
+
+  public static Text2VecContextionaryVectorizer of() {
+    return of(ObjectBuilder.identity());
+  }
+
+  public static Text2VecContextionaryVectorizer of(
+      Function<Builder, ObjectBuilder<Text2VecContextionaryVectorizer>> fn) {
+    return fn.apply(new Builder()).build();
+  }
+
+  public Text2VecContextionaryVectorizer(Builder builder) {
+    this(builder.vectorizeCollectionName);
+  }
+
+  public static class Builder implements ObjectBuilder<Text2VecContextionaryVectorizer> {
+    private boolean vectorizeCollectionName = false;
+
+    public Builder vectorizeCollectionName(boolean enable) {
+      this.vectorizeCollectionName = enable;
+      return this;
+    }
+
+    public Text2VecContextionaryVectorizer build() {
+      return new Text2VecContextionaryVectorizer(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecWeaviateVectorizer.java b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecWeaviateVectorizer.java
new file mode 100644
index 000000000..134a6513a
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/api/collections/vectorizers/Text2VecWeaviateVectorizer.java
@@ -0,0 +1,74 @@
+package io.weaviate.client6.v1.api.collections.vectorizers;
+
+import java.util.function.Function;
+
+import com.google.gson.annotations.SerializedName;
+
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.internal.ObjectBuilder;
+
+public record Text2VecWeaviateVectorizer(
+    @SerializedName("vectorizeClassName") boolean vectorizeCollectionName,
+    @SerializedName("baseUrl") String inferenceUrl,
+    @SerializedName("dimensions") Integer dimensions,
+    @SerializedName("model") String model) implements Vectorizer {
+
+  @Override
+  public Vectorizer.Kind _kind() {
+    return Vectorizer.Kind.TEXT2VEC_WEAVIATE;
+  }
+
+  @Override
+  public Object _self() {
+    return this;
+  }
+
+  public static Text2VecWeaviateVectorizer of() {
+    return of(ObjectBuilder.identity());
+  }
+
+  public static Text2VecWeaviateVectorizer of(Function<Builder, ObjectBuilder<Text2VecWeaviateVectorizer>> fn) {
+    return fn.apply(new Builder()).build();
+  }
+
+  public Text2VecWeaviateVectorizer(Builder builder) {
+    this(builder.vectorizeCollectionName,
+        builder.inferenceUrl,
+        builder.dimensions,
+        builder.model);
+  }
+
+  public static final String SNOWFLAKE_ARCTIC_EMBED_L_20 = "Snowflake/snowflake-arctic-embed-l-v2.0";
+  public static final String SNOWFLAKE_ARCTIC_EMBED_M_15 = "Snowflake/snowflake-arctic-embed-m-v1.5";
+
+  public static class Builder implements ObjectBuilder<Text2VecWeaviateVectorizer> {
+    private boolean vectorizeCollectionName = false;
+    private String inferenceUrl;
+    private Integer dimensions;
+    private String model;
+
+    public Builder vectorizeCollectionName(boolean enable) {
+      this.vectorizeCollectionName = enable;
+      return this;
+    }
+
+    public Builder inferenceUrl(String inferenceUrl) {
+      this.inferenceUrl = inferenceUrl;
+      return this;
+    }
+
+    public Builder dimensions(int dimensions) {
+      this.dimensions = dimensions;
+      return this;
+    }
+
+    public Builder model(String model) {
+      this.model = model;
+      return this;
+    }
+
+    public Text2VecWeaviateVectorizer build() {
+      return new Text2VecWeaviateVectorizer(this);
+    }
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/AtomicDataType.java b/src/main/java/io/weaviate/client6/v1/collections/AtomicDataType.java
deleted file mode 100644
index 38c33ed22..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/AtomicDataType.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import com.google.gson.annotations.SerializedName;
-
-public enum AtomicDataType {
-  @SerializedName("text")
-  TEXT,
-  @SerializedName("int")
-  INT,
-  @SerializedName("blob")
-  BLOB;
-
-  public static boolean isAtomic(String type) {
-    return type.equals(TEXT.name().toLowerCase())
-        || type.equals(INT.name().toLowerCase())
-        || type.equals(BLOB.name().toLowerCase());
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Collection.java b/src/main/java/io/weaviate/client6/v1/collections/Collection.java
deleted file mode 100644
index 870701311..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Collection.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.function.Consumer;
-
-import io.weaviate.client6.v1.collections.Vectors.NamedVectors;
-
-public record Collection(String name, List<Property> properties, List<ReferenceProperty> references, Vectors vectors) {
-
-  public static Collection with(String name, Consumer<Builder> options) {
-    var config = new Builder(options);
-    return new Collection(name, config.properties, config.references, config.vectors);
-  }
-
-  public static class Builder {
-    private List<Property> properties = new ArrayList<>();
-    public List<ReferenceProperty> references = new ArrayList<>();
-    private Vectors vectors;
-
-    public Builder properties(Property... properties) {
-      this.properties = Arrays.asList(properties);
-      return this;
-    }
-
-    public Builder references(ReferenceProperty... references) {
-      this.references = Arrays.asList(references);
-      return this;
-    }
-
-    public <V extends Vectorizer> Builder vectors(Vectors vectors) {
-      this.vectors = vectors;
-      return this;
-    }
-
-    public <V extends Vectorizer> Builder vector(VectorIndex<V> vector) {
-      this.vectors = Vectors.of(vector);
-      return this;
-    }
-
-    public <V extends Vectorizer> Builder vector(String name, VectorIndex<V> vector) {
-      this.vectors = new Vectors(name, vector);
-      return this;
-    }
-
-    public Builder vectors(Consumer<NamedVectors> named) {
-      this.vectors = Vectors.with(named);
-      return this;
-    }
-
-    Builder(Consumer<Builder> options) {
-      options.accept(this);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/CollectionClient.java b/src/main/java/io/weaviate/client6/v1/collections/CollectionClient.java
deleted file mode 100644
index 76d840a03..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/CollectionClient.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import io.weaviate.client6.Config;
-import io.weaviate.client6.internal.GrpcClient;
-import io.weaviate.client6.internal.HttpClient;
-import io.weaviate.client6.v1.api.collections.aggregate.WeaviateAggregateClient;
-import io.weaviate.client6.v1.api.collections.query.WeaviateQueryClient;
-import io.weaviate.client6.v1.collections.data.DataClient;
-import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
-import io.weaviate.client6.v1.internal.orm.CollectionDescriptor;
-
-public class CollectionClient<T> {
-  public final WeaviateQueryClient<T> query;
-  public final WeaviateAggregateClient aggregate;
-
-  public final DataClient<T> data;
-  public final CollectionConfigClient config;
-
-  public CollectionClient(String collectionName, Config config, GrpcClient grpc, HttpClient http,
-      GrpcTransport grpcTransport, CollectionDescriptor<T> collectionDescriptor) {
-    this.query = new WeaviateQueryClient<>(collectionDescriptor, grpcTransport);
-    this.aggregate = new WeaviateAggregateClient(collectionDescriptor, grpcTransport);
-
-    this.data = new DataClient<>(collectionName, config, http, grpc);
-    this.config = new CollectionConfigClient(collectionName, config, http);
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/CollectionConfigClient.java b/src/main/java/io/weaviate/client6/v1/collections/CollectionConfigClient.java
deleted file mode 100644
index 926a335bb..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/CollectionConfigClient.java
+++ /dev/null
@@ -1,159 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.lang.reflect.Type;
-import java.util.Map;
-import java.util.Optional;
-
-import org.apache.hc.core5.http.ClassicHttpRequest;
-import org.apache.hc.core5.http.ContentType;
-import org.apache.hc.core5.http.HttpStatus;
-import org.apache.hc.core5.http.io.entity.EntityUtils;
-import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonDeserializationContext;
-import com.google.gson.JsonDeserializer;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonParseException;
-import com.google.gson.JsonSerializationContext;
-import com.google.gson.JsonSerializer;
-import com.google.gson.TypeAdapter;
-import com.google.gson.reflect.TypeToken;
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonWriter;
-
-import io.weaviate.client6.Config;
-import io.weaviate.client6.internal.DtoTypeAdapterFactory;
-import io.weaviate.client6.internal.HttpClient;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class CollectionConfigClient {
-  // TODO: hide befind an internal HttpClient
-  private final String collectionName;
-  private final Config config;
-  private final HttpClient httpClient;
-
-  static {
-    DtoTypeAdapterFactory.register(
-        Collection.class,
-        CollectionDefinitionDTO.class,
-        m -> new CollectionDefinitionDTO(m));
-  }
-
-  // Gson cannot deserialize interfaces:
-  // https://stackoverflow.com/a/49871339/14726116
-  private static class IndexingStrategySerde
-      implements JsonDeserializer<IndexingStrategy>, JsonSerializer<IndexingStrategy> {
-
-    @Override
-    public IndexingStrategy deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-        throws JsonParseException {
-      return IndexingStrategy.hnsw();
-    }
-
-    @Override
-    public JsonElement serialize(IndexingStrategy src, Type typeOfSrc, JsonSerializationContext context) {
-      return context.serialize(src);
-    }
-  }
-
-  // Gson cannot deserialize interfaces:
-  // https://stackoverflow.com/a/49871339/14726116
-  private static class VectorizerSerde
-      implements JsonDeserializer<Vectorizer>, JsonSerializer<Vectorizer> {
-
-    @Override
-    public Vectorizer deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-        throws JsonParseException {
-      return Vectorizer.none();
-    }
-
-    @Override
-    public JsonElement serialize(Vectorizer src, Type typeOfSrc, JsonSerializationContext context) {
-      return context.serialize(src);
-    }
-  }
-
-  private static final Gson gson = new GsonBuilder()
-      .registerTypeAdapterFactory(new DtoTypeAdapterFactory())
-      .registerTypeAdapter(Vectorizer.class, new VectorizerSerde())
-      .registerTypeAdapter(IndexingStrategy.class, new IndexingStrategySerde())
-      .registerTypeAdapter(Vectors.class, new TypeAdapter<Vectors>() {
-        Gson gson = new GsonBuilder()
-            .registerTypeAdapter(Vectorizer.class, new VectorizerSerde())
-            .registerTypeAdapter(IndexingStrategy.class, new IndexingStrategySerde())
-            .create();
-
-        @Override
-        public void write(JsonWriter out, Vectors value) throws IOException {
-          if (value != null) {
-            gson.toJson(value.asMap(), Map.class, out);
-          } else {
-            out.nullValue();
-          }
-        }
-
-        @Override
-        public Vectors read(JsonReader in) throws IOException {
-          Map<String, VectorIndex<? extends Vectorizer>> vectors = gson.fromJson(in,
-              new TypeToken<Map<String, VectorIndex<? extends Vectorizer>>>() {
-              }.getType());
-          return Vectors.of(vectors);
-        }
-      })
-      .create();
-
-  public Optional<Collection> get() throws IOException {
-    ClassicHttpRequest httpGet = ClassicRequestBuilder
-        .get(config.baseUrl() + "/schema/" + collectionName)
-        .build();
-
-    return httpClient.http.execute(httpGet, response -> {
-      if (response.getCode() == HttpStatus.SC_NOT_FOUND) {
-        return Optional.empty();
-      }
-      try (var r = new InputStreamReader(response.getEntity().getContent())) {
-        var collection = gson.fromJson(r, Collection.class);
-        return Optional.ofNullable(collection);
-      }
-    });
-  }
-
-  public void addProperty(Property property) throws IOException {
-    ClassicHttpRequest httpPost = ClassicRequestBuilder
-        .post(config.baseUrl() + "/schema/" + collectionName + "/properties")
-        .setEntity(gson.toJson(property), ContentType.APPLICATION_JSON)
-        .build();
-
-    httpClient.http.execute(httpPost, response -> {
-      var entity = response.getEntity();
-      if (response.getCode() != HttpStatus.SC_SUCCESS) {
-        var message = EntityUtils.toString(entity);
-        throw new RuntimeException("HTTP " + response.getCode() + ": " + message);
-      }
-      return null;
-    });
-  }
-
-  public void addReference(String name, String... dataTypes) throws IOException {
-    var property = Property.reference(name, dataTypes);
-    ClassicHttpRequest httpPost = ClassicRequestBuilder
-        .post(config.baseUrl() + "/schema/" + collectionName + "/properties")
-        .setEntity(gson.toJson(property), ContentType.APPLICATION_JSON)
-        .build();
-
-    httpClient.http.execute(httpPost, response -> {
-      var entity = response.getEntity();
-      if (response.getCode() != HttpStatus.SC_SUCCESS) {
-        var message = EntityUtils.toString(entity);
-        throw new RuntimeException("HTTP " + response.getCode() + ": " + message);
-      }
-      return null;
-    });
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/CollectionDefinitionDTO.java b/src/main/java/io/weaviate/client6/v1/collections/CollectionDefinitionDTO.java
deleted file mode 100644
index 9a3bb6422..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/CollectionDefinitionDTO.java
+++ /dev/null
@@ -1,63 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.stream.Stream;
-
-import com.google.gson.annotations.SerializedName;
-
-import io.weaviate.client6.internal.DtoTypeAdapterFactory;
-
-class CollectionDefinitionDTO implements DtoTypeAdapterFactory.Dto<Collection> {
-  @SerializedName("class")
-  String collection;
-
-  @SerializedName("properties")
-  List<Property> properties;
-
-  @SerializedName("vectorConfig")
-  Vectors vectors;
-
-  @SerializedName("vectorIndexType")
-  private VectorIndex.IndexType vectorIndexType;
-
-  @SerializedName("vectorIndexConfig")
-  private VectorIndex.IndexingStrategy vectorIndexConfig;
-
-  @SerializedName("vectorizer")
-  private Vectorizer vectorizer;
-
-  public CollectionDefinitionDTO(Collection colDef) {
-    this.collection = colDef.name();
-    this.properties = Stream.concat(
-        colDef.properties().stream(),
-        colDef.references().stream().map(r -> new Property(r.name(),
-            r.dataTypes())))
-        .toList();
-    this.vectors = colDef.vectors();
-
-    if (this.vectors != null) {
-      var unnamed = this.vectors.getUnnamed();
-      if (unnamed.isPresent()) {
-        var index = unnamed.get();
-        this.vectorIndexType = index.type();
-        this.vectorIndexConfig = index.configuration();
-        this.vectorizer = index.vectorizer();
-      }
-    }
-  }
-
-  public Collection toModel() {
-    var onlyProperties = new ArrayList<Property>();
-    var references = new ArrayList<ReferenceProperty>();
-
-    for (var p : properties) {
-      if (p.isReference()) {
-        references.add(Property.reference(p.name(), p.dataTypes()));
-      } else {
-        onlyProperties.add(p);
-      }
-    }
-    return new Collection(collection, onlyProperties, references, vectors);
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/CollectionsClient.java b/src/main/java/io/weaviate/client6/v1/collections/CollectionsClient.java
deleted file mode 100644
index 6ff496972..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/CollectionsClient.java
+++ /dev/null
@@ -1,178 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.lang.reflect.Type;
-import java.util.Map;
-import java.util.Optional;
-import java.util.function.Consumer;
-
-import org.apache.hc.core5.http.ClassicHttpRequest;
-import org.apache.hc.core5.http.ContentType;
-import org.apache.hc.core5.http.HttpStatus;
-import org.apache.hc.core5.http.io.entity.EntityUtils;
-import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
-
-import com.google.common.reflect.TypeToken;
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonDeserializationContext;
-import com.google.gson.JsonDeserializer;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonParseException;
-import com.google.gson.JsonSerializationContext;
-import com.google.gson.JsonSerializer;
-import com.google.gson.TypeAdapter;
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonWriter;
-
-import io.weaviate.client6.Config;
-import io.weaviate.client6.internal.DtoTypeAdapterFactory;
-import io.weaviate.client6.internal.GrpcClient;
-import io.weaviate.client6.internal.HttpClient;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-import io.weaviate.client6.v1.internal.grpc.GrpcTransport;
-import io.weaviate.client6.v1.internal.orm.MapDescriptor;
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class CollectionsClient {
-  // TODO: hide befind an internal HttpClient
-  private final Config config;
-
-  private final HttpClient httpClient;
-  private final GrpcClient grpcClient;
-
-  // TODO: Some commong AbstractWeaviateClient should hold these.
-  private final GrpcTransport grpcTransport;
-
-  static {
-    DtoTypeAdapterFactory.register(
-        Collection.class,
-        CollectionDefinitionDTO.class,
-        m -> new CollectionDefinitionDTO(m));
-  }
-
-  // Gson cannot deserialize interfaces:
-  // https://stackoverflow.com/a/49871339/14726116
-  private static class IndexingStrategySerde
-      implements JsonDeserializer<IndexingStrategy>, JsonSerializer<IndexingStrategy> {
-
-    @Override
-    public IndexingStrategy deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-        throws JsonParseException {
-      return IndexingStrategy.hnsw();
-    }
-
-    @Override
-    public JsonElement serialize(IndexingStrategy src, Type typeOfSrc, JsonSerializationContext context) {
-      return context.serialize(src);
-    }
-  }
-
-  // Gson cannot deserialize interfaces:
-  // https://stackoverflow.com/a/49871339/14726116
-  private static class VectorizerSerde
-      implements JsonDeserializer<Vectorizer>, JsonSerializer<Vectorizer> {
-
-    @Override
-    public Vectorizer deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
-        throws JsonParseException {
-      // TODO: deserialize different kinds of vectorizers
-      return Vectorizer.none();
-    }
-
-    @Override
-    public JsonElement serialize(Vectorizer src, Type typeOfSrc, JsonSerializationContext context) {
-      return context.serialize(src);
-    }
-  }
-
-  private static final Gson gson = new GsonBuilder()
-      .registerTypeAdapterFactory(new DtoTypeAdapterFactory())
-      .registerTypeAdapter(IndexingStrategy.class, new IndexingStrategySerde())
-      .registerTypeAdapter(Vectorizer.class, new VectorizerSerde())
-      .registerTypeAdapter(Vectors.class, new TypeAdapter<Vectors>() {
-        Gson gson = new GsonBuilder()
-            .registerTypeAdapter(Vectorizer.class, new VectorizerSerde())
-            .registerTypeAdapter(IndexingStrategy.class, new IndexingStrategySerde())
-            .create();
-
-        @Override
-        public void write(JsonWriter out, Vectors value) throws IOException {
-          if (value != null) {
-            gson.toJson(value.asMap(), Map.class, out);
-          } else {
-            out.nullValue();
-          }
-        }
-
-        @Override
-        public Vectors read(JsonReader in) throws IOException {
-          Map<String, VectorIndex<? extends Vectorizer>> vectors = gson.fromJson(in,
-              new TypeToken<Map<String, VectorIndex<? extends Vectorizer>>>() {
-              }.getType());
-          return Vectors.of(vectors);
-        }
-      })
-      .create();
-
-  public void create(String name) throws IOException {
-    create(name, opt -> {
-    });
-  }
-
-  public void create(String name, Consumer<Collection.Builder> options) throws IOException {
-    var collection = Collection.with(name, options);
-    ClassicHttpRequest httpPost = ClassicRequestBuilder
-        .post(config.baseUrl() + "/schema")
-        .setEntity(gson.toJson(collection), ContentType.APPLICATION_JSON)
-        .build();
-
-    // TODO: do not expose Apache HttpClient directly
-    httpClient.http.execute(httpPost, response -> {
-      var entity = response.getEntity();
-      if (response.getCode() != HttpStatus.SC_SUCCESS) { // Does not return 201
-        var message = EntityUtils.toString(entity);
-        throw new RuntimeException("HTTP " + response.getCode() + ": " + message);
-      }
-      return null;
-    });
-  }
-
-  public Optional<Collection> getConfig(String name) throws IOException {
-    ClassicHttpRequest httpGet = ClassicRequestBuilder
-        .get(config.baseUrl() + "/schema/" + name)
-        .build();
-
-    return httpClient.http.execute(httpGet, response -> {
-      if (response.getCode() == HttpStatus.SC_NOT_FOUND) {
-        return Optional.empty();
-      }
-      try (var r = new InputStreamReader(response.getEntity().getContent())) {
-        var collection = gson.fromJson(r, Collection.class);
-        return Optional.ofNullable(collection);
-      }
-    });
-  }
-
-  public void delete(String name) throws IOException {
-    ClassicHttpRequest httpDelete = ClassicRequestBuilder
-        .delete(config.baseUrl() + "/schema/" + name)
-        .build();
-
-    httpClient.http.execute(httpDelete, response -> {
-      var entity = response.getEntity();
-      if (response.getCode() != HttpStatus.SC_SUCCESS) { // Does not return 201
-        var message = EntityUtils.toString(entity);
-        throw new RuntimeException("HTTP " + response.getCode() + ": " + message);
-      }
-      return null;
-    });
-  }
-
-  public CollectionClient<Map<String, Object>> use(String collectionName) {
-    return new CollectionClient<>(collectionName, config, grpcClient, httpClient, grpcTransport,
-        new MapDescriptor(collectionName));
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/ContextionaryVectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/ContextionaryVectorizer.java
deleted file mode 100644
index 1bb580ada..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/ContextionaryVectorizer.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.Map;
-import java.util.function.Consumer;
-
-import com.google.gson.annotations.SerializedName;
-
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class ContextionaryVectorizer extends Vectorizer {
-  @SerializedName("text2vec-contextionary")
-  private Map<String, Object> configuration;
-
-  public static ContextionaryVectorizer of() {
-    return new Builder().build();
-  }
-
-  public static ContextionaryVectorizer of(Consumer<Builder> fn) {
-    var builder = new Builder();
-    fn.accept(builder);
-    return builder.build();
-  }
-
-  public static class Builder {
-    private boolean vectorizeCollectionName = false;
-
-    public Builder vectorizeCollectionName() {
-      this.vectorizeCollectionName = true;
-      return this;
-    }
-
-    public ContextionaryVectorizer build() {
-      return new ContextionaryVectorizer(Map.of("vectorizeClassName", vectorizeCollectionName));
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/HNSW.java b/src/main/java/io/weaviate/client6/v1/collections/HNSW.java
deleted file mode 100644
index 938c44ffa..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/HNSW.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.function.Consumer;
-
-import io.weaviate.client6.v1.collections.VectorIndex.IndexType;
-
-public final record HNSW(Distance distance, Boolean skip) implements VectorIndex.IndexingStrategy {
-  public VectorIndex.IndexType type() {
-    return IndexType.HNSW;
-  }
-
-  public enum Distance {
-    COSINE;
-  }
-
-  HNSW() {
-    this(null, null);
-  }
-
-  static HNSW with(Consumer<Builder> options) {
-    var opt = new Builder(options);
-    return new HNSW(opt.distance, opt.skip);
-  }
-
-  public static class Builder {
-    private Distance distance;
-    private Boolean skip;
-
-    public Builder distance(Distance distance) {
-      this.distance = distance;
-      return this;
-    }
-
-    public Builder disableIndexation() {
-      this.skip = true;
-      return this;
-    }
-
-    public Builder(Consumer<Builder> options) {
-      options.accept(this);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Img2VecNeuralVectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/Img2VecNeuralVectorizer.java
deleted file mode 100644
index a0efc5c61..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Img2VecNeuralVectorizer.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Consumer;
-
-import com.google.gson.annotations.SerializedName;
-
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class Img2VecNeuralVectorizer extends Vectorizer {
-  @SerializedName("img2vec-neural")
-  private Map<String, Object> configuration;
-
-  public static Img2VecNeuralVectorizer of() {
-    return new Builder().build();
-  }
-
-  public static Img2VecNeuralVectorizer of(Consumer<Builder> fn) {
-    var builder = new Builder();
-    fn.accept(builder);
-    return builder.build();
-  }
-
-  public static class Builder {
-    private List<String> imageFields = new ArrayList<>();
-
-    public Builder imageFields(String... fields) {
-      this.imageFields = Arrays.asList(fields);
-      return this;
-    }
-
-    public Img2VecNeuralVectorizer build() {
-      return new Img2VecNeuralVectorizer(Map.of("imageFields", imageFields));
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Multi2VecClipVectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/Multi2VecClipVectorizer.java
deleted file mode 100644
index 305e8373a..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Multi2VecClipVectorizer.java
+++ /dev/null
@@ -1,100 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Consumer;
-
-import com.google.gson.annotations.SerializedName;
-
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class Multi2VecClipVectorizer extends Vectorizer {
-  @SerializedName("multi2vec-clip")
-  private Map<String, Object> configuration;
-
-  public static Multi2VecClipVectorizer of() {
-    return new Builder().build();
-  }
-
-  public static Multi2VecClipVectorizer of(Consumer<Builder> fn) {
-    var builder = new Builder();
-    fn.accept(builder);
-    return builder.build();
-  }
-
-  public static class Builder {
-    private boolean vectorizeCollectionName = false;
-    private String inferenceUrl;
-    private Map<String, Float> imageFields = new HashMap<>();
-    private Map<String, Float> textFields = new HashMap<>();
-
-    public Builder inferenceUrl(String inferenceUrl) {
-      this.inferenceUrl = inferenceUrl;
-      return this;
-    }
-
-    public Builder imageFields(String... fields) {
-      Arrays.stream(fields).forEach(f -> imageFields.put(f, null));
-      return this;
-    }
-
-    public Builder imageField(String field, float weight) {
-      imageFields.put(field, weight);
-      return this;
-    }
-
-    public Builder textFields(String... fields) {
-      Arrays.stream(fields).forEach(f -> textFields.put(f, null));
-      return this;
-    }
-
-    public Builder textField(String field, float weight) {
-      textFields.put(field, weight);
-      return this;
-    }
-
-    public Builder vectorizeCollectionName() {
-      this.vectorizeCollectionName = true;
-      return this;
-    }
-
-    public Multi2VecClipVectorizer build() {
-      return new Multi2VecClipVectorizer(new HashMap<>() {
-        {
-          put("vectorizeClassName", vectorizeCollectionName);
-          if (inferenceUrl != null) {
-            put("inferenceUrl", inferenceUrl);
-          }
-
-          var _imageFields = new ArrayList<String>();
-          var _imageWeights = new ArrayList<Float>();
-          splitEntries(imageFields, _imageFields, _imageWeights);
-
-          var _textFields = new ArrayList<String>();
-          var _textWeights = new ArrayList<Float>();
-          splitEntries(imageFields, _textFields, _textWeights);
-
-          put("imageFields", _imageFields);
-          put("textFields", _textFields);
-          put("weights", Map.of(
-              "imageWeights", _imageWeights,
-              "textWeights", _textWeights));
-        }
-      });
-    }
-
-    private void splitEntries(Map<String, Float> map, List<String> keys, List<Float> values) {
-      map.entrySet().forEach(entry -> {
-        keys.add(entry.getKey());
-        var value = entry.getValue();
-        if (value != null) {
-          values.add(value);
-        }
-      });
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/NoneVectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/NoneVectorizer.java
deleted file mode 100644
index 014ed7cca..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/NoneVectorizer.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.Map;
-
-import com.google.gson.annotations.SerializedName;
-
-public class NoneVectorizer extends Vectorizer {
-  @SerializedName("none")
-  private final Map<String, Object> _configuration = Map.of();
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Reference.java b/src/main/java/io/weaviate/client6/v1/collections/Reference.java
deleted file mode 100644
index b17799911..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Reference.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.List;
-
-import com.google.gson.stream.JsonWriter;
-
-import io.weaviate.client6.v1.collections.object.WeaviateObject;
-
-public record Reference(String collection, List<String> uuids) {
-
-  public Reference(String collection, String uuid) {
-    this(collection, List.of(uuid));
-  }
-
-  /**
-   * Create reference to objects by their UUIDs.
-   * <p>
-   * Weaviate will search each of the existing collections to identify
-   * the objects before inserting the references, so this may include
-   * some performance overhead.
-   */
-  public static Reference uuids(String... uuids) {
-    return new Reference(null, Arrays.asList(uuids));
-  }
-
-  /** Create references to {@link WeaviateObject}. */
-  public static Reference[] objects(WeaviateObject<?>... objects) {
-    return Arrays.stream(objects)
-        .map(o -> new Reference(o.collection(), o.metadata().id()))
-        .toArray(Reference[]::new);
-  }
-
-  /** Create references to objects in a collection by their UUIDs. */
-  public static Reference collection(String collection, String... uuids) {
-    return new Reference(collection, Arrays.asList(uuids));
-  }
-
-  // TODO: put this in a type adapter.
-  /** writeValue assumes an array has been started will be ended by the caller. */
-  public void writeValue(JsonWriter w) throws IOException {
-    for (var uuid : uuids) {
-      w.beginObject();
-      w.name("beacon");
-      w.value(toBeacon(uuid));
-      w.endObject();
-    }
-  }
-
-  private String toBeacon(String uuid) {
-    var beacon = "weaviate://localhost/";
-    if (collection != null) {
-      beacon += collection + "/";
-    }
-    beacon += uuid;
-    return beacon;
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Text2VecWeaviateVectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/Text2VecWeaviateVectorizer.java
deleted file mode 100644
index db1f9a0f3..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Text2VecWeaviateVectorizer.java
+++ /dev/null
@@ -1,72 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.function.Consumer;
-
-import com.google.gson.annotations.SerializedName;
-
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class Text2VecWeaviateVectorizer extends Vectorizer {
-  @SerializedName("text2vec-weaviate")
-  private Map<String, Object> configuration;
-
-  public static Text2VecWeaviateVectorizer of() {
-    return new Builder().build();
-  }
-
-  public static Text2VecWeaviateVectorizer of(Consumer<Builder> fn) {
-    var builder = new Builder();
-    fn.accept(builder);
-    return builder.build();
-  }
-
-  public static final String SNOWFLAKE_ARCTIC_EMBED_L_20 = "Snowflake/snowflake-arctic-embed-l-v2.0";
-  public static final String SNOWFLAKE_ARCTIC_EMBED_M_15 = "Snowflake/snowflake-arctic-embed-m-v1.5";
-
-  public static class Builder {
-    private boolean vectorizeCollectionName = false;
-    private String baseUrl;
-    private Integer dimensions;
-    private String model;
-
-    public Builder baseUrl(String baseUrl) {
-      this.baseUrl = baseUrl;
-      return this;
-    }
-
-    public Builder dimensions(int dimensions) {
-      this.dimensions = dimensions;
-      return this;
-    }
-
-    public Builder model(String model) {
-      this.model = model;
-      return this;
-    }
-
-    public Builder vectorizeCollectionName() {
-      this.vectorizeCollectionName = true;
-      return this;
-    }
-
-    public Text2VecWeaviateVectorizer build() {
-      return new Text2VecWeaviateVectorizer(new HashMap<>() {
-        {
-          put("vectorizeClassName", vectorizeCollectionName);
-          if (baseUrl != null) {
-            put("baseURL", baseUrl);
-          }
-          if (dimensions != null) {
-            put("dimensions", dimensions);
-          }
-          if (model != null) {
-            put("model", model);
-          }
-        }
-      });
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/VectorIndex.java b/src/main/java/io/weaviate/client6/v1/collections/VectorIndex.java
deleted file mode 100644
index b8aea7f0c..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/VectorIndex.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.function.Consumer;
-
-import com.google.gson.annotations.SerializedName;
-
-public record VectorIndex<V extends Vectorizer>(
-    @SerializedName("vectorIndexType") IndexType type,
-    @SerializedName("vectorizer") V vectorizer,
-    @SerializedName("vectorIndexConfig") IndexingStrategy configuration) {
-
-  public enum IndexType {
-    @SerializedName("hnsw")
-    HNSW;
-  }
-
-  public VectorIndex(IndexingStrategy index, V vectorizer) {
-    this(index.type(), vectorizer, index);
-  }
-
-  public VectorIndex(V vectorizer) {
-    this(IndexingStrategy.hnsw(), vectorizer);
-  }
-
-  public static sealed interface IndexingStrategy permits HNSW {
-    IndexType type();
-
-    public static IndexingStrategy hnsw() {
-      return new HNSW();
-    }
-
-    public static IndexingStrategy hnsw(Consumer<HNSW.Builder> options) {
-      return HNSW.with(options);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Vectorizer.java b/src/main/java/io/weaviate/client6/v1/collections/Vectorizer.java
deleted file mode 100644
index f2e07be5a..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Vectorizer.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.function.Consumer;
-
-// This class is WIP, I haven't decided how to structure it yet.
-public abstract class Vectorizer {
-  public static NoneVectorizer none() {
-    return new NoneVectorizer();
-  }
-
-  public static ContextionaryVectorizer text2vecContextionary() {
-    return ContextionaryVectorizer.of();
-  }
-
-  public static ContextionaryVectorizer text2vecContextionary(Consumer<ContextionaryVectorizer.Builder> fn) {
-    return ContextionaryVectorizer.of(fn);
-  }
-
-  // TODO: add test cases
-  public static Text2VecWeaviateVectorizer text2vecWeaviate() {
-    return Text2VecWeaviateVectorizer.of();
-  }
-
-  public static Text2VecWeaviateVectorizer text2vecWeaviate(Consumer<Text2VecWeaviateVectorizer.Builder> fn) {
-    return Text2VecWeaviateVectorizer.of(fn);
-  }
-
-  // TODO: add test cases
-  public static Multi2VecClipVectorizer multi2vecClip() {
-    return Multi2VecClipVectorizer.of();
-  }
-
-  public static Multi2VecClipVectorizer multi2vecClip(Consumer<Multi2VecClipVectorizer.Builder> fn) {
-    return Multi2VecClipVectorizer.of(fn);
-  }
-
-  public static Img2VecNeuralVectorizer img2VecNeuralVectorizer() {
-    return Img2VecNeuralVectorizer.of();
-  }
-
-  public static Img2VecNeuralVectorizer img2VecNeuralVectorizer(Consumer<Img2VecNeuralVectorizer.Builder> fn) {
-    return Img2VecNeuralVectorizer.of(fn);
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/Vectors.java b/src/main/java/io/weaviate/client6/v1/collections/Vectors.java
deleted file mode 100644
index 345442914..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/Vectors.java
+++ /dev/null
@@ -1,80 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-import java.util.function.Consumer;
-
-public class Vectors {
-  public static final String DEFAULT = "default";
-
-  private final VectorIndex<? extends Vectorizer> unnamedVector;
-  private final Map<String, VectorIndex<? extends Vectorizer>> namedVectors;
-
-  public static <V extends Vectorizer> Vectors unnamed(VectorIndex<V> vector) {
-    return new Vectors(vector);
-  }
-
-  public static <V extends Vectorizer> Vectors of(String name, VectorIndex<V> vector) {
-    return new Vectors(name, vector);
-  }
-
-  public static <V extends Vectorizer> Vectors of(VectorIndex<V> vector) {
-    return new Vectors(DEFAULT, vector);
-  }
-
-  public static Vectors of(Map<String, VectorIndex<? extends Vectorizer>> vectors) {
-    return new Vectors(vectors);
-  }
-
-  public static Vectors with(Consumer<NamedVectors> named) {
-    var vectors = new NamedVectors(named);
-    return new Vectors(vectors.namedVectors);
-  }
-
-  public VectorIndex<? extends Vectorizer> get(String name) {
-    return namedVectors.get(name);
-  }
-
-  public Optional<VectorIndex<? extends Vectorizer>> getUnnamed() {
-    return Optional.ofNullable(unnamedVector);
-  }
-
-  public VectorIndex<? extends Vectorizer> getDefault() {
-    return namedVectors.get(DEFAULT);
-  }
-
-  // This needs to document the fact that this only returns named vectors.
-  // Rename to "getNamedVectors()"
-  public Map<String, Object> asMap() {
-    return Map.copyOf(namedVectors);
-  }
-
-  <V extends Vectorizer> Vectors(VectorIndex<V> vector) {
-    this.unnamedVector = vector;
-    this.namedVectors = Map.of();
-  }
-
-  <V extends Vectorizer> Vectors(String name, VectorIndex<V> vector) {
-    this.unnamedVector = null;
-    this.namedVectors = Map.of(name, vector);
-  }
-
-  Vectors(Map<String, VectorIndex<? extends Vectorizer>> vectors) {
-    this.unnamedVector = null;
-    this.namedVectors = vectors;
-  }
-
-  public static class NamedVectors {
-    private final Map<String, VectorIndex<? extends Vectorizer>> namedVectors = new HashMap<>();
-
-    public <V extends Vectorizer> NamedVectors vector(String name, VectorIndex<V> vector) {
-      this.namedVectors.put(name, vector);
-      return this;
-    }
-
-    NamedVectors(Consumer<NamedVectors> options) {
-      options.accept(this);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/ConsistencyLevel.java b/src/main/java/io/weaviate/client6/v1/collections/data/ConsistencyLevel.java
deleted file mode 100644
index 3347b012c..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/ConsistencyLevel.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-public enum ConsistencyLevel {
-  ONE, QUORUM, ALL
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/DataClient.java b/src/main/java/io/weaviate/client6/v1/collections/data/DataClient.java
deleted file mode 100644
index 5580ba95d..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/DataClient.java
+++ /dev/null
@@ -1,238 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import java.io.IOException;
-import java.time.OffsetDateTime;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.function.Consumer;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
-import org.apache.hc.client5.http.impl.classic.HttpClients;
-import org.apache.hc.core5.http.ClassicHttpRequest;
-import org.apache.hc.core5.http.ContentType;
-import org.apache.hc.core5.http.HttpStatus;
-import org.apache.hc.core5.http.io.entity.EntityUtils;
-import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
-
-import com.google.gson.Gson;
-
-import io.weaviate.client6.Config;
-import io.weaviate.client6.internal.GRPC;
-import io.weaviate.client6.internal.GrpcClient;
-import io.weaviate.client6.internal.HttpClient;
-import io.weaviate.client6.v1.collections.object.ObjectMetadata;
-import io.weaviate.client6.v1.collections.object.ObjectReference;
-import io.weaviate.client6.v1.collections.object.Vectors;
-import io.weaviate.client6.v1.collections.object.WeaviateObject;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase.Vectors.VectorType;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoProperties.Value;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.MetadataResult;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.PropertiesResult;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.SearchRequest;
-import lombok.AllArgsConstructor;
-
-@AllArgsConstructor
-public class DataClient<T> {
-  // TODO: inject singleton as dependency
-  private static final Gson gson = new Gson();
-
-  // TODO: this should be wrapped around in some TypeInspector etc.
-  private final String collectionName;
-
-  // TODO: hide befind an internal HttpClient
-  private final Config config;
-  private final HttpClient httpClient;
-  private final GrpcClient grpcClient;
-
-  public WeaviateObject<T> insert(T properties) throws IOException {
-    return insert(properties, opt -> {
-    });
-  }
-
-  public WeaviateObject<T> insert(T properties, Consumer<InsertObjectRequest.Builder<T>> fn) throws IOException {
-    return insert(InsertObjectRequest.of(collectionName, properties, fn));
-  }
-
-  public WeaviateObject<T> insert(InsertObjectRequest<T> request) throws IOException {
-    ClassicHttpRequest httpPost = ClassicRequestBuilder
-        .post(config.baseUrl() + "/objects")
-        .setEntity(request.serialize(gson), ContentType.APPLICATION_JSON)
-        .build();
-
-    return httpClient.http.execute(httpPost, response -> {
-      var entity = response.getEntity();
-      if (response.getCode() != HttpStatus.SC_SUCCESS) { // Does not return 201
-        var message = EntityUtils.toString(entity);
-        throw new RuntimeException("HTTP " + response.getCode() + ": " + message);
-      }
-
-      return WeaviateObject.fromJson(gson, entity.getContent());
-    });
-  }
-
-  public Optional<WeaviateObject<T>> get(String id) throws IOException {
-    return get(id, q -> {
-    });
-  }
-
-  public Optional<WeaviateObject<T>> get(String id, Consumer<FetchByIdRequest.Builder> fn) throws IOException {
-    return findById(FetchByIdRequest.of(collectionName, id, fn));
-  }
-
-  private Optional<WeaviateObject<T>> findById(FetchByIdRequest request) {
-    var req = SearchRequest.newBuilder();
-    req.setUses127Api(true);
-    req.setUses125Api(true);
-    req.setUses123Api(true);
-    request.appendTo(req);
-    var result = grpcClient.grpc.search(req.build());
-    var objects = result.getResultsList().stream().map(r -> {
-      var tempObj = readPropertiesResult(r.getProperties());
-      MetadataResult meta = r.getMetadata();
-      Vectors vectors;
-      if (!meta.getVectorBytes().isEmpty()) {
-        vectors = Vectors.of(GRPC.fromByteString(meta.getVectorBytes()));
-      } else {
-        vectors = Vectors.of(meta.getVectorsList().stream().collect(
-            Collectors.<WeaviateProtoBase.Vectors, String, Object>toMap(
-                WeaviateProtoBase.Vectors::getName,
-                v -> {
-                  if (v.getType().equals(VectorType.VECTOR_TYPE_SINGLE_FP32)) {
-                    return GRPC.fromByteString(v.getVectorBytes());
-                  } else {
-                    return GRPC.fromByteStringMulti(v.getVectorBytes());
-                  }
-                })));
-      }
-      var metadata = new ObjectMetadata(meta.getId(), vectors);
-      return new WeaviateObject<>(
-          tempObj.collection(),
-          tempObj.properties(),
-          tempObj.references(),
-          metadata);
-    }).toList();
-    if (objects.isEmpty()) {
-      return Optional.empty();
-    }
-    return Optional.ofNullable((WeaviateObject<T>) objects.get(0));
-  }
-
-  private static WeaviateObject<?> readPropertiesResult(PropertiesResult res) {
-    var collection = res.getTargetCollection();
-    var objectProperties = convertProtoMap(res.getNonRefProps().getFieldsMap());
-
-    // In case a reference is multi-target, there will be a separate
-    // "reference property" for each of the targets, so instead of
-    // `collect` we need to `reduce` the map, merging related references
-    // as we go.
-    // I.e. { "ref": A-1 } , { "ref": B-1 } => { "ref": [A-1, B-1] }
-    var referenceProperties = res.getRefPropsList().stream().reduce(
-        new HashMap<String, ObjectReference>(),
-        (map, ref) -> {
-          var refObjects = ref.getPropertiesList().stream()
-              .map(DataClient::readPropertiesResult)
-              .toList();
-
-          // Merge ObjectReferences by joining the underlying WeaviateObjects.
-          map.merge(
-              ref.getPropName(),
-              new ObjectReference((List<WeaviateObject<?>>) refObjects),
-              (left, right) -> {
-                var joined = Stream.concat(
-                    left.objects().stream(),
-                    right.objects().stream()).toList();
-                return new ObjectReference(joined);
-              });
-          return map;
-        },
-        (left, right) -> {
-          left.putAll(right);
-          return left;
-        });
-
-    MetadataResult meta = res.getMetadata();
-    Vectors vectors;
-    if (meta.getVectorBytes() != null) {
-      vectors = Vectors.of(GRPC.fromByteString(meta.getVectorBytes()));
-    } else {
-      vectors = Vectors.of(meta.getVectorsList().stream().collect(
-          Collectors.<WeaviateProtoBase.Vectors, String, Object>toMap(
-              WeaviateProtoBase.Vectors::getName,
-              v -> {
-                if (v.getType().equals(VectorType.VECTOR_TYPE_MULTI_FP32)) {
-                  return GRPC.fromByteString(v.getVectorBytes());
-                } else {
-                  return GRPC.fromByteStringMulti(v.getVectorBytes());
-                }
-              })));
-    }
-    var metadata = new ObjectMetadata(meta.getId(), vectors);
-    return new WeaviateObject<>(collection, objectProperties, referenceProperties, metadata);
-  }
-
-  /*
-   * Convert Map<String, Value> to Map<String,Object> such that can be
-   * (de-)serialized by {@link Gson}.
-   */
-  private static Map<String, Object> convertProtoMap(Map<String, Value> map) {
-    return map.entrySet().stream()
-        // We cannot use Collectors.toMap() here, because convertProtoValue may
-        // return null (a collection property can be null), which breaks toMap().
-        // See: https://bugs.openjdk.org/browse/JDK-8148463
-        .collect(
-            HashMap::new,
-            (m, e) -> m.put(e.getKey(), convertProtoValue(e.getValue())),
-            HashMap::putAll);
-  }
-
-  /**
-   * Convert protobuf's Value stub to an Object by extracting the first available
-   * field. The checks are non-exhaustive and only cover text, boolean, and
-   * integer values.
-   */
-  private static Object convertProtoValue(Value value) {
-    if (value.hasNullValue()) {
-      // return value.getNullValue();
-      return null;
-    } else if (value.hasTextValue()) {
-      return value.getTextValue();
-    } else if (value.hasBoolValue()) {
-      return value.getBoolValue();
-    } else if (value.hasIntValue()) {
-      return value.getIntValue();
-    } else if (value.hasNumberValue()) {
-      return value.getNumberValue();
-    } else if (value.hasBlobValue()) {
-      return value.getBlobValue();
-    } else if (value.hasDateValue())
-
-    {
-      OffsetDateTime offsetDateTime = OffsetDateTime.parse(value.getDateValue());
-      return Date.from(offsetDateTime.toInstant());
-    } else {
-      assert false : "branch not covered";
-    }
-    return null;
-  }
-
-  public void delete(String id) throws IOException {
-    try (CloseableHttpClient httpclient = HttpClients.createDefault()) {
-      ClassicHttpRequest httpGet = ClassicRequestBuilder
-          .delete(config.baseUrl() + "/objects/" + collectionName + "/" + id)
-          .build();
-
-      httpClient.http.execute(httpGet, response -> {
-        if (response.getCode() != HttpStatus.SC_NO_CONTENT) {
-          throw new RuntimeException(EntityUtils.toString(response.getEntity()));
-        }
-        return null;
-      });
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/FetchByIdRequest.java b/src/main/java/io/weaviate/client6/v1/collections/data/FetchByIdRequest.java
deleted file mode 100644
index bc0c7819f..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/FetchByIdRequest.java
+++ /dev/null
@@ -1,112 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.function.Consumer;
-
-import io.weaviate.client6.v1.api.collections.query.QueryReference;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase.FilterTarget;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase.Filters;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoBase.Filters.Operator;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.MetadataRequest;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.PropertiesRequest;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.RefPropertiesRequest;
-import io.weaviate.client6.v1.internal.grpc.protocol.WeaviateProtoSearchGet.SearchRequest;
-
-public record FetchByIdRequest(
-    String collection,
-    String id,
-    boolean includeVector,
-    List<String> includeVectors,
-    List<String> returnProperties,
-    List<QueryReference> returnReferences) {
-
-  public FetchByIdRequest(Builder options) {
-    this(
-        options.collection,
-        options.uuid,
-        options.includeVector,
-        options.includeVectors,
-        options.returnProperties,
-        options.returnReferences);
-  }
-
-  public static FetchByIdRequest of(String collection, String uuid, Consumer<Builder> fn) {
-    var builder = new Builder(collection, uuid);
-    fn.accept(builder);
-    return new FetchByIdRequest(builder);
-  }
-
-  public static class Builder {
-    private final String collection;
-    private final String uuid;
-
-    public Builder(String collection, String uuid) {
-      this.collection = collection;
-      this.uuid = uuid;
-    }
-
-    private boolean includeVector;
-    private List<String> includeVectors = new ArrayList<>();
-    private List<String> returnProperties = new ArrayList<>();
-    private List<QueryReference> returnReferences = new ArrayList<>();
-
-    public final Builder includeVector() {
-      this.includeVector = true;
-      return this;
-    }
-
-    public final Builder includeVectors(String... vectors) {
-      this.includeVectors = Arrays.asList(vectors);
-      return this;
-    }
-
-    public final Builder returnProperties(String... properties) {
-      this.returnProperties = Arrays.asList(properties);
-      return this;
-    }
-
-    public final Builder returnReferences(QueryReference... references) {
-      this.returnReferences = Arrays.asList(references);
-      return this;
-    }
-
-  }
-
-  void appendTo(SearchRequest.Builder req) {
-    req.setLimit(1);
-    req.setCollection(collection);
-
-    req.setFilters(Filters.newBuilder()
-        .setTarget(FilterTarget.newBuilder().setProperty("_id"))
-        .setValueText(id)
-        .setOperator(Operator.OPERATOR_EQUAL));
-
-    if (!returnProperties.isEmpty() || !returnReferences.isEmpty()) {
-      var properties = PropertiesRequest.newBuilder();
-
-      if (!returnProperties.isEmpty()) {
-        properties.addAllNonRefProperties(returnProperties);
-      }
-
-      if (!returnReferences.isEmpty()) {
-        returnReferences.forEach(r -> {
-          var references = RefPropertiesRequest.newBuilder();
-          r.appendTo(references);
-          properties.addRefProperties(references);
-        });
-      }
-      req.setProperties(properties);
-    }
-
-    // Always request UUID back in this request.
-    var metadata = MetadataRequest.newBuilder().setUuid(true);
-    if (includeVector) {
-      metadata.setVector(true);
-    } else if (!includeVectors.isEmpty()) {
-      metadata.addAllVectors(includeVectors);
-    }
-    req.setMetadata(metadata);
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/GetParameters.java b/src/main/java/io/weaviate/client6/v1/collections/data/GetParameters.java
deleted file mode 100644
index a0e4afd43..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/GetParameters.java
+++ /dev/null
@@ -1,76 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.function.Consumer;
-
-public class GetParameters implements QueryParameters {
-  private enum Include {
-    VECTOR, CLASSIFICATION, INTERPRETATION;
-
-    String toLowerCase() {
-      return this.name().toLowerCase();
-    }
-  }
-
-  private Set<Include> include = new LinkedHashSet<>(); // Preserves insertion order, helps testing
-  private ConsistencyLevel consistency;
-  private String nodeName;
-  private String tenant;
-
-  GetParameters(Consumer<GetParameters> options) {
-    options.accept(this);
-  }
-
-  public GetParameters withVector() {
-    include.add(Include.VECTOR);
-    return this;
-  }
-
-  public GetParameters withClassification() {
-    include.add(Include.CLASSIFICATION);
-    return this;
-  }
-
-  public GetParameters withInterpretation() {
-    include.add(Include.INTERPRETATION);
-    return this;
-  }
-
-  public GetParameters consistencyLevel(ConsistencyLevel consistency) {
-    this.consistency = consistency;
-    return this;
-  }
-
-  public GetParameters nodeName(String name) {
-    this.nodeName = name;
-    return this;
-  }
-
-  public GetParameters tenant(String name) {
-    this.tenant = name;
-    return this;
-  }
-
-  @Override
-  public String encode() {
-    var sb = new StringBuilder();
-
-    if (!include.isEmpty()) {
-      List<String> includeString = include.stream().map(Include::toLowerCase).toList();
-      QueryParameters.addRaw(sb, "include", String.join(",", includeString));
-    }
-
-    if (consistency != null) {
-      QueryParameters.add(sb, "consistency_level", consistency.name());
-    }
-    if (nodeName != null) {
-      QueryParameters.add(sb, "node_name", nodeName);
-    }
-    if (tenant != null) {
-      QueryParameters.add(sb, "tenant", tenant);
-    }
-    return sb.toString();
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/InsertObjectRequest.java b/src/main/java/io/weaviate/client6/v1/collections/data/InsertObjectRequest.java
deleted file mode 100644
index d2dd6d482..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/InsertObjectRequest.java
+++ /dev/null
@@ -1,150 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import java.io.IOException;
-import java.io.StringWriter;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Consumer;
-import java.util.function.Function;
-
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
-
-import io.weaviate.client6.v1.api.collections.Vectors;
-import io.weaviate.client6.v1.collections.Reference;
-
-public record InsertObjectRequest<T>(String collection, T properties, String id, Vectors vectors,
-    Map<String, List<Reference>> references) {
-
-  /** Create InsertObjectRequest from Builder options. */
-  public InsertObjectRequest(Builder<T> builder) {
-    this(builder.collection, builder.properties, builder.id, builder.vectors, builder.references);
-  }
-
-  /**
-   * Construct InsertObjectRequest with optional parameters.
-   *
-   * @param <T>        Shape of the object properties, e.g.
-   *                   {@code Map<String, Object>}
-   * @param collection Collection to insert to.
-   * @param properties Object properties.
-   * @param fn         Optional parameters
-   * @return InsertObjectRequest
-   */
-  static <T> InsertObjectRequest<T> of(String collection, T properties, Consumer<Builder<T>> fn) {
-    var builder = new Builder<>(collection, properties);
-    fn.accept(builder);
-    return builder.build();
-  }
-
-  public static class Builder<T> {
-    private final String collection; // Required
-    private final T properties; // Required
-
-    private String id;
-    private Vectors vectors;
-    private final Map<String, List<Reference>> references = new HashMap<>();
-
-    Builder(String collection, T properties) {
-      this.collection = collection;
-      this.properties = properties;
-    }
-
-    /** Define custom object id. Must be a valid UUID. */
-    public Builder<T> id(String id) {
-      this.id = id;
-      return this;
-    }
-
-    /**
-     * Supply one or more (named) vectors. Calls to {@link #vectors} are not
-     * chainable. Use {@link Vectors#of(Function)} to pass multiple vectors.
-     */
-    public Builder<T> vectors(Vectors vectors) {
-      this.vectors = vectors;
-      return this;
-    }
-
-    /**
-     * Add a reference. Calls to {@link #reference} can be chained
-     * to add multiple references.
-     */
-    public Builder<T> reference(String property, Reference... references) {
-      for (var ref : references) {
-        addReference(property, ref);
-      }
-      return this;
-    }
-
-    private void addReference(String property, Reference reference) {
-      if (!references.containsKey(property)) {
-        references.put(property, new ArrayList<>());
-      }
-      references.get(property).add(reference);
-    }
-
-    /** Build a new InsertObjectRequest. */
-    public InsertObjectRequest<T> build() {
-      return new InsertObjectRequest<>(this);
-    }
-  }
-
-  // Here we're just rawdogging JSON serialization just to get a good feel for it.
-  public String serialize(Gson gson) throws IOException {
-    var buf = new StringWriter();
-    var w = gson.newJsonWriter(buf);
-
-    w.beginObject();
-
-    w.name("class");
-    w.value(collection);
-
-    if (id != null) {
-      w.name("id");
-      w.value(id);
-    }
-
-    if (vectors != null) {
-      var unnamed = vectors.getUnnamed();
-      if (unnamed.isPresent()) {
-        w.name("vector");
-        gson.getAdapter(Float[].class).write(w, unnamed.get());
-      } else {
-        w.name("vectors");
-        gson.getAdapter(new TypeToken<Map<String, Object>>() {
-        }).write(w, vectors.getNamed());
-      }
-    }
-
-    if (properties != null || references != null) {
-      w.name("properties");
-      w.beginObject();
-
-      if (properties != null) {
-        assert properties instanceof Map : "properties not a Map";
-        for (var entry : ((Map<String, Object>) properties).entrySet()) {
-          w.name(entry.getKey());
-          gson.getAdapter(Object.class).write(w, entry.getValue());
-        }
-
-      }
-      if (references != null && !references.isEmpty()) {
-        for (var entry : references.entrySet()) {
-          w.name(entry.getKey());
-          w.beginArray();
-          for (var ref : entry.getValue()) {
-            ref.writeValue(w);
-          }
-          w.endArray();
-        }
-      }
-
-      w.endObject();
-    }
-
-    w.endObject();
-    return buf.toString();
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/data/QueryParameters.java b/src/main/java/io/weaviate/client6/v1/collections/data/QueryParameters.java
deleted file mode 100644
index 6f7eda826..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/data/QueryParameters.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import java.io.UnsupportedEncodingException;
-import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
-import java.util.function.Consumer;
-
-interface QueryParameters {
-  /* Implementations must return an empty string if there're no parameters. */
-  String encode();
-
-  static String encodeGet(Consumer<GetParameters> options) {
-    return with(new GetParameters(options));
-  }
-
-  private static <P extends QueryParameters> String with(P parameters) {
-    var encoded = parameters.encode();
-    return encoded.isEmpty() ? "" : "?" + encoded;
-  }
-
-  static void add(StringBuilder sb, String key, String value) {
-    addRaw(sb, encode(key), encode(value));
-  }
-
-  static void addRaw(StringBuilder sb, String key, String value) {
-    if (!sb.isEmpty()) {
-      sb.append("&");
-    }
-    sb.append(key).append("=").append(value);
-  }
-
-  static String encode(String value) {
-    try {
-      return URLEncoder.encode(value, StandardCharsets.UTF_8.name());
-    } catch (UnsupportedEncodingException e) {
-      // Will never happen, as we are using standard encoding.
-      return value;
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/object/ObjectMetadata.java b/src/main/java/io/weaviate/client6/v1/collections/object/ObjectMetadata.java
deleted file mode 100644
index 61ffcb9de..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/object/ObjectMetadata.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package io.weaviate.client6.v1.collections.object;
-
-import java.util.function.Consumer;
-
-public record ObjectMetadata(String id, Vectors vectors) {
-
-  public static ObjectMetadata with(Consumer<Builder> options) {
-    var opt = new Builder(options);
-    return new ObjectMetadata(opt.id, opt.vectors);
-  }
-
-  public static class Builder {
-    private String id;
-    private Vectors vectors;
-
-    public Builder id(String id) {
-      this.id = id;
-      return this;
-    }
-
-    public Builder vectors(Vectors vectors) {
-      this.vectors = vectors;
-      return this;
-    }
-
-    private Builder(Consumer<Builder> options) {
-      options.accept(this);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/object/ObjectReference.java b/src/main/java/io/weaviate/client6/v1/collections/object/ObjectReference.java
deleted file mode 100644
index bc5c82c04..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/object/ObjectReference.java
+++ /dev/null
@@ -1,6 +0,0 @@
-package io.weaviate.client6.v1.collections.object;
-
-import java.util.List;
-
-public record ObjectReference(List<WeaviateObject<?>> objects) {
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/object/Vectors.java b/src/main/java/io/weaviate/client6/v1/collections/object/Vectors.java
deleted file mode 100644
index db0669e90..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/object/Vectors.java
+++ /dev/null
@@ -1,134 +0,0 @@
-package io.weaviate.client6.v1.collections.object;
-
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-import java.util.function.Consumer;
-
-import lombok.ToString;
-
-/**
- * Vectors is an abstraction over named vectors.
- * It may contain both 1-dimensional and 2-dimensional vectors.
- */
-@ToString
-public class Vectors {
-  private static final String DEFAULT = "default";
-
-  private Float[] unnamedVector;
-  private Map<String, Object> namedVectors;
-
-  public Float[] getSingle(String name) {
-    return (Float[]) namedVectors.get(name);
-  }
-
-  public Float[] getDefaultSingle() {
-    return getSingle(DEFAULT);
-  }
-
-  @SuppressWarnings("unchecked")
-  public Optional<Float[]> getSingle() {
-    return (Optional<Float[]>) getOnly();
-  }
-
-  public Float[][] getMulti(String name) {
-    return (Float[][]) namedVectors.get(name);
-  }
-
-  public Float[][] getDefaultMulti() {
-    return getMulti(DEFAULT);
-  }
-
-  @SuppressWarnings("unchecked")
-  public Optional<Float[][]> getMulti() {
-    return (Optional<Float[][]>) getOnly();
-  }
-
-  public Optional<Float[]> getUnnamed() {
-    return Optional.ofNullable(unnamedVector);
-  }
-
-  private Optional<?> getOnly() {
-    if (namedVectors == null || namedVectors.isEmpty() || namedVectors.size() > 1) {
-      return Optional.empty();
-    }
-    return Optional.ofNullable(namedVectors.values().iterator().next());
-  }
-
-  public Map<String, Object> getNamed() {
-    return Map.copyOf(namedVectors);
-  }
-
-  /** Creates Vectors with a single unnamed vector. */
-  private Vectors(Float[] vector) {
-    this(Map.of());
-    this.unnamedVector = vector;
-  }
-
-  /** Creates Vectors with one named vector. */
-  private Vectors(String name, Object vector) {
-    this.namedVectors = Map.of(name, vector);
-  }
-
-  /** Creates immutable set of vectors. */
-  private Vectors(Map<String, ? extends Object> vectors) {
-    this.namedVectors = Collections.unmodifiableMap(vectors);
-  }
-
-  private Vectors(NamedVectors named) {
-    this.namedVectors = named.namedVectors;
-  }
-
-  /**
-   * Pass legacy unnamed vector.
-   * Multi-vectors can only be passed as named vectors.
-   */
-  public static Vectors unnamed(Float[] vector) {
-    return new Vectors(vector);
-  }
-
-  public static Vectors of(Float[] vector) {
-    return new Vectors(DEFAULT, vector);
-  }
-
-  public static Vectors of(Float[][] vector) {
-    return new Vectors(DEFAULT, vector);
-  }
-
-  public static Vectors of(String name, Float[] vector) {
-    return new Vectors(name, vector);
-  }
-
-  public static Vectors of(String name, Float[][] vector) {
-    return new Vectors(name, vector);
-  }
-
-  public static Vectors of(Map<String, ? extends Object> vectors) {
-    return new Vectors(vectors);
-  }
-
-  public static Vectors of(Consumer<NamedVectors> fn) {
-    var named = new NamedVectors();
-    fn.accept(named);
-    return named.build();
-  }
-
-  public static class NamedVectors {
-    private Map<String, Object> namedVectors = new HashMap<>();
-
-    public NamedVectors vector(String name, Float[] vector) {
-      this.namedVectors.put(name, vector);
-      return this;
-    }
-
-    public NamedVectors vector(String name, Float[][] vector) {
-      this.namedVectors.put(name, vector);
-      return this;
-    }
-
-    public Vectors build() {
-      return new Vectors(this);
-    }
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObject.java b/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObject.java
deleted file mode 100644
index 28d5cc3b2..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObject.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package io.weaviate.client6.v1.collections.object;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.util.Map;
-import java.util.function.Consumer;
-
-import com.google.common.reflect.TypeToken;
-import com.google.gson.Gson;
-
-public record WeaviateObject<T>(
-    String collection,
-    T properties,
-    Map<String, ObjectReference> references,
-    ObjectMetadata metadata) {
-
-  public WeaviateObject(String collection, T properties, Map<String, ObjectReference> references,
-      Consumer<ObjectMetadata.Builder> options) {
-    this(collection, properties, references, ObjectMetadata.with(options));
-  }
-
-  // JSON serialization ----------------
-  public static <T> WeaviateObject<T> fromJson(Gson gson, InputStream input) throws IOException {
-    try (var r = new InputStreamReader(input)) {
-      WeaviateObjectDTO<T> dto = gson.fromJson(r, new TypeToken<WeaviateObjectDTO<T>>() {
-      }.getType());
-      return dto.toWeaviateObject();
-    }
-  }
-
-  public String toJson(Gson gson) {
-    return gson.toJson(new WeaviateObjectDTO<>(this));
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObjectDTO.java b/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObjectDTO.java
deleted file mode 100644
index e57afc1b5..000000000
--- a/src/main/java/io/weaviate/client6/v1/collections/object/WeaviateObjectDTO.java
+++ /dev/null
@@ -1,49 +0,0 @@
-package io.weaviate.client6.v1.collections.object;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Map;
-
-import com.google.gson.annotations.SerializedName;
-
-class WeaviateObjectDTO<T> {
-  @SerializedName("class")
-  String collection;
-  @SerializedName("id")
-  String id;
-  @SerializedName("properties")
-  T properties;
-  @SerializedName("vectors")
-  Map<String, Object> vectors;
-
-  WeaviateObjectDTO(WeaviateObject<T> object) {
-    this.collection = object.collection();
-    this.properties = object.properties();
-
-    if (object.metadata() != null) {
-      this.id = object.metadata().id();
-      if (object.metadata().vectors() != null) {
-        this.vectors = object.metadata().vectors().getNamed();
-      }
-    }
-  }
-
-  WeaviateObject<T> toWeaviateObject() {
-    Map<String, Object> arrayVectors = new HashMap<>();
-    if (vectors != null) {
-      for (var entry : vectors.entrySet()) {
-        var value = (ArrayList<Double>) entry.getValue();
-        var vector = new Float[value.size()];
-        int i = 0;
-        for (var v : value) {
-          vector[i++] = v.floatValue();
-        }
-        arrayVectors.put(entry.getKey(), vector);
-      }
-    }
-
-    return new WeaviateObject<T>(collection, properties,
-        /* no references through HTTP */ new HashMap<>(),
-        new ObjectMetadata(id, Vectors.of(arrayVectors)));
-  }
-}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/grpc/DefaultGrpcTransport.java b/src/main/java/io/weaviate/client6/v1/internal/grpc/DefaultGrpcTransport.java
index 442947a97..f071c9005 100644
--- a/src/main/java/io/weaviate/client6/v1/internal/grpc/DefaultGrpcTransport.java
+++ b/src/main/java/io/weaviate/client6/v1/internal/grpc/DefaultGrpcTransport.java
@@ -82,7 +82,7 @@ private static ManagedChannel buildChannel(GrpcChannelOptions options) {
     }
 
     var headers = new Metadata();
-    for (final var header : options.headers()) {
+    for (final var header : options.headers().entrySet()) {
       var key = Metadata.Key.of(header.getKey(), Metadata.ASCII_STRING_MARSHALLER);
       headers.put(key, header.getValue());
 
diff --git a/src/main/java/io/weaviate/client6/internal/GRPC.java b/src/main/java/io/weaviate/client6/v1/internal/grpc/GRPC.java
similarity index 98%
rename from src/main/java/io/weaviate/client6/internal/GRPC.java
rename to src/main/java/io/weaviate/client6/v1/internal/grpc/GRPC.java
index bd9bdd6c1..e5a6c0b5a 100644
--- a/src/main/java/io/weaviate/client6/internal/GRPC.java
+++ b/src/main/java/io/weaviate/client6/v1/internal/grpc/GRPC.java
@@ -1,4 +1,4 @@
-package io.weaviate.client6.internal;
+package io.weaviate.client6.v1.internal.grpc;
 
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
diff --git a/src/main/java/io/weaviate/client6/v1/internal/grpc/GrpcChannelOptions.java b/src/main/java/io/weaviate/client6/v1/internal/grpc/GrpcChannelOptions.java
index d6fed091a..517345844 100644
--- a/src/main/java/io/weaviate/client6/v1/internal/grpc/GrpcChannelOptions.java
+++ b/src/main/java/io/weaviate/client6/v1/internal/grpc/GrpcChannelOptions.java
@@ -1,12 +1,15 @@
 package io.weaviate.client6.v1.internal.grpc;
 
-import java.util.Collection;
+import java.util.Collections;
 import java.util.Map;
 
+// TODO: unify with rest.TransportOptions?
 public interface GrpcChannelOptions {
   String host();
 
-  Collection<Map.Entry<String, String>> headers();
+  default Map<String, String> headers() {
+    return Collections.emptyMap();
+  }
 
   boolean useTls();
 }
diff --git a/src/main/java/io/weaviate/client6/v1/internal/grpc/WeaviateObjectTypeAdapter.java b/src/main/java/io/weaviate/client6/v1/internal/grpc/WeaviateObjectTypeAdapter.java
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/main/java/io/weaviate/client6/v1/internal/json/JSON.java b/src/main/java/io/weaviate/client6/v1/internal/json/JSON.java
new file mode 100644
index 000000000..91ae742ce
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/json/JSON.java
@@ -0,0 +1,54 @@
+package io.weaviate.client6.v1.internal.json;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+
+public final class JSON {
+  private static final Gson gson;
+
+  static {
+    var gsonBuilder = new GsonBuilder();
+    gsonBuilder.registerTypeAdapterFactory(
+        io.weaviate.client6.v1.api.collections.WeaviateObject.CustomTypeAdapterFactory.INSTANCE);
+    gsonBuilder.registerTypeAdapterFactory(
+        io.weaviate.client6.v1.api.collections.WeaviateCollection.CustomTypeAdapterFactory.INSTANCE);
+    gsonBuilder.registerTypeAdapterFactory(
+        io.weaviate.client6.v1.api.collections.Vectors.CustomTypeAdapterFactory.INSTANCE);
+    gsonBuilder.registerTypeAdapterFactory(
+        io.weaviate.client6.v1.api.collections.Vectorizer.CustomTypeAdapterFactory.INSTANCE);
+    gsonBuilder.registerTypeAdapterFactory(
+        io.weaviate.client6.v1.api.collections.VectorIndex.CustomTypeAdapterFactory.INSTANCE);
+
+    gsonBuilder.registerTypeAdapter(
+        io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer.class,
+        io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer.TYPE_ADAPTER);
+    gsonBuilder.registerTypeAdapter(
+        io.weaviate.client6.v1.api.collections.data.Reference.class,
+        io.weaviate.client6.v1.api.collections.data.Reference.TYPE_ADAPTER);
+    gson = gsonBuilder.create();
+  }
+
+  public static final Gson getGson() {
+    return gson;
+  }
+
+  public static final String serialize(Object value) {
+    if (value == null) {
+      return null;
+    }
+    return serialize(value, TypeToken.get(value.getClass()));
+  }
+
+  public static final String serialize(Object value, TypeToken<?> typeToken) {
+    return gson.toJson(value, typeToken.getType());
+  }
+
+  public static final <T> T deserialize(String json, Class<T> cls) {
+    return gson.fromJson(json, cls);
+  }
+
+  public static final <T> T deserialize(String json, TypeToken<T> token) {
+    return gson.fromJson(json, token);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/json/JsonEnum.java b/src/main/java/io/weaviate/client6/v1/internal/json/JsonEnum.java
new file mode 100644
index 000000000..c68a64892
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/json/JsonEnum.java
@@ -0,0 +1,26 @@
+package io.weaviate.client6.v1.internal.json;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public interface JsonEnum<E extends Enum<E>> {
+  String jsonValue();
+
+  static <E extends Enum<E>> Map<String, E> collectNames(JsonEnum<E>[] values) {
+    final var jsonValueMap = new HashMap<String, E>(values.length);
+    for (var value : values) {
+      @SuppressWarnings("unchecked")
+      var enumInstance = (E) value;
+      jsonValueMap.put(value.jsonValue(), enumInstance);
+    }
+    return Collections.unmodifiableMap(jsonValueMap);
+  }
+
+  static <E extends Enum<E>> E valueOfJson(String jsonValue, Map<String, E> enums, Class<E> cls) {
+    if (!enums.containsKey(jsonValue)) {
+      throw new IllegalArgumentException("%s does not have a member with jsonValue=%s".formatted(cls, jsonValue));
+    }
+    return enums.get(jsonValue);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/orm/CollectionDescriptor.java b/src/main/java/io/weaviate/client6/v1/internal/orm/CollectionDescriptor.java
index 9ab299a16..a122c7214 100644
--- a/src/main/java/io/weaviate/client6/v1/internal/orm/CollectionDescriptor.java
+++ b/src/main/java/io/weaviate/client6/v1/internal/orm/CollectionDescriptor.java
@@ -1,9 +1,19 @@
 package io.weaviate.client6.v1.internal.orm;
 
-public interface CollectionDescriptor<T> {
+import java.util.Map;
+
+import com.google.gson.reflect.TypeToken;
+
+public sealed interface CollectionDescriptor<T> permits MapDescriptor {
   String name();
 
+  TypeToken<T> typeToken();
+
   PropertiesReader<T> propertiesReader(T properties);
 
   PropertiesBuilder<T> propertiesBuilder();
+
+  static CollectionDescriptor<Map<String, Object>> ofMap(String collectionName) {
+    return new MapDescriptor(collectionName);
+  }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/internal/orm/MapDescriptor.java b/src/main/java/io/weaviate/client6/v1/internal/orm/MapDescriptor.java
index f8c9477ee..2910f2db4 100644
--- a/src/main/java/io/weaviate/client6/v1/internal/orm/MapDescriptor.java
+++ b/src/main/java/io/weaviate/client6/v1/internal/orm/MapDescriptor.java
@@ -2,7 +2,9 @@
 
 import java.util.Map;
 
-public class MapDescriptor implements CollectionDescriptor<Map<String, Object>> {
+import com.google.gson.reflect.TypeToken;
+
+public final class MapDescriptor implements CollectionDescriptor<Map<String, Object>> {
   private final String collectionName;
 
   public MapDescriptor(String collectionName) {
@@ -23,4 +25,10 @@ public PropertiesReader<Map<String, Object>> propertiesReader(Map<String, Object
   public PropertiesBuilder<Map<String, Object>> propertiesBuilder() {
     return new MapBuilder();
   }
+
+  @SuppressWarnings("unchecked")
+  @Override
+  public TypeToken<Map<String, Object>> typeToken() {
+    return (TypeToken<Map<String, Object>>) TypeToken.getParameterized(Map.class, String.class, Object.class);
+  }
 }
diff --git a/src/main/java/io/weaviate/client6/v1/internal/rest/DefaultRestTransport.java b/src/main/java/io/weaviate/client6/v1/internal/rest/DefaultRestTransport.java
new file mode 100644
index 000000000..470df5e89
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/rest/DefaultRestTransport.java
@@ -0,0 +1,108 @@
+package io.weaviate.client6.v1.internal.rest;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+
+import org.apache.hc.client5.http.async.methods.SimpleHttpRequest;
+import org.apache.hc.client5.http.async.methods.SimpleHttpResponse;
+import org.apache.hc.client5.http.impl.async.CloseableHttpAsyncClient;
+import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
+import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
+import org.apache.hc.client5.http.impl.classic.HttpClients;
+import org.apache.hc.core5.concurrent.FutureCallback;
+import org.apache.hc.core5.http.ClassicHttpRequest;
+import org.apache.hc.core5.http.ContentType;
+import org.apache.hc.core5.http.io.entity.EntityUtils;
+import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
+import org.apache.hc.core5.io.CloseMode;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+public class DefaultRestTransport implements RestTransport {
+  private final CloseableHttpClient httpClient;
+  private final CloseableHttpAsyncClient httpClientAsync;
+  private final TransportOptions transportOptions;
+
+  private static final Gson gson = new GsonBuilder().create();
+
+  public DefaultRestTransport(TransportOptions options) {
+    this.transportOptions = options;
+    this.httpClient = HttpClients.createDefault();
+    this.httpClientAsync = HttpAsyncClients.createDefault();
+    httpClientAsync.start();
+  }
+
+  @Override
+  public <RequestT, ResponseT> ResponseT performRequest(RequestT request, Endpoint<RequestT, ResponseT> endpoint)
+      throws IOException {
+    var req = prepareClassicRequest(request, endpoint);
+    // FIXME: we need to differentiate between "no body" and "soumething's wrong"
+    return this.httpClient.execute(req,
+        response -> response.getEntity() != null
+            ? endpoint.deserializeResponse(gson, EntityUtils.toString(response.getEntity()))
+            : null);
+  }
+
+  @Override
+  public <RequestT, ResponseT> CompletableFuture<ResponseT> performRequestAsync(RequestT request,
+      Endpoint<RequestT, ResponseT> endpoint) {
+    var req = prepareSimpleRequest(request, endpoint);
+
+    var completable = new CompletableFuture<SimpleHttpResponse>();
+    this.httpClientAsync.execute(req, new FutureCallback<>() {
+
+      @Override
+      public void completed(SimpleHttpResponse result) {
+        completable.complete(result);
+      }
+
+      @Override
+      public void failed(Exception ex) {
+        completable.completeExceptionally(ex);
+      }
+
+      @Override
+      public void cancelled() {
+        completable.cancel(false);
+      }
+
+    });
+    // FIXME: we need to differentiate between "no body" and "soumething's wrong"
+    return completable.thenApply(r -> r.getBody() == null
+        ? endpoint.deserializeResponse(gson, r.getBody().getBodyText())
+        : null);
+  }
+
+  private <RequestT> SimpleHttpRequest prepareSimpleRequest(RequestT request, Endpoint<RequestT, ?> endpoint) {
+    var method = endpoint.method(request);
+    var uri = transportOptions.host() + endpoint.requestUrl(request);
+    // TODO: apply options;
+
+    var body = endpoint.body(gson, request);
+    var req = SimpleHttpRequest.create(method, uri);
+    if (body != null) {
+      req.setBody(body.getBytes(), ContentType.APPLICATION_JSON);
+    }
+    return req;
+  }
+
+  private <RequestT> ClassicHttpRequest prepareClassicRequest(RequestT request, Endpoint<RequestT, ?> endpoint) {
+    var method = endpoint.method(request);
+    var uri = transportOptions.host() + endpoint.requestUrl(request);
+
+    // TODO: apply options;
+    var req = ClassicRequestBuilder.create(method).setUri(uri);
+    var body = endpoint.body(gson, request);
+    if (body != null) {
+      req.setEntity(body, ContentType.APPLICATION_JSON);
+    }
+    return req.build();
+  }
+
+  @Override
+  public void close() throws IOException {
+    httpClient.close();
+    httpClientAsync.close(CloseMode.GRACEFUL);
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/rest/Endpoint.java b/src/main/java/io/weaviate/client6/v1/internal/rest/Endpoint.java
new file mode 100644
index 000000000..7c8998a61
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/rest/Endpoint.java
@@ -0,0 +1,65 @@
+package io.weaviate.client6.v1.internal.rest;
+
+import java.util.Map;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+
+import com.google.gson.Gson;
+
+public interface Endpoint<RequestT, ResponseT> {
+
+  String method(RequestT request);
+
+  String requestUrl(RequestT request);
+
+  // Gson is leaking.
+  String body(Gson gson, RequestT request);
+
+  Map<String, String> queryParameters(RequestT request);
+
+  /** Should this status code be considered an error? */
+  boolean isError(int code);
+
+  ResponseT deserializeResponse(Gson gson, String response);
+
+  public static <RequestT, ResponseT> Endpoint<RequestT, ResponseT> of(
+      Function<RequestT, String> method,
+      Function<RequestT, String> requestUrl,
+      BiFunction<Gson, RequestT, String> body,
+      Function<RequestT, Map<String, String>> queryParameters,
+      Function<Integer, Boolean> isError,
+      BiFunction<Gson, String, ResponseT> deserialize) {
+    return new Endpoint<RequestT, ResponseT>() {
+
+      @Override
+      public String method(RequestT request) {
+        return method.apply(request);
+      }
+
+      @Override
+      public String requestUrl(RequestT request) {
+        return requestUrl.apply(request);
+      }
+
+      @Override
+      public String body(Gson gson, RequestT request) {
+        return body.apply(gson, request);
+      }
+
+      @Override
+      public Map<String, String> queryParameters(RequestT request) {
+        return queryParameters.apply(request);
+      }
+
+      @Override
+      public ResponseT deserializeResponse(Gson gson, String response) {
+        return deserialize.apply(gson, response);
+      }
+
+      @Override
+      public boolean isError(int code) {
+        return isError.apply(code);
+      }
+    };
+  }
+}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/rest/RestTransport.java b/src/main/java/io/weaviate/client6/v1/internal/rest/RestTransport.java
new file mode 100644
index 000000000..b20c98fbd
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/rest/RestTransport.java
@@ -0,0 +1,13 @@
+package io.weaviate.client6.v1.internal.rest;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+
+public interface RestTransport extends Closeable {
+  <RequestT, ResponseT> ResponseT performRequest(RequestT request, Endpoint<RequestT, ResponseT> endpoint)
+      throws IOException;
+
+  <RequestT, ResponseT> CompletableFuture<ResponseT> performRequestAsync(RequestT request,
+      Endpoint<RequestT, ResponseT> endpoint);
+}
diff --git a/src/main/java/io/weaviate/client6/v1/internal/rest/TransportOptions.java b/src/main/java/io/weaviate/client6/v1/internal/rest/TransportOptions.java
new file mode 100644
index 000000000..9ddb3fa70
--- /dev/null
+++ b/src/main/java/io/weaviate/client6/v1/internal/rest/TransportOptions.java
@@ -0,0 +1,12 @@
+package io.weaviate.client6.v1.internal.rest;
+
+import java.util.Collections;
+import java.util.Map;
+
+public interface TransportOptions {
+  String host();
+
+  default Map<String, String> headers() {
+    return Collections.emptyMap();
+  }
+}
diff --git a/src/test/java/io/weaviate/client6/internal/DtoTypeAdapterFactoryTest.java b/src/test/java/io/weaviate/client6/internal/DtoTypeAdapterFactoryTest.java
deleted file mode 100644
index f3ca920db..000000000
--- a/src/test/java/io/weaviate/client6/internal/DtoTypeAdapterFactoryTest.java
+++ /dev/null
@@ -1,76 +0,0 @@
-package io.weaviate.client6.internal;
-
-import org.assertj.core.api.Assertions;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonParser;
-import com.jparams.junit4.JParamsTestRunner;
-import com.jparams.junit4.data.DataMethod;
-
-@RunWith(JParamsTestRunner.class)
-public class DtoTypeAdapterFactoryTest {
-  /** Person should be serialized to PersonDto. */
-  record Person(String name) {
-  }
-
-  record PersonDto(String nickname) implements DtoTypeAdapterFactory.Dto<Person> {
-    PersonDto(Person p) {
-      this(p.name);
-    }
-
-    @Override
-    public Person toModel() {
-      return new Person(nickname);
-    }
-  }
-
-  /** Car's DTO is a nested record. */
-  record Car(String brand) {
-    record CarDto(String manufacturer, Integer version) implements DtoTypeAdapterFactory.Dto<Car> {
-      CarDto(Car c) {
-        this(c.brand, 1);
-      }
-
-      @Override
-      public Car toModel() {
-        return new Car(manufacturer);
-      }
-    }
-  }
-
-  /** Normal does not have a DTO and should be serialized as usual. */
-  record Normal(String key, String value) {
-  }
-
-  static {
-    DtoTypeAdapterFactory.register(Person.class, PersonDto.class, m -> new PersonDto(m));
-    DtoTypeAdapterFactory.register(Car.class, Car.CarDto.class, m -> new Car.CarDto(m));
-  }
-
-  private static final Gson gson = new GsonBuilder()
-      .registerTypeAdapterFactory(new DtoTypeAdapterFactory())
-      .create();
-
-  public static Object[][] testCases() {
-    return new Object[][] {
-        { new Person("Josh"), "{\"nickname\": \"Josh\"}" },
-        { new Car("Porsche"), "{\"manufacturer\": \"Porsche\", \"version\": 1}" },
-        { new Normal("foo", "bar"), "{\"key\": \"foo\", \"value\": \"bar\"}" },
-    };
-  }
-
-  @Test
-  @DataMethod(source = DtoTypeAdapterFactoryTest.class, method = "testCases")
-  public void testRoundtrip(Object model, String wantJson) {
-    var gotJson = gson.toJson(model);
-    Assertions.assertThat(JsonParser.parseString(gotJson))
-        .as("serialized")
-        .isEqualTo(JsonParser.parseString(wantJson));
-
-    var deserialized = gson.fromJson(gotJson, model.getClass());
-    Assertions.assertThat(deserialized).as("deserialized").isEqualTo(model);
-  }
-}
diff --git a/src/test/java/io/weaviate/client6/v1/ObjectMetadataTest.java b/src/test/java/io/weaviate/client6/v1/ObjectMetadataTest.java
deleted file mode 100644
index f95446fdc..000000000
--- a/src/test/java/io/weaviate/client6/v1/ObjectMetadataTest.java
+++ /dev/null
@@ -1,96 +0,0 @@
-package io.weaviate.client6.v1;
-
-import java.util.Optional;
-
-import org.assertj.core.api.Assertions;
-import org.junit.Test;
-
-import io.weaviate.client6.v1.collections.object.ObjectMetadata;
-import io.weaviate.client6.v1.collections.object.Vectors;
-
-public class ObjectMetadataTest {
-
-  @Test
-  public final void testMetadata_id() {
-    var metadata = ObjectMetadata.with(m -> m.id("object-1"));
-    Assertions.assertThat(metadata.id())
-        .as("object id").isEqualTo("object-1");
-  }
-
-  @Test
-  public final void testVectorsMetadata_unnamed() {
-    Float[] vector = { 1f, 2f, 3f };
-    var metadata = ObjectMetadata.with(m -> m.vectors(Vectors.unnamed(vector)));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("unnamed vector").isNotNull()
-        .returns(Optional.of(vector), Vectors::getUnnamed)
-        .returns(Optional.empty(), Vectors::getSingle);
-  }
-
-  @Test
-  public final void testVectorsMetadata_default() {
-    Float[] vector = { 1f, 2f, 3f };
-    var metadata = ObjectMetadata.with(m -> m.vectors(Vectors.of(vector)));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("default vector").isNotNull()
-        .returns(vector, Vectors::getDefaultSingle)
-        .returns(Optional.of(vector), Vectors::getSingle)
-        .returns(Optional.empty(), Vectors::getUnnamed);
-  }
-
-  @Test
-  public final void testVectorsMetadata_default_2d() {
-    Float[][] vector = { { 1f, 2f, 3f }, { 1f, 2f, 3f } };
-    var metadata = ObjectMetadata.with(m -> m.vectors(Vectors.of(vector)));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("default 2d vector").isNotNull()
-        .returns(vector, Vectors::getDefaultMulti)
-        .returns(Optional.of(vector), Vectors::getMulti)
-        .returns(Optional.empty(), Vectors::getUnnamed);
-  }
-
-  @Test
-  public final void testVectorsMetadata_named() {
-    Float[] vector = { 1f, 2f, 3f };
-    var metadata = ObjectMetadata.with(m -> m.vectors(Vectors.of("vector-1", vector)));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("named vector").isNotNull()
-        .returns(vector, v -> v.getSingle("vector-1"))
-        .returns(Optional.of(vector), Vectors::getSingle)
-        .returns(null, Vectors::getDefaultSingle);
-  }
-
-  @Test
-  public final void testVectorsMetadata_named_2d() {
-    Float[][] vector = { { 1f, 2f, 3f }, { 1f, 2f, 3f } };
-    var metadata = ObjectMetadata.with(m -> m.vectors(Vectors.of("vector-1", vector)));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("named 2d vector").isNotNull()
-        .returns(vector, v -> v.getMulti("vector-1"))
-        .returns(Optional.of(vector), Vectors::getMulti)
-        .returns(null, Vectors::getDefaultMulti);
-  }
-
-  @Test
-  public final void testVectorsMetadata_multiple_named() {
-    Float[][] vector_1 = { { 1f, 2f, 3f }, { 1f, 2f, 3f } };
-    Float[] vector_2 = { 4f, 5f, 6f };
-    var metadata = ObjectMetadata.with(m -> m.vectors(
-        Vectors.of(named -> named
-            .vector("vector-1", vector_1)
-            .vector("vector-2", vector_2))));
-
-    Assertions.assertThat(metadata.vectors())
-        .as("multiple named vectors").isNotNull()
-        .returns(vector_1, v -> v.getMulti("vector-1"))
-        .returns(vector_2, v -> v.getSingle("vector-2"))
-        .returns(Optional.empty(), Vectors::getMulti)
-        .returns(Optional.empty(), Vectors::getSingle)
-        .returns(null, Vectors::getDefaultMulti);
-  }
-}
diff --git a/src/test/java/io/weaviate/client6/v1/collections/VectorsTest.java b/src/test/java/io/weaviate/client6/v1/collections/VectorsTest.java
deleted file mode 100644
index 949a8dbb4..000000000
--- a/src/test/java/io/weaviate/client6/v1/collections/VectorsTest.java
+++ /dev/null
@@ -1,135 +0,0 @@
-package io.weaviate.client6.v1.collections;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
-import org.assertj.core.api.Assertions;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
-import com.google.gson.JsonParser;
-import com.google.gson.TypeAdapter;
-import com.google.gson.stream.JsonReader;
-import com.google.gson.stream.JsonWriter;
-import com.jparams.junit4.JParamsTestRunner;
-import com.jparams.junit4.data.DataMethod;
-
-import io.weaviate.client6.internal.DtoTypeAdapterFactory;
-import io.weaviate.client6.v1.collections.VectorIndex.IndexingStrategy;
-
-@RunWith(JParamsTestRunner.class)
-public class VectorsTest {
-  // private static final Gson gson = new Gson();
-
-  static {
-    DtoTypeAdapterFactory.register(Collection.class, CollectionDefinitionDTO.class,
-        m -> new CollectionDefinitionDTO(m));
-  }
-  private static final Gson gson = new GsonBuilder()
-      .registerTypeAdapterFactory(new DtoTypeAdapterFactory())
-      // TODO: create TypeAdapters via TypeAdapterFactory
-      .registerTypeAdapter(Vectors.class, new TypeAdapter<Vectors>() {
-        Gson gson = new Gson();
-
-        @Override
-        public void write(JsonWriter out, Vectors value) throws IOException {
-          gson.toJson(value.asMap(), Map.class, out);
-        }
-
-        @Override
-        public Vectors read(JsonReader in) throws IOException {
-          // TODO Auto-generated method stub
-          throw new UnsupportedOperationException("Unimplemented method 'read'");
-        }
-
-      })
-      .create();
-
-  public static Object[][] testCases() {
-    return new Object[][] {
-        {
-            """
-                {
-                  "vectorConfig": {
-                    "default": {
-                      "vectorizer": { "none": {}},
-                      "vectorIndexType": "hnsw",
-                      "vectorIndexConfig": {}
-                    }
-                  }
-                }
-                  """,
-            collectionWithVectors(Vectors.of(new VectorIndex<>(Vectorizer.none()))),
-            new String[] { "vectorConfig" },
-        },
-        {
-            """
-                {
-                  "vectorConfig": {
-                    "vector-1": {
-                      "vectorizer": { "none": {}},
-                      "vectorIndexType": "hnsw",
-                      "vectorIndexConfig": {}
-                    },
-                    "vector-2": {
-                      "vectorizer": { "none": {}},
-                      "vectorIndexType": "hnsw",
-                      "vectorIndexConfig": {}
-                    }
-                  }
-                }
-                  """,
-            collectionWithVectors(Vectors.with(named -> named
-                .vector("vector-1", new VectorIndex<>(Vectorizer.none()))
-                .vector("vector-2", new VectorIndex<>(IndexingStrategy.hnsw(), Vectorizer.none())))),
-            new String[] { "vectorConfig" },
-        },
-        {
-            """
-                {
-                  "vectorizer": { "none": {}},
-                  "vectorIndexType": "hnsw",
-                  "vectorIndexConfig": { "distance": "COSINE", "skip": true }
-                }
-                  """,
-            collectionWithVectors(Vectors.unnamed(
-                new VectorIndex<>(
-                    IndexingStrategy.hnsw(opt -> opt
-                        .distance(HNSW.Distance.COSINE)
-                        .disableIndexation()),
-                    Vectorizer.none()))),
-            new String[] { "vectorIndexType", "vectorIndexConfig", "vectorizer" },
-        },
-    };
-  }
-
-  @Test
-  @DataMethod(source = VectorsTest.class, method = "testCases")
-  public void test_toJson(String want, Collection collection, String... compareKeys) {
-    var got = gson.toJson(collection);
-    assertEqual(want, got, compareKeys);
-  }
-
-  private static Collection collectionWithVectors(Vectors vectors) {
-    return new Collection("Things", List.of(), List.of(), vectors);
-  }
-
-  private void assertEqual(String wantJson, String gotJson, String... compareKeys) {
-    var want = JsonParser.parseString(wantJson).getAsJsonObject();
-    var got = JsonParser.parseString(gotJson).getAsJsonObject();
-
-    if (compareKeys == null || compareKeys.length == 0) {
-      Assertions.assertThat(got).isEqualTo(want);
-      return;
-    }
-
-    for (var key : compareKeys) {
-      Assertions.assertThat(got.get(key))
-          .isEqualTo(want.get(key))
-          .as(key);
-    }
-  }
-}
diff --git a/src/test/java/io/weaviate/client6/v1/collections/data/QueryParametersTest.java b/src/test/java/io/weaviate/client6/v1/collections/data/QueryParametersTest.java
deleted file mode 100644
index 275c8a9b7..000000000
--- a/src/test/java/io/weaviate/client6/v1/collections/data/QueryParametersTest.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package io.weaviate.client6.v1.collections.data;
-
-import org.assertj.core.api.Assertions;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import com.jparams.junit4.JParamsTestRunner;
-import com.jparams.junit4.data.DataMethod;
-
-@RunWith(JParamsTestRunner.class)
-public class QueryParametersTest {
-
-  public static Object[][] testCases() {
-    return new Object[][] {
-        {
-            QueryParameters.encodeGet(q -> q
-                .withVector()
-                .nodeName("node-1")),
-            "?include=vector&node_name=node-1",
-        },
-        {
-            QueryParameters.encodeGet(q -> q
-                .withVector()
-                .withClassification()
-                .tenant("JohnDoe")),
-            "?include=vector,classification&tenant=JohnDoe",
-        },
-        {
-            QueryParameters.encodeGet(q -> q
-                .consistencyLevel(ConsistencyLevel.ALL)
-                .nodeName("node-1")
-                .tenant("JohnDoe")),
-            "?consistency_level=ALL&node_name=node-1&tenant=JohnDoe",
-        },
-        {
-            QueryParameters.encodeGet(q -> {
-            }),
-            "",
-        },
-    };
-  }
-
-  @Test
-  @DataMethod(source = QueryParametersTest.class, method = "testCases")
-  public void testEncode(String got, String want) {
-    Assertions.assertThat(got).isEqualTo(want).as("expected query parameters");
-  }
-}
diff --git a/src/test/java/io/weaviate/client6/internal/GRPCTest.java b/src/test/java/io/weaviate/client6/v1/internal/grpc/GRPCTest.java
similarity index 97%
rename from src/test/java/io/weaviate/client6/internal/GRPCTest.java
rename to src/test/java/io/weaviate/client6/v1/internal/grpc/GRPCTest.java
index ab14b6aaa..d18f4a00e 100644
--- a/src/test/java/io/weaviate/client6/internal/GRPCTest.java
+++ b/src/test/java/io/weaviate/client6/v1/internal/grpc/GRPCTest.java
@@ -1,4 +1,4 @@
-package io.weaviate.client6.internal;
+package io.weaviate.client6.v1.internal.grpc;
 
 import static org.junit.Assert.assertArrayEquals;
 
diff --git a/src/test/java/io/weaviate/client6/v1/internal/json/JSONTest.java b/src/test/java/io/weaviate/client6/v1/internal/json/JSONTest.java
new file mode 100644
index 000000000..0be90cba7
--- /dev/null
+++ b/src/test/java/io/weaviate/client6/v1/internal/json/JSONTest.java
@@ -0,0 +1,309 @@
+package io.weaviate.client6.v1.internal.json;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiConsumer;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import com.google.gson.JsonParser;
+import com.google.gson.reflect.TypeToken;
+import com.jparams.junit4.JParamsTestRunner;
+import com.jparams.junit4.data.DataMethod;
+
+import io.weaviate.client6.v1.api.collections.ObjectMetadata;
+import io.weaviate.client6.v1.api.collections.Property;
+import io.weaviate.client6.v1.api.collections.VectorIndex;
+import io.weaviate.client6.v1.api.collections.Vectorizer;
+import io.weaviate.client6.v1.api.collections.Vectors;
+import io.weaviate.client6.v1.api.collections.WeaviateCollection;
+import io.weaviate.client6.v1.api.collections.WeaviateObject;
+import io.weaviate.client6.v1.api.collections.data.Reference;
+import io.weaviate.client6.v1.api.collections.vectorindex.Distance;
+import io.weaviate.client6.v1.api.collections.vectorindex.Flat;
+import io.weaviate.client6.v1.api.collections.vectorindex.Hnsw;
+import io.weaviate.client6.v1.api.collections.vectorizers.Img2VecNeuralVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Multi2VecClipVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.NoneVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Text2VecContextionaryVectorizer;
+import io.weaviate.client6.v1.api.collections.vectorizers.Text2VecWeaviateVectorizer;
+
+/** Unit tests for custom POJO-to-JSON serialization. */
+@RunWith(JParamsTestRunner.class)
+public class JSONTest {
+  public static Object[][] testCases() {
+    return new Object[][] {
+        // Vectorizer.CustomTypeAdapterFactory
+        {
+            Vectorizer.class,
+            new NoneVectorizer(),
+            "{\"none\": {}}",
+        },
+        {
+            Vectorizer.class,
+            Img2VecNeuralVectorizer.of(i2v -> i2v.imageFields("jpeg", "png")),
+            """
+                {"img2vec-neural": {
+                  "imageFields": ["jpeg", "png"]
+                }}
+                """,
+        },
+        {
+            Vectorizer.class,
+            Multi2VecClipVectorizer.of(m2v -> m2v
+                .inferenceUrl("http://example.com")
+                .imageField("img", 1f)
+                .textField("txt", 2f)
+                .vectorizeCollectionName(true)),
+            """
+                {"multi2vec-clip": {
+                  "inferenceUrl": "http://example.com",
+                  "vectorizeClassName": true,
+                  "imageFields": ["img"],
+                  "textFields": ["txt"],
+                  "weights": {
+                    "imageWeights": [1.0],
+                    "textWeights": [2.0]
+                  }
+                }}
+                """,
+        },
+        {
+            Vectorizer.class,
+            Text2VecContextionaryVectorizer.of(t2v -> t2v
+                .vectorizeCollectionName(true)),
+            """
+                {"text2vec-contextionary": {
+                  "vectorizeClassName": true
+                }}
+                """,
+        },
+        {
+            Vectorizer.class,
+            Text2VecWeaviateVectorizer.of(t2v -> t2v
+                .inferenceUrl("http://example.com")
+                .dimensions(4)
+                .model("very-good-model")
+                .vectorizeCollectionName(true)),
+            """
+                {"text2vec-weaviate": {
+                  "baseUrl": "http://example.com",
+                  "vectorizeClassName": true,
+                  "dimensions": 4,
+                  "model": "very-good-model"
+                }}
+                """,
+        },
+
+        // VectorIndex.CustomTypeAdapterFactory
+        {
+            VectorIndex.class,
+            Flat.of(new NoneVectorizer(), flat -> flat
+                .vectorCacheMaxObjects(100)),
+            """
+                {
+                  "vectorIndexType": "flat",
+                  "vectorizer": {"none": {}},
+                  "vectorIndexConfig": {"vectorCacheMaxObjects": 100}
+                }
+                """,
+        },
+        {
+            VectorIndex.class,
+            Hnsw.of(new NoneVectorizer(), hnsw -> hnsw
+                .distance(Distance.DOT)
+                .ef(1)
+                .efConstruction(2)
+                .maxConnections(3)
+                .vectorCacheMaxObjects(4)
+                .cleanupIntervalSeconds(5)
+                .dynamicEfMin(6)
+                .dynamicEfMax(7)
+                .dynamicEfFactor(8)
+                .flatSearchCutoff(9)
+                .skipVectorization(true)
+                .filterStrategy(Hnsw.FilterStrategy.ACORN)),
+            """
+                {
+                  "vectorIndexType": "hnsw",
+                  "vectorizer": {"none": {}},
+                  "vectorIndexConfig": {
+                    "distance": "dot",
+                    "ef": 1,
+                    "efConstruction": 2,
+                    "maxConnections": 3,
+                    "vectorCacheMaxObjects": 4,
+                    "cleanupIntervalSeconds": 5,
+                    "dynamicEfMin": 6,
+                    "dynamicEfMax": 7,
+                    "dynamicEfFactor": 8,
+                    "flatSearchCutoff": 9,
+                    "skip": true,
+                    "filterStrategy":"acorn"
+                  }
+                }
+                """,
+        },
+
+        // Vectors.CustomTypeAdapterFactory
+        {
+            Vectors.class,
+            Vectors.of(new Float[] { 1f, 2f }),
+            "{\"default\": [1.0, 2.0]}",
+            (CustomAssert) JSONTest::compareVectors,
+        },
+        {
+            Vectors.class,
+            Vectors.of(new Float[][] { { 1f, 2f }, { 3f, 4f } }),
+            "{\"default\": [[1.0, 2.0], [3.0, 4.0]]}",
+            (CustomAssert) JSONTest::compareVectors,
+        },
+        {
+            Vectors.class,
+            Vectors.of("custom", new Float[] { 1f, 2f }),
+            "{\"custom\": [1.0, 2.0]}",
+            (CustomAssert) JSONTest::compareVectors,
+        },
+        {
+            Vectors.class,
+            Vectors.of("custom", new Float[][] { { 1f, 2f }, { 3f, 4f } }),
+            "{\"custom\": [[1.0, 2.0], [3.0, 4.0]]}",
+            (CustomAssert) JSONTest::compareVectors,
+        },
+        {
+            Vectors.class,
+            Vectors.of(named -> named
+                .vector("1d", new Float[] { 1f, 2f })
+                .vector("2d", new Float[][] { { 1f, 2f }, { 3f, 4f } })),
+            "{\"1d\": [1.0, 2.0], \"2d\": [[1.0, 2.0], [3.0, 4.0]]}",
+            (CustomAssert) JSONTest::compareVectors,
+        },
+
+        // WeaviateCollection.CustomTypeAdapterFactory
+        {
+            WeaviateCollection.class,
+            WeaviateCollection.of("Things", things -> things
+                .description("A collection of things")
+                .properties(
+                    Property.text("shape"),
+                    Property.integer("size"))
+                .references(
+                    Property.reference("owner", "Person", "Company"))
+                .vectors(named -> named
+                    .vector("v-shape", Hnsw.of(Img2VecNeuralVectorizer.of(
+                        i2v -> i2v.imageFields("img")))))),
+            """
+                {
+                  "class": "Things",
+                  "description": "A collection of things",
+                  "properties": [
+                    {"name": "shape", "dataType": ["text"]},
+                    {"name": "size", "dataType": ["int"]},
+                    {"name": "owner", "dataType": ["Person", "Company"]}
+                  ],
+                  "vectorConfig": {
+                    "v-shape": {
+                      "vectorIndexType": "hnsw",
+                      "vectorIndexConfig": {},
+                      "vectorizer": {"img2vec-neural": {
+                        "imageFields": ["img"]
+                      }}
+                    }
+                  }
+                }
+                """,
+        },
+
+        // Reference.TYPE_ADAPTER
+        {
+            Reference.class,
+            Reference.uuids("id-1"),
+            "{\"beacon\": \"weaviate://localhost/id-1\"}",
+        },
+        {
+            Reference.class,
+            Reference.collection("Doodlebops", "id-1"),
+            "{\"beacon\": \"weaviate://localhost/Doodlebops/id-1\"}",
+        },
+
+        // WeaviateObject.CustomTypeAdapterFactory.INSTANCE
+        {
+            new TypeToken<WeaviateObject<Map<String, Object>, Reference, ObjectMetadata>>() {
+            },
+            new WeaviateObject<>(
+                "Things",
+                Map.of("title", "ThingOne"),
+                Map.of("hasRef", List.of(Reference.uuids("ref-1"))),
+                ObjectMetadata.of(meta -> meta.id("thing-1"))),
+            """
+                {
+                  "class": "Things",
+                  "properties": {
+                    "title": "ThingOne",
+                    "hasRef": [{"beacon": "weaviate://localhost/ref-1"}]
+                  },
+                  "id": "thing-1"
+                }
+                  """,
+        },
+    };
+  }
+
+  @Test
+  @DataMethod(source = JSONTest.class, method = "testCases")
+  public void test_serialize(Object cls, Object in, String want) {
+    String got;
+    if (cls instanceof TypeToken typeToken) {
+      got = JSON.serialize(in, typeToken);
+    } else {
+      got = JSON.serialize(in);
+    }
+    assertEqualJson(want, got);
+
+  }
+
+  private interface CustomAssert extends BiConsumer<Object, Object> {
+  }
+
+  @Test
+  @SuppressWarnings("unchecked")
+  @DataMethod(source = JSONTest.class, method = "testCases")
+  public void test_deserialize(Object target, Object want, String in, CustomAssert assertion) {
+
+    Object got;
+    if (target instanceof Class targetClass) {
+      got = JSON.deserialize(in, targetClass);
+    } else if (target instanceof TypeToken targetToken) {
+      got = JSON.deserialize(in, targetToken);
+    } else {
+      throw new IllegalArgumentException("target must be either Class<?> or TypeToken<?>");
+    }
+
+    if (assertion != null) {
+      assertion.accept(got, want);
+    } else {
+      Assertions.assertThat(got).isEqualTo(want);
+    }
+  }
+
+  private static void assertEqualJson(String want, String got) {
+    var wantJson = JsonParser.parseString(want);
+    var gotJson = JsonParser.parseString(got);
+    Assertions.assertThat(gotJson).isEqualTo(wantJson);
+  }
+
+  /**
+   * Custom assert function that uses deep array equality
+   * to correctly compare Float[] and Float[][] nested in the object.
+   */
+  private static void compareVectors(Object got, Object want) {
+    Assertions.assertThat(got)
+        .usingRecursiveComparison()
+        .withEqualsForType(Arrays::equals, Float[].class)
+        .withEqualsForType(Arrays::deepEquals, Float[][].class)
+        .isEqualTo(want);
+  }
+}