diff --git a/bin/console b/bin/console
new file mode 100755
index 0000000..089d452
--- /dev/null
+++ b/bin/console
@@ -0,0 +1,20 @@
+#!/usr/bin/env php
+<?php
+// application.php
+
+require __DIR__.'/../vendor/autoload.php';
+
+use Symfony\Component\Config\FileLocator;
+use Atoolo\Search\Console\Application;
+
+$container = new Symfony\Component\DependencyInjection\ContainerBuilder();
+$loader    = new Symfony\Component\DependencyInjection\Loader\YamlFileLoader(
+    $container,
+    new FileLocator(__DIR__ . '/../config'));
+
+$loader->load('services.yml');
+$container->compile();
+
+$application = $container->get(Application::class);
+
+$application->run();
\ No newline at end of file
diff --git a/config/services.yml b/config/services.yml
new file mode 100644
index 0000000..1b29748
--- /dev/null
+++ b/config/services.yml
@@ -0,0 +1,15 @@
+services:
+    _defaults:
+        autowire: true
+        autoconfigure: true
+    _instanceof:
+        Symfony\Component\Console\Command\Command:
+            tags: ['command']
+
+    Atoolo\Search\Console\:
+        resource: '../src/Console'
+
+    Atoolo\Search\Console\Application:
+        public: true
+        arguments:
+            - !tagged command
\ No newline at end of file
diff --git a/src/Console/Application.php b/src/Console/Application.php
new file mode 100644
index 0000000..0fcfbbe
--- /dev/null
+++ b/src/Console/Application.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console;
+
+use Symfony\Component\Console\Application as BaseApplication;
+
+class Application extends BaseApplication
+{
+    public function __construct(iterable $commands = [])
+    {
+        parent::__construct();
+        foreach ($commands as $command) {
+            $this->add($command);
+        }
+    }
+}
diff --git a/src/Console/Command/Indexer.php b/src/Console/Command/Indexer.php
new file mode 100644
index 0000000..7ef089b
--- /dev/null
+++ b/src/Console/Command/Indexer.php
@@ -0,0 +1,132 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console\Command;
+
+use Atoolo\Resource\Exception\InvalidResourceException;
+use Atoolo\Resource\Loader\SiteKitLoader;
+use Atoolo\Resource\Loader\SiteKitNavigationHierarchyLoader;
+use Atoolo\Search\Console\Command\Io\IndexerProgressProgressBar;
+use Atoolo\Search\Dto\Indexer\IndexerParameter;
+use Atoolo\Search\Service\Indexer\SiteKit\DefaultSchema21DocumentEnricher;
+use Atoolo\Search\Service\Indexer\SolrIndexer;
+use Atoolo\Search\Service\SolrParameterClientFactory;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand(
+    name: 'atoolo:indexer',
+    description: 'Fill a search index'
+)]
+class Indexer extends Command
+{
+    private IndexerProgressProgressBar $progressBar;
+    private SymfonyStyle $io;
+    private string $resourceDir;
+
+    protected function configure(): void
+    {
+        $this
+            ->setHelp('Command to fill a search index')
+            ->addArgument(
+                'solr-core',
+                InputArgument::REQUIRED,
+                'Solr core to be used.'
+            )
+            ->addArgument(
+                'resource-dir',
+                InputArgument::REQUIRED,
+                'Resource directory whose data is to be indexed.'
+            )
+            ->addArgument(
+                'directories',
+                InputArgument::OPTIONAL | InputArgument::IS_ARRAY,
+                'Resources or directories of the resource to be indexed.'
+            )
+            ->addOption(
+                'cleanup-threshold',
+                null,
+                InputArgument::OPTIONAL,
+                'Specifies the number of indexed documents from ' .
+                'which indexing is considered successful and old entries ' .
+                'can be deleted. Is only used for full indexing.',
+                0
+            )
+        ;
+    }
+
+    protected function execute(
+        InputInterface $input,
+        OutputInterface $output
+    ): int {
+
+        $this->io = new SymfonyStyle($input, $output);
+        $this->progressBar = new IndexerProgressProgressBar($output);
+        $this->resourceDir = $input->getArgument('resource-dir');
+        $directories = $input->getArgument('directories');
+
+        $cleanupThreshold = empty($directories)
+            ? $input->getArgument('cleanup-threshold')
+            : 0;
+
+        if (empty($directories)) {
+            $this->io->title('Index all resources');
+        } else {
+            $this->io->title('Index resources subdirectories');
+            $this->io->listing($directories);
+        }
+
+        $parameter = new IndexerParameter(
+            $input->getArgument('solr-core'),
+            $this->resourceDir,
+            $cleanupThreshold,
+            $directories
+        );
+
+        $indexer = $this->createIndexer();
+        $indexer->index($parameter);
+
+        $this->errorReport();
+
+        return Command::SUCCESS;
+    }
+
+    protected function errorReport(): void
+    {
+        foreach ($this->progressBar->getErrors() as $error) {
+            if ($error instanceof InvalidResourceException) {
+                $this->io->error(
+                    $error->getLocation() . ': ' .
+                    $error->getMessage()
+                );
+            } else {
+                $this->io->error($error->getMessage());
+            }
+        }
+    }
+
+    protected function createIndexer(): SolrIndexer
+    {
+        $resourceLoader = new SiteKitLoader($this->resourceDir);
+        $navigationLoader = new SiteKitNavigationHierarchyLoader(
+            $resourceLoader
+        );
+        $schema21 = new DefaultSchema21DocumentEnricher(
+            $navigationLoader
+        );
+
+        $clientFactory = new SolrParameterClientFactory();
+        return new SolrIndexer(
+            [$schema21],
+            $this->progressBar,
+            $resourceLoader,
+            $clientFactory,
+            'internal'
+        );
+    }
+}
diff --git a/src/Console/Command/Io/IndexerProgressProgressBar.php b/src/Console/Command/Io/IndexerProgressProgressBar.php
new file mode 100644
index 0000000..13b156c
--- /dev/null
+++ b/src/Console/Command/Io/IndexerProgressProgressBar.php
@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console\Command\Io;
+
+use Atoolo\Search\Service\Indexer\IndexerProgressHandler;
+use Exception;
+use Symfony\Component\Console\Helper\ProgressBar;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class IndexerProgressProgressBar implements IndexerProgressHandler
+{
+    private OutputInterface $output;
+    private ProgressBar $progressBar;
+
+    private array $errors = [];
+
+    public function __construct(OutputInterface $output)
+    {
+        $this->output = $output;
+    }
+
+    public function start(int $total): void
+    {
+        $this->progressBar = new ProgressBar($this->output, $total);
+        $this->formatProgressBar('green');
+    }
+
+    public function advance(int $step): void
+    {
+        $this->progressBar->advance($step);
+    }
+
+    private function formatProgressBar(string $color): void
+    {
+        $this->progressBar->setBarCharacter('<fg=' . $color . '>•</>');
+        $this->progressBar->setEmptyBarCharacter('<fg=' . $color . '>⚬</>');
+        $this->progressBar->setProgressCharacter('<fg=' . $color . '>➤</>');
+        $this->progressBar->setFormat(
+            "%current%/%max% [%bar%] %percent:3s%%\n" .
+                   "  %estimated:-20s%  %memory:20s%"
+        );
+    }
+
+    public function error(Exception $exception): void
+    {
+        $this->formatProgressBar('red');
+        $this->errors[] = $exception;
+    }
+
+    public function finish(): void
+    {
+        $this->progressBar->finish();
+    }
+
+    /**
+     * @return array<Exception>
+     */
+    public function getErrors(): array
+    {
+        return $this->errors;
+    }
+}
diff --git a/src/Console/Command/MoreLikeThis.php b/src/Console/Command/MoreLikeThis.php
new file mode 100644
index 0000000..ab8cc33
--- /dev/null
+++ b/src/Console/Command/MoreLikeThis.php
@@ -0,0 +1,114 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console\Command;
+
+use Atoolo\Resource\Loader\SiteKitLoader;
+use Atoolo\Search\Dto\Search\Query\MoreLikeThisQuery;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+use Atoolo\Search\Service\Search\ExternalResourceFactory;
+use Atoolo\Search\Service\Search\InternalMediaResourceFactory;
+use Atoolo\Search\Service\Search\InternalResourceFactory;
+use Atoolo\Search\Service\Search\SolrMoreLikeThis;
+use Atoolo\Search\Service\Search\SolrResultToResourceResolver;
+use Atoolo\Search\Service\SolrParameterClientFactory;
+use Psr\Log\NullLogger;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand(
+    name: 'atoolo:mlt',
+    description: 'Performs a more-like-this search'
+)]
+class MoreLikeThis extends Command
+{
+    private SymfonyStyle $io;
+    private string $solrCore;
+    private string $resourceDir;
+
+    protected function configure(): void
+    {
+        $this
+            ->setHelp('Command to performs a more-like-this search')
+            ->addArgument(
+                'solr-core',
+                InputArgument::REQUIRED,
+                'Solr core to be used.'
+            )
+            ->addArgument(
+                'resource-dir',
+                InputArgument::REQUIRED,
+                'Resource directory whose data is to be indexed.'
+            )
+            ->addArgument(
+                'location',
+                InputArgument::REQUIRED,
+                'Resource directory whose data is to be indexed.'
+            )
+        ;
+    }
+
+    protected function execute(
+        InputInterface $input,
+        OutputInterface $output
+    ): int {
+
+        $this->io = new SymfonyStyle($input, $output);
+
+        $this->solrCore = $input->getArgument('solr-core');
+        $this->resourceDir = $input->getArgument('resource-dir');
+        $location = $input->getArgument('location');
+
+        $searcher = $this->createSearcher();
+        $query = $this->buildQuery($location);
+        $result = $searcher->moreLikeThis($query);
+        $this->outputResult($result);
+
+        return Command::SUCCESS;
+    }
+
+    protected function createSearcher(): SolrMoreLikeThis
+    {
+        $resourceLoader = new SiteKitLoader($this->resourceDir);
+        $clientFactory = new SolrParameterClientFactory();
+        $resourceFactoryList = [
+            new ExternalResourceFactory(),
+            new InternalResourceFactory($resourceLoader),
+            new InternalMediaResourceFactory($resourceLoader)
+        ];
+        $solrResultToResourceResolver = new SolrResultToResourceResolver(
+            $resourceFactoryList
+        );
+
+        return new SolrMoreLikeThis(
+            $clientFactory,
+            $solrResultToResourceResolver
+        );
+    }
+
+    protected function buildQuery(string $location): MoreLikeThisQuery
+    {
+        $filterList = [];
+        return new MoreLikeThisQuery(
+            $this->solrCore,
+            $location,
+            $filterList,
+            5,
+            ['content']
+        );
+    }
+
+    protected function outputResult(ResourceSearchResult $result): void
+    {
+        $this->io->text($result->getTotal() . " Results:");
+        foreach ($result as $resource) {
+            $this->io->text($resource->getLocation());
+        }
+        $this->io->text('Query-Time: ' . $result->getQueryTime() . 'ms');
+    }
+}
diff --git a/src/Console/Command/Search.php b/src/Console/Command/Search.php
new file mode 100644
index 0000000..999715d
--- /dev/null
+++ b/src/Console/Command/Search.php
@@ -0,0 +1,140 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console\Command;
+
+use Atoolo\Resource\Loader\SiteKitLoader;
+use Atoolo\Search\Dto\Search\Query\SelectQuery;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+use Atoolo\Search\Service\Search\ExternalResourceFactory;
+use Atoolo\Search\Service\Search\InternalMediaResourceFactory;
+use Atoolo\Search\Service\Search\InternalResourceFactory;
+use Atoolo\Search\Service\Search\SiteKit\DefaultBoostModifier;
+use Atoolo\Search\Service\Search\SolrResultToResourceResolver;
+use Atoolo\Search\Service\Search\SolrSelect;
+use Atoolo\Search\Service\SolrParameterClientFactory;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand(
+    name: 'atoolo:search',
+    description: 'Performs a search'
+)]
+class Search extends Command
+{
+    private SymfonyStyle $io;
+    private string $solrCore;
+    private string $resourceDir;
+
+
+    protected function configure(): void
+    {
+        $this
+            ->setHelp('Command to performs a search')
+            ->addArgument(
+                'solr-core',
+                InputArgument::REQUIRED,
+                'Solr core to be used.'
+            )
+            ->addArgument(
+                'resource-dir',
+                InputArgument::REQUIRED,
+                'Resource directory whose data is to be indexed.'
+            )
+            ->addArgument(
+                'text',
+                InputArgument::IS_ARRAY,
+                'Text with which to search.'
+            )
+        ;
+    }
+
+    protected function execute(
+        InputInterface $input,
+        OutputInterface $output
+    ): int {
+
+        $this->io = new SymfonyStyle($input, $output);
+        $this->resourceDir = $input->getArgument('resource-dir');
+        $this->solrCore = $input->getArgument('solr-core');
+
+        $searcher = $this->createSearch();
+        $query = $this->buildQuery($input);
+
+        $result = $searcher->select($query);
+
+        $this->outputResult($result);
+
+        return Command::SUCCESS;
+    }
+
+    protected function createSearch(): SolrSelect
+    {
+        $resourceLoader = new SiteKitLoader($this->resourceDir);
+        $clientFactory = new SolrParameterClientFactory();
+        $defaultBoosting = new DefaultBoostModifier();
+
+        $resourceFactoryList = [
+            new ExternalResourceFactory(),
+            new InternalResourceFactory($resourceLoader),
+            new InternalMediaResourceFactory($resourceLoader)
+        ];
+
+        $solrResultToResourceResolver = new SolrResultToResourceResolver(
+            $resourceFactoryList
+        );
+
+        return new SolrSelect(
+            $clientFactory,
+            [$defaultBoosting],
+            $solrResultToResourceResolver
+        );
+    }
+
+    protected function buildQuery(InputInterface $input): SelectQuery
+    {
+        $builder = SelectQuery::builder();
+        $builder->core($this->solrCore);
+
+        $text = $input->getArgument('text');
+        if (is_array($text)) {
+            $builder->text(implode(' ', $text));
+        }
+
+        // TODO: filter
+
+        // TODO: facet
+
+        return $builder->build();
+    }
+
+    protected function outputResult(
+        ResourceSearchResult $result
+    ) {
+        $this->io->title('Results (' . $result->getTotal() . ')');
+        foreach ($result as $resource) {
+            $this->io->text($resource->getLocation());
+        }
+
+        if (count($result->getFacetGroupList()) > 0) {
+            $this->io->title('Facets');
+            foreach ($result->getFacetGroupList() as $facetGroup) {
+                $this->io->section($facetGroup->getKey());
+                $listing = [];
+                foreach ($facetGroup->getFacetList() as $facet) {
+                    $listing[] =
+                        $facet->getKey() .
+                        ' (' . $facet->getHits() . ')';
+                }
+                $this->io->listing($listing);
+            }
+        }
+
+        $this->io->text('Query-Time: ' . $result->getQueryTime() . 'ms');
+    }
+}
diff --git a/src/Console/Command/Suggest.php b/src/Console/Command/Suggest.php
new file mode 100644
index 0000000..a431467
--- /dev/null
+++ b/src/Console/Command/Suggest.php
@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Console\Command;
+
+use Atoolo\Search\Dto\Search\Query\Filter\ArchiveFilter;
+use Atoolo\Search\Dto\Search\Query\Filter\ObjectTypeFilter;
+use Atoolo\Search\Dto\Search\Query\SuggestQuery;
+use Atoolo\Search\Dto\Search\Result\SuggestResult;
+use Atoolo\Search\Service\Search\SolrSuggest;
+use Atoolo\Search\Service\SolrParameterClientFactory;
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+
+#[AsCommand(
+    name: 'atoolo:suggest',
+    description: 'Performs a suggest search'
+)]
+class Suggest extends Command
+{
+    private SymfonyStyle $io;
+    private string $solrCore;
+
+    protected function configure(): void
+    {
+        $this
+            ->setHelp('Command to performs a suggest search')
+            ->addArgument(
+                'solr-core',
+                InputArgument::REQUIRED,
+                'Solr core to be used.'
+            )
+            ->addArgument(
+                'terms',
+                InputArgument::REQUIRED | InputArgument::IS_ARRAY,
+                'Suggest terms.'
+            )
+        ;
+    }
+
+    protected function execute(
+        InputInterface $input,
+        OutputInterface $output
+    ): int {
+
+        $this->io = new SymfonyStyle($input, $output);
+        $this->solrCore = $input->getArgument('solr-core');
+        $terms = $input->getArgument('terms');
+
+        $search = $this->createSearcher();
+        $query = $this->buildQuery($terms);
+
+        $result = $search->suggest($query);
+
+        $this->outputResult($result);
+
+        return Command::SUCCESS;
+    }
+
+    protected function createSearcher(): SolrSuggest
+    {
+        $clientFactory = new SolrParameterClientFactory();
+        return new SolrSuggest($clientFactory);
+    }
+
+    protected function buildQuery(array $terms): SuggestQuery
+    {
+        $excludeMedia = new ObjectTypeFilter('media', 'media');
+        $excludeMedia = $excludeMedia->exclude();
+        return new SuggestQuery(
+            $this->solrCore,
+            $terms,
+            [
+                new ArchiveFilter(),
+                $excludeMedia
+            ]
+        );
+    }
+
+    protected function outputResult(SuggestResult $result): void
+    {
+        foreach ($result as $suggest) {
+            $this->io->text(
+                $suggest->getTerm() .
+                ' (' . $suggest->getHits() . ')'
+            );
+        }
+        $this->io->text('Query-Time: ' . $result->getQueryTime() . 'ms');
+    }
+}
diff --git a/src/Dto/Indexer/IndexerParameter.php b/src/Dto/Indexer/IndexerParameter.php
new file mode 100644
index 0000000..b1ce85e
--- /dev/null
+++ b/src/Dto/Indexer/IndexerParameter.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Indexer;
+
+class IndexerParameter
+{
+    public function __construct(
+        public readonly string $coreId,
+        public readonly string $basePath,
+        public readonly int $cleanupThreshold = 0,
+        public readonly array $directories = []
+    ) {
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/CategoryFacet.php b/src/Dto/Search/Query/Facet/CategoryFacet.php
new file mode 100644
index 0000000..d501b6b
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/CategoryFacet.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class CategoryFacet extends FacetField
+{
+    public function __construct(string $key, string ...$category)
+    {
+        parent::__construct($key, 'sp_category_path', $category);
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/ContentSectionTypeFacet.php b/src/Dto/Search/Query/Facet/ContentSectionTypeFacet.php
new file mode 100644
index 0000000..5245211
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/ContentSectionTypeFacet.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class ContentSectionTypeFacet extends FacetField
+{
+    public function __construct(string $key, string ...$terms)
+    {
+        parent::__construct($key, 'sp_contenttype', $terms);
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/Facet.php b/src/Dto/Search/Query/Facet/Facet.php
new file mode 100644
index 0000000..3cf4060
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/Facet.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+interface Facet
+{
+    public function getKey(): string;
+}
diff --git a/src/Dto/Search/Query/Facet/FacetField.php b/src/Dto/Search/Query/Facet/FacetField.php
new file mode 100644
index 0000000..74f7c9d
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/FacetField.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class FacetField implements Facet
+{
+    /**
+     * @param string[] $terms
+     */
+    public function __construct(
+        private readonly string $key,
+        private readonly string $field,
+        private readonly array $terms
+    ) {
+    }
+
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+
+    public function getField(): string
+    {
+        return $this->field;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getTerms(): array
+    {
+        return $this->terms;
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/FacetMultiQuery.php b/src/Dto/Search/Query/Facet/FacetMultiQuery.php
new file mode 100644
index 0000000..e93d210
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/FacetMultiQuery.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class FacetMultiQuery implements Facet
+{
+    /**
+     * @param string $key
+     * @param FacetQuery[] $queryList
+     */
+    public function __construct(
+        private readonly string $key,
+        private readonly array $queryList
+    ) {
+    }
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+    /**
+     * @return FacetQuery[]
+     */
+    public function getQueryList(): array
+    {
+        return $this->queryList;
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/FacetQuery.php b/src/Dto/Search/Query/Facet/FacetQuery.php
new file mode 100644
index 0000000..8c02fe3
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/FacetQuery.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class FacetQuery implements Facet
+{
+    public function __construct(
+        private readonly string $key,
+        private readonly string $query
+    ) {
+    }
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+    public function getQuery(): string
+    {
+        return $this->query;
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/GroupFacet.php b/src/Dto/Search/Query/Facet/GroupFacet.php
new file mode 100644
index 0000000..39dbcdb
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/GroupFacet.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class GroupFacet extends FacetField
+{
+    public function __construct(string $key, string ...$group)
+    {
+        parent::__construct($key, 'sp_group_path', $group);
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/ObjectTypeFacet.php b/src/Dto/Search/Query/Facet/ObjectTypeFacet.php
new file mode 100644
index 0000000..555c38b
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/ObjectTypeFacet.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class ObjectTypeFacet extends FacetField
+{
+    public function __construct(string $key, string ...$terms)
+    {
+        parent::__construct($key, 'sp_objecttype', $terms);
+    }
+}
diff --git a/src/Dto/Search/Query/Facet/SiteFacet.php b/src/Dto/Search/Query/Facet/SiteFacet.php
new file mode 100644
index 0000000..367df95
--- /dev/null
+++ b/src/Dto/Search/Query/Facet/SiteFacet.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Facet;
+
+class SiteFacet extends FacetField
+{
+    public function __construct(string $key, string ...$site)
+    {
+        parent::__construct($key, 'sp_site', $site);
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/ArchiveFilter.php b/src/Dto/Search/Query/Filter/ArchiveFilter.php
new file mode 100644
index 0000000..8527623
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/ArchiveFilter.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class ArchiveFilter extends Filter
+{
+    public function __construct()
+    {
+        parent::__construct(
+            'archive',
+            '-sp_archive:true'
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/CategoryFilter.php b/src/Dto/Search/Query/Filter/CategoryFilter.php
new file mode 100644
index 0000000..0882d4b
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/CategoryFilter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class CategoryFilter extends FieldFilter
+{
+    public function __construct(string $key, string ...$category)
+    {
+        parent::__construct(
+            $key,
+            'sp_category_path',
+            ...$category
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/ContentSectionTypeFilter.php b/src/Dto/Search/Query/Filter/ContentSectionTypeFilter.php
new file mode 100644
index 0000000..29c29c9
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/ContentSectionTypeFilter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class ContentSectionTypeFilter extends FieldFilter
+{
+    public function __construct(string $key, string ...$contentTypes)
+    {
+        parent::__construct(
+            $key,
+            'sp_contenttype',
+            ...$contentTypes
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/FieldFilter.php b/src/Dto/Search/Query/Filter/FieldFilter.php
new file mode 100644
index 0000000..673d01b
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/FieldFilter.php
@@ -0,0 +1,57 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class FieldFilter extends Filter
+{
+    /**
+     * @var string[]
+     */
+    private readonly array $values;
+    /**
+     * @param string[] $values
+     */
+    public function __construct(
+        string $key,
+        private readonly string $field,
+        string ...$values
+    ) {
+        if (count($values) === 0) {
+            throw new \InvalidArgumentException(
+                'values is an empty array'
+            );
+        }
+        $this->values = $values;
+        parent::__construct(
+            $key,
+            $this->toQuery(),
+            [$key]
+        );
+    }
+
+    /**
+     * @param string[] $values
+     */
+    private function toQuery(): string
+    {
+        $filterValue = count($this->values) === 1
+            ? $this->values[0]
+            : '('  . implode(' ', $this->values) . ')';
+        return $this->field . ':' . $filterValue;
+    }
+
+    public function exclude(): FieldFilter
+    {
+        $field = $this->field;
+        if (!str_starts_with($field, '-')) {
+            $field = '-' . $field;
+        }
+        return new FieldFilter(
+            $this->getKey(),
+            $field,
+            ...$this->values
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/Filter.php b/src/Dto/Search/Query/Filter/Filter.php
new file mode 100644
index 0000000..6d26936
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/Filter.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class Filter
+{
+    /**
+     * @param string[] $tags
+     */
+    public function __construct(
+        private readonly string $key,
+        private readonly string $query,
+        private readonly array $tags = []
+    ) {
+    }
+
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+
+    public function getQuery(): string
+    {
+        return $this->query;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getTags(): array
+    {
+        return $this->tags;
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/GroupFilter.php b/src/Dto/Search/Query/Filter/GroupFilter.php
new file mode 100644
index 0000000..e5d22e6
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/GroupFilter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class GroupFilter extends FieldFilter
+{
+    public function __construct(string $key, string ...$group)
+    {
+        parent::__construct(
+            $key,
+            'sp_group_path',
+            ...$group
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/ObjectTypeFilter.php b/src/Dto/Search/Query/Filter/ObjectTypeFilter.php
new file mode 100644
index 0000000..da16963
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/ObjectTypeFilter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class ObjectTypeFilter extends FieldFilter
+{
+    public function __construct(string $key, string ...$objectTypes)
+    {
+        parent::__construct(
+            $key,
+            'sp_objecttype',
+            ...$objectTypes
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/Filter/SiteFilter.php b/src/Dto/Search/Query/Filter/SiteFilter.php
new file mode 100644
index 0000000..4fa4565
--- /dev/null
+++ b/src/Dto/Search/Query/Filter/SiteFilter.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query\Filter;
+
+class SiteFilter extends FieldFilter
+{
+    public function __construct(string $key, string ...$site)
+    {
+        parent::__construct(
+            $key,
+            'sp_site',
+            ...$site
+        );
+    }
+}
diff --git a/src/Dto/Search/Query/MoreLikeThisQuery.php b/src/Dto/Search/Query/MoreLikeThisQuery.php
new file mode 100644
index 0000000..2757a24
--- /dev/null
+++ b/src/Dto/Search/Query/MoreLikeThisQuery.php
@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query;
+
+use Atoolo\Search\Dto\Search\Query\Filter\Filter;
+
+class MoreLikeThisQuery
+{
+    /**
+     * @param string[] $fields
+     * @param Filter[] $filterList
+     */
+    public function __construct(
+        private readonly string $core,
+        private readonly string $location,
+        private readonly array $filterList = [],
+        private readonly int $limit = 5,
+        private readonly array $fieldList = ['description', 'content']
+    ) {
+    }
+
+    public function getCore(): string
+    {
+        return $this->core;
+    }
+
+    public function getLocation(): string
+    {
+        return $this->location;
+    }
+
+    /**
+     * @return Filter[]
+     */
+    public function getFilterList(): array
+    {
+        return $this->filterList;
+    }
+
+    public function getLimit(): int
+    {
+        return $this->limit;
+    }
+
+    /**
+     * @return array<string>
+     */
+    public function getFieldList(): array
+    {
+        return $this->fieldList;
+    }
+}
diff --git a/src/Dto/Search/Query/QueryDefaultOperator.php b/src/Dto/Search/Query/QueryDefaultOperator.php
new file mode 100644
index 0000000..b485d5d
--- /dev/null
+++ b/src/Dto/Search/Query/QueryDefaultOperator.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Atoolo\Search\Dto\Search\Query;
+
+enum QueryDefaultOperator
+{
+    case AND;
+    case OR;
+}
diff --git a/src/Dto/Search/Query/SelectQuery.php b/src/Dto/Search/Query/SelectQuery.php
new file mode 100644
index 0000000..d1ba7c5
--- /dev/null
+++ b/src/Dto/Search/Query/SelectQuery.php
@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query;
+
+use Atoolo\Search\Dto\Search\Query\Facet\Facet;
+use Atoolo\Search\Dto\Search\Query\Filter\Filter;
+
+class SelectQuery
+{
+    private readonly string $core;
+    private readonly string $text;
+    private readonly int $offset;
+    private readonly int $limit;
+    /**
+     * @var Filter[]
+     */
+    private readonly array $filterList;
+    /**
+     * @var Facet[]
+     */
+    private readonly array $facetList;
+    private readonly QueryDefaultOperator $queryDefaultOperator;
+
+    /**
+     * @internal
+     */
+    public function __construct(SelectQueryBuilder $builder)
+    {
+        $this->core = $builder->getCore();
+        $this->text = $builder->getText();
+        $this->offset = $builder->getOffset();
+        $this->limit = $builder->getLimit();
+        $this->filterList = $builder->getFilterList();
+        $this->facetList = $builder->getFacetList();
+        $this->queryDefaultOperator = $builder->getQueryDefaultOperator();
+    }
+
+    public static function builder(): SelectQueryBuilder
+    {
+        return new SelectQueryBuilder();
+    }
+
+    public function getCore(): string
+    {
+        return $this->core;
+    }
+
+    public function getText(): string
+    {
+        return $this->text;
+    }
+
+    public function getOffset(): int
+    {
+        return $this->offset;
+    }
+
+    public function getLimit(): int
+    {
+        return $this->limit;
+    }
+
+    /**
+     * @return Filter[]
+     */
+    public function getFilterList(): array
+    {
+        return $this->filterList;
+    }
+    /**
+     * @return Facet[]
+     */
+    public function getFacetList(): array
+    {
+        return $this->facetList;
+    }
+    public function getQueryDefaultOperator(): QueryDefaultOperator
+    {
+        return $this->queryDefaultOperator;
+    }
+}
diff --git a/src/Dto/Search/Query/SelectQueryBuilder.php b/src/Dto/Search/Query/SelectQueryBuilder.php
new file mode 100644
index 0000000..38033b5
--- /dev/null
+++ b/src/Dto/Search/Query/SelectQueryBuilder.php
@@ -0,0 +1,171 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query;
+
+use Atoolo\Search\Dto\Search\Query\Facet\Facet;
+use Atoolo\Search\Dto\Search\Query\Filter\Filter;
+
+class SelectQueryBuilder
+{
+    private string $core = '';
+    private string $text = '';
+    private int $offset = 0;
+    private int $limit = 10;
+    /**
+     * @var array<string,Filter>
+     */
+    private array $filterList = [];
+
+    /**
+     * @var array<string,Facet>
+     */
+    private array $facetList = [];
+
+    private QueryDefaultOperator $queryDefaultOperator = QueryDefaultOperator::AND;
+
+    /**
+     * @internal
+     */
+    public function __construct()
+    {
+    }
+
+    public function core(string $core): SelectQueryBuilder
+    {
+        if (empty($core)) {
+            throw new \InvalidArgumentException('core is empty');
+        }
+        $this->core = $core;
+        return $this;
+    }
+
+    /**
+     * @internal
+     */
+    public function getCore(): string
+    {
+        return $this->core;
+    }
+
+    public function text(string $text): SelectQueryBuilder
+    {
+        $this->text = $text;
+        return $this;
+    }
+
+    /**
+     * @internal
+     */
+    public function getText(): string
+    {
+        return $this->text;
+    }
+
+    public function offset(int $offset): SelectQueryBuilder
+    {
+        if ($offset < 0) {
+            throw new \InvalidArgumentException('offset is lower then 0');
+        }
+        $this->offset = $offset;
+        return $this;
+    }
+
+    /**
+     * @internal
+     */
+    public function getOffset(): int
+    {
+        return $this->offset;
+    }
+
+    public function limit(int $limit): SelectQueryBuilder
+    {
+        if ($limit < 0) {
+            throw new \InvalidArgumentException('offset is lower then 0');
+        }
+        $this->limit = $limit;
+        return $this;
+    }
+
+    /**
+     * @internal
+     */
+    public function getLimit(): int
+    {
+        return $this->limit;
+    }
+
+    /**
+     * @param Filter[] $filterList
+     */
+    public function filter(Filter ...$filterList): SelectQueryBuilder
+    {
+        foreach ($filterList as $filter) {
+            if (isset($this->filterList[$filter->getKey()])) {
+                throw new \InvalidArgumentException(
+                    'filter key "' . $filter->getKey() .
+                            '" already exists'
+                );
+            }
+            $this->filterList[$filter->getKey()] = $filter;
+        }
+        return $this;
+    }
+
+    /**
+     * @internal
+     * @return Filter[]
+     */
+    public function getFilterList(): array
+    {
+        return array_values($this->filterList);
+    }
+
+    /**
+     * @param Filter[] $filterList
+     */
+    public function facet(Facet ...$facetList): SelectQueryBuilder
+    {
+        foreach ($facetList as $facet) {
+            if (isset($this->facetList[$facet->getKey()])) {
+                throw new \InvalidArgumentException(
+                    'facet key "' . $facet->getKey() .
+                    '" already exists'
+                );
+            }
+            $this->facetList[$facet->getKey()] = $facet;
+        }
+        return $this;
+    }
+
+    /**
+     * @internal
+     * @return Facet[]
+     */
+    public function getFacetList(): array
+    {
+        return array_values($this->facetList);
+    }
+
+    public function queryDefaultOperator(
+        QueryDefaultOperator $queryDefaultOperator
+    ): SelectQueryBuilder {
+        $this->queryDefaultOperator = $queryDefaultOperator;
+        return $this;
+    }
+
+    public function getQueryDefaultOperator(): QueryDefaultOperator
+    {
+        return $this->queryDefaultOperator;
+    }
+
+    public function build(): SelectQuery
+    {
+        if (empty($this->core)) {
+            throw new \InvalidArgumentException('core is not set');
+        }
+        return new SelectQuery($this);
+    }
+}
diff --git a/src/Dto/Search/Query/SuggestQuery.php b/src/Dto/Search/Query/SuggestQuery.php
new file mode 100644
index 0000000..144c168
--- /dev/null
+++ b/src/Dto/Search/Query/SuggestQuery.php
@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Query;
+
+use Atoolo\Search\Dto\Search\Query\Filter\Filter;
+
+class SuggestQuery
+{
+    /**
+     * @param string[] $termList
+     * @param Filter[] $filterList
+     */
+    public function __construct(
+        private readonly string $core,
+        private readonly array $termList,
+        private readonly array $filterList = [],
+        private readonly int $limit = 10,
+        private readonly string $field = 'raw_content'
+    ) {
+    }
+
+    public function getCore(): string
+    {
+        return $this->core;
+    }
+    /**
+     * @return string[]
+     */
+    public function getTermList(): array
+    {
+        return $this->termList;
+    }
+
+    public function getLimit(): int
+    {
+        return $this->limit;
+    }
+
+    /**
+     * @return Filter[]
+     */
+    public function getFilterList(): array
+    {
+        return $this->filterList;
+    }
+    public function getField(): string
+    {
+        return $this->field;
+    }
+}
diff --git a/src/Dto/Search/Result/Facet.php b/src/Dto/Search/Result/Facet.php
new file mode 100644
index 0000000..8e19cd0
--- /dev/null
+++ b/src/Dto/Search/Result/Facet.php
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Result;
+
+class Facet
+{
+    public function __construct(
+        private readonly string $key,
+        private readonly int $hits
+    ) {
+    }
+
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+
+    public function getHits(): int
+    {
+        return $this->hits;
+    }
+}
\ No newline at end of file
diff --git a/src/Dto/Search/Result/FacetGroup.php b/src/Dto/Search/Result/FacetGroup.php
new file mode 100644
index 0000000..300b2ca
--- /dev/null
+++ b/src/Dto/Search/Result/FacetGroup.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Result;
+
+class FacetGroup
+{
+    /**
+     * @param Facet[] $facetList
+     */
+    public function __construct(
+        private readonly string $key,
+        private readonly array $facetList
+    ) {
+    }
+
+    public function getKey(): string
+    {
+        return $this->key;
+    }
+
+    /**
+     * @return Facet[]
+     */
+    public function getFacetList(): array
+    {
+        return $this->facetList;
+    }
+}
diff --git a/src/Dto/Search/Result/ResourceSearchResult.php b/src/Dto/Search/Result/ResourceSearchResult.php
new file mode 100644
index 0000000..9f3cd68
--- /dev/null
+++ b/src/Dto/Search/Result/ResourceSearchResult.php
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Result;
+
+use ArrayIterator;
+use Atoolo\Resource\Resource;
+use IteratorAggregate;
+use Traversable;
+
+/**
+ * @implements IteratorAggregate<Resource>
+ */
+class ResourceSearchResult implements IteratorAggregate
+{
+    /**
+     * @param Resource[] $resourceList
+     * @param FacetGroup[] $facetGroupList
+     */
+    public function __construct(
+        private readonly int $total,
+        private readonly int $offset,
+        private readonly array $resourceList,
+        private readonly array $facetGroupList,
+        private readonly int $queryTime
+    ) {
+    }
+
+    public function getIterator(): Traversable
+    {
+        return new ArrayIterator($this->resourceList);
+    }
+
+    /**
+     * @return Resource[]
+     */
+    public function getResourceList(): array
+    {
+        return $this->resourceList;
+    }
+
+    public function getTotal(): int
+    {
+        return $this->total;
+    }
+
+    public function getOffset(): int
+    {
+        return $this->offset;
+    }
+
+    /**
+     * @return FacetGroup[]
+     */
+    public function getFacetGroupList(): array
+    {
+        return $this->facetGroupList;
+    }
+
+    public function getQueryTime(): int
+    {
+        return $this->queryTime;
+    }
+}
diff --git a/src/Dto/Search/Result/SuggestResult.php b/src/Dto/Search/Result/SuggestResult.php
new file mode 100644
index 0000000..9b4770a
--- /dev/null
+++ b/src/Dto/Search/Result/SuggestResult.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Result;
+
+use ArrayIterator;
+use IteratorAggregate;
+
+/**
+ * @implements IteratorAggregate<Suggestion>
+ */
+class SuggestResult implements IteratorAggregate
+{
+    public function __construct(
+        private readonly array $suggestions,
+        private readonly int $queryTime
+    ) {
+    }
+
+    public function getIterator(): ArrayIterator
+    {
+        return new ArrayIterator($this->suggestions);
+    }
+
+    public function getQueryTime(): int
+    {
+        return $this->queryTime;
+    }
+}
diff --git a/src/Dto/Search/Result/Suggestion.php b/src/Dto/Search/Result/Suggestion.php
new file mode 100644
index 0000000..bfe9293
--- /dev/null
+++ b/src/Dto/Search/Result/Suggestion.php
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Dto\Search\Result;
+
+class Suggestion
+{
+    public function __construct(
+        private readonly string $term,
+        private readonly int $hits
+    ) {
+    }
+
+    public function getTerm(): string
+    {
+        return $this->term;
+    }
+
+    public function getHits(): int
+    {
+        return $this->hits;
+    }
+}
diff --git a/src/Exception/MissMatchingResourceFactoryException.php b/src/Exception/MissMatchingResourceFactoryException.php
new file mode 100644
index 0000000..e01833a
--- /dev/null
+++ b/src/Exception/MissMatchingResourceFactoryException.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Exception;
+
+use RuntimeException;
+
+class MissMatchingResourceFactoryException extends RuntimeException
+{
+    public function __construct(
+        private readonly string $location,
+        string $message = "",
+        int $code = 0,
+        ?\Throwable $previous = null
+    ) {
+        parent::__construct(
+            $location . ': ' . $message,
+            $code,
+            $previous
+        );
+    }
+
+    public function getLocation(): string
+    {
+        return $this->location;
+    }
+}
diff --git a/src/Exception/UnexpectedResultException.php b/src/Exception/UnexpectedResultException.php
new file mode 100644
index 0000000..0a5ffda
--- /dev/null
+++ b/src/Exception/UnexpectedResultException.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Exception;
+
+use RuntimeException;
+
+class UnexpectedResultException extends RuntimeException
+{
+    public function __construct(
+        private readonly string $result,
+        string $message = "",
+        int $code = 0,
+        ?\Throwable $previous = null
+    ) {
+        parent::__construct(
+            $message . "\n" . $this->result,
+            $code,
+            $previous
+        );
+    }
+
+    public function getResult(): string
+    {
+        return $this->result;
+    }
+}
diff --git a/src/Indexer.php b/src/Indexer.php
new file mode 100644
index 0000000..55d4f58
--- /dev/null
+++ b/src/Indexer.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search;
+
+use Atoolo\Search\Dto\Indexer\IndexerParameter;
+
+/**
+ * The service interface for indexing a search index.
+ *
+ * The main task of an indexer is to systematically analyze documents or
+ * content in order to extract relevant information from them. This information
+ * is structured and stored in a search index to enable efficient search
+ * queries. The indexer organizes the data and extract hierarchical structure
+ * that search engines use to deliver fast and accurate search results.
+ */
+interface Indexer
+{
+    public function index(IndexerParameter $parameter): void;
+}
diff --git a/src/MoreLikeThisSearcher.php b/src/MoreLikeThisSearcher.php
new file mode 100644
index 0000000..3721e25
--- /dev/null
+++ b/src/MoreLikeThisSearcher.php
@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search;
+
+use Atoolo\Search\Dto\Search\Query\MoreLikeThisQuery;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+
+/**
+ * The service interface for a "More-Like-This" search.
+ *
+ * A "More-Like-This" search is a technique in which a source document or item
+ * is used as a reference point to find similar documents in the search index.
+ * It is based on extracting characteristics from the source object and
+ * searching for other objects that have similar characteristics in order to
+ * present relevant results to the user.
+ *
+ * The reference point is specified via the location of a resource.
+ */
+interface MoreLikeThisSearcher
+{
+    public function moreLikeThis(
+        MoreLikeThisQuery $query
+    ): ResourceSearchResult;
+}
diff --git a/src/SelectSearcher.php b/src/SelectSearcher.php
new file mode 100644
index 0000000..e478d22
--- /dev/null
+++ b/src/SelectSearcher.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search;
+
+use Atoolo\Search\Dto\Search\Query\SelectQuery;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+
+/**
+ * The service interface for a search with full-text, filter and facet support.
+ */
+interface SelectSearcher
+{
+    public function select(SelectQuery $query): ResourceSearchResult;
+}
diff --git a/src/Service/Indexer/DocumentEnricher.php b/src/Service/Indexer/DocumentEnricher.php
new file mode 100644
index 0000000..e360252
--- /dev/null
+++ b/src/Service/Indexer/DocumentEnricher.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Indexer;
+
+use Atoolo\Resource\Resource;
+use Solarium\Core\Query\DocumentInterface;
+
+/**
+ * This interface can be used to implement enricher with the help of which a
+ * Solr document can be enriched on the basis of a resource.
+ */
+interface DocumentEnricher
+{
+    public function enrichDocument(
+        Resource $resource,
+        DocumentInterface $doc,
+        string $processId
+    ): DocumentInterface;
+}
diff --git a/src/Service/Indexer/IndexerProgressHandler.php b/src/Service/Indexer/IndexerProgressHandler.php
new file mode 100644
index 0000000..0e65499
--- /dev/null
+++ b/src/Service/Indexer/IndexerProgressHandler.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Indexer;
+
+use Atoolo\Resource\Resource;
+use Solarium\QueryType\Update\Result;
+
+interface IndexerProgressHandler
+{
+    public function start(int $total): void;
+    public function advance(int $step): void;
+    public function error(\Exception $exception): void;
+    public function finish(): void;
+}
diff --git a/src/Service/Indexer/LocationFinder.php b/src/Service/Indexer/LocationFinder.php
new file mode 100644
index 0000000..974ad50
--- /dev/null
+++ b/src/Service/Indexer/LocationFinder.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Indexer;
+
+use Symfony\Component\Finder\Finder;
+
+class LocationFinder
+{
+    private readonly string $basePath;
+
+    public function __construct(string $basePath)
+    {
+        $this->basePath = rtrim($basePath, '/');
+    }
+
+    /**
+     * @return string[]
+     */
+    public function findAll(): array
+    {
+
+        $finder = new Finder();
+        $finder->in($this->basePath);
+        $finder->name('*.php');
+        $finder->files();
+
+        $pathList = [];
+        foreach ($finder as $file) {
+            $pathList[] = $this->toRelativePath($file->getPathname());
+        }
+
+        return $pathList;
+    }
+
+    /**
+     * @param string[] $directories
+     */
+    public function findInSubdirectories(array $directories): array
+    {
+        $finder = new Finder();
+        foreach ($directories as $directory) {
+            $finder->in($this->basePath . '/' . $directory);
+        }
+        $finder->name('*.php');
+        $finder->files();
+
+        $pathList = [];
+        foreach ($finder as $file) {
+            $pathList[] = $this->toRelativePath($file->getPathname());
+        }
+
+        return $pathList;
+    }
+
+    private function toRelativePath(string $path): string
+    {
+        return substr($path, strlen($this->basePath));
+    }
+}
diff --git a/src/Service/Indexer/SiteKit/DefaultSchema21DocumentEnricher.php b/src/Service/Indexer/SiteKit/DefaultSchema21DocumentEnricher.php
new file mode 100644
index 0000000..129e367
--- /dev/null
+++ b/src/Service/Indexer/SiteKit/DefaultSchema21DocumentEnricher.php
@@ -0,0 +1,290 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Indexer\SiteKit;
+
+use Atoolo\Resource\Loader\SiteKitNavigationHierarchyLoader;
+use Atoolo\Resource\Resource;
+use Atoolo\Search\Service\Indexer\DocumentEnricher;
+use DateTime;
+use Solarium\Core\Query\DocumentInterface;
+
+class DefaultSchema21DocumentEnricher implements DocumentEnricher
+{
+    public function __construct(
+        private readonly SiteKitNavigationHierarchyLoader $navigationLoader
+    ) {
+    }
+
+    public function enrichDocument(
+        Resource $resource,
+        DocumentInterface $doc,
+        string $processId
+    ): DocumentInterface {
+        $doc->sp_id = $resource->getId();
+        $doc->sp_name = $resource->getName();
+        $doc->sp_anchor = $resource->getData('init.anchor');
+        $doc->title = $resource->getData('base.title');
+        $doc->description = $resource->getData('metadata.description');
+        $doc->sp_objecttype = $resource->getObjectType();
+        $doc->sp_canonical = true;
+        $doc->crawl_process_id = $processId;
+
+        $mediaUrl = $resource->getData('init.mediaUrl');
+        if ($mediaUrl !== null) {
+            $doc->id = $mediaUrl;
+            $doc->url = $mediaUrl;
+        } else {
+            $doc->id = $resource->getLocation();
+            $doc->url = $resource->getLocation();
+        }
+
+        $spContentType = [$resource->getObjectType()];
+        if ($resource->getData('init.media') !== true) {
+            $spContentType[] = 'article';
+        }
+        $contentSectionTypes = $resource->getData('init.contentSectionTypes');
+        if (is_array($contentSectionTypes)) {
+            $spContentType = array_merge($spContentType, $contentSectionTypes);
+        }
+        if ($resource->getData('base.teaser.image') !== null) {
+            $spContentType[] = 'teaserImage';
+        }
+        if ($resource->getData('base.teaser.image.copyright') !== null) {
+            $spContentType[] = 'teaserImageCopyright';
+        }
+        if ($resource->getData('base.teaser.headline') !== null) {
+            $spContentType[] = 'teaserHeadline';
+        }
+        if ($resource->getData('base.teaser.text') !== null) {
+            $spContentType[] = 'teaserText';
+        }
+        $doc->sp_contenttype = $spContentType;
+
+        $locale = $this->getLocaleFromResource($resource);
+        $lang = $this->toLangFromLocale($locale);
+        $doc->sp_language = $lang;
+        $doc->meta_content_language = $lang;
+
+        $doc->sp_changed = $this->toDateTime(
+            $resource->getData('init.changed')
+        );
+        $doc->sp_date = $this->toDateTime(
+            $resource->getData('base.date')
+        );
+
+        $doc->sp_archive = $resource->getData('base.archive') ?? false;
+
+        $headline = $resource->getData('metadata.headline');
+        if (empty($headline)) {
+            $headline = $resource->getData('base.teaser.headline');
+        }
+        if (empty($headline)) {
+            $headline = $resource->getData('base.title');
+        }
+        $doc->sp_title = $headline;
+
+        // However, the teaser heading, if specified, must be used for sorting
+        $sortHeadline = $resource->getData('base.teaser.headline');
+        if (empty($sortHeadline)) {
+            $sortHeadline = $resource->getData('metadata.headline');
+        }
+        if (empty($sortHeadline)) {
+            $sortHeadline = $resource->getData('base.title');
+        }
+        $doc->sp_sortvalue = $sortHeadline;
+
+        $doc->sp_boost_keywords = $resource->getData('metadata.boostKeywords');
+
+        $sites = $this->getParentSiteGroupIdList($resource);
+
+        $navigationRoot = $this->navigationLoader->loadRoot(
+            $resource->getLocation()
+        );
+        $siteGroupId = $navigationRoot->getData('init.siteGroup.id');
+        if ($siteGroupId !== null) {
+            $sites[] = $siteGroupId;
+        }
+        $doc->sp_site = array_unique($sites);
+
+        $wktPrimaryList = $resource->getData('base.geo.wkt.primary');
+        if (is_array($wktPrimaryList)) {
+            $allWkt = [];
+            foreach ($wktPrimaryList as $wkt) {
+                $allWkt[] = $wkt;
+            }
+            if (count($allWkt) > 0) {
+                $doc->sp_geo_points = $allWkt;
+            }
+        }
+
+        $categoryList = $resource->getData('metadata.categories');
+        if (is_array($categoryList)) {
+            $categoryIdList = [];
+            foreach ($categoryList as $category) {
+                $categoryIdList[] = $category['id'];
+            }
+            $doc->sp_category = $categoryIdList;
+        }
+
+        $categoryPath = $resource->getData('metadata.categoriesPath');
+        if (is_array($categoryPath)) {
+            $categoryIdPath = [];
+            foreach ($categoryPath as $category) {
+                $categoryIdPath[] = $category['id'];
+            }
+            $doc->sp_category_path = $categoryIdPath;
+        }
+
+        $groupPath = $resource->getData('init.groupPath');
+        $groupPathAsIdList = [];
+        if (is_array($groupPath)) {
+            foreach ($groupPath as $group) {
+                $groupPathAsIdList[] = $group['id'];
+            }
+        }
+        $doc->sp_group = $groupPathAsIdList[count($groupPathAsIdList) - 2];
+        $doc->sp_group_path = $groupPathAsIdList;
+
+        $schedulingList = $resource->getData('metadata.scheduling');
+        if (is_array($schedulingList) && count($schedulingList) > 0) {
+            $doc->sp_date = $this->toDateTime($schedulingList[0]['from']);
+            $dateList = [];
+            $contentTypeList = [];
+            foreach ($schedulingList as $scheduling) {
+                $contentTypeList[] = explode(' ', $scheduling['contentType']);
+                $dateList[] = $this->toDateTime($scheduling['from']);
+            }
+            $doc->sp_contenttype = array_merge(
+                $doc->sp_contenttype,
+                ...$contentTypeList
+            );
+            $doc->sp_contenttype = array_unique($doc->sp_contenttype);
+
+            $doc->sp_date_list = $dateList;
+        }
+
+        $contentType = $resource->getData('base.mime');
+        if ($contentType === null) {
+            $contentType = 'text/html; charset=UTF-8';
+        }
+        $doc->meta_content_type = $contentType;
+        $doc->content = $resource->getData('searchindexdata.content');
+
+        $accessType = $resource->getData('init.access.type');
+        $groups = $resource->getData('init.access.groups');
+
+
+        if ($accessType === 'allow' && is_array($groups)) {
+            $doc->include_groups = array_map(
+                fn($id): int => $this->idWithoutSignature($id),
+                $groups
+            );
+        } elseif ($accessType === 'deny' && is_array($groups)) {
+            $doc->exclude_groups = array_map(
+                fn($id): int => $this->idWithoutSignature($id),
+                $groups
+            );
+        } else {
+            $doc->exclude_groups = ['none'];
+            $doc->include_groups = ['all'];
+        }
+
+        $doc->sp_source = ['internal'];
+
+        return $doc;
+    }
+
+    private function idWithoutSignature(string $id): int
+    {
+        $s = substr($id, -11);
+        return (int)$s;
+    }
+
+    /* Customization
+     * - https://gitlab.sitepark.com/customer-projects/fhdo/blob/develop/fhdo-module/src/publish/php/SP/Fhdo/Component/Content/DetailPage/StartletterIndexSupplier.php#L31
+     * - https://gitlab.sitepark.com/apis/sitekit-php/blob/develop/php/SP/SiteKit/Component/Content/NewsdeskRss.php#L235
+     * - https://gitlab.sitepark.com/customer-projects/fhdo/blob/develop/fhdo-module/src/publish/php/SP/Fhdo/Component/SearchMetadataExtension.php#L41
+     * - https://gitlab.sitepark.com/customer-projects/paderborn/blob/develop/paderborn-module/src/publish/php/SP/Paderborn/Component/FscEntity.php#L67
+     * - https://gitlab.sitepark.com/customer-projects/paderborn/blob/develop/paderborn-module/src/publish/php/SP/Paderborn/Component/FscContactPerson.php#L24
+     * - https://gitlab.sitepark.com/customer-projects/stadtundland/blob/develop/stadtundland-module/src/publish/php/SP/Stadtundland/Component/ParkingSpaceExpose.php#L38
+     * - https://gitlab.sitepark.com/customer-projects/stadtundland/blob/develop/stadtundland-module/src/publish/php/SP/Stadtundland/Component/Expose.php#L38
+     * - https://gitlab.sitepark.com/customer-projects/stadtundland/blob/develop/stadtundland-module/src/publish/php/SP/Stadtundland/Component/PurchaseExpose.php#L38
+     * - https://gitlab.sitepark.com/customer-projects/stuttgart/blob/develop/stuttgart-module/src/publish/php/SP/Stuttgart/Component/JobOffer.php#L29
+     * - https://gitlab.sitepark.com/customer-projects/stuttgart/blob/develop/stuttgart-module/src/publish/php/SP/Stuttgart/Component/EventsCalendarExtension.php#L124
+     * - https://gitlab.sitepark.com/ies-modules/citycall/blob/develop/citycall-module/src/main/php/src/SP/CityCall/Component/Intro.php#L51
+     * - https://gitlab.sitepark.com/ies-modules/citycall/blob/develop/citycall-module/src/main/php/src/SP/CityCall/Controller/Environment.php#L76
+     * - https://gitlab.sitepark.com/ies-modules/sitekit-real-estate/blob/develop/src/publish/php/SP/RealEstate/Component/Expose.php#L47
+     */
+
+    private function getLocaleFromResource(Resource $resource): string
+    {
+
+        $locale = $resource->getData('init.locale');
+        if ($locale !== null) {
+            return $locale;
+        }
+        $groupPath = $resource->getData('init.groupPath');
+        $len = count($groupPath);
+        if (is_array($groupPath)) {
+            for ($i = $len - 1; $i >= 0; $i--) {
+                $group = $groupPath[$i];
+                if (isset($group['locale'])) {
+                    return $group['locale'];
+                }
+            }
+        }
+
+        return 'de_DE';
+    }
+
+    private function toLangFromLocale(string $locale): string
+    {
+        if (str_contains($locale, '_')) {
+            $parts = explode('_', $locale);
+            return $parts[0];
+        }
+        return $locale;
+    }
+
+    private function toDateTime(?int $timestamp): ?DateTime
+    {
+        if ($timestamp === null) {
+            return null;
+        }
+        if ($timestamp <= 0) {
+            return null;
+        }
+
+        $dateTime = new DateTime();
+        $dateTime->setTimestamp($timestamp);
+        return $dateTime;
+    }
+
+    private function getParentSiteGroupIdList(Resource $resource): array
+    {
+        $parents = $this->getNavigationParents($resource);
+        if (empty($parents)) {
+            return [];
+        }
+
+        $siteGroupIdList = [];
+        foreach ($parents as $parent) {
+            if (isset($parent['siteGroup']['id'])) {
+                $siteGroupIdList[] = $parent['siteGroup']['id'];
+            }
+        }
+
+        return $siteGroupIdList;
+    }
+
+    /**
+     * @return array
+     */
+    private function getNavigationParents(Resource $resource): array
+    {
+        $parents = $resource->getData('base.trees.navigation.parents');
+        return $parents ?? [];
+    }
+}
diff --git a/src/Service/Indexer/SolrIndexer.php b/src/Service/Indexer/SolrIndexer.php
new file mode 100644
index 0000000..4bf37ee
--- /dev/null
+++ b/src/Service/Indexer/SolrIndexer.php
@@ -0,0 +1,215 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Indexer;
+
+use Atoolo\Resource\Exception\InvalidResourceException;
+use Atoolo\Resource\Resource;
+use Atoolo\Resource\ResourceLoader;
+use Atoolo\Search\Dto\Indexer\IndexerParameter;
+use Atoolo\Search\Indexer;
+use Atoolo\Search\Service\SolrClientFactory;
+use Exception;
+use Solarium\Core\Query\Result\ResultInterface;
+use Solarium\QueryType\Update\Result;
+
+/**
+ *  Implementation of the indexer on the basis of a Solr index.
+ */
+class SolrIndexer implements Indexer
+{
+    /**
+     * @param iterable<DocumentEnricher> $documentEnricherList
+     */
+    public function __construct(
+        private readonly iterable $documentEnricherList,
+        private readonly IndexerProgressHandler $indexerProgressHandler,
+        private readonly ResourceLoader $resourceLoader,
+        private readonly SolrClientFactory $clientFactory,
+        private readonly string $source
+    ) {
+    }
+
+    public function index(IndexerParameter $parameter): void
+    {
+        $finder = new LocationFinder($parameter->basePath);
+        if (empty($parameter->directories)) {
+            $pathList = $finder->findAll();
+        } else {
+            $pathList = $finder->findInSubdirectories($parameter->directories);
+        }
+        $this->indexResources($parameter, $pathList);
+    }
+
+        /**
+     * @param array<string> $pathList
+     */
+    private function indexResources(
+        IndexerParameter $parameter,
+        array $pathList
+    ): void {
+        if (count($pathList) === 0) {
+            return;
+        }
+
+        $total = count($pathList);
+        $this->indexerProgressHandler->start($total);
+
+        $processId = uniqid('', true);
+        $offset = 0;
+        $chunkSize = 500;
+        $successCount = 0;
+
+        try {
+            while (true) {
+                $indexedCount = $this->indexChunks(
+                    $processId,
+                    $parameter->coreId,
+                    $pathList,
+                    $offset,
+                    $chunkSize
+                );
+                if ($indexedCount === false) {
+                    break;
+                }
+                $successCount += $indexedCount;
+                $offset += $chunkSize;
+            }
+
+            if (
+                $parameter->cleanupThreshold > 0 &&
+                $successCount >= $parameter->cleanupThreshold
+            ) {
+                $this->deleteByProcessId($parameter->coreId, $processId);
+            }
+            $this->commit($parameter->coreId);
+        } finally {
+            $this->indexerProgressHandler->finish();
+        }
+    }
+
+    /**
+     * @param string[] $pathList
+     */
+    private function indexChunks(
+        string $processId,
+        string $solrCore,
+        array $pathList,
+        int $offset,
+        int $length
+    ): int|false {
+        $resourceList = $this->loadResources(
+            $pathList,
+            $offset,
+            $length
+        );
+        if ($resourceList === false) {
+            return false;
+        }
+        $this->indexerProgressHandler->advance(count($resourceList));
+        $result = $this->add($solrCore, $processId, $resourceList);
+
+        if ($result->getStatus() !== 0) {
+            $this->indexerProgressHandler->error(new Exception(
+                $result->getResponse()->getStatusMessage()
+            ));
+            return 0;
+        }
+
+        return count($resourceList);
+    }
+
+    /**
+     * @param string[] $pathList
+     * @return Resource[]|false
+     */
+    private function loadResources(
+        array $pathList,
+        int $offset,
+        int $length
+    ): array | false {
+
+        $maxLength = (count($pathList) ?? 0) - $offset;
+        if ($maxLength <= 0) {
+            return false;
+        }
+
+        if ($length > $maxLength) {
+            $length = $maxLength;
+        }
+
+        $resourceList = [];
+        for ($i = $offset; $i < ($length + $offset); $i++) {
+            $path = $pathList[$i];
+            try {
+                $resource = $this->resourceLoader->load($path);
+                $resourceList[] = $resource;
+            } catch (InvalidResourceException $e) {
+                $this->indexerProgressHandler->error($e);
+            }
+        }
+        return $resourceList;
+    }
+
+    /**
+     * @param string $solrCore
+     * @param string $processId
+     * @param array<Resource> $resources
+     * @return ResultInterface|Result
+     */
+    private function add(
+        string $solrCore,
+        string $processId,
+        array $resources
+    ): ResultInterface|Result {
+        $client = $this->clientFactory->create($solrCore);
+
+        $update = $client->createUpdate();
+
+        $documents = [];
+        foreach ($resources as $resource) {
+            $doc = $update->createDocument();
+            foreach ($this->documentEnricherList as $enricher) {
+                $doc = $enricher->enrichDocument(
+                    $resource,
+                    $doc,
+                    $processId
+                );
+            }
+            $documents[] = $doc;
+        }
+
+        // add the documents and a commit command to the update query
+        $update->addDocuments($documents);
+
+        // this executes the query and returns the result
+        return $client->update($update);
+    }
+
+    private function deleteByProcessId(string $core, string $processId): void
+    {
+        $this->deleteByQuery(
+            $core,
+            '-crawl_process_id:' . $processId . ' AND ' .
+            ' sp_source:' . $this->source
+        );
+    }
+
+    private function deleteByQuery(string $core, string $query): void
+    {
+        $client = $this->clientFactory->create($core);
+        $update = $client->createUpdate();
+        $update->addDeleteQuery($query);
+        $client->update($update);
+    }
+
+    private function commit(string $core): void
+    {
+        $client = $this->clientFactory->create($core);
+        $update = $client->createUpdate();
+        $update->addCommit();
+        $update->addOptimize();
+        $client->update($update);
+    }
+}
diff --git a/src/Service/Search/ExternalResourceFactory.php b/src/Service/Search/ExternalResourceFactory.php
new file mode 100644
index 0000000..9d09cf9
--- /dev/null
+++ b/src/Service/Search/ExternalResourceFactory.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Resource\Resource;
+use Solarium\QueryType\Select\Result\Document;
+
+/**
+ * External resources are data that are not provided by the CMS, but are
+ * transferred to the Solr index via special indexers, for example.
+ * In these cases, the search result leads to an external page.
+ * This factory recognizes external content using the Solr document field url.
+ * It is an external resource if the URL begins with https:// or http://.
+ */
+class ExternalResourceFactory implements ResourceFactory
+{
+    public function accept(Document $document): bool
+    {
+        $location = $document->url;
+        return (
+            str_starts_with($location, 'http://') ||
+            str_starts_with($location, 'https://')
+        );
+    }
+
+    public function create(Document $document): Resource
+    {
+        return new Resource(
+            $document->url,
+            '',
+            $document->title,
+            'external',
+            []
+        );
+    }
+}
diff --git a/src/Service/Search/InternalMediaResourceFactory.php b/src/Service/Search/InternalMediaResourceFactory.php
new file mode 100644
index 0000000..753e138
--- /dev/null
+++ b/src/Service/Search/InternalMediaResourceFactory.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Resource\Resource;
+use Atoolo\Resource\ResourceLoader;
+use Atoolo\Search\Service\Search\ResourceFactory;
+use Solarium\QueryType\Select\Result\Document;
+
+/**
+ * The metadata is indexed for media and the full text is also indexed for
+ * text documents. To load the resource of a medium, the meta file of the
+ * medium is required. The medium meta file is identical to the path of the
+ * medium plus the suffix .meta.php. If this file exists for the URL of the
+ * Solr document, the media resource is created.
+ */
+class InternalMediaResourceFactory implements ResourceFactory
+{
+    public function __construct(
+        private readonly ResourceLoader $resourceLoader
+    ) {
+    }
+
+    public function accept(Document $document): bool
+    {
+        $metaLocation = $this->getMetaLocation($document);
+        return $this->resourceLoader->exists($metaLocation);
+    }
+
+    public function create(Document $document): Resource
+    {
+        $metaLocation = $this->getMetaLocation($document);
+        return $this->resourceLoader->load($metaLocation);
+    }
+
+    private function getMetaLocation(Document $document): string
+    {
+        return $document->url . '.meta.php';
+    }
+}
diff --git a/src/Service/Search/InternalResourceFactory.php b/src/Service/Search/InternalResourceFactory.php
new file mode 100644
index 0000000..0217adc
--- /dev/null
+++ b/src/Service/Search/InternalResourceFactory.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Resource\Resource;
+use Atoolo\Resource\ResourceLoader;
+use Atoolo\Search\Service\Search\ResourceFactory;
+use Solarium\QueryType\Select\Result\Document;
+
+/**
+ * Internal resources are the data that the CMS provides in the form of
+ * aggregated PHP files. The Solr document field url specifies which resource
+ * is required. If the URL ends with .php, this factory is used.
+ */
+class InternalResourceFactory implements ResourceFactory
+{
+    public function __construct(
+        private readonly ResourceLoader $resourceLoader
+    ) {
+    }
+
+    public function accept(Document $document): bool
+    {
+        return str_ends_with($document->url, '.php');
+    }
+
+    public function create(Document $document): Resource
+    {
+        return $this->resourceLoader->load($document->url);
+    }
+}
diff --git a/src/Service/Search/ResourceFactory.php b/src/Service/Search/ResourceFactory.php
new file mode 100644
index 0000000..6fbaea0
--- /dev/null
+++ b/src/Service/Search/ResourceFactory.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Resource\Resource;
+use Solarium\QueryType\Select\Result\Document;
+
+/**
+ * There are different types of resources e.g.
+ * - External
+ * - Internal-Media
+ * - Internal
+ * - Customized
+ *
+ * This interface makes the methods available that must be implemented by the
+ * resource factories. The factory can use the accept() method to check whether
+ * the resource can be created with the transferred Solr document. If this is
+ * the case, true must be returned and the create method called, with which the
+ * resource can then be created and returned.
+ */
+interface ResourceFactory
+{
+    public function accept(Document $document): bool;
+    public function create(Document $document): Resource;
+}
diff --git a/src/Service/Search/SiteKit/DefaultBoostModifier.php b/src/Service/Search/SiteKit/DefaultBoostModifier.php
new file mode 100644
index 0000000..e209bb0
--- /dev/null
+++ b/src/Service/Search/SiteKit/DefaultBoostModifier.php
@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search\SiteKit;
+
+use Atoolo\Search\Service\Search\SolrQueryModifier;
+use Solarium\QueryType\Select\Query\Query as SelectQuery;
+
+class DefaultBoostModifier implements SolrQueryModifier
+{
+    public function modify(SelectQuery $query): SelectQuery
+    {
+        $edismax = $query->getEDisMax();
+        $edismax->setQueryFields(implode(' ', [
+            'sp_title^1.4',
+            'keywords^1.2',
+            'description^1.0',
+            'title^1.0',
+            'url^0.9',
+            'content^0.8'
+        ]));
+        $edismax->setPhraseFields(implode(' ', [
+            'sp_title^1.5',
+            'description^1',
+            'content^0.8'
+        ]));
+        $edismax->setBoostQuery('sp_objecttype:searchTip^100');
+
+        return $query;
+    }
+}
diff --git a/src/Service/Search/SolrMoreLikeThis.php b/src/Service/Search/SolrMoreLikeThis.php
new file mode 100644
index 0000000..11e87b8
--- /dev/null
+++ b/src/Service/Search/SolrMoreLikeThis.php
@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Search\Dto\Search\Query\MoreLikeThisQuery;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+use Atoolo\Search\MoreLikeThisSearcher;
+use Atoolo\Search\Service\SolrClientFactory;
+use Solarium\Core\Client\Client;
+use Solarium\Core\Query\Result\ResultInterface;
+use Solarium\QueryType\MoreLikeThis\Query as SolrMoreLikeThisQuery;
+
+/**
+ * Implementation of the "More-Like-This" on the basis of a Solr index.
+ */
+class SolrMoreLikeThis implements MoreLikeThisSearcher
+{
+    /**
+     * @param iterable<ResourceFactory> $resourceFactoryList
+     */
+    public function __construct(
+        private readonly SolrClientFactory $clientFactory,
+        private readonly SolrResultToResourceResolver $resultToResourceResolver
+    ) {
+    }
+
+    public function moreLikeThis(MoreLikeThisQuery $query): ResourceSearchResult
+    {
+        $client = $this->clientFactory->create($query->getCore());
+        $solrQuery = $this->buildSolrQuery($client, $query);
+        $result = $client->execute($solrQuery);
+        return $this->buildResult($result);
+    }
+
+    private function buildSolrQuery(
+        Client $client,
+        MoreLikeThisQuery $query
+    ): SolrMoreLikeThisQuery {
+
+        $solrQuery = $client->createMoreLikeThis();
+        $solrQuery->setOmitHeader(false);
+        $solrQuery->setQuery('url:"' . $query->getLocation() . '"');
+        $solrQuery->setMltFields($query->getFieldList());
+        $solrQuery->setRows($query->getLimit());
+        $solrQuery->setMinimumTermFrequency(2);
+        $solrQuery->setMatchInclude(true);
+        $solrQuery->createFilterQuery('nomedia')
+            ->setQuery('-sp_objecttype:media');
+
+        // Filter
+        foreach ($query->getFilterList() as $filter) {
+            $solrQuery->createFilterQuery($filter->getKey())
+                ->setQuery($filter->getQuery())
+                ->setTags($filter->getTags());
+        }
+
+        return $solrQuery;
+    }
+
+    private function buildResult(
+        ResultInterface $result
+    ): ResourceSearchResult {
+
+        $resourceList = $this->resultToResourceResolver
+            ->loadResourceList($result);
+
+        return new ResourceSearchResult(
+            $result->getNumFound(),
+            0,
+            $resourceList,
+            [],
+            $result->getQueryTime()
+        );
+    }
+}
diff --git a/src/Service/Search/SolrQueryModifier.php b/src/Service/Search/SolrQueryModifier.php
new file mode 100644
index 0000000..ab51430
--- /dev/null
+++ b/src/Service/Search/SolrQueryModifier.php
@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Solarium\QueryType\Select\Query\Query as SelectQuery;
+
+/**
+ * SolrQueryModifiers can be passed to the search service to make additional
+ * modifications to the search query. This is used, for example, to set the
+ * same boosting for all queries.
+ */
+interface SolrQueryModifier
+{
+    public function modify(SelectQuery $query): SelectQuery;
+}
diff --git a/src/Service/Search/SolrResultToResourceResolver.php b/src/Service/Search/SolrResultToResourceResolver.php
new file mode 100644
index 0000000..aa23465
--- /dev/null
+++ b/src/Service/Search/SolrResultToResourceResolver.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Resource\Resource;
+use Atoolo\Resource\ResourceLoader;
+use Atoolo\Search\Exception\MissMatchingResourceFactoryException;
+use Psr\Log\LoggerInterface;
+use Psr\Log\NullLogger;
+use Solarium\Core\Query\Result\ResultInterface;
+use Solarium\QueryType\Select\Result\Document;
+
+/**
+ * The loadResourceList() method receives a Solr result and generates the
+ * corresponding resource objects from each hit with the help of the resource
+ * factories and returns them as a list.
+ */
+class SolrResultToResourceResolver
+{
+    /**
+     * @param iterable<ResourceFactory> $resourceFactoryList
+     */
+    public function __construct(
+        private readonly iterable $resourceFactoryList,
+        private readonly LoggerInterface $logger = new NullLogger()
+    ) {
+    }
+
+    /**
+     * @return array<Resource>
+     */
+    public function loadResourceList(ResultInterface $result): array
+    {
+        $resourceList = [];
+        foreach ($result as $document) {
+            try {
+                $resourceList[] = $this->loadResource($document);
+            } catch (\Exception $e) {
+                $this->logger->error($e->getMessage(), ['exception' => $e]);
+            }
+        }
+        return $resourceList;
+    }
+
+    private function loadResource(Document $document): Resource
+    {
+
+        foreach ($this->resourceFactoryList as $resourceFactory) {
+            if ($resourceFactory->accept($document)) {
+                return $resourceFactory->create($document);
+            }
+        }
+
+        throw new MissMatchingResourceFactoryException($document->url);
+    }
+}
diff --git a/src/Service/Search/SolrSelect.php b/src/Service/Search/SolrSelect.php
new file mode 100644
index 0000000..b5b289a
--- /dev/null
+++ b/src/Service/Search/SolrSelect.php
@@ -0,0 +1,260 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Search\Dto\Search\Query\Facet\FacetField;
+use Atoolo\Search\Dto\Search\Query\Facet\FacetMultiQuery;
+use Atoolo\Search\Dto\Search\Query\Facet\FacetQuery;
+use Atoolo\Search\Dto\Search\Query\Filter\Filter;
+use Atoolo\Search\Dto\Search\Query\QueryDefaultOperator;
+use Atoolo\Search\Dto\Search\Query\SelectQuery;
+use Atoolo\Search\Dto\Search\Result\Facet;
+use Atoolo\Search\Dto\Search\Result\FacetGroup;
+use Atoolo\Search\Dto\Search\Result\ResourceSearchResult;
+use Atoolo\Search\SelectSearcher;
+use Atoolo\Search\Service\SolrClientFactory;
+use Solarium\Component\Result\Facet\FacetResultInterface;
+use Solarium\Core\Client\Client;
+use Solarium\Core\Query\Result\ResultInterface;
+use Solarium\QueryType\Select\Query\Query as SolrSelectQuery;
+
+/**
+ * Implementation of the searcher on the basis of a Solr index.
+ */
+class SolrSelect implements SelectSearcher
+{
+    /**
+     * @param iterable<SolrQueryModifier> $solrQueryModifierList
+     */
+    public function __construct(
+        private readonly SolrClientFactory $clientFactory,
+        private readonly iterable $solrQueryModifierList,
+        private readonly SolrResultToResourceResolver $resultToResourceResolver
+    ) {
+    }
+
+    public function select(SelectQuery $query): ResourceSearchResult
+    {
+        $client = $this->clientFactory->create($query->getCore());
+
+        $solrQuery = $this->buildSolrQuery($client, $query);
+        $result = $client->execute($solrQuery);
+        return $this->buildResult($query, $result);
+    }
+
+    private function buildSolrQuery(
+        Client $client,
+        SelectQuery $query
+    ): SolrSelectQuery {
+
+        $solrQuery = $client->createSelect();
+
+        // supplements the query with standard values, e.g. for boosting
+        foreach ($this->solrQueryModifierList as $solrQueryModifier) {
+            $solrQuery = $solrQueryModifier->modify($solrQuery);
+        }
+
+        $solrQuery->setStart($query->getOffset());
+        $solrQuery->setRows($query->getLimit());
+
+        // to get query-time
+        $solrQuery->setOmitHeader(false);
+
+        $this->addRequiredFieldListToSolrQuery($solrQuery);
+        $this->addTextFilterToSolrQuery($solrQuery, $query->getText());
+        $this->addQueryDefaultOperatorToSolrQuery(
+            $solrQuery,
+            $query->getQueryDefaultOperator()
+        );
+        $this->addFilterQueriesToSolrQuery(
+            $solrQuery,
+            $query->getFilterList()
+        );
+        $this->addFacetListToSolrQuery(
+            $solrQuery,
+            $query->getFacetList()
+        );
+
+        return $solrQuery;
+    }
+
+    private function addRequiredFieldListToSolrQuery(
+        SolrSelectQuery $solrQuery
+    ): void {
+        $fields = $solrQuery->getFields();
+        if (in_array('url', $fields, true)) {
+            return;
+        }
+        $fields[] = 'url';
+        $solrQuery->setFields($fields);
+    }
+
+    private function addTextFilterToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        string $text
+    ): void {
+        if (empty($text)) {
+            return;
+        }
+        $terms = explode(' ', $text);
+        $terms = array_map(function ($term) use ($solrQuery) {
+            $term = trim($term);
+            return $solrQuery->getHelper()->escapeTerm($term);
+        },
+            $terms);
+        $text = implode(' ', $terms);
+        $solrQuery->setQuery($text);
+    }
+
+    private function addQueryDefaultOperatorToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        QueryDefaultOperator $operator
+    ): void {
+        if ($operator === QueryDefaultOperator::OR) {
+            $solrQuery->setQueryDefaultOperator(
+                SolrSelectQuery::QUERY_OPERATOR_OR
+            );
+        } else {
+            $solrQuery->setQueryDefaultOperator(
+                SolrSelectQuery::QUERY_OPERATOR_AND
+            );
+        }
+    }
+
+    /**
+     * @param Filter[] $filterList
+     */
+    private function addFilterQueriesToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        array $filterList
+    ): void {
+
+        foreach ($filterList as $filter) {
+            $solrQuery->createFilterQuery($filter->getKey())
+                ->setQuery($filter->getQuery())
+                ->setTags($filter->getTags());
+        }
+    }
+
+    /**
+     * @param \Atoolo\Search\Dto\Search\Query\Facet\Facet[] $filterList
+     */
+    private function addFacetListToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        array $facetList
+    ): void {
+        foreach ($facetList as $facet) {
+            if ($facet instanceof FacetField) {
+                $this->addFacetFieldToSolrQuery($solrQuery, $facet);
+            } elseif ($facet instanceof FacetQuery) {
+                $this->addFacetQueryToSolrQuery($solrQuery, $facet);
+            } elseif ($facet instanceof FacetMultiQuery) {
+                $this->addFacetMultiQueryToSolrQuery($solrQuery, $facet);
+            } else {
+                throw new \InvalidArgumentException(
+                    'Unsupported facet-class ' . get_class($facet)
+                );
+            }
+        }
+    }
+
+    /**
+     * https://solarium.readthedocs.io/en/stable/queries/select-query/building-a-select-query/components/facetset-component/facet-field/
+     */
+    private function addFacetFieldToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        FacetField $facet
+    ): void {
+        $facetSet = $solrQuery->getFacetSet();
+        // https://solr.apache.org/guide/solr/latest/query-guide/faceting.html#tagging-and-excluding-filters
+        $fieldWithExclude = '{!ex=' . $facet->getKey() . '}' .
+            $facet->getField();
+        $facetSet->createFacetField($facet->getKey())
+            ->setField($fieldWithExclude)
+            ->setTerms($facet->getTerms());
+    }
+
+    /**
+     * https://solarium.readthedocs.io/en/stable/queries/select-query/building-a-select-query/components/facetset-component/facet-query/
+     */
+    private function addFacetQueryToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        FacetQuery $facet
+    ): void {
+        $facetSet = $solrQuery->getFacetSet();
+        $facetSet->createFacetQuery($facet->getKey())
+            ->setQuery($facet->getQuery());
+    }
+
+    /**
+     * https://solarium.readthedocs.io/en/stable/queries/select-query/building-a-select-query/components/facetset-component/facet-multiquery/
+     */
+    private function addFacetMultiQueryToSolrQuery(
+        SolrSelectQuery $solrQuery,
+        FacetMultiQuery $facet
+    ): void {
+        $facetSet = $solrQuery->getFacetSet();
+        $solrFacet = $facetSet->createFacetMultiQuery($facet->getKey());
+        foreach ($facet->getQueryList() as $facetQuery) {
+            $solrFacet->createQuery(
+                $facetQuery->getKey(),
+                $facetQuery->getQuery()
+            );
+        }
+    }
+
+    private function buildResult(
+        SelectQuery $query,
+        ResultInterface $result
+    ): ResourceSearchResult {
+
+        $resourceList = $this->resultToResourceResolver
+            ->loadResourceList($result);
+        $facetGroupList = $this->buildFacetGroupList($query, $result);
+
+        return new ResourceSearchResult(
+            $result->getNumFound(),
+            $query->getOffset(),
+            $resourceList,
+            $facetGroupList,
+            $result->getQueryTime()
+        );
+    }
+
+    /**
+     * @param ResultInterface $result
+     * @return FacetGroup[]
+     */
+    private function buildFacetGroupList(
+        SelectQuery $query,
+        ResultInterface $result
+    ): array {
+
+        $facetSet = $result->getFacetSet();
+        if ($facetSet === null) {
+            return [];
+        }
+
+        $facetGroupList = [];
+        foreach ($query->getFacetList() as $facet) {
+            $facetGroupList[] = $this->buildFacetGroup(
+                $facet->getKey(),
+                $facetSet->getFacet($facet->getKey())
+            );
+        }
+        return $facetGroupList;
+    }
+
+    private function buildFacetGroup(
+        string $key,
+        FacetResultInterface $solrFacet
+    ): FacetGroup {
+        $facetList = [];
+        foreach ($solrFacet as $value => $count) {
+            $facetList[] = new Facet((string)$value, $count);
+        }
+        return new FacetGroup($key, $facetList);
+    }
+}
diff --git a/src/Service/Search/SolrSuggest.php b/src/Service/Search/SolrSuggest.php
new file mode 100644
index 0000000..17b9a48
--- /dev/null
+++ b/src/Service/Search/SolrSuggest.php
@@ -0,0 +1,127 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service\Search;
+
+use Atoolo\Search\Dto\Search\Query\SuggestQuery;
+use Atoolo\Search\Dto\Search\Result\Suggestion;
+use Atoolo\Search\Dto\Search\Result\SuggestResult;
+use Atoolo\Search\Exception\UnexpectedResultException;
+use Atoolo\Search\Service\SolrParameterClientFactory;
+use Atoolo\Search\SuggestSearcher;
+use Solarium\Core\Client\Client;
+use Solarium\QueryType\Select\Query\Query as SolrSelectQuery;
+use Solarium\QueryType\Select\Result\Result as SolrSelectResult;
+use JsonException;
+
+/**
+ * Implementation of the "suggest search" based on a Solr index.
+ */
+class SolrSuggest implements SuggestSearcher
+{
+    public function __construct(
+        private readonly SolrParameterClientFactory $clientFactory
+    ) {
+    }
+
+    /**
+     * @throws UnexpectedResultException
+     */
+    public function suggest(SuggestQuery $query): SuggestResult
+    {
+        $client = $this->clientFactory->create($query->getCore());
+
+        $solrQuery = $this->buildSolrQuery($client, $query);
+        $solrResult = $client->select($solrQuery);
+        return $this->buildResult($solrResult, $query->getField());
+    }
+
+    private function buildSolrQuery(
+        Client $client,
+        SuggestQuery $query
+    ): SolrSelectQuery {
+        $solrQuery = $client->createSelect();
+        $solrQuery->addParam("spellcheck", "true");
+        $solrQuery->addParam("spellcheck.accuracy", "0.6");
+        $solrQuery->addParam("spellcheck.onlyMorePopular", "false");
+        $solrQuery->addParam("spellcheck.count", "15");
+        $solrQuery->addParam("spellcheck.maxCollations", "5");
+        $solrQuery->addParam("spellcheck.maxCollationTries", "15");
+        $solrQuery->addParam("spellcheck.collate", "true");
+        $solrQuery->addParam("spellcheck.collateExtendedResults", "true");
+        $solrQuery->addParam("spellcheck.extendedResults", "true");
+        $solrQuery->addParam("facet", "true");
+        $solrQuery->addParam("facet.sort", "count");
+        $solrQuery->addParam("facet.method", "enum");
+        $solrQuery->addParam(
+            "facet.prefix",
+            implode(' ', $query->getTermList())
+        );
+        $solrQuery->addParam("facet.limit", $query->getLimit());
+        $solrQuery->addParam("facet.field", $query->getField());
+
+        $solrQuery->setOmitHeader(false);
+        $solrQuery->setStart(0);
+        $solrQuery->setRows(0);
+
+        // Filter
+        foreach ($query->getFilterList() as $filter) {
+            $solrQuery->createFilterQuery($filter->getKey())
+                ->setQuery($filter->getQuery())
+                ->setTags($filter->getTags());
+        }
+
+        return $solrQuery;
+    }
+
+    private function buildResult(
+        SolrSelectResult $solrResult,
+        string $resultField
+    ): SuggestResult {
+        $suggestions = $this->parseSuggestion(
+            $solrResult->getResponse()->getBody(),
+            $resultField
+        );
+        return new SuggestResult($suggestions, $solrResult->getQueryTime());
+    }
+
+    /**
+     * @throws UnexpectedResultException
+     * @return Suggestion[]
+     */
+    private function parseSuggestion(
+        string $responseBody,
+        string $facetField
+    ): array {
+        try {
+            $json = json_decode(
+                $responseBody,
+                true,
+                5,
+                JSON_THROW_ON_ERROR
+            );
+            $facets =
+                $json['facet_counts']['facet_fields'][$facetField]
+                ?? [];
+
+            $len = count($facets);
+
+            $suggestions = [];
+            for ($i = 0; $i < $len; $i += 2) {
+                $term = $facets[$i];
+                $hits = $facets[$i + 1];
+                $suggestions[] = new Suggestion($term, $hits);
+            }
+
+            return $suggestions;
+        } catch (JsonException $e) {
+            throw new UnexpectedResultException(
+                $responseBody,
+                "Invalid JSON for suggest result",
+                0,
+                $e
+            );
+        }
+    }
+}
diff --git a/src/Service/SolrClientFactory.php b/src/Service/SolrClientFactory.php
new file mode 100644
index 0000000..ce26af6
--- /dev/null
+++ b/src/Service/SolrClientFactory.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service;
+
+use Solarium\Client;
+
+/**
+ * This interface is provided to make it possible to create a Solr client in
+ * various ways.
+ */
+interface SolrClientFactory
+{
+    public function create(string $core): Client;
+}
diff --git a/src/Service/SolrParameterClientFactory.php b/src/Service/SolrParameterClientFactory.php
new file mode 100644
index 0000000..207c0b0
--- /dev/null
+++ b/src/Service/SolrParameterClientFactory.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Service;
+
+use Solarium\Client;
+use Solarium\Core\Client\Adapter\Curl;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+
+/**
+ * With this SolrClientFactory implementation, the necessary connection data
+ * for the Solr client is transferred via the client constructor argument.
+ * The SolrParameterClientFactory can be registered as a DependencyInjection
+ * service by passing the necessary transfer arguments as parameters.
+ */
+class SolrParameterClientFactory implements SolrClientFactory
+{
+    public function create(string $core): Client
+    {
+        $host = 'solr-neu-isenburg-whinchat.veltrup.sitepark.de';
+
+        $adapter = new Curl();
+        $adapter->setTimeout(30);
+        //$adapter->setProxy('http://localhost:8889');
+        $eventDispatcher = new EventDispatcher();
+        $config = [
+            'endpoint' => [
+                $host => [
+                    'scheme' => 'https',
+                    'host' => $host,
+                    'port' => 443,
+                    'path' => '',
+                    'core' => $core,
+                ]
+            ]
+        ];
+
+        // create a client instance
+        return new Client(
+            $adapter,
+            $eventDispatcher,
+            $config
+        );
+    }
+}
diff --git a/src/SuggestSearcher.php b/src/SuggestSearcher.php
new file mode 100644
index 0000000..e5ff274
--- /dev/null
+++ b/src/SuggestSearcher.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search;
+
+use Atoolo\Search\Dto\Search\Query\SuggestQuery;
+use Atoolo\Search\Dto\Search\Result\SuggestResult;
+
+/**
+ * The service interface for a suggest search.
+ *
+ * A "suggest search" is a search function that automatically displays
+ * suggestions or auto-completions to users as they enter search queries.
+ */
+interface SuggestSearcher
+{
+    public function suggest(SuggestQuery $query): SuggestResult;
+}
diff --git a/test/Console/ApplicationTest.php b/test/Console/ApplicationTest.php
new file mode 100644
index 0000000..3e174ac
--- /dev/null
+++ b/test/Console/ApplicationTest.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Test\Console;
+
+use Atoolo\Search\Console\Application;
+use Atoolo\Search\Console\Command\Indexer;
+use PHPUnit\Framework\TestCase;
+
+class ApplicationTest extends TestCase
+{
+    public function testConstruct(): void
+    {
+        $application = new Application([
+            new Indexer()
+        ]);
+        $command = $application->get('atoolo:indexer');
+        $this->assertInstanceOf(
+            Indexer::class,
+            $command,
+            'unexpected indexer command'
+        );
+    }
+}
diff --git a/test/Console/Command/IndexerTest.php b/test/Console/Command/IndexerTest.php
new file mode 100644
index 0000000..855b898
--- /dev/null
+++ b/test/Console/Command/IndexerTest.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Test\Console\Command;
+
+use Atoolo\Search\Console\Application;
+use Atoolo\Search\Console\Command\Indexer;
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Console\Tester\CommandTester;
+
+class IndexerTest extends TestCase
+{
+    public function testExecute(): void
+    {
+        $application = new Application([
+            new Indexer()
+        ]);
+
+        $command = $application->find('atoolo:indexer');
+        $commandTester = new CommandTester($command);
+        $commandTester->execute([
+            // pass arguments to the helper
+            'resource-dir' => 'abc',
+
+            // prefix the key with two dashes when passing options,
+            // e.g: '--some-option' => 'option_value',
+            // use brackets for testing array value,
+            // e.g: '--some-option' => ['option_value'],
+        ]);
+
+        $commandTester->assertCommandIsSuccessful();
+
+        // the output of the command in the console
+        $output = $commandTester->getDisplay();
+        $this->assertStringContainsString('Whoa!', $output);
+
+        // ...
+    }
+
+}
diff --git a/test/Service/IndexerTest.php b/test/Service/IndexerTest.php
new file mode 100644
index 0000000..ae1a00d
--- /dev/null
+++ b/test/Service/IndexerTest.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Atoolo\Search\Test\Service;
+
+use Atoolo\Search\Service\SolrIndexer;
+use PHPUnit\Framework\TestCase;
+
+class IndexerTest extends TestCase
+{
+    public function testConstruct(): void
+    {
+        /*
+        $indexer = new SolrIndexer();
+        $indexer->index();
+        */
+    }
+}