diff --git a/composer.json b/composer.json
index 82e41759..a645f715 100644
--- a/composer.json
+++ b/composer.json
@@ -41,6 +41,7 @@
         "setasign/fpdf": "^1",
         "setasign/fpdi": "^2",
         "symfony/yaml": "^5|^6",
+        "symfony/process": "^5|^6",
         "horstoeko/stringmanagement": "^1",
         "horstoeko/mimedb": "^1"
     },
diff --git a/examples/KositValidator.php b/examples/KositValidator.php
new file mode 100644
index 00000000..f0abff01
--- /dev/null
+++ b/examples/KositValidator.php
@@ -0,0 +1,25 @@
+<?php
+
+use horstoeko\zugferd\ZugferdDocumentPdfReader;
+use horstoeko\zugferd\ZugferdKositValidator;
+
+require dirname(__FILE__) . "/../vendor/autoload.php";
+
+function showValidationResult($kositValidator)
+{
+    if ($kositValidator->validationFailed()) {
+        echo "\033[01;31mValidation failed\e[0m\n";
+        foreach ($kositValidator->validationErrors() as $validationError) {
+            echo $validationError . PHP_EOL;
+        }
+    } else {
+        echo "\033[01;32mValidation passed\e[0m\n";
+    }
+}
+
+$document = ZugferdDocumentPdfReader::readAndGuessFromFile(dirname(__FILE__) . "/invoice_1.pdf");
+
+$kositValidator = new ZugferdKositValidator($document);
+$kositValidator->validate();
+
+showValidationResult($kositValidator);
diff --git a/src/ZugferdKositValidator.php b/src/ZugferdKositValidator.php
new file mode 100644
index 00000000..3179a989
--- /dev/null
+++ b/src/ZugferdKositValidator.php
@@ -0,0 +1,516 @@
+<?php
+
+/**
+ * This file is a part of horstoeko/zugferd.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace horstoeko\zugferd;
+
+use Exception;
+use horstoeko\stringmanagement\PathUtils;
+use Symfony\Component\Process\Process;
+use Symfony\Component\Process\Exception\ProcessFailedException;
+use Symfony\Component\Process\ExecutableFinder;
+use Throwable;
+
+/**
+ * Class representing the validator against Schematron (Kosit) for documents
+ *
+ * @category Zugferd
+ * @package  Zugferd
+ * @author   D. Erling <horstoeko@erling.com.de>
+ * @license  https://opensource.org/licenses/MIT MIT
+ * @link     https://github.com/horstoeko/zugferd
+ */
+class ZugferdKositValidator
+{
+    /**
+     * The invoice document reference
+     *
+     * @var ZugferdDocument
+     */
+    private $document = null;
+
+    /**
+     * Internal error bag
+     *
+     * @var array
+     */
+    private $errorBag = [];
+
+    /**
+     * Base directory (download)
+     *
+     * @var string
+     */
+    private $baseDirectory;
+
+    /**
+     * Kosit Validator download url
+     *
+     * @var string
+     */
+    private $validatorDownloadUrl = "https://github.com/itplr-kosit/validator/releases/download/v1.5.0/validator-1.5.0-distribution.zip";
+
+    /**
+     * Kosit Validator scenarios download url
+     *
+     * @var string
+     */
+    private $validatorScenarioDownloadUrl = "https://github.com/itplr-kosit/validator-configuration-xrechnung/releases/download/release-2023-07-31/validator-configuration-xrechnung_3.0.0_2023-07-31.zip";
+
+    /**
+     * The filename of the validation application zip archive
+     *
+     * @var string $validatorAppZipFilename
+     */
+    private $validatorAppZipFilename = "validator.zip";
+
+    /**
+     * The filename of the validation scenario zip archive
+     *
+     * @var string $validatorScenarioZipFilename
+     */
+    private $validatorScenarioZipFilename = "validator-configuration.zip";
+
+    /**
+     * The java application filename
+     *
+     * @var string $validatorAppJarFilename
+     */
+    private $validatorAppJarFilename = "validationtool-1.5.0-standalone.jar";
+
+    /**
+     * Internal status of the requirements check
+     *
+     * @var boolean
+     */
+    private $requirementsChecked = false;
+
+    /**
+     * Internal state of the download of requirements
+     *
+     * @var boolean
+     */
+    private $requiredFilesDownloaded = false;
+
+    /**
+     * Internal state of the unpack of requirements
+     *
+     * @var boolean
+     */
+    private $requiredFilesUnpacked = false;
+
+    /**
+     * Constructor
+     *
+     * @codeCoverageIgnore
+     * @param ZugferdDocument|null $document
+     */
+    public function __construct(?ZugferdDocument $document = null)
+    {
+        $this->document = $document;
+        $this->baseDirectory = sys_get_temp_dir();
+    }
+
+    /**
+     * Set the ZugferdDocument instance to validate
+     *
+     * @param ZugferdDocument $document
+     * @return ZugferdKositValidator
+     */
+    public function setDocument(ZugferdDocument $document): ZugferdKositValidator
+    {
+        $this->document = $document;
+
+        return $this;
+    }
+
+    /**
+     * Setup the base directory. In the base directory all files will be downloaded
+     * and created
+     *
+     * @param string $newBaseDirectory
+     * @return ZugferdKositValidator
+     */
+    public function setBaseDirectory(string $newBaseDirectory): ZugferdKositValidator
+    {
+        if (is_dir($newBaseDirectory)) {
+            $this->baseDirectory = $newBaseDirectory;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Setup the KOSIT validator application download url
+     *
+     * @param string $newValidatorDownloadUrl
+     * @return ZugferdKositValidator
+     */
+    public function setValidatorDownloadUrl(string $newValidatorDownloadUrl): ZugferdKositValidator
+    {
+        if (filter_var($newValidatorDownloadUrl, FILTER_VALIDATE_URL) !== false) {
+            $this->validatorDownloadUrl = $newValidatorDownloadUrl;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Setup the KOSIT validator scenario download url
+     *
+     * @param string $newValidatorScenarioDownloadUrl
+     * @return ZugferdKositValidator
+     */
+    public function setValidatorScenarioDownloadUrl(string $newValidatorScenarioDownloadUrl): ZugferdKositValidator
+    {
+        if (filter_var($newValidatorScenarioDownloadUrl, FILTER_VALIDATE_URL) !== false) {
+            $this->validatorScenarioDownloadUrl = $newValidatorScenarioDownloadUrl;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Set the filename of the ZIP file which contains the validation application
+     *
+     * @param string $newValidatorAppZipFilename
+     * @return ZugferdKositValidator
+     */
+    public function setValidatorAppZipFilename(string $newValidatorAppZipFilename): ZugferdKositValidator
+    {
+        $this->validatorAppZipFilename = $newValidatorAppZipFilename;
+
+        return $this;
+    }
+
+    /**
+     * Set the filename of the ZIP file which contains the validation scenarios
+     *
+     * @param string $newValidatorScenarioZipFilename
+     * @return ZugferdKositValidator
+     */
+    public function setValidatorScenarioZipFilename(string $newValidatorScenarioZipFilename): ZugferdKositValidator
+    {
+        $this->validatorScenarioZipFilename = $newValidatorScenarioZipFilename;
+
+        return $this;
+    }
+
+    /**
+     * Set the filename of the applications JAR
+     *
+     * @param string $newValidatorAppJarFilename
+     * @return ZugferdKositValidator
+     */
+    public function setValidatorAppJarFilename(string $newValidatorAppJarFilename): ZugferdKositValidator
+    {
+        $this->validatorAppJarFilename = $newValidatorAppJarFilename;
+
+        return $this;
+    }
+
+    /**
+     * Perform validation
+     *
+     * @return ZugferdKositValidator
+     */
+    public function validate(): ZugferdKositValidator
+    {
+        $this->clearErrorBag();
+
+        if ($this->checkRequirements()) {
+            if ($this->downloadRequiredFiles()) {
+                if ($this->unpackRequiredFiles()) {
+                    $this->runValidator();
+                }
+            }
+        }
+
+        $this->cleanupBaseDirectory();
+
+        return $this;
+    }
+
+    /**
+     * Internal get (and create) the directory for downloads and file creation
+     *
+     * @return string
+     */
+    private function resolveBaseDirectory(): string
+    {
+        $baseDirectory = PathUtils::combinePathWithPath($this->baseDirectory, "kositvalidator");
+
+        if (!is_dir($baseDirectory)) {
+            @mkdir($baseDirectory);
+        }
+
+        return $baseDirectory;
+    }
+
+    /**
+     * Clear the internal error bag
+     *
+     * @return void
+     */
+    private function clearErrorBag(): void
+    {
+        $this->errorBag = [];
+    }
+
+    /**
+     * Add message to error bag
+     *
+     * @param string|Exception|Throwable $error
+     * @return void
+     */
+    private function addToErrorBag($error): void
+    {
+        if (is_string($error)) {
+            $this->errorBag[] = $error;
+        } elseif ($error instanceof Exception) {
+            $this->errorBag[] = $error->getMessage();
+        } elseif ($error instanceof Throwable) {
+            $this->errorBag[] = $error->getMessage();
+        }
+    }
+
+    /**
+     * Returns true if validation passed otherwise false
+     *
+     * @return boolean
+     */
+    public function validationPased(): bool
+    {
+        return empty($this->errorBag);
+    }
+
+    /**
+     * Returns true if validation failed otherwise false
+     *
+     * @return boolean
+     */
+    public function validationFailed(): bool
+    {
+        return !$this->validationPased();
+    }
+
+    /**
+     * Returns an array of all validation errors
+     *
+     * @return array
+     */
+    public function validationErrors(): array
+    {
+        return $this->errorBag;
+    }
+
+    /**
+     * Check Requirements
+     *
+     * @return boolean
+     */
+    private function checkRequirements(): bool
+    {
+        if ($this->requirementsChecked === true) {
+            return true;
+        }
+
+        if (is_null($this->document)) {
+            $this->addToErrorBag("You must specify an instance of the ZugferdDocument class");
+            return false;
+        }
+
+        $executeableFinder = new ExecutableFinder();
+
+        if (is_null($executeableFinder->find('unzip'))) {
+            $this->addToErrorBag("UNZIP not installed on this machine");
+            return false;
+        }
+
+        if (is_null($executeableFinder->find('java'))) {
+            $this->addToErrorBag("JAVA not installed on this machine");
+            return false;
+        }
+
+        $this->requirementsChecked = true;
+
+        return true;
+    }
+
+    /**
+     * Download required files
+     *
+     * @return boolean
+     */
+    private function downloadRequiredFiles(): bool
+    {
+        if ($this->requiredFilesDownloaded === true) {
+            return true;
+        }
+
+        $validatorAppFile = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), $this->validatorAppZipFilename);
+        $validatorScenarioFile = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), $this->validatorScenarioZipFilename);
+
+        if (!$this->runFileDownload($this->validatorDownloadUrl, $validatorAppFile)) {
+            return false;
+        }
+
+        if (!$this->runFileDownload($this->validatorScenarioDownloadUrl, $validatorScenarioFile)) {
+            return false;
+        }
+
+        $this->requiredFilesDownloaded = true;
+
+        return true;
+    }
+
+    /**
+     * Unpack required files
+     *
+     * @return boolean
+     */
+    private function unpackRequiredFiles(): bool
+    {
+        if ($this->requiredFilesUnpacked === true) {
+            return true;
+        }
+
+        $validatorAppFile = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), $this->validatorAppZipFilename);
+        $validatorScenarioFile = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), $this->validatorScenarioZipFilename);
+
+        if (!$this->runProcess(['unzip', $validatorAppFile, '-d', $this->resolveBaseDirectory()])) {
+            return false;
+        }
+
+        if (!$this->runProcess(['unzip', $validatorScenarioFile, '-d', $this->resolveBaseDirectory()])) {
+            return false;
+        }
+
+        $this->requiredFilesUnpacked = true;
+
+        return true;
+    }
+
+    /**
+     * Runs the validator java application
+     *
+     * @return boolean
+     */
+    private function runValidator(): bool
+    {
+        $jarFilename = PathUtils::combineAllPaths($this->resolveBaseDirectory(), $this->validatorAppJarFilename);
+        $scenarioFilename = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), 'scenarios.xml', '');
+        $xmlFilename = PathUtils::combinePathWithFile($this->resolveBaseDirectory(), 'filetovalidate.xml', '');
+
+        if (file_put_contents($xmlFilename, $this->document->serializeAsXml()) === false) {
+            $this->addToErrorBag("Cannot create temporary file which contains the XML to validate");
+            return false;
+        }
+
+        if (!$this->runProcess(['java', '-jar', $jarFilename, '-r', $this->resolveBaseDirectory(), '-s', $scenarioFilename, $xmlFilename])) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Cleanup downloads and created files
+     *
+     * @return void
+     */
+    private function cleanupBaseDirectory(): void
+    {
+        if (!is_dir($this->resolveBaseDirectory())) {
+            return;
+        }
+
+        $this->cleanupBaseDirectoryInternal($this->resolveBaseDirectory());
+    }
+
+    /**
+     * Helper method for removeBaseDirectory
+     *
+     * @param string $directoryToRemove
+     * @return void
+     */
+    private function cleanupBaseDirectoryInternal(string $directoryToRemove): void
+    {
+        if (!is_dir($directoryToRemove)) {
+            return;
+        }
+
+        $objects = scandir($directoryToRemove);
+
+        foreach ($objects as $object) {
+            if ($object != "." && $object != "..") {
+                $fullFilename = PathUtils::combinePathWithFile($directoryToRemove, $object);
+                if (is_dir($fullFilename) && !is_link($fullFilename))
+                    $this->cleanupBaseDirectoryInternal($fullFilename);
+                else
+                    unlink($fullFilename);
+            }
+        }
+
+        rmdir($directoryToRemove);
+    }
+
+    /**
+     * Runs a process. If the process runned successfully this method
+     * returns true, otherwise false
+     *
+     * @param array $command
+     * @return boolean
+     */
+    private function runProcess(array $command): bool
+    {
+        try {
+            $process = new Process($command);
+            $process->setTimeout(0.0);
+            $process->run();
+
+            if (!$process->isSuccessful()) {
+                throw new ProcessFailedException($process);
+            }
+        } catch (ProcessFailedException $e) {
+            $this->addToErrorBag($e);
+            return false;
+        } catch (Exception $e) {
+            $this->addToErrorBag($e);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Run a file download.
+     *
+     * @param string $url
+     * @param string $toFilePath
+     * @param boolean $forceOverwrite
+     * @return boolean
+     */
+    private function runFileDownload(string $url, string $toFilePath, bool $forceOverwrite = false): bool
+    {
+        try {
+            if (file_exists($toFilePath) && !$forceOverwrite) {
+                return true;
+            }
+            file_put_contents($toFilePath, file_get_contents($url));
+        } catch (Exception $e) {
+            $this->addToErrorBag($e);
+            return false;
+        } catch (Throwable $e) {
+            $this->addToErrorBag($e);
+            return false;
+        }
+
+        return true;
+    }
+}