diff --git a/islandora.module b/islandora.module
index 1accbe16..dc580398 100644
--- a/islandora.module
+++ b/islandora.module
@@ -181,3 +181,13 @@ function islandora_entity_delete(EntityInterface $entity) {
     }
   }
 }
+
+/**
+ * Implements hook_jsonld_alter_normalized_array().
+ */
+function islandora_jsonld_alter_normalized_array(EntityInterface $entity, array &$normalized, array $context) {
+  $context_manager = \Drupal::service('context.manager');
+  foreach ($context_manager->getActiveReactions('\Drupal\islandora\ContextReaction\NormalizerAlterReaction') as $reaction) {
+    $reaction->execute($entity, $normalized, $context);
+  }
+}
diff --git a/src/ContextReaction/NormalizerAlterReaction.php b/src/ContextReaction/NormalizerAlterReaction.php
new file mode 100644
index 00000000..3b7f807b
--- /dev/null
+++ b/src/ContextReaction/NormalizerAlterReaction.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace Drupal\islandora\ContextReaction;
+
+use Drupal\context\ContextReactionPluginBase;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Base class to alter the normalizes Json-ld.
+ *
+ * Plugins must extend this class to be considered for execution.
+ *
+ * @package Drupal\islandora\ContextReaction
+ */
+abstract class NormalizerAlterReaction extends ContextReactionPluginBase {
+
+  /**
+   * This reaction takes can alter the array of json-ld built from the entity.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface|null $entity
+   *   The entity we are normalizing.
+   * @param array|null $normalized
+   *   The normalized json-ld before encoding.
+   * @param array|null $context
+   *   The context used in the normalizer.
+   */
+  abstract public function execute(EntityInterface $entity = NULL, array &$normalized = NULL, array $context = NULL);
+
+}
diff --git a/src/Plugin/ContextReaction/MappingUriPredicateReaction.php b/src/Plugin/ContextReaction/MappingUriPredicateReaction.php
new file mode 100644
index 00000000..fc25fbdc
--- /dev/null
+++ b/src/Plugin/ContextReaction/MappingUriPredicateReaction.php
@@ -0,0 +1,126 @@
+<?php
+
+namespace Drupal\islandora\Plugin\ContextReaction;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\islandora\ContextReaction\NormalizerAlterReaction;
+use Drupal\jsonld\Normalizer\NormalizerBase;
+
+/**
+ * Map URI to predicate context reaction.
+ *
+ * @ContextReaction(
+ *   id = "islandora_map_uri_predicate",
+ *   label = @Translation("Map URI to predicate")
+ * )
+ */
+class MappingUriPredicateReaction extends NormalizerAlterReaction {
+
+  const URI_PREDICATE = 'drupal_uri_predicate';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function summary() {
+    return $this->t('Map Drupal URI to configured predicate.');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function execute(EntityInterface $entity = NULL, array &$normalized = NULL, array $context = NULL) {
+    $config = $this->getConfiguration();
+    $drupal_predicate = $config[self::URI_PREDICATE];
+    if (!is_null($drupal_predicate) && !empty($drupal_predicate)) {
+      $url = $entity
+        ->toUrl('canonical', ['absolute' => TRUE])
+        ->setRouteParameter('_format', 'jsonld')
+        ->toString();
+      if ($context['needs_jsonldcontext'] === FALSE) {
+        $drupal_predicate = NormalizerBase::escapePrefix($drupal_predicate, $context['namespaces']);
+      }
+      if (isset($normalized['@graph']) && is_array($normalized['@graph'])) {
+        foreach ($normalized['@graph'] as &$graph) {
+          if (isset($graph['@id']) && $graph['@id'] == $url) {
+            if (isset($graph[$drupal_predicate])) {
+              if (!is_array($graph[$drupal_predicate])) {
+                if ($graph[$drupal_predicate] == $url) {
+                  // Don't add it if it already exists.
+                  return;
+                }
+                $tmp = $graph[$drupal_predicate];
+                $graph[$drupal_predicate] = [$tmp];
+              }
+              elseif (array_search($url, array_column($graph[$drupal_predicate], '@value'))) {
+                // Don't add it if it already exists.
+                return;
+              }
+            }
+            else {
+              $graph[$drupal_predicate] = [];
+            }
+            $graph[$drupal_predicate][] = ["@value" => $url];
+            return;
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+    $config = $this->getConfiguration();
+    $form[self::URI_PREDICATE] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('Drupal URI predicate'),
+      '#description' => $this->t("The Drupal object's URI will be added to the resource with this predicate. Must use a defined prefix."),
+      '#default_value' => isset($config[self::URI_PREDICATE]) ? $config[self::URI_PREDICATE] : '',
+      '#size' => 35,
+    ];
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
+    $drupal_predicate = $form_state->getValue(self::URI_PREDICATE);
+    if (!is_null($drupal_predicate) and !empty($drupal_predicate)) {
+      if (preg_match('/^https?:\/\//', $drupal_predicate)) {
+        // Can't validate all URIs so we have to trust them.
+        return;
+      }
+      elseif (preg_match('/^([^\s:]+):/', $drupal_predicate, $matches)) {
+        $predicate_prefix = $matches[1];
+        $rdf = rdf_get_namespaces();
+        $rdf_prefixes = array_keys($rdf);
+        if (!in_array($predicate_prefix, $rdf_prefixes)) {
+          $form_state->setErrorByName(
+            self::URI_PREDICATE,
+            $this->t('Namespace prefix @prefix is not registered.',
+              ['@prefix' => $predicate_prefix]
+            )
+          );
+        }
+      }
+      else {
+        $form_state->setErrorByName(
+          self::URI_PREDICATE,
+          $this->t('Predicate must use a defined prefix or be a full URI')
+        );
+      }
+    }
+    parent::validateConfigurationForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
+    $this->setConfiguration([self::URI_PREDICATE => $form_state->getValue(self::URI_PREDICATE)]);
+  }
+
+}
diff --git a/tests/src/Functional/MappingUriPredicateReactionTest.php b/tests/src/Functional/MappingUriPredicateReactionTest.php
new file mode 100644
index 00000000..6b95e087
--- /dev/null
+++ b/tests/src/Functional/MappingUriPredicateReactionTest.php
@@ -0,0 +1,156 @@
+<?php
+
+namespace Drupal\Tests\islandora\Functional;
+
+/**
+ * Class MappingUriPredicateReactionTest.
+ *
+ * @package Drupal\Tests\islandora\Functional
+ * @group islandora
+ */
+class MappingUriPredicateReactionTest extends IslandoraFunctionalTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+
+    $types = ['schema:Thing'];
+    $created_mapping = [
+      'properties' => ['schema:dateCreated'],
+      'datatype' => 'xsd:dateTime',
+      'datatype_callback' => ['callable' => 'Drupal\rdf\CommonDataConverter::dateIso8601Value'],
+    ];
+
+    // Save bundle mapping config.
+    $this->rdfMapping = rdf_get_mapping('node', 'test_type')
+      ->setBundleMapping(['types' => $types])
+      ->setFieldMapping('created', $created_mapping)
+      ->setFieldMapping('title', [
+        'properties' => ['dc:title'],
+        'datatype' => 'xsd:string',
+      ])
+      ->save();
+
+    $resourceConfigStorage = $this->container
+      ->get('entity_type.manager')
+      ->getStorage('rest_resource_config');
+    // There is already a setting for entity.node, so delete it.
+    $resourceConfigStorage
+      ->delete($resourceConfigStorage
+        ->loadMultiple(['entity.node']));
+    // Create it new.
+    $resourceConfigStorage->create([
+      'id' => 'entity.node',
+      'granularity' => 'resource',
+      'configuration' => [
+        'methods' => ['GET'],
+        'authentication' => ['basic_auth', 'cookie'],
+        'formats' => ['jsonld'],
+      ],
+      'status' => TRUE,
+    ])->save(TRUE);
+
+    $this->container->get('router.builder')->rebuildIfNeeded();
+  }
+
+  /**
+   * @covers \Drupal\islandora\Plugin\ContextReaction\MappingUriPredicateReaction
+   */
+  public function testMappingReaction() {
+    $account = $this->drupalCreateUser([
+      'bypass node access',
+      'administer contexts',
+    ]);
+    $this->drupalLogin($account);
+
+    $context_name = 'test';
+    $reaction_id = 'islandora_map_uri_predicate';
+
+    $this->postNodeAddForm('test_type',
+      ['title[0][value]' => 'Test Node'],
+      t('Save'));
+    $this->assertSession()->pageTextContains("Test Node");
+    $url = $this->getUrl();
+
+    // Make sure the node exists.
+    $this->drupalGet($url);
+    $this->assertSession()->statusCodeEquals(200);
+
+    $contents = $this->drupalGet($url . '?_format=jsonld');
+    $this->assertSession()->statusCodeEquals(200);
+    $json = \GuzzleHttp\json_decode($contents, TRUE);
+    $this->assertArrayHasKey('http://purl.org/dc/terms/title',
+      $json['@graph'][0], 'Missing dcterms:title key');
+    $this->assertEquals(
+      'Test Node',
+      $json['@graph'][0]['http://purl.org/dc/terms/title'][0]['@value'],
+      'Missing title value'
+    );
+    $this->assertArrayNotHasKey('http://www.w3.org/2002/07/owl#sameAs',
+      $json['@graph'][0], 'Has predicate when not configured');
+
+    $this->createContext('Test', $context_name);
+    $this->drupalGet("admin/structure/context/$context_name/reaction/add/$reaction_id");
+    $this->assertSession()->statusCodeEquals(200);
+
+    $this->drupalGet("admin/structure/context/$context_name");
+    // Can't use an undefined prefix.
+    $this->getSession()->getPage()
+      ->fillField("Drupal URI predicate", "bob:smith");
+    $this->getSession()->getPage()->pressButton("Save and continue");
+    $this->assertSession()
+      ->pageTextContains("Namespace prefix bob is not registered");
+
+    // Can't use a straight string.
+    $this->getSession()->getPage()
+      ->fillField("Drupal URI predicate", "woohoo");
+    $this->getSession()->getPage()->pressButton("Save and continue");
+    $this->assertSession()
+      ->pageTextContains("Predicate must use a defined prefix or be a full URI");
+
+    // Use an existing prefix.
+    $this->getSession()->getPage()
+      ->fillField("Drupal URI predicate", "owl:sameAs");
+    $this->getSession()->getPage()->pressButton("Save and continue");
+    $this->assertSession()
+      ->pageTextContains("The context $context_name has been saved");
+
+    $new_contents = $this->drupalGet($url . '?_format=jsonld');
+    $json = \GuzzleHttp\json_decode($new_contents, TRUE);
+    $this->assertEquals(
+      'Test Node',
+      $json['@graph'][0]['http://purl.org/dc/terms/title'][0]['@value'],
+      'Missing title value'
+    );
+    $this->assertEquals(
+      "$url?_format=jsonld",
+      $json['@graph'][0]['http://www.w3.org/2002/07/owl#sameAs'][0]['@value'],
+      'Missing alter added predicate.'
+    );
+
+    $this->drupalGet("admin/structure/context/$context_name");
+    // Change to a random URL.
+    $this->getSession()->getPage()
+      ->fillField("Drupal URI predicate", "http://example.org/first/second");
+    $this->getSession()->getPage()->pressButton("Save and continue");
+    $this->assertSession()
+      ->pageTextContains("The context $context_name has been saved");
+    $new_contents = $this->drupalGet($url . '?_format=jsonld');
+    $json = \GuzzleHttp\json_decode($new_contents, TRUE);
+    $this->assertEquals(
+      'Test Node',
+      $json['@graph'][0]['http://purl.org/dc/terms/title'][0]['@value'],
+      'Missing title value'
+    );
+    $this->assertArrayNotHasKey('http://www.w3.org/2002/07/owl#sameAs',
+      $json['@graph'][0], 'Still has old predicate');
+    $this->assertEquals(
+      "$url?_format=jsonld",
+      $json['@graph'][0]['http://example.org/first/second'][0]['@value'],
+      'Missing alter added predicate.'
+    );
+  }
+
+}