diff --git a/CRM/Contact/DAO/RelationshipCache.php b/CRM/Contact/DAO/RelationshipCache.php
index 5b8f62cb2f59..ddb541bb7027 100644
--- a/CRM/Contact/DAO/RelationshipCache.php
+++ b/CRM/Contact/DAO/RelationshipCache.php
@@ -6,7 +6,7 @@
  *
  * Generated from xml/schema/CRM/Contact/RelationshipCache.xml
  * DO NOT EDIT.  Generated by CRM_Core_CodeGen
- * (GenCodeChecksum:6a586a5a5550a64db4c9907387c1411d)
+ * (GenCodeChecksum:d511533f30d5d2d8deac82664a6288d1)
  */
 
 /**
@@ -207,6 +207,9 @@ public static function &fields() {
           'entity' => 'RelationshipCache',
           'bao' => 'CRM_Contact_BAO_RelationshipCache',
           'localizable' => 0,
+          'pseudoconstant' => [
+            'callback' => 'CRM_Core_SelectValues::relationshipOrientation',
+          ],
           'add' => '5.29',
         ],
         'near_contact_id' => [
@@ -221,6 +224,9 @@ public static function &fields() {
           'bao' => 'CRM_Contact_BAO_RelationshipCache',
           'localizable' => 0,
           'FKClassName' => 'CRM_Contact_DAO_Contact',
+          'html' => [
+            'type' => 'EntityRef',
+          ],
           'add' => '5.29',
         ],
         'near_relation' => [
@@ -235,6 +241,9 @@ public static function &fields() {
           'entity' => 'RelationshipCache',
           'bao' => 'CRM_Contact_BAO_RelationshipCache',
           'localizable' => 0,
+          'pseudoconstant' => [
+            'callback' => 'CRM_Core_PseudoConstant::relationshipTypeOptions',
+          ],
           'add' => '5.29',
         ],
         'far_contact_id' => [
@@ -266,6 +275,9 @@ public static function &fields() {
           'entity' => 'RelationshipCache',
           'bao' => 'CRM_Contact_BAO_RelationshipCache',
           'localizable' => 0,
+          'pseudoconstant' => [
+            'callback' => 'CRM_Core_PseudoConstant::relationshipTypeOptions',
+          ],
           'add' => '5.29',
         ],
         'is_active' => [
diff --git a/CRM/Core/PseudoConstant.php b/CRM/Core/PseudoConstant.php
index 2fdc70868235..758db214acba 100644
--- a/CRM/Core/PseudoConstant.php
+++ b/CRM/Core/PseudoConstant.php
@@ -952,6 +952,23 @@ public static function relationshipType($valueColumnName = 'label', $reset = FAL
     return self::$relationshipType[$cacheKey];
   }
 
+  /**
+   * Name => Label pairs for all relationship types
+   *
+   * @return array
+   */
+  public static function relationshipTypeOptions() {
+    $relationshipTypes = [];
+    $relationshipLabels = self::relationshipType();
+    foreach (self::relationshipType('name') as $id => $type) {
+      $relationshipTypes[$type['name_a_b']] = $relationshipLabels[$id]['label_a_b'];
+      if ($type['name_b_a'] && $type['name_b_a'] != $type['name_a_b']) {
+        $relationshipTypes[$type['name_b_a']] = $relationshipLabels[$id]['label_b_a'];
+      }
+    }
+    return $relationshipTypes;
+  }
+
   /**
    * Get all the ISO 4217 currency codes
    *
diff --git a/CRM/Core/SelectValues.php b/CRM/Core/SelectValues.php
index 02d654549993..92a534d37d92 100644
--- a/CRM/Core/SelectValues.php
+++ b/CRM/Core/SelectValues.php
@@ -1196,4 +1196,14 @@ public static function navigationMenuSeparator() {
     ];
   }
 
+  /**
+   * @return array
+   */
+  public static function relationshipOrientation() {
+    return [
+      'a_b' => ts('A to B'),
+      'b_a' => ts('B to A'),
+    ];
+  }
+
 }
diff --git a/Civi/Api4/RelationshipCache.php b/Civi/Api4/RelationshipCache.php
new file mode 100644
index 000000000000..4030d331807b
--- /dev/null
+++ b/Civi/Api4/RelationshipCache.php
@@ -0,0 +1,49 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ *
+ * @package CRM
+ * @copyright CiviCRM LLC https://civicrm.org/licensing
+ */
+
+
+namespace Civi\Api4;
+
+/**
+ * RelationshipCache - readonly table to facilitate joining and finding contacts by relationship.
+ *
+ * @see \Civi\Api4\Relationship
+ *
+ * @package Civi\Api4
+ */
+class RelationshipCache extends Generic\AbstractEntity {
+
+  /**
+   * @param bool $checkPermissions
+   * @return Generic\DAOGetAction
+   */
+  public static function get($checkPermissions = TRUE) {
+    return (new Generic\DAOGetAction(static::class, __FUNCTION__))
+      ->setCheckPermissions($checkPermissions);
+  }
+
+  /**
+   * @param bool $checkPermissions
+   * @return Generic\DAOGetFieldsAction
+   */
+  public static function getFields($checkPermissions = TRUE) {
+    return (new Generic\DAOGetFieldsAction(static::class, __FUNCTION__))
+      ->setCheckPermissions($checkPermissions);
+  }
+
+}
diff --git a/tests/phpunit/api/v4/Entity/RelationshipTest.php b/tests/phpunit/api/v4/Entity/RelationshipTest.php
new file mode 100644
index 000000000000..81ab67d9b1bf
--- /dev/null
+++ b/tests/phpunit/api/v4/Entity/RelationshipTest.php
@@ -0,0 +1,50 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------+
+ | Copyright CiviCRM LLC. All rights reserved.                        |
+ |                                                                    |
+ | This work is published under the GNU AGPLv3 license with some      |
+ | permitted exceptions and without any warranty. For full license    |
+ | and copyright information, see https://civicrm.org/licensing       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ *
+ * @package CRM
+ * @copyright CiviCRM LLC https://civicrm.org/licensing
+ */
+
+namespace api\v4\Entity;
+
+use Civi\Api4\Contact;
+use api\v4\UnitTestCase;
+use Civi\Api4\Relationship;
+use Civi\Api4\RelationshipCache;
+use Civi\Test\TransactionalInterface;
+
+/**
+ * Assert that interchanging data between APIv3 and APIv4 yields consistent
+ * encodings.
+ *
+ * @group headless
+ */
+class RelationshipTest extends UnitTestCase implements TransactionalInterface {
+
+  public function testRelCache() {
+    $c1 = Contact::create(FALSE)->addValue('first_name', '1')->execute()->first()['id'];
+    $c2 = Contact::create(FALSE)->addValue('first_name', '2')->execute()->first()['id'];
+    Relationship::create(FALSE)
+      ->setValues([
+        'contact_id_a' => $c1,
+        'contact_id_b' => $c2,
+        'relationship_type_id' => 1,
+      ])->execute();
+    $cacheRecords = RelationshipCache::get(FALSE)
+      ->addClause('OR', ['near_contact_id', '=', $c1], ['far_contact_id', '=', $c1])
+      ->execute();
+    $this->assertCount(2, $cacheRecords);
+  }
+
+}
diff --git a/xml/schema/Contact/RelationshipCache.xml b/xml/schema/Contact/RelationshipCache.xml
index e522e4588b3f..dd6c2c401a7d 100644
--- a/xml/schema/Contact/RelationshipCache.xml
+++ b/xml/schema/Contact/RelationshipCache.xml
@@ -60,7 +60,9 @@
     <length>3</length>
     <title>Orientation (a_b or b_a)</title>
     <required>true</required>
-    <default></default>
+    <pseudoconstant>
+      <callback>CRM_Core_SelectValues::relationshipOrientation</callback>
+    </pseudoconstant>
     <comment>The cache record is a permutation of the original relationship record. The orientation indicates whether it is forward (a_b) or reverse (b_a) relationship.</comment>
     <add>5.29</add>
   </field>
@@ -72,6 +74,9 @@
     <required>true</required>
     <comment>id of the first contact</comment>
     <add>5.29</add>
+    <html>
+      <type>EntityRef</type>
+    </html>
   </field>
   <foreignKey>
     <name>near_contact_id</name>
@@ -88,6 +93,9 @@
     <length>64</length>
     <comment>name for relationship of near_contact to far_contact.</comment>
     <add>5.29</add>
+    <pseudoconstant>
+      <callback>CRM_Core_PseudoConstant::relationshipTypeOptions</callback>
+    </pseudoconstant>
   </field>
 
   <field>
@@ -116,6 +124,9 @@
     <length>64</length>
     <comment>name for relationship of far_contact to near_contact.</comment>
     <add>5.29</add>
+    <pseudoconstant>
+      <callback>CRM_Core_PseudoConstant::relationshipTypeOptions</callback>
+    </pseudoconstant>
   </field>
 
   <index>