diff --git a/generator/config/accumulator/concatArrays.yaml b/generator/config/accumulator/concatArrays.yaml
new file mode 100644
index 000000000..baf61b5e3
--- /dev/null
+++ b/generator/config/accumulator/concatArrays.yaml
@@ -0,0 +1,30 @@
+# $schema: ../schema.json
+name: $concatArrays
+link: 'https://www.mongodb.com/docs/manual/reference/operator/aggregation/concatArrays/'
+type:
+  - accumulator
+  - window
+  - resolvesToArray
+encode: single
+description: |
+  Concatenates arrays to return the concatenated array.
+arguments:
+  -
+    name: array
+    type:
+      - resolvesToArray # of arrays
+    variadic: array
+    description: |
+      An array of expressions that resolve to an array. 
+      If any argument resolves to a value of null or refers to a field that is missing, `$concatArrays` returns `null`.
+tests:
+  -
+    name: 'Warehouse collection'
+    link: 'https://www.mongodb.com/docs/manual/reference/operator/aggregation/concatArrays/#example'
+    pipeline:
+      -
+        $project:
+          items:
+            $concatArrays:
+              - '$instock'
+              - '$ordered'
diff --git a/generator/config/accumulator/setUnion.yaml b/generator/config/accumulator/setUnion.yaml
new file mode 100644
index 000000000..8c8419f9e
--- /dev/null
+++ b/generator/config/accumulator/setUnion.yaml
@@ -0,0 +1,32 @@
+# $schema: ../schema.json
+name: $setUnion
+link: 'https://www.mongodb.com/docs/manual/reference/operator/aggregation/setUnion/'
+type:
+  - accumulator
+  - window
+  - resolvesToArray
+encode: single
+description: |
+  Takes two or more arrays and returns an array containing the elements that appear in any input array.
+arguments:
+  -
+    name: array
+    type:
+      - resolvesToArray # of arrays
+    variadic: array
+    description: |
+      An array of expressions that resolve to an array.
+tests:
+  -
+    name: 'Flowers collection'
+    link: 'https://www.mongodb.com/docs/manual/reference/operator/aggregation/setUnion/#example'
+    pipeline:
+      -
+        $project:
+          flowerFieldA: 1
+          flowerFieldB: 1
+          allValues:
+            $setUnion:
+              - "$flowerFieldA"
+              - "$flowerFieldB"
+          _id: 0
diff --git a/src/Builder/Accumulator/ConcatArraysAccumulator.php b/src/Builder/Accumulator/ConcatArraysAccumulator.php
new file mode 100644
index 000000000..90ab96fa9
--- /dev/null
+++ b/src/Builder/Accumulator/ConcatArraysAccumulator.php
@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * THIS FILE IS AUTO-GENERATED. ANY CHANGES WILL BE LOST!
+ */
+
+declare(strict_types=1);
+
+namespace MongoDB\Builder\Accumulator;
+
+use MongoDB\BSON\PackedArray;
+use MongoDB\Builder\Expression\ResolvesToArray;
+use MongoDB\Builder\Type\AccumulatorInterface;
+use MongoDB\Builder\Type\Encode;
+use MongoDB\Builder\Type\OperatorInterface;
+use MongoDB\Builder\Type\WindowInterface;
+use MongoDB\Exception\InvalidArgumentException;
+use MongoDB\Model\BSONArray;
+
+use function array_is_list;
+
+/**
+ * Concatenates arrays to return the concatenated array.
+ *
+ * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/concatArrays/
+ * @internal
+ */
+final class ConcatArraysAccumulator implements AccumulatorInterface, WindowInterface, ResolvesToArray, OperatorInterface
+{
+    public const ENCODE = Encode::Single;
+    public const NAME = '$concatArrays';
+    public const PROPERTIES = ['array' => 'array'];
+
+    /**
+     * @var list<BSONArray|PackedArray|ResolvesToArray|array|string> $array An array of expressions that resolve to an array.
+     * If any argument resolves to a value of null or refers to a field that is missing, `$concatArrays` returns `null`.
+     */
+    public readonly array $array;
+
+    /**
+     * @param BSONArray|PackedArray|ResolvesToArray|array|string ...$array An array of expressions that resolve to an array.
+     * If any argument resolves to a value of null or refers to a field that is missing, `$concatArrays` returns `null`.
+     * @no-named-arguments
+     */
+    public function __construct(PackedArray|ResolvesToArray|BSONArray|array|string ...$array)
+    {
+        if (\count($array) < 1) {
+            throw new InvalidArgumentException(\sprintf('Expected at least %d values for $array, got %d.', 1, \count($array)));
+        }
+
+        if (! array_is_list($array)) {
+            throw new InvalidArgumentException('Expected $array arguments to be a list (array), named arguments are not supported');
+        }
+
+        $this->array = $array;
+    }
+}
diff --git a/src/Builder/Accumulator/FactoryTrait.php b/src/Builder/Accumulator/FactoryTrait.php
index 9e9257549..486eb43a5 100644
--- a/src/Builder/Accumulator/FactoryTrait.php
+++ b/src/Builder/Accumulator/FactoryTrait.php
@@ -117,6 +117,20 @@ public static function bottomN(
         return new BottomNAccumulator($n, $sortBy, $output);
     }
 
+    /**
+     * Concatenates arrays to return the concatenated array.
+     *
+     * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/concatArrays/
+     * @no-named-arguments
+     * @param BSONArray|PackedArray|ResolvesToArray|array|string ...$array An array of expressions that resolve to an array.
+     * If any argument resolves to a value of null or refers to a field that is missing, `$concatArrays` returns `null`.
+     */
+    public static function concatArrays(
+        PackedArray|ResolvesToArray|BSONArray|array|string ...$array,
+    ): ConcatArraysAccumulator {
+        return new ConcatArraysAccumulator(...$array);
+    }
+
     /**
      * Returns the number of documents in the group or window.
      * Distinct from the $count pipeline stage.
@@ -453,6 +467,18 @@ public static function rank(): RankAccumulator
         return new RankAccumulator();
     }
 
+    /**
+     * Takes two or more arrays and returns an array containing the elements that appear in any input array.
+     *
+     * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/setUnion/
+     * @no-named-arguments
+     * @param BSONArray|PackedArray|ResolvesToArray|array|string ...$array An array of expressions that resolve to an array.
+     */
+    public static function setUnion(PackedArray|ResolvesToArray|BSONArray|array|string ...$array): SetUnionAccumulator
+    {
+        return new SetUnionAccumulator(...$array);
+    }
+
     /**
      * Returns the value from an expression applied to a document in a specified position relative to the current document in the $setWindowFields stage partition.
      * New in MongoDB 5.0.
diff --git a/src/Builder/Accumulator/SetUnionAccumulator.php b/src/Builder/Accumulator/SetUnionAccumulator.php
new file mode 100644
index 000000000..e8ee446cc
--- /dev/null
+++ b/src/Builder/Accumulator/SetUnionAccumulator.php
@@ -0,0 +1,53 @@
+<?php
+
+/**
+ * THIS FILE IS AUTO-GENERATED. ANY CHANGES WILL BE LOST!
+ */
+
+declare(strict_types=1);
+
+namespace MongoDB\Builder\Accumulator;
+
+use MongoDB\BSON\PackedArray;
+use MongoDB\Builder\Expression\ResolvesToArray;
+use MongoDB\Builder\Type\AccumulatorInterface;
+use MongoDB\Builder\Type\Encode;
+use MongoDB\Builder\Type\OperatorInterface;
+use MongoDB\Builder\Type\WindowInterface;
+use MongoDB\Exception\InvalidArgumentException;
+use MongoDB\Model\BSONArray;
+
+use function array_is_list;
+
+/**
+ * Takes two or more arrays and returns an array containing the elements that appear in any input array.
+ *
+ * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/setUnion/
+ * @internal
+ */
+final class SetUnionAccumulator implements AccumulatorInterface, WindowInterface, ResolvesToArray, OperatorInterface
+{
+    public const ENCODE = Encode::Single;
+    public const NAME = '$setUnion';
+    public const PROPERTIES = ['array' => 'array'];
+
+    /** @var list<BSONArray|PackedArray|ResolvesToArray|array|string> $array An array of expressions that resolve to an array. */
+    public readonly array $array;
+
+    /**
+     * @param BSONArray|PackedArray|ResolvesToArray|array|string ...$array An array of expressions that resolve to an array.
+     * @no-named-arguments
+     */
+    public function __construct(PackedArray|ResolvesToArray|BSONArray|array|string ...$array)
+    {
+        if (\count($array) < 1) {
+            throw new InvalidArgumentException(\sprintf('Expected at least %d values for $array, got %d.', 1, \count($array)));
+        }
+
+        if (! array_is_list($array)) {
+            throw new InvalidArgumentException('Expected $array arguments to be a list (array), named arguments are not supported');
+        }
+
+        $this->array = $array;
+    }
+}
diff --git a/tests/Builder/Accumulator/ConcatArraysAccumulatorTest.php b/tests/Builder/Accumulator/ConcatArraysAccumulatorTest.php
new file mode 100644
index 000000000..24d811d30
--- /dev/null
+++ b/tests/Builder/Accumulator/ConcatArraysAccumulatorTest.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Tests\Builder\Accumulator;
+
+use MongoDB\Builder\Accumulator;
+use MongoDB\Builder\Expression;
+use MongoDB\Builder\Pipeline;
+use MongoDB\Builder\Stage;
+use MongoDB\Tests\Builder\PipelineTestCase;
+
+/**
+ * Test $concatArrays accumulator
+ */
+class ConcatArraysAccumulatorTest extends PipelineTestCase
+{
+    public function testWarehouseCollection(): void
+    {
+        $concatArrays = Accumulator::concatArrays(...);
+
+        $pipeline = new Pipeline(
+            Stage::project(
+                items: $concatArrays(
+                    Expression::arrayFieldPath('instock'),
+                    Expression::arrayFieldPath('ordered'),
+                ),
+            ),
+        );
+
+        $this->assertSamePipeline(Pipelines::ConcatArraysWarehouseCollection, $pipeline);
+    }
+}
diff --git a/tests/Builder/Accumulator/Pipelines.php b/tests/Builder/Accumulator/Pipelines.php
index fedc91ab4..23b313828 100644
--- a/tests/Builder/Accumulator/Pipelines.php
+++ b/tests/Builder/Accumulator/Pipelines.php
@@ -374,6 +374,26 @@ enum Pipelines: string
     ]
     JSON;
 
+    /**
+     * Warehouse collection
+     *
+     * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/concatArrays/#example
+     */
+    case ConcatArraysWarehouseCollection = <<<'JSON'
+    [
+        {
+            "$project": {
+                "items": {
+                    "$concatArrays": [
+                        "$instock",
+                        "$ordered"
+                    ]
+                }
+            }
+        }
+    ]
+    JSON;
+
     /**
      * Use in $group Stage
      *
@@ -1913,6 +1933,35 @@ enum Pipelines: string
     ]
     JSON;
 
+    /**
+     * Flowers collection
+     *
+     * @see https://www.mongodb.com/docs/manual/reference/operator/aggregation/setUnion/#example
+     */
+    case SetUnionFlowersCollection = <<<'JSON'
+    [
+        {
+            "$project": {
+                "flowerFieldA": {
+                    "$numberInt": "1"
+                },
+                "flowerFieldB": {
+                    "$numberInt": "1"
+                },
+                "allValues": {
+                    "$setUnion": [
+                        "$flowerFieldA",
+                        "$flowerFieldB"
+                    ]
+                },
+                "_id": {
+                    "$numberInt": "0"
+                }
+            }
+        }
+    ]
+    JSON;
+
     /**
      * Shift Using a Positive Integer
      *
diff --git a/tests/Builder/Accumulator/SetUnionAccumulatorTest.php b/tests/Builder/Accumulator/SetUnionAccumulatorTest.php
new file mode 100644
index 000000000..a6b83c5c2
--- /dev/null
+++ b/tests/Builder/Accumulator/SetUnionAccumulatorTest.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Tests\Builder\Accumulator;
+
+use MongoDB\Builder\Accumulator;
+use MongoDB\Builder\Expression;
+use MongoDB\Builder\Pipeline;
+use MongoDB\Builder\Stage;
+use MongoDB\Tests\Builder\PipelineTestCase;
+
+/**
+ * Test $setUnion accumulator
+ */
+class SetUnionAccumulatorTest extends PipelineTestCase
+{
+    public function testFlowersCollection(): void
+    {
+        $setUnion = Accumulator::setUnion(...);
+
+        $pipeline = new Pipeline(
+            Stage::project(
+                flowerFieldA: 1,
+                flowerFieldB: 1,
+                allValues: $setUnion(
+                    Expression::arrayFieldPath('flowerFieldA'),
+                    Expression::arrayFieldPath('flowerFieldB'),
+                ),
+                _id: 0,
+            ),
+        );
+
+        $this->assertSamePipeline(Pipelines::SetUnionFlowersCollection, $pipeline);
+    }
+}
diff --git a/tests/drivers-evergreen-tools b/tests/drivers-evergreen-tools
index 147364aa4..92e5f9336 160000
--- a/tests/drivers-evergreen-tools
+++ b/tests/drivers-evergreen-tools
@@ -1 +1 @@
-Subproject commit 147364aa42c825a6176a5b5f43c1eff4af24b2bd
+Subproject commit 92e5f93363ed12e91f1ef95a42575f47621365c8
diff --git a/tests/specifications b/tests/specifications
index db693517d..4e5d62456 160000
--- a/tests/specifications
+++ b/tests/specifications
@@ -1 +1 @@
-Subproject commit db693517de561465621b474558ded99eaf38757d
+Subproject commit 4e5d6245655f30f13e42a15bd340f57f6729bb27