diff --git a/Neos.Flow/Classes/Http/BaseUriProvider.php b/Neos.Flow/Classes/Http/BaseUriProvider.php
index 22ea717d62..ca3cf35b4e 100644
--- a/Neos.Flow/Classes/Http/BaseUriProvider.php
+++ b/Neos.Flow/Classes/Http/BaseUriProvider.php
@@ -32,7 +32,7 @@ class BaseUriProvider
     /**
      * Get the configured framework base URI.
      *
-     * @return Uri|null
+     * @return UriInterface|null
      */
     private function getConfiguredBaseUri(): ?UriInterface
     {
diff --git a/Neos.Flow/Classes/Http/UriHelper.php b/Neos.Flow/Classes/Http/UriHelper.php
new file mode 100644
index 0000000000..fc73e8872e
--- /dev/null
+++ b/Neos.Flow/Classes/Http/UriHelper.php
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Neos\Flow\Http;
+
+use Neos\Utility\Arrays;
+use Psr\Http\Message\UriInterface;
+
+final class UriHelper
+{
+    // this class only has static helpers
+    private function __construct()
+    {
+    }
+
+    /**
+     * Merges recursively into the current {@see UriInterface::getQuery} these additional query parameters.
+     *
+     * @param array $queryParameters
+     * @return UriInterface A new instance with the additional query.
+     */
+    public static function withAdditionalQueryParameters(UriInterface $uri, array $queryParameters): UriInterface
+    {
+        if ($queryParameters === []) {
+            return $uri;
+        }
+        if ($uri->getQuery() === '') {
+            $mergedQuery = $queryParameters;
+        } else {
+            $queryParametersFromUri = [];
+            parse_str($uri->getQuery(), $queryParametersFromUri);
+            $mergedQuery = Arrays::arrayMergeRecursiveOverrule($queryParametersFromUri, $queryParameters);
+        }
+        return $uri->withQuery(http_build_query($mergedQuery, '', '&'));
+    }
+}
diff --git a/Neos.Flow/Tests/Unit/Http/UriHelperTest.php b/Neos.Flow/Tests/Unit/Http/UriHelperTest.php
new file mode 100644
index 0000000000..e68800cf13
--- /dev/null
+++ b/Neos.Flow/Tests/Unit/Http/UriHelperTest.php
@@ -0,0 +1,54 @@
+<?php
+namespace Neos\Flow\Tests\Unit\Http;
+
+/*
+ * This file is part of the Neos.Flow package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use GuzzleHttp\Psr7\Uri;
+use Neos\Flow\Http\UriHelper;
+use Neos\Flow\Tests\UnitTestCase;
+
+class UriHelperTest extends UnitTestCase
+{
+    /** @test */
+    public function specificationWithoutQueryParametersDontModifyTheUri()
+    {
+        self::assertEquals(
+            new Uri('http://localhost/index?param1=foo&param2[0]=bar'),
+            UriHelper::withAdditionalQueryParameters(new Uri('http://localhost/index?param1=foo&param2[0]=bar'), [])
+        );
+    }
+
+    /** @test */
+    public function queryParametersAddedToUriWithoutQueryParameters()
+    {
+        self::assertEquals(
+            new Uri('http://localhost/index?param=123'),
+            UriHelper::withAdditionalQueryParameters(new Uri('http://localhost/index'), ['param' => 123])
+        );
+    }
+
+    /** @test */
+    public function nestedQueryParametersAreMergedCorrectly()
+    {
+        self::assertEquals(
+            new Uri('http://localhost/index?param1=foo&param2[a]=bar&param2[b]=huhu&param3=123'),
+            UriHelper::withAdditionalQueryParameters(
+                new Uri('http://localhost/index?param1=foo&param2[a]=bar'),
+                [
+                    'param2' => [
+                        'b' => 'huhu'
+                    ],
+                    'param3' => 123,
+                ]
+            )
+        );
+    }
+}
diff --git a/Neos.Flow/Tests/Unit/Http/UriTest.php b/Neos.Flow/Tests/Unit/Http/UriTest.php
deleted file mode 100644
index 9e2031c11a..0000000000
--- a/Neos.Flow/Tests/Unit/Http/UriTest.php
+++ /dev/null
@@ -1,191 +0,0 @@
-<?php
-namespace Neos\Flow\Tests\Unit\Http;
-
-/*
- * This file is part of the Neos.Flow package.
- *
- * (c) Contributors of the Neos Project - www.neos.io
- *
- * This package is Open Source Software. For the full copyright and license
- * information, please view the LICENSE file which was distributed with this
- * source code.
- */
-
-use GuzzleHttp\Psr7\Uri;
-use Neos\Flow\Tests\UnitTestCase;
-
-/**
- * Testcase for the URI class
- *
- */
-class UriTest extends UnitTestCase
-{
-    /**
-     * Checks if a complete URI with all parts is transformed into an object correctly.
-     *
-     * @test
-     */
-    public function constructorParsesAFullBlownUriStringCorrectly()
-    {
-        $uriString = 'http://username:password@subdomain.domain.com:8080/path1/path2/index.php?argument1=value1&argument2=value2&argument3[subargument1]=subvalue1#anchor';
-        $uri = new Uri($uriString);
-
-        $check = (
-            $uri->getScheme() === 'http' &&
-            $uri->getUserInfo() === 'username:password' &&
-            $uri->getHost() === 'subdomain.domain.com' &&
-            $uri->getPort() === 8080 &&
-            $uri->getPath() === '/path1/path2/index.php' &&
-            urldecode($uri->getQuery()) === 'argument1=value1&argument2=value2&argument3[subargument1]=subvalue1' &&
-            $uri->getFragment() === 'anchor'
-        );
-
-        self::assertTrue($check, 'The valid and complete URI has not been correctly transformed to an URI object');
-    }
-
-    /**
-     * Uri strings
-     */
-    public function uriStrings()
-    {
-        return [
-            ['http://flow.neos.io/x'],
-            ['http://flow.neos.io/foo/bar?baz=1&quux=true'],
-            ['https://robert@localhost/arabica/coffee.html'],
-            ['http://127.0.0.1/bar.baz.com/foo.js'],
-            ['http://localhost:8080?foo=bar'],
-            ['http://localhost:443#hashme!x'],
-            ['http://[3b00:f59:1008::212:183:20]'],
-            ['http://[3b00:f59:1008::212:183:20]:443#hashme!x'],
-        ];
-    }
-
-    /**
-     * Checks round trips for various URIs
-     *
-     * @dataProvider uriStrings
-     * @test
-     */
-    public function urisCanBeConvertedForthAndBackWithoutLoss(string $uriString)
-    {
-        $uri = new Uri($uriString);
-        self::assertSame($uriString, (string)$uri);
-    }
-
-    /**
-     * Checks round trips for various URIs
-     *
-     * @test
-     */
-    public function settingSchemeAndHostOnUriDoesNotConfuseToString()
-    {
-        $uri = new Uri('/no/scheme/or/host');
-        $uri = $uri->withScheme('http')
-                   ->withHost('localhost');
-        self::assertSame('http://localhost/no/scheme/or/host', (string)$uri);
-    }
-
-    /**
-     * @test
-     */
-    public function toStringOmitsStandardPorts()
-    {
-        $uri = new Uri('http://flow.neos.io');
-        self::assertSame('http://flow.neos.io', (string)$uri);
-        self::assertNull($uri->getPort());
-
-        $uri = new Uri('https://flow.neos.io');
-        self::assertSame('https://flow.neos.io', (string)$uri);
-        self::assertNull($uri->getPort());
-    }
-
-    /**
-     * @test
-     */
-    public function constructorParsesArgumentsWithSpecialCharactersCorrectly()
-    {
-        $uriString = 'http://www.neos.io/path1/?argumentäöü1=' . urlencode('valueåø€œ');
-        $uri = new Uri($uriString);
-
-        $check = (
-            $uri->getScheme() === 'http' &&
-            $uri->getHost() === 'www.neos.io' &&
-            $uri->getPath() === '/path1/' &&
-            $uri->getQuery() === 'argument%C3%A4%C3%B6%C3%BC1=value%C3%A5%C3%B8%E2%82%AC%C5%93'
-        );
-        self::assertTrue($check, 'The URI with special arguments has not been correctly transformed to an URI object');
-    }
-
-    /**
-     * URIs for testing host parsing
-     */
-    public function hostTestUris()
-    {
-        return [
-            ['http://www.neos.io/about/project', 'www.neos.io'],
-            ['http://flow.neos.io/foo', 'flow.neos.io'],
-            ['http://[3b00:f59:1008::212:183:20]', '[3b00:f59:1008::212:183:20]'],
-        ];
-    }
-
-    /**
-     * @dataProvider hostTestUris
-     * @test
-     */
-    public function constructorParsesHostCorrectly(string $uriString, string $expectedHost)
-    {
-        $uri = new Uri($uriString);
-        self::assertSame($expectedHost, $uri->getHost());
-    }
-
-    /**
-     * @dataProvider hostTestUris
-     * @test
-     */
-    public function settingValidHostPassesRegexCheck(string $uriString, string $plainHost)
-    {
-        $uri = (new Uri(''))->withHost($plainHost);
-        self::assertEquals($plainHost, $uri->getHost());
-    }
-
-    public function uriStringTestUris()
-    {
-        return [
-            ['http://username:password@subdomain.domain.com:1234/pathx1/pathx2/index.php?argument1=value1&argument2=value2&argument3%5Bsubargument1%5D=subvalue1#anchorman'],
-            ['http://username:password@[2a00:f48:1008::212:183:10]:1234/pathx1/pathx2/index.php?argument1=value1&argument2=value2&argument3%5Bsubargument1%5D=subvalue1#anchorman'],
-        ];
-    }
-    /**
-     * Checks if a complete URI with all parts is transformed into an object correctly.
-     *
-     * @test
-     * @dataProvider uriStringTestUris
-     */
-    public function stringRepresentationIsCorrect(string $uriString)
-    {
-        $uri = new Uri($uriString);
-        self::assertEquals($uriString, (string)$uri, 'The string representation of the URI is not equal to the original URI string.');
-    }
-
-    /**
-     * @test
-     */
-    public function constructingWithNotAStringThrowsException()
-    {
-        $error = null;
-        try {
-            new Uri(['foo']);
-        } catch (\Throwable $error) {
-        }
-        $this->assertNotEmpty($error);
-    }
-
-    /**
-     * @test
-     */
-    public function unparsableUriStringThrowsException()
-    {
-        $this->expectException(\InvalidArgumentException::class);
-        new Uri('http:////localhost');
-    }
-}
diff --git a/Neos.Http.Factories/Classes/PsrHttpFactory.php b/Neos.Http.Factories/Classes/PsrHttpFactory.php
index 27f0ecd68f..25f3a2a40c 100644
--- a/Neos.Http.Factories/Classes/PsrHttpFactory.php
+++ b/Neos.Http.Factories/Classes/PsrHttpFactory.php
@@ -10,6 +10,11 @@
 use Psr\Http\Message\UploadedFileFactoryInterface;
 use Psr\Http\Message\UriFactoryInterface;
 
+/**
+ * A factory that implements all interfaces of PSR 17
+ *
+ * This factory can be used to simply create Requests, Uris and Streams without having to inject the traits yourself.
+ */
 class PsrHttpFactory implements ServerRequestFactoryInterface, RequestFactoryInterface, ResponseFactoryInterface,
                                 UriFactoryInterface, StreamFactoryInterface, UploadedFileFactoryInterface
 {
diff --git a/Neos.Http.Factories/Classes/UriFactoryTrait.php b/Neos.Http.Factories/Classes/UriFactoryTrait.php
index 6144747458..57eb3e9adf 100644
--- a/Neos.Http.Factories/Classes/UriFactoryTrait.php
+++ b/Neos.Http.Factories/Classes/UriFactoryTrait.php
@@ -4,7 +4,6 @@
 namespace Neos\Http\Factories;
 
 use GuzzleHttp\Psr7\Uri;
-use Psr\Http\Message\UriFactoryInterface;
 use Psr\Http\Message\UriInterface;
 
 /**