--- /dev/null
+<?php
+
+/*
+ * This file is part of the Behat Testwork.
+ * (c) Konstantin Kudryashov <ever.zet@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Behat\Testwork\Output;
+
+use Behat\Testwork\Output\Printer\OutputPrinter;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Represents Testwork output formatter.
+ *
+ * @see OutputManager
+ *
+ * @author Konstantin Kudryashov <ever.zet@gmail.com>
+ */
+interface Formatter extends EventSubscriberInterface
+{
+ /**
+ * Returns formatter name.
+ *
+ * @return string
+ */
+ public function getName();
+
+ /**
+ * Returns formatter description.
+ *
+ * @return string
+ */
+ public function getDescription();
+
+ /**
+ * Returns formatter output printer.
+ *
+ * @return OutputPrinter
+ */
+ public function getOutputPrinter();
+
+ /**
+ * Sets formatter parameter.
+ *
+ * @param string $name
+ * @param mixed $value
+ */
+ public function setParameter($name, $value);
+
+ /**
+ * Returns parameter name.
+ *
+ * @param string $name
+ *
+ * @return mixed
+ */
+ public function getParameter($name);
+}