diff --git a/benchmarks/build.gradle b/benchmarks/build.gradle
index acb990048c069..fc013d3af5e85 100644
--- a/benchmarks/build.gradle
+++ b/benchmarks/build.gradle
@@ -28,6 +28,7 @@ dependencies {
     // us to invoke the JMH uberjar as usual.
     exclude group: 'net.sf.jopt-simple', module: 'jopt-simple'
   }
+  api(project(':modules:aggregations'))
   expression(project(path: ':modules:lang-expression', configuration: 'zip'))
   painless(project(path: ':modules:lang-painless', configuration: 'zip'))
   api "org.openjdk.jmh:jmh-core:$versions.jmh"
@@ -49,7 +50,7 @@ tasks.register('copyExpression', Copy) {
   into "${buildDir}/plugins/expression"
 }
 
-tasks.register("copyPainless", Copy) { 
+tasks.register("copyPainless", Copy) {
   dependsOn configurations.painless
   from { configurations.painless.collect { zipTree(it) } }
   into "${buildDir}/plugins/painless"
diff --git a/benchmarks/src/main/java/org/elasticsearch/benchmark/search/aggregations/bucket/terms/LongKeyedBucketOrdsBenchmark.java b/benchmarks/src/main/java/org/elasticsearch/benchmark/search/aggregations/bucket/terms/LongKeyedBucketOrdsBenchmark.java
index 0d73f06891c29..38cebcd42e62d 100644
--- a/benchmarks/src/main/java/org/elasticsearch/benchmark/search/aggregations/bucket/terms/LongKeyedBucketOrdsBenchmark.java
+++ b/benchmarks/src/main/java/org/elasticsearch/benchmark/search/aggregations/bucket/terms/LongKeyedBucketOrdsBenchmark.java
@@ -8,11 +8,11 @@
 
 package org.elasticsearch.benchmark.search.aggregations.bucket.terms;
 
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.PageCacheRecycler;
 import org.elasticsearch.search.aggregations.CardinalityUpperBound;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.LongKeyedBucketOrds;
 import org.openjdk.jmh.annotations.Benchmark;
 import org.openjdk.jmh.annotations.BenchmarkMode;
diff --git a/client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java b/client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java
index a017c4567dbb3..736010996aa1a 100644
--- a/client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java
+++ b/client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java
@@ -38,8 +38,10 @@
 import org.elasticsearch.action.search.SearchScrollRequest;
 import org.elasticsearch.action.update.UpdateRequest;
 import org.elasticsearch.action.update.UpdateResponse;
-import org.elasticsearch.aggregations.bucket.AdjacencyMatrixAggregationBuilder;
-import org.elasticsearch.aggregations.bucket.ParsedAdjacencyMatrix;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrixAggregationBuilder;
+import org.elasticsearch.aggregations.bucket.adjacency.ParsedAdjacencyMatrix;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
+import org.elasticsearch.aggregations.bucket.histogram.ParsedAutoDateHistogram;
 import org.elasticsearch.client.analytics.ParsedStringStats;
 import org.elasticsearch.client.analytics.ParsedTopMetrics;
 import org.elasticsearch.client.analytics.StringStatsAggregationBuilder;
@@ -77,10 +79,8 @@
 import org.elasticsearch.search.aggregations.bucket.geogrid.ParsedGeoTileGrid;
 import org.elasticsearch.search.aggregations.bucket.global.GlobalAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.global.ParsedGlobal;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
-import org.elasticsearch.search.aggregations.bucket.histogram.ParsedAutoDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedVariableWidthHistogram;
diff --git a/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixIT.java b/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixIT.java
index 550227d03bd1d..0dd6b37475451 100644
--- a/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixIT.java
+++ b/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixIT.java
@@ -14,7 +14,9 @@
 import org.elasticsearch.action.search.SearchPhaseExecutionException;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.aggregations.AggregationsPlugin;
-import org.elasticsearch.aggregations.bucket.AdjacencyMatrix.Bucket;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrix;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrix.Bucket;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrixAggregationBuilder;
 import org.elasticsearch.index.query.BoolQueryBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.plugins.Plugin;
diff --git a/server/src/internalClusterTest/java/org/elasticsearch/search/aggregations/pipeline/SerialDiffIT.java b/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/pipeline/SerialDiffIT.java
similarity index 95%
rename from server/src/internalClusterTest/java/org/elasticsearch/search/aggregations/pipeline/SerialDiffIT.java
rename to modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/pipeline/SerialDiffIT.java
index 10a3d9ce1ccf0..66b7bcf9f773e 100644
--- a/server/src/internalClusterTest/java/org/elasticsearch/search/aggregations/pipeline/SerialDiffIT.java
+++ b/modules/aggregations/src/internalClusterTest/java/org/elasticsearch/aggregations/pipeline/SerialDiffIT.java
@@ -6,19 +6,24 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.action.index.IndexRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.aggregations.AggregationsPlugin;
 import org.elasticsearch.common.collect.EvictingQueue;
 import org.elasticsearch.common.util.Maps;
+import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.Histogram.Bucket;
+import org.elasticsearch.search.aggregations.pipeline.BucketHelpers;
+import org.elasticsearch.search.aggregations.pipeline.SimpleValue;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.hamcrest.Matchers;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -66,6 +71,12 @@ public String toString() {
         }
     }
 
+    // TODO: maybe add base class that overwrites nodePlugins(...) for all tests that will be added to this module.
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return List.of(AggregationsPlugin.class);
+    }
+
     private ValuesSourceAggregationBuilder<? extends ValuesSourceAggregationBuilder<?>> randomMetric(String name, String field) {
         int rand = randomIntBetween(0, 3);
 
diff --git a/modules/aggregations/src/main/java/module-info.java b/modules/aggregations/src/main/java/module-info.java
index b64b761fc90b3..a41affa5ba4b6 100644
--- a/modules/aggregations/src/main/java/module-info.java
+++ b/modules/aggregations/src/main/java/module-info.java
@@ -12,6 +12,7 @@
     requires org.elasticsearch.xcontent;
     requires org.apache.lucene.core;
 
-    exports org.elasticsearch.aggregations.bucket;
+    exports org.elasticsearch.aggregations.bucket.histogram;
+    exports org.elasticsearch.aggregations.bucket.adjacency;
 
 }
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
index 8f7f2c7fc75b0..d13cc20cb2d2d 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/AggregationsPlugin.java
@@ -8,8 +8,10 @@
 
 package org.elasticsearch.aggregations;
 
-import org.elasticsearch.aggregations.bucket.AdjacencyMatrixAggregationBuilder;
-import org.elasticsearch.aggregations.bucket.InternalAdjacencyMatrix;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrixAggregationBuilder;
+import org.elasticsearch.aggregations.bucket.adjacency.InternalAdjacencyMatrix;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
+import org.elasticsearch.aggregations.bucket.histogram.InternalAutoDateHistogram;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.SearchPlugin;
 
@@ -24,7 +26,13 @@ public List<AggregationSpec> getAggregations() {
                 AdjacencyMatrixAggregationBuilder.NAME,
                 AdjacencyMatrixAggregationBuilder::new,
                 AdjacencyMatrixAggregationBuilder::parse
-            ).addResultReader(InternalAdjacencyMatrix::new)
+            ).addResultReader(InternalAdjacencyMatrix::new),
+            new AggregationSpec(
+                AutoDateHistogramAggregationBuilder.NAME,
+                AutoDateHistogramAggregationBuilder::new,
+                AutoDateHistogramAggregationBuilder.PARSER
+            ).addResultReader(InternalAutoDateHistogram::new)
+                .setAggregatorRegistrar(AutoDateHistogramAggregationBuilder::registerAggregators)
         );
     }
 }
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrix.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrix.java
similarity index 94%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrix.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrix.java
index efba2d802474d..d08ac4c28139d 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrix.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrix.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;
 
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregationBuilder.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregationBuilder.java
similarity index 98%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregationBuilder.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregationBuilder.java
index c75f7de77cae6..8867ba732df11 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregationBuilder.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregationBuilder.java
@@ -6,11 +6,11 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.apache.lucene.search.IndexSearcher;
 import org.elasticsearch.Version;
-import org.elasticsearch.aggregations.bucket.AdjacencyMatrixAggregator.KeyedFilter;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrixAggregator.KeyedFilter;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.util.Maps;
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregator.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregator.java
similarity index 99%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregator.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregator.java
index c7832f18f211e..e6367fa369f21 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregator.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregator.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.util.Bits;
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorFactory.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorFactory.java
similarity index 93%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorFactory.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorFactory.java
index 4f0ac900f20b5..1d7353628e2c5 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorFactory.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorFactory.java
@@ -6,13 +6,13 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.search.Weight;
-import org.elasticsearch.aggregations.bucket.AdjacencyMatrixAggregator.KeyedFilter;
+import org.elasticsearch.aggregations.bucket.adjacency.AdjacencyMatrixAggregator.KeyedFilter;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrix.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrix.java
similarity index 99%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrix.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrix.java
index c766824b0463e..84765a1432210 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrix.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrix.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/ParsedAdjacencyMatrix.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/ParsedAdjacencyMatrix.java
similarity index 97%
rename from modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/ParsedAdjacencyMatrix.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/ParsedAdjacencyMatrix.java
index 14ee2797be9dd..efd5e498c9a91 100644
--- a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/ParsedAdjacencyMatrix.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/adjacency/ParsedAdjacencyMatrix.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.elasticsearch.common.util.Maps;
 import org.elasticsearch.search.aggregations.ParsedMultiBucketAggregation;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java
similarity index 99%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java
index 0b12c7aedc4fb..8002d1c34f606 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.elasticsearch.Version;
 import org.elasticsearch.common.Rounding;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
similarity index 99%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
index c54f6a0c6d609..3a73e65d6b604 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregator.java
@@ -5,11 +5,12 @@
  * in compliance with, at your election, the Elastic License 2.0 or the Server
  * Side Public License, v 1.
  */
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.search.ScoreMode;
 import org.apache.lucene.util.CollectionUtil;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
 import org.elasticsearch.common.Rounding;
 import org.elasticsearch.common.util.ByteArray;
 import org.elasticsearch.common.util.IntArray;
@@ -27,7 +28,6 @@
 import org.elasticsearch.search.aggregations.bucket.BestBucketsDeferringCollector;
 import org.elasticsearch.search.aggregations.bucket.DeferableBucketAggregator;
 import org.elasticsearch.search.aggregations.bucket.DeferringBucketCollector;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
 import org.elasticsearch.search.aggregations.bucket.terms.LongKeyedBucketOrds;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java
similarity index 96%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java
index a19ed7bf7fede..f517291d96d90 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorFactory.java
@@ -6,15 +6,15 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
 import org.elasticsearch.common.logging.DeprecationCategory;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.CardinalityUpperBound;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.CoreValuesSourceType;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java
similarity index 95%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java
index be69b2c5aa68c..71d7b987ffae2 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorSupplier.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.search.aggregations.Aggregator;
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogram.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java
similarity index 98%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogram.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java
index 98e2849384d06..4860bedaee61a 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogram.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java
@@ -5,10 +5,11 @@
  * in compliance with, at your election, the Elastic License 2.0 or the Server
  * Side Public License, v 1.
  */
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.apache.lucene.util.PriorityQueue;
 import org.elasticsearch.Version;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
 import org.elasticsearch.common.Rounding;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -21,7 +22,9 @@
 import org.elasticsearch.search.aggregations.KeyComparable;
 import org.elasticsearch.search.aggregations.bucket.IteratorAndCurrent;
 import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
+import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramInterval;
+import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
+import org.elasticsearch.search.aggregations.bucket.histogram.HistogramFactory;
 import org.elasticsearch.search.aggregations.support.SamplingContext;
 import org.elasticsearch.xcontent.XContentBuilder;
 
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/ParsedAutoDateHistogram.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/ParsedAutoDateHistogram.java
similarity index 96%
rename from server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/ParsedAutoDateHistogram.java
rename to modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/ParsedAutoDateHistogram.java
index 7e3b0ce9b31b4..1ba29602ed45b 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/ParsedAutoDateHistogram.java
+++ b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/ParsedAutoDateHistogram.java
@@ -6,9 +6,10 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.elasticsearch.search.aggregations.ParsedMultiBucketAggregation;
+import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
 import org.elasticsearch.xcontent.ObjectParser;
 import org.elasticsearch.xcontent.ParseField;
 import org.elasticsearch.xcontent.XContentBuilder;
diff --git a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorTests.java
similarity index 98%
rename from modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorTests.java
index 94e3462b4b6f7..3e3ef8e7c89bf 100644
--- a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixAggregatorTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixAggregatorTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.apache.lucene.search.IndexSearcher;
 import org.elasticsearch.aggregations.AggregationsPlugin;
diff --git a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixTests.java
similarity index 97%
rename from modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixTests.java
index 4c42bc79098a1..23f6f1327110b 100644
--- a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/AdjacencyMatrixTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/AdjacencyMatrixTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.elasticsearch.aggregations.AggregationsPlugin;
 import org.elasticsearch.common.util.Maps;
diff --git a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrixTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrixTests.java
similarity index 99%
rename from modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrixTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrixTests.java
index 3e00e1ba8dc6b..f706db9582bb5 100644
--- a/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/InternalAdjacencyMatrixTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/adjacency/InternalAdjacencyMatrixTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.adjacency;
 
 import org.elasticsearch.aggregations.AggregationsPlugin;
 import org.elasticsearch.common.util.CollectionUtils;
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java
similarity index 97%
rename from server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java
index fcfa6cf092f9f..a1da557562f31 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilderTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.elasticsearch.test.ESTestCase;
 
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
similarity index 98%
rename from server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
index fd4b55d7e6418..35939a724781e 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramAggregatorTests.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
@@ -25,6 +25,7 @@
 import org.apache.lucene.tests.index.RandomIndexWriter;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.Version;
+import org.elasticsearch.aggregations.AggregationsPlugin;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.CheckedBiConsumer;
 import org.elasticsearch.common.network.InetAddresses;
@@ -37,10 +38,15 @@
 import org.elasticsearch.index.mapper.KeywordFieldMapper;
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.NumberFieldMapper;
+import org.elasticsearch.plugins.SearchPlugin;
 import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.AggregationBuilders;
 import org.elasticsearch.search.aggregations.MultiBucketConsumerService;
+import org.elasticsearch.search.aggregations.bucket.DateHistogramAggregatorTestCase;
+import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
+import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
+import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram;
 import org.elasticsearch.search.aggregations.bucket.range.InternalBinaryRange;
 import org.elasticsearch.search.aggregations.bucket.range.InternalRange;
 import org.elasticsearch.search.aggregations.bucket.range.IpRangeAggregationBuilder;
@@ -99,6 +105,12 @@ public class AutoDateHistogramAggregatorTests extends DateHistogramAggregatorTes
 
     private static final Query DEFAULT_QUERY = new MatchAllDocsQuery();
 
+    // TODO: maybe add base class that overwrites getSearchPlugins(...) for all tests that will be added to this module.
+    @Override
+    protected List<SearchPlugin> getSearchPlugins() {
+        return List.of(new AggregationsPlugin());
+    }
+
     public void testMatchNoDocs() throws IOException {
         testSearchCase(
             new MatchNoDocsQuery(),
@@ -907,10 +919,13 @@ public void testWithPipelineReductions() throws IOException {
                 InternalHistogram histo = (InternalHistogram) bucket.getAggregations().asList().get(0);
                 assertThat(histo.getBuckets().size(), equalTo(10));
                 for (int i = 0; i < 10; i++) {
-                    assertThat(histo.getBuckets().get(i).key, equalTo((double) i));
-                    assertThat(((Max) histo.getBuckets().get(i).aggregations.get("max")).value(), equalTo((double) i));
+                    assertThat(histo.getBuckets().get(i).getKey(), equalTo((double) i));
+                    assertThat(((Max) histo.getBuckets().get(i).getAggregations().get("max")).value(), equalTo((double) i));
                     if (i > 0) {
-                        assertThat(((InternalSimpleValue) histo.getBuckets().get(i).aggregations.get("deriv")).getValue(), equalTo(1.0));
+                        assertThat(
+                            ((InternalSimpleValue) histo.getBuckets().get(i).getAggregations().get("deriv")).getValue(),
+                            equalTo(1.0)
+                        );
                     }
                 }
 
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/AutoDateHistogramTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramTests.java
similarity index 72%
rename from server/src/test/java/org/elasticsearch/search/aggregations/bucket/AutoDateHistogramTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramTests.java
index 08e9998388451..71d536ed45184 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/AutoDateHistogramTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/AutoDateHistogramTests.java
@@ -6,13 +6,23 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket;
+package org.elasticsearch.aggregations.bucket.histogram;
 
+import org.elasticsearch.aggregations.AggregationsPlugin;
+import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.search.aggregations.BaseAggregationTestCase;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
+
+import java.util.Collection;
+import java.util.List;
 
 public class AutoDateHistogramTests extends BaseAggregationTestCase<AutoDateHistogramAggregationBuilder> {
 
+    // TODO: maybe add base class that overwrites getPlugins(...) for all tests that will be added to this module.
+    @Override
+    protected Collection<Class<? extends Plugin>> getPlugins() {
+        return List.of(AggregationsPlugin.class);
+    }
+
     @Override
     protected AutoDateHistogramAggregationBuilder createTestAggregatorBuilder() {
         AutoDateHistogramAggregationBuilder builder = new AutoDateHistogramAggregationBuilder(randomAlphaOfLengthBetween(1, 10));
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java
similarity index 93%
rename from server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java
index d0ddf2eeaa70a..89911402ed680 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java
@@ -6,24 +6,33 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.aggregations.bucket.histogram;
 
 import org.elasticsearch.Version;
+import org.elasticsearch.aggregations.AggregationsPlugin;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
+import org.elasticsearch.aggregations.bucket.histogram.InternalAutoDateHistogram.BucketInfo;
 import org.elasticsearch.common.Rounding;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.time.DateFormatter;
+import org.elasticsearch.common.util.CollectionUtils;
 import org.elasticsearch.common.util.Maps;
 import org.elasticsearch.index.mapper.DateFieldMapper;
+import org.elasticsearch.plugins.SearchPlugin;
 import org.elasticsearch.search.DocValueFormat;
+import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder.RoundingInfo;
-import org.elasticsearch.search.aggregations.bucket.histogram.InternalAutoDateHistogram.BucketInfo;
+import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramInterval;
+import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
 import org.elasticsearch.test.InternalMultiBucketAggregationTestCase;
 import org.elasticsearch.test.VersionUtils;
+import org.elasticsearch.xcontent.ContextParser;
+import org.elasticsearch.xcontent.NamedXContentRegistry;
+import org.elasticsearch.xcontent.ParseField;
 
 import java.io.IOException;
 import java.time.Instant;
@@ -49,6 +58,23 @@
 import static org.mockito.Mockito.mock;
 
 public class InternalAutoDateHistogramTests extends InternalMultiBucketAggregationTestCase<InternalAutoDateHistogram> {
+
+    // TODO: maybe add base class that overwrites registerPlugin(...) for all tests that will be added to this module.
+    @Override
+    protected SearchPlugin registerPlugin() {
+        return new AggregationsPlugin();
+    }
+
+    // TODO: the base test class should be able to get this from the search plugin? (^)
+    @Override
+    protected List<NamedXContentRegistry.Entry> getNamedXContents() {
+        ContextParser<Object, Aggregation> parser = (p, c) -> ParsedAutoDateHistogram.fromXContent(p, (String) c);
+        return CollectionUtils.appendToCopy(
+            getDefaultNamedXContents(),
+            new NamedXContentRegistry.Entry(Aggregation.class, new ParseField(AutoDateHistogramAggregationBuilder.NAME), parser)
+        );
+    }
+
     protected InternalAutoDateHistogram createTestInstance(
         String name,
         Map<String, Object> metadata,
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/CumulativeSumTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/CumulativeSumTests.java
similarity index 94%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/CumulativeSumTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/CumulativeSumTests.java
index 21beed053efca..7cab1eb5cfd0e 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/CumulativeSumTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/CumulativeSumTests.java
@@ -6,11 +6,12 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
+import org.elasticsearch.search.aggregations.pipeline.CumulativeSumPipelineAggregationBuilder;
 
 import java.io.IOException;
 
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/DerivativeTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/DerivativeTests.java
similarity index 95%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/DerivativeTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/DerivativeTests.java
index 9de23d9f83722..dcd958b604ea1 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/DerivativeTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/DerivativeTests.java
@@ -6,13 +6,14 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
 import org.elasticsearch.search.aggregations.PipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
+import org.elasticsearch.search.aggregations.pipeline.DerivativePipelineAggregationBuilder;
 
 import java.io.IOException;
 import java.util.HashSet;
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
similarity index 95%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
index 8f432f420e1bd..5149570d1f7af 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/MovFnPipelineAggregationBuilderSerializationTests.java
@@ -6,12 +6,13 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.script.Script;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
+import org.elasticsearch.search.aggregations.pipeline.MovFnPipelineAggregationBuilder;
 
 import java.io.IOException;
 import java.util.Collections;
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/PipelineAggregationHelperTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
similarity index 97%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/PipelineAggregationHelperTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
index 0bc85cb175b2f..71f2ec284f8c2 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/PipelineAggregationHelperTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/PipelineAggregationHelperTests.java
@@ -6,10 +6,10 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.metrics.AvgAggregationBuilder;
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/SerialDifferenceTests.java b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/SerialDifferenceTests.java
similarity index 95%
rename from server/src/test/java/org/elasticsearch/search/aggregations/pipeline/SerialDifferenceTests.java
rename to modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/SerialDifferenceTests.java
index db001a1a13c14..28378b8cd8708 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/pipeline/SerialDifferenceTests.java
+++ b/modules/aggregations/src/test/java/org/elasticsearch/aggregations/pipeline/SerialDifferenceTests.java
@@ -6,13 +6,14 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.pipeline;
+package org.elasticsearch.aggregations.pipeline;
 
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
 import org.elasticsearch.search.aggregations.PipelineAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
 import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
+import org.elasticsearch.search.aggregations.pipeline.SerialDiffPipelineAggregationBuilder;
 
 import java.io.IOException;
 import java.util.HashSet;
diff --git a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/330_auto_date_histogram.yml b/modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/330_auto_date_histogram.yml
similarity index 100%
rename from rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.aggregation/330_auto_date_histogram.yml
rename to modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/330_auto_date_histogram.yml
diff --git a/server/src/main/java/org/elasticsearch/search/SearchModule.java b/server/src/main/java/org/elasticsearch/search/SearchModule.java
index 9697833f83616..bd29d9fc9cf02 100644
--- a/server/src/main/java/org/elasticsearch/search/SearchModule.java
+++ b/server/src/main/java/org/elasticsearch/search/SearchModule.java
@@ -103,10 +103,8 @@
 import org.elasticsearch.search.aggregations.bucket.geogrid.InternalGeoTileGrid;
 import org.elasticsearch.search.aggregations.bucket.global.GlobalAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.global.InternalGlobal;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
-import org.elasticsearch.search.aggregations.bucket.histogram.InternalAutoDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalVariableWidthHistogram;
@@ -559,15 +557,6 @@ private ValuesSourceRegistry registerAggregations(List<SearchPlugin> plugins) {
             ).addResultReader(InternalDateHistogram::new).setAggregatorRegistrar(DateHistogramAggregationBuilder::registerAggregators),
             builder
         );
-        registerAggregation(
-            new AggregationSpec(
-                AutoDateHistogramAggregationBuilder.NAME,
-                AutoDateHistogramAggregationBuilder::new,
-                AutoDateHistogramAggregationBuilder.PARSER
-            ).addResultReader(InternalAutoDateHistogram::new)
-                .setAggregatorRegistrar(AutoDateHistogramAggregationBuilder::registerAggregators),
-            builder
-        );
         registerAggregation(
             new AggregationSpec(
                 VariableWidthHistogramAggregationBuilder.NAME,
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/support/AggregationInspectionHelper.java b/server/src/main/java/org/elasticsearch/search/aggregations/support/AggregationInspectionHelper.java
index 017a6235c385a..74c4ce507523c 100644
--- a/server/src/main/java/org/elasticsearch/search/aggregations/support/AggregationInspectionHelper.java
+++ b/server/src/main/java/org/elasticsearch/search/aggregations/support/AggregationInspectionHelper.java
@@ -13,7 +13,6 @@
 import org.elasticsearch.search.aggregations.bucket.filter.InternalFilters;
 import org.elasticsearch.search.aggregations.bucket.geogrid.InternalGeoGrid;
 import org.elasticsearch.search.aggregations.bucket.global.InternalGlobal;
-import org.elasticsearch.search.aggregations.bucket.histogram.InternalAutoDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalVariableWidthHistogram;
@@ -110,10 +109,6 @@ public static boolean hasValue(InternalDateHistogram agg) {
         return agg.getBuckets().stream().anyMatch(bucket -> bucket.getDocCount() > 0);
     }
 
-    public static boolean hasValue(InternalAutoDateHistogram agg) {
-        return agg.getBuckets().stream().anyMatch(bucket -> bucket.getDocCount() > 0);
-    }
-
     public static boolean hasValue(InternalVariableWidthHistogram agg) {
         return agg.getBuckets().stream().anyMatch(bucket -> bucket.getDocCount() > 0);
     }
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/AggregationsTests.java b/server/src/test/java/org/elasticsearch/search/aggregations/AggregationsTests.java
index 3a35db05159ce..76b8380101d5b 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/AggregationsTests.java
+++ b/server/src/test/java/org/elasticsearch/search/aggregations/AggregationsTests.java
@@ -19,7 +19,6 @@
 import org.elasticsearch.search.aggregations.bucket.geogrid.GeoHashGridTests;
 import org.elasticsearch.search.aggregations.bucket.geogrid.GeoTileGridTests;
 import org.elasticsearch.search.aggregations.bucket.global.InternalGlobalTests;
-import org.elasticsearch.search.aggregations.bucket.histogram.InternalAutoDateHistogramTests;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalDateHistogramTests;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogramTests;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalVariableWidthHistogramTests;
@@ -118,7 +117,6 @@ public class AggregationsTests extends ESTestCase {
         new InternalGeoCentroidTests(),
         new InternalHistogramTests(),
         new InternalDateHistogramTests(),
-        new InternalAutoDateHistogramTests(),
         new InternalVariableWidthHistogramTests(),
         new LongTermsTests(),
         new DoubleTermsTests(),
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java b/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
index e9c8f12672d05..fdd7855adadbe 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
+++ b/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTests.java
@@ -34,6 +34,7 @@
 import org.elasticsearch.search.aggregations.AggregationReduceContext;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.BucketOrder;
+import org.elasticsearch.search.aggregations.bucket.DateHistogramAggregatorTestCase;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
diff --git a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java b/test/framework/src/main/java/org/elasticsearch/search/aggregations/bucket/DateHistogramAggregatorTestCase.java
similarity index 99%
rename from server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java
rename to test/framework/src/main/java/org/elasticsearch/search/aggregations/bucket/DateHistogramAggregatorTestCase.java
index 7af1782d23367..ad24b2b82794b 100644
--- a/server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramAggregatorTestCase.java
+++ b/test/framework/src/main/java/org/elasticsearch/search/aggregations/bucket/DateHistogramAggregatorTestCase.java
@@ -6,7 +6,7 @@
  * Side Public License, v 1.
  */
 
-package org.elasticsearch.search.aggregations.bucket.histogram;
+package org.elasticsearch.search.aggregations.bucket;
 
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.SortedNumericDocValuesField;
diff --git a/test/framework/src/main/java/org/elasticsearch/test/InternalAggregationTestCase.java b/test/framework/src/main/java/org/elasticsearch/test/InternalAggregationTestCase.java
index 55166659abd94..ca83722501f04 100644
--- a/test/framework/src/main/java/org/elasticsearch/test/InternalAggregationTestCase.java
+++ b/test/framework/src/main/java/org/elasticsearch/test/InternalAggregationTestCase.java
@@ -52,10 +52,8 @@
 import org.elasticsearch.search.aggregations.bucket.geogrid.ParsedGeoTileGrid;
 import org.elasticsearch.search.aggregations.bucket.global.GlobalAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.global.ParsedGlobal;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
-import org.elasticsearch.search.aggregations.bucket.histogram.ParsedAutoDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedDateHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedHistogram;
 import org.elasticsearch.search.aggregations.bucket.histogram.ParsedVariableWidthHistogram;
@@ -274,7 +272,6 @@ public AggregationReduceContext forFinalReduction() {
         map.put(GeoCentroidAggregationBuilder.NAME, (p, c) -> ParsedGeoCentroid.fromXContent(p, (String) c));
         map.put(HistogramAggregationBuilder.NAME, (p, c) -> ParsedHistogram.fromXContent(p, (String) c));
         map.put(DateHistogramAggregationBuilder.NAME, (p, c) -> ParsedDateHistogram.fromXContent(p, (String) c));
-        map.put(AutoDateHistogramAggregationBuilder.NAME, (p, c) -> ParsedAutoDateHistogram.fromXContent(p, (String) c));
         map.put(VariableWidthHistogramAggregationBuilder.NAME, (p, c) -> ParsedVariableWidthHistogram.fromXContent(p, (String) c));
         map.put(StringTerms.NAME, (p, c) -> ParsedStringTerms.fromXContent(p, (String) c));
         map.put(LongTerms.NAME, (p, c) -> ParsedLongTerms.fromXContent(p, (String) c));
diff --git a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/cumulativecardinality/CumulativeCardinalityTests.java b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/cumulativecardinality/CumulativeCardinalityTests.java
index fa4bd029cebb8..772ccfb012c2e 100644
--- a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/cumulativecardinality/CumulativeCardinalityTests.java
+++ b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/cumulativecardinality/CumulativeCardinalityTests.java
@@ -7,10 +7,10 @@
 
 package org.elasticsearch.xpack.analytics.cumulativecardinality;
 
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.plugins.SearchPlugin;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
diff --git a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/movingPercentiles/MovingPercentilesTests.java b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/movingPercentiles/MovingPercentilesTests.java
index 83ff13866d37c..7d59e59adb83b 100644
--- a/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/movingPercentiles/MovingPercentilesTests.java
+++ b/x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/movingPercentiles/MovingPercentilesTests.java
@@ -8,10 +8,10 @@
 package org.elasticsearch.xpack.analytics.movingPercentiles;
 
 import org.apache.lucene.tests.util.TestUtil;
+import org.elasticsearch.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.plugins.SearchPlugin;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.BasePipelineAggregationTestCase;
-import org.elasticsearch.search.aggregations.bucket.histogram.AutoDateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.histogram.HistogramAggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;