diff --git a/feeds_tamper.routing.yml b/feeds_tamper.routing.yml
new file mode 100644
index 0000000..3bfa261
--- /dev/null
+++ b/feeds_tamper.routing.yml
@@ -0,0 +1,23 @@
+entity.feeds_feed_type.tamper_add:
+  path: '/admin/structure/feeds/manage/{feeds_feed_type}/tamper/add/{source_field}'
+  defaults:
+    _form: '\Drupal\feeds_tamper\Form\TamperAddForm'
+    _title_callback: '\Drupal\feeds_tamper\Form\TamperAddForm::tamperTitle'
+  requirements:
+    _custom_access: '\Drupal\feeds_tamper\Form\TamperAddForm::checkAccess'
+  options:
+    parameters:
+      feeds_feed_type:
+        type: 'entity:feeds_feed_type'
+
+entity.feeds_feed_type.tamper_edit:
+  path: '/admin/structure/feeds/manage/{feeds_feed_type}/tamper/{tamper_uuid}/edit'
+  defaults:
+    _form: '\Drupal\feeds_tamper\Form\TamperEditForm'
+    _title_callback: '\Drupal\feeds_tamper\Form\TamperEditForm::tamperTitle'
+  requirements:
+    _custom_access: '\Drupal\feeds_tamper\Form\TamperEditForm::checkAccess'
+  options:
+    parameters:
+      feeds_feed_type:
+        type: 'entity:feeds_feed_type'
diff --git a/feeds_tamper_ui/feeds_tamper_ui.admin.inc b/feeds_tamper_ui/feeds_tamper_ui.admin.inc
index 5fdd64e..342c4d2 100755
--- a/feeds_tamper_ui/feeds_tamper_ui.admin.inc
+++ b/feeds_tamper_ui/feeds_tamper_ui.admin.inc
@@ -289,204 +289,6 @@ function theme_feeds_tamper_ui_list_form($variables) {
 }
 
 /**
- * Add plugin form.
- */
-function feeds_tamper_ui_add_plugin_form($form, &$form_state, $importer, $source) {
-  // Set importer and source for use in validate and submit.
-  $form_state['importer'] = $importer;
-  $form_state['source'] = $source;
-
-  // Build plugin select list.
-  $feeds_tamper_plugins = feeds_tamper_get_plugins();
-  $plugins = array();
-  foreach ($feeds_tamper_plugins as $plugin_id => $plugin) {
-    $plugins[t($plugin['category'])][$plugin_id] = t($plugin['name']);
-  }
-  ksort($plugins);
-  foreach ($plugins as &$p) {
-    asort($p);
-  }
-
-  $machine_name = key(reset($plugins));
-  if (!empty($form_state['values']['plugin_id'])) {
-    $machine_name = $form_state['values']['plugin_id'];
-  }
-  // Add css.
-  $form['#attached']['css'][] = drupal_get_path('module', 'feeds_tamper_ui') . '/feeds_tamper_ui.css';
-
-  $plugin = feeds_tamper_get_plugin($machine_name);
-
-  $form['plugin_id'] = array(
-    '#title' => t('The plugin to add'),
-    '#type' => 'select',
-    '#options' => $plugins,
-    '#default_value' => '',
-    '#tree' => TRUE,
-    '#ajax' => array(
-      'callback' => 'feeds_tamper_ajax_callback',
-      'wrapper' => 'feeds-tamper-plugin',
-      'progress' => 'none',
-    ),
-  );
-  $form['update'] = array(
-    '#type' => 'submit',
-    '#limit_validation_errors' => array(
-      array('plugin_id')
-    ),
-    '#submit' => array('feeds_tamper_ui_add_plugin_form_submit'),
-    '#value' => t('Choose'),
-    '#attributes' => array('class' => array('no-js')),
-  );
-  $form['plugin']['#prefix'] = '<div class="clear-fix" id="feeds-tamper-plugin">';
-  $form['plugin']['#suffix'] = '</div>';
-
-  $form['plugin']['description'] = array(
-    '#title' => t('Description'),
-    '#type' => 'textfield',
-    '#default_value' => $plugin['default description'] ? t($plugin['default description']) : t($plugin['name']),
-    '#required' => TRUE,
-    '#description' => t('A useful description of what this plugin is doing.'),
-  );
-  $form['plugin']['id'] = array(
-    '#title' => t('Machine name'),
-    '#type' => 'machine_name',
-    '#maxlength' => 32,
-    '#machine_name' => array(
-      'exists' => 'feeds_tamper_machine_name_callback',
-      'source' => array('plugin', 'description'),
-    ),
-    '#default_value' => $machine_name,
-    // '#disabled' => FALSE,
-    // '#size' => 60,
-  );
-  $form['plugin']['settings'] = array(
-    '#title' => t('Configure @name', array('@name' => $plugin['name'])),
-    '#type' => 'fieldset',
-    '#tree' => TRUE,
-  );
-  $form['plugin']['settings'] += $plugin['form']($importer, $source, array(), $form_state);
-
-  $form['add'] = array(
-    '#type' => 'submit',
-    '#value' => t('Add'),
-  );
-
-  return $form;
-}
-
-/**
- * Add plugin form validate handler.
- */
-function feeds_tamper_ui_add_plugin_form_validate($form, &$form_state) {
-  if ($form_state['triggering_element']['#value'] == t('Add')) {
-    if (feeds_tamper_machine_name_callback($form_state['values']['id'], $form, $form_state)) {
-      form_set_error('id', t('The machine-readable name is already in use. It must be unique.'));
-      return;
-    }
-    $plugin_id = $form_state['values']['plugin_id'];
-    $plugin = feeds_tamper_get_plugin($plugin_id);
-    if ($plugin['validate'] && isset($form_state['values']['settings'])) {
-      $plugin['validate']($form_state['values']['settings']);
-    }
-    $id = $form_state['values']['id'];
-    $importer_id = $form_state['importer']->id;
-    $source = feeds_tamper_make_machine($form_state['source']);
-    $form_state['values']['id'] = "$importer_id-$source-$id";
-    return;
-  }
-  unset($form_state['input']['id']);
-  unset($form_state['input']['description']);
-  unset($form_state['input']['settings']);
-}
-
-/**
- * Add plugin form submit handler.
- */
-function feeds_tamper_ui_add_plugin_form_submit($form, &$form_state) {
-  if ($form_state['triggering_element']['#value'] == t('Add')) {
-    $obj = feeds_tamper_new_instance();
-    $obj->plugin_id = $form_state['values']['plugin_id'];
-    if (isset($form_state['values']['settings'])) {
-      $obj->settings = $form_state['values']['settings'];
-    }
-    $obj->importer = $form_state['importer']->id;
-
-    $obj->source = $form_state['source'];
-    $obj->description = $form_state['values']['description'];
-    $obj->id = $form_state['values']['id'];
-
-    feeds_tamper_save_instance($obj);
-    $form_state['redirect'] = 'admin/structure/feeds/' . $obj->importer . '/tamper';
-    $source_name = feeds_tamper_ui_source_name($obj);
-    drupal_set_message(t('Plugin %description was successfully added to %source.', array('%description' => $obj->description, '%source' => $source_name)));
-    return;
-  }
-  $form_state['rebuild'] = TRUE;
-}
-
-/**
- * Edit plugin form.
- *
- * @todo Combine add and edit forms?
- */
-function feeds_tamper_ui_edit_plugin_form($form, &$form_state, $instance) {
-  // Set breadcrumb.
-  $importer = feeds_importer($instance->importer);
-
-  $form_state['instance'] = $instance;
-  $plugin = feeds_tamper_get_plugin($instance->plugin_id);
-  $form['#tree'] = TRUE;
-
-  $form['description'] = array(
-    '#title' => t('Description'),
-    '#type' => 'textfield',
-    '#description' => t('A useful description of what this plugin is doing.'),
-    '#default_value' => $instance->description,
-  );
-  $form['settings'] = array(
-    '#title' => t('Configure @plugin', array('@plugin' => $plugin['name'])),
-    '#type' => 'fieldset',
-    '#tree' => TRUE,
-  );
-  $form['settings'] += $plugin['form']($importer, $instance->source, $instance->settings, $form_state);
-
-  $form['save'] = array(
-    '#type' => 'submit',
-    '#value' => t('Save'),
-  );
-
-  $form['#attached']['css'][] = drupal_get_path('module', 'feeds_tamper_ui') . '/feeds_tamper_ui.css';
-
-  return $form;
-}
-
-/**
- * Edit plugin form validate handler.
- */
-function feeds_tamper_ui_edit_plugin_form_validate($form, &$form_state) {
-  $plugin_id = $form_state['instance']->plugin_id;
-  $plugin = feeds_tamper_get_plugin($plugin_id);
-  if ($plugin['validate']) {
-    $plugin['validate']($form_state['values']['settings']);
-  }
-}
-
-/**
- * Edit plugin form submit handler.
- */
-function feeds_tamper_ui_edit_plugin_form_submit($form, &$form_state) {
-  $instance = $form_state['instance'];
-  if (isset($form_state['values']['settings'])) {
-    $instance->settings = $form_state['values']['settings'];
-  }
-  $instance->description = $form_state['values']['description'];
-
-  feeds_tamper_save_instance($instance);
-  drupal_set_message(t('The plugin %plugin has been updated.', array('%plugin' => $instance->description)));
-  $form_state['redirect'] = 'admin/structure/feeds/' . $instance->importer . '/tamper';
-}
-
-/**
  * Delete plugin form.
  */
 function feeds_tamper_ui_delete_form($form, &$form_state, $instance) {
diff --git a/feeds_tamper_ui/feeds_tamper_ui.module b/feeds_tamper_ui/feeds_tamper_ui.module
index dd98d83..fa79c87 100755
--- a/feeds_tamper_ui/feeds_tamper_ui.module
+++ b/feeds_tamper_ui/feeds_tamper_ui.module
@@ -42,18 +42,6 @@ function feeds_tamper_ui_menu() {
     'weight' => 10,
   ) + $defaults;
 
-  $items['admin/structure/feeds/%feeds_importer/tamper/add/%feeds_tamper_ui_source'] = array(
-    'title callback' => 'feeds_tamper_ui_add_title',
-    'title arguments' => array(6),
-    'page arguments' => array('feeds_tamper_ui_add_plugin_form', 3, 6),
-  ) + $defaults;
-
-  $items['admin/structure/feeds/%feeds_importer/tamper/%feeds_tamper_plugin_instance/edit'] = array(
-    'title callback' => 'feeds_tamper_ui_edit_title',
-    'page arguments' => array('feeds_tamper_ui_edit_plugin_form', 5),
-    'access arguments' => array(NULL, 5),
-  ) + $defaults;
-
   $items['admin/structure/feeds/%feeds_importer/tamper/%feeds_tamper_plugin_instance/delete'] = array(
     'title callback' => 'feeds_tamper_ui_delete_title',
     'page arguments' => array('feeds_tamper_ui_delete_form', 5),
@@ -91,24 +79,6 @@ function feeds_tamper_ui_source_load($source) {
 }
 
 /**
- * Add plugin title callback.
- */
-function feeds_tamper_ui_add_title($source) {
-  // Title callbacks get check_plain'ed already.
-  return t('Add plugin to: !source', array('!source' => $source));
-}
-
-/**
- * Edit plugin title callback.
- */
-function feeds_tamper_ui_edit_title($instance) {
-  if ($instance->export_type == EXPORT_IN_DATABASE) {
-    return t('Edit: @id', array('@id' => $instance->description));
-  }
-  return t('Override: @id', array('@id' => $instance->description));
-}
-
-/**
  * Delete plugin title callback.
  */
 function feeds_tamper_ui_delete_title($instance) {
diff --git a/src/FeedTypeTamperMeta.php b/src/FeedTypeTamperMeta.php
index be09bf0..6c83878 100644
--- a/src/FeedTypeTamperMeta.php
+++ b/src/FeedTypeTamperMeta.php
@@ -125,6 +125,15 @@ class FeedTypeTamperMeta implements FeedTypeTamperMetaInterface {
   /**
    * {@inheritdoc}
    */
+  public function updateTamper(TamperInterface $tamper, array $configuration) {
+    $this->getTampers()->setInstanceConfiguration($tamper->getSetting('uuid'), $configuration);
+    $this->updateFeedType();
+    return $tamper;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function removeTamper(TamperInterface $tamper) {
     $this->getTampers()->removeInstanceId($tamper->getSetting('uuid'));
     $this->updateFeedType();
diff --git a/src/FeedTypeTamperMetaInterface.php b/src/FeedTypeTamperMetaInterface.php
index 8f3bbc9..4cbacd4 100644
--- a/src/FeedTypeTamperMetaInterface.php
+++ b/src/FeedTypeTamperMetaInterface.php
@@ -49,6 +49,19 @@ interface FeedTypeTamperMetaInterface extends ObjectWithPluginCollectionInterfac
   public function addTamper(array $configuration);
 
   /**
+   * Updates the tamper plugin instance.
+   *
+   * @param \Drupal\tamper\TamperInterface $tamper
+   *   The tamper plugin instance.
+   * @param array $configuration
+   *   An array of tamper configuration.
+   *
+   * @return \Drupal\tamper\TamperInterface
+   *   The updated tamper plugin instance.
+   */
+  public function updateTamper(TamperInterface $tamper, array $configuration);
+
+  /**
    * Removes a tamper plugin instance from this feed type.
    *
    * @param \Drupal\tamper\TamperInterface $tamper
diff --git a/src/Form/TamperAddForm.php b/src/Form/TamperAddForm.php
new file mode 100644
index 0000000..27bbb03
--- /dev/null
+++ b/src/Form/TamperAddForm.php
@@ -0,0 +1,109 @@
+<?php
+
+namespace Drupal\feeds_tamper\Form;
+
+use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\feeds\FeedTypeInterface;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Provides a form to add a tamper plugin to a feed type.
+ */
+class TamperAddForm extends TamperFormBase {
+
+  /**
+   * The source field on the feed type.
+   *
+   * @var string
+   */
+  protected $sourceField;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'feeds_tamper_add_form';
+  }
+
+  /**
+   * Makes sure that the source field exists.
+   *
+   * @param \Drupal\feeds\FeedTypeInterface $feeds_feed_type
+   *   The feed.
+   * @param string $source_field
+   *   The source field.
+   */
+  private function assertSourceField(FeedTypeInterface $feeds_feed_type, $source_field) {
+    $sources = $feeds_feed_type->getMappingSources();
+    if (!isset($sources[$source_field])) {
+      throw new NotFoundHttpException();
+    }
+  }
+
+  /**
+   * Prepares the tamper plugin.
+   *
+   * @param string $tamper_id
+   *   The id of the tamper plugin.
+   *
+   * @return \Drupal\tamper\TamperInterface
+   *   The tamper plugin instance.
+   */
+  protected function preparePlugin($tamper_id = NULL) {
+    if (empty($tamper_id)) {
+      return NULL;
+    }
+
+    try {
+      /** @var \Drupal\tamper\TamperInterface $tamper */
+      $tamper = $this->tamperManager->createInstance($tamper_id);
+      return $tamper;
+    }
+    catch (PluginException $e) {
+      drupal_set_message($this->t('The specified plugin is invalid.'), 'error');
+    }
+  }
+
+  /**
+   * Form constructor.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param \Drupal\feeds\FeedTypeInterface $feeds_feed_type
+   *   The feed that we are adding a tamper plugin to.
+   * @param string $source_field
+   *   The source field we are adding the tamper plugin to.
+   *
+   * @return array
+   *   The form structure.
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, FeedTypeInterface $feeds_feed_type = NULL, $source_field = NULL) {
+    $this->assertSourceField($feeds_feed_type, $source_field);
+
+    $this->feedsFeedType = $feeds_feed_type;
+    $this->sourceField = $source_field;
+    $this->plugin = $this->preparePlugin($form_state->getValue(self::VAR_TAMPER_ID));
+
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $config = $this->prepareConfig($this->sourceField, $form_state);
+    $tamper_meta = $this->feedTypeTamperManager->getTamperMeta($this->feedsFeedType);
+    $tamper_meta->addTamper($config);
+    $this->feedsFeedType->save();
+
+    drupal_set_message($this->t('Plugin %plugin_label was successfully added to %source.', [
+      '%plugin_label' => $this->plugin->getPluginDefinition()['label'],
+      '%source' => $this->sourceField,
+    ]));
+    // TODO Add a form state redirect back to the overview page.
+  }
+
+}
diff --git a/src/Form/TamperEditForm.php b/src/Form/TamperEditForm.php
new file mode 100644
index 0000000..6adc30b
--- /dev/null
+++ b/src/Form/TamperEditForm.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace Drupal\feeds_tamper\Form;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\feeds\FeedTypeInterface;
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
+use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
+
+/**
+ * Tamper edit form.
+ *
+ * @package Drupal\feeds_tamper\Form
+ */
+class TamperEditForm extends TamperFormBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'feeds_tamper_edit_form';
+  }
+
+  /**
+   * Makes sure that the tamper exists.
+   *
+   * @param \Drupal\feeds\FeedTypeInterface $feeds_feed_type
+   *   The feed.
+   * @param string $tamper_uuid
+   *   The tamper uuid.
+   */
+  private function assertTamper(FeedTypeInterface $feeds_feed_type, $tamper_uuid) {
+    $tamper_meta = $this->feedTypeTamperManager->getTamperMeta($feeds_feed_type);
+
+    try {
+      $tamper_meta->getTamper($tamper_uuid);
+    }
+    catch (PluginNotFoundException $e) {
+      throw new NotFoundHttpException();
+    }
+  }
+
+  /**
+   * Form constructor.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   * @param \Drupal\feeds\FeedTypeInterface $feeds_feed_type
+   *   The feed that we are adding a tamper plugin to.
+   * @param string $tamper_uuid
+   *   The tamper uuid.
+   *
+   * @return array
+   *   The form structure.
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, FeedTypeInterface $feeds_feed_type = NULL, $tamper_uuid = NULL) {
+    $this->assertTamper($feeds_feed_type, $tamper_uuid);
+
+    $this->feedsFeedType = $feeds_feed_type;
+    $tamper_meta = $this->feedTypeTamperManager->getTamperMeta($feeds_feed_type);
+    $this->plugin = $tamper_meta->getTamper($tamper_uuid);
+
+    $form = parent::buildForm($form, $form_state);
+    $form[self::VAR_TAMPER_ID]['#disabled'] = TRUE;
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    $tamper_meta = $this->feedTypeTamperManager->getTamperMeta($this->feedsFeedType);
+    $uuid = $this->plugin->getSetting('uuid');
+    $tempers_config = $tamper_meta->getTampers()->getConfiguration();
+
+    $config = $this->prepareConfig($tempers_config[$uuid]['source'], $form_state);
+    $tamper_meta->updateTamper($this->plugin, $config);
+    $this->feedsFeedType->save();
+
+    drupal_set_message($this->t('The plugin %plugin_label has been updated.', [
+      '%plugin_label' => $this->plugin->getPluginDefinition()['label'],
+    ]));
+    // TODO Add a form state redirect back to the overview page.
+  }
+
+}
diff --git a/src/Form/TamperFormBase.php b/src/Form/TamperFormBase.php
new file mode 100644
index 0000000..77c6099
--- /dev/null
+++ b/src/Form/TamperFormBase.php
@@ -0,0 +1,233 @@
+<?php
+
+namespace Drupal\feeds_tamper\Form;
+
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Form\SubformState;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\feeds_tamper\FeedTypeTamperManagerInterface;
+use Drupal\tamper\ConfigurableTamperInterface;
+use Drupal\tamper\TamperManagerInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * The base class for add/edit tamper forms.
+ *
+ * @package Drupal\feeds_tamper\Form
+ */
+abstract class TamperFormBase extends FormBase {
+
+  use TamperFormTrait;
+
+  // Form fields.
+  const VAR_TAMPER_ID = 'tamper_id';
+  const VAR_PLUGIN_CONFIGURATION = 'plugin_configuration';
+
+  /**
+   * The feed item we are adding a tamper plugin to.
+   *
+   * @var \Drupal\feeds\FeedTypeInterface
+   */
+  protected $feedsFeedType;
+
+  /**
+   * The tamper plugin instance.
+   *
+   * @var \Drupal\tamper\TamperInterface
+   */
+  protected $plugin;
+
+  /**
+   * The tamper plugin manager.
+   *
+   * @var \Drupal\tamper\TamperManagerInterface
+   */
+  protected $tamperManager;
+
+  /**
+   * The feeds tamper metadata manager.
+   *
+   * @var \Drupal\feeds_tamper\FeedTypeTamperManagerInterface
+   */
+  protected $feedTypeTamperManager;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    /** @var self $form */
+    $form = parent::create($container);
+    $form->setTamperManager($container->get('plugin.manager.tamper'));
+    $form->setTamperMetaManager($container->get('feeds_tamper.feed_type_tamper_manager'));
+    return $form;
+  }
+
+  /**
+   * Set the tamper manager.
+   *
+   * @param \Drupal\tamper\TamperManagerInterface $tamper_manager
+   *   Tamper plugin manager.
+   */
+  public function setTamperManager(TamperManagerInterface $tamper_manager) {
+    $this->tamperManager = $tamper_manager;
+  }
+
+  /**
+   * Set the feed type tamper manager.
+   *
+   * @param \Drupal\feeds_tamper\FeedTypeTamperManagerInterface $feed_type_tamper_manager
+   *   Feed type tamper manager.
+   */
+  public function setTamperMetaManager(FeedTypeTamperManagerInterface $feed_type_tamper_manager) {
+    $this->feedTypeTamperManager = $feed_type_tamper_manager;
+  }
+
+  /**
+   * Page title callback.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match.
+   *
+   * @return \Drupal\Core\StringTranslation\TranslatableMarkup|null
+   *   Translated string to use as the title.
+   */
+  public function tamperTitle(RouteMatchInterface $route_match) {
+    /** @var \Drupal\feeds\Entity\FeedType $feed_type */
+    $feed_type = $route_match->getParameter('feeds_feed_type');
+    $source_field = $route_match->getParameter('source_field');
+    $tamper_uuid = $route_match->getParameter('tamper_uuid');
+
+    if ($source_field) {
+      return $this->t('Add a tamper plugin to @label : @source', [
+        '@label' => $feed_type->label(),
+        '@source' => $source_field,
+      ]);
+    }
+    elseif ($tamper_uuid) {
+      $tamper_meta = $this->feedTypeTamperManager->getTamperMeta($feed_type);
+      $tamper = $tamper_meta->getTamper($tamper_uuid);
+      return $this->t('Edit @label', [
+        '@label' => $tamper->getPluginDefinition()['label'],
+      ]);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state) {
+    $form[self::VAR_TAMPER_ID] = [
+      '#type' => 'select',
+      '#title' => $this->t('The plugin to add'),
+      '#options' => $this->getPluginOptions(),
+      '#required' => TRUE,
+      '#default_value' => $this->plugin ? $this->plugin->getPluginDefinition()['id'] : NULL,
+      '#ajax' => [
+        'callback' => self::class . '::getPluginForm',
+        'wrapper' => 'plugin-config',
+      ],
+    ];
+    $form[self::VAR_PLUGIN_CONFIGURATION] = [
+      '#type' => 'container',
+      '#tree' => TRUE,
+      '#attributes' => ['id' => ['plugin-config']],
+    ];
+
+    if ($this->plugin) {
+      $form[self::VAR_PLUGIN_CONFIGURATION]['description'] = [
+        '#markup' => $this->plugin->getPluginDefinition()['description'],
+      ];
+    }
+
+    if ($this->plugin instanceof ConfigurableTamperInterface) {
+      $subform_state = SubformState::createForSubform($form[self::VAR_PLUGIN_CONFIGURATION], $form, $form_state);
+      $form[self::VAR_PLUGIN_CONFIGURATION] = $this->plugin->buildConfigurationForm($form[self::VAR_PLUGIN_CONFIGURATION], $subform_state);
+    }
+
+    $form['actions'] = ['#type' => 'actions'];
+    $form['actions']['submit'] = [
+      '#type' => 'submit',
+      '#value' => $this->t('Submit'),
+      '#button_type' => 'primary',
+    ];
+    // TODO Add a cancel button back to the overview page.
+    return $form;
+  }
+
+  /**
+   * Ajax callback.
+   *
+   * Returns the plugin configuration form from an ajax request.
+   *
+   * @param array $form
+   *   Drupal form array.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   Form state interface.
+   *
+   * @return array
+   *   Plugin form.
+   */
+  public function getPluginForm(array $form, FormStateInterface $form_state) {
+    return $form[self::VAR_PLUGIN_CONFIGURATION];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateForm(array &$form, FormStateInterface $form_state) {
+    if (empty($this->plugin)) {
+      $form_state->setError($form[self::VAR_TAMPER_ID], $this->t('Plugin not selected'));
+    }
+
+    if ($this->plugin instanceof ConfigurableTamperInterface) {
+      $subform_state = SubformState::createForSubform($form[self::VAR_PLUGIN_CONFIGURATION], $form, $form_state);
+      $this->plugin->validateConfigurationForm($form[self::VAR_PLUGIN_CONFIGURATION], $subform_state);
+    }
+  }
+
+  /**
+   * Get the tamper plugin options.
+   *
+   * @return array
+   *   List of tamper plugin groups, keyed by group, where the value is another
+   *   array of plugin labels keyed by plugin id.
+   */
+  protected function getPluginOptions() {
+    // TODO - Move this logic to the tamper manager interface?
+    $plugin_options = array_map(function ($grouped_plugins) {
+      $group_options = [];
+      foreach ($grouped_plugins as $id => $plugin_definition) {
+        $group_options[$id] = $plugin_definition['label'];
+      }
+      return $group_options;
+    }, $this->tamperManager->getGroupedDefinitions());
+
+    return $plugin_options;
+  }
+
+  /**
+   * Prepares a configuration array.
+   *
+   * @param string $source
+   *   The source.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   *
+   * @return array
+   *   The configuration array.
+   */
+  protected function prepareConfig($source, FormStateInterface $form_state) {
+    $config = [
+      'plugin' => $this->plugin->getPluginId(),
+      'source' => $source,
+    ];
+
+    if ($this->plugin instanceof ConfigurableTamperInterface) {
+      $config += $form_state->getValue(self::VAR_PLUGIN_CONFIGURATION);
+    }
+
+    return $config;
+  }
+
+}
diff --git a/src/Form/TamperFormTrait.php b/src/Form/TamperFormTrait.php
new file mode 100644
index 0000000..92b26af
--- /dev/null
+++ b/src/Form/TamperFormTrait.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Drupal\feeds_tamper\Form;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Trait TamperFormTrait.
+ *
+ * Provides helper methods for the Tamper forms.
+ *
+ * @package Drupal\feeds_tamper\Form
+ */
+trait TamperFormTrait {
+
+  /**
+   * Checks access for the form page.
+   *
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match.
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   The current user account.
+   *
+   * @return \Drupal\Core\Access\AccessResult
+   *   The access result.
+   */
+  public function checkAccess(RouteMatchInterface $route_match, AccountInterface $account) {
+    if ($account->hasPermission('administer feeds_tamper')) {
+      return AccessResult::allowed();
+    }
+
+    /** @var \Drupal\feeds\Entity\FeedType $feed_type */
+    $feed_type = $route_match->getParameter('feeds_feed_type');
+    return AccessResult::allowedIf($account->hasPermission('tamper ' . $feed_type->id()))
+      ->addCacheableDependency($feed_type);
+  }
+
+}
diff --git a/tests/src/Kernel/FeedTypeTamperMetaTest.php b/tests/src/Kernel/FeedTypeTamperMetaTest.php
index 9078015..38a12f0 100644
--- a/tests/src/Kernel/FeedTypeTamperMetaTest.php
+++ b/tests/src/Kernel/FeedTypeTamperMetaTest.php
@@ -109,6 +109,24 @@ class FeedTypeTamperMetaTest extends KernelTestBase {
   }
 
   /**
+   * @covers ::updateTamper
+   */
+  public function testUpdateTamper() {
+    $separator = ':';
+    $description = 'Explode with pipe character updated';
+    $tamper = $this->feedTypeTamperMeta->getTamper('uuid1');
+    $this->feedTypeTamperMeta->updateTamper($tamper, [
+      'separator' => $separator,
+      'description' => $description,
+    ]);
+    $tempers_config = $this->feedTypeTamperMeta->getTampers()->getConfiguration();
+    $config = $tempers_config['uuid1'];
+
+    $this->assertEquals($separator, $config['separator']);
+    $this->assertEquals($description, $config['description']);
+  }
+
+  /**
    * @covers ::removeTamper
    */
   public function testRemoveTamper() {