diff --git a/addons/api/addon/generated/models/credential.js b/addons/api/addon/generated/models/credential.js
index 4620e5106..e596d15bd 100644
--- a/addons/api/addon/generated/models/credential.js
+++ b/addons/api/addon/generated/models/credential.js
@@ -47,13 +47,6 @@ export default class GeneratedCredentialModel extends BaseModel {
   version;
 
   // =attributes (username_password)
-  @attr('string', {
-    for: 'username_password',
-    isNestedAttribute: true,
-    description: 'The password hmac for credential.',
-  })
-  password_hmac;
-
   @attr('string', {
     for: 'username_password',
     isNestedAttribute: true,
diff --git a/addons/api/addon/serializers/credential.js b/addons/api/addon/serializers/credential.js
index 222316f9c..7aa3f19e2 100644
--- a/addons/api/addon/serializers/credential.js
+++ b/addons/api/addon/serializers/credential.js
@@ -3,7 +3,7 @@ import { copy } from 'ember-copy';
 
 export default class CredentialSerializer extends ApplicationSerializer {
   serialize() {
-    let serialized = super.serialize(...arguments);
+    const serialized = super.serialize(...arguments);
     delete serialized['attributes']['password_hmac'];
     return serialized;
   }
diff --git a/addons/api/mirage/config.js b/addons/api/mirage/config.js
index 0e1dc1d27..92a5435e8 100644
--- a/addons/api/mirage/config.js
+++ b/addons/api/mirage/config.js
@@ -592,7 +592,20 @@ export default function () {
 
   // credentials
 
+  this.get(
+    '/credentials',
+    (
+      { credentials },
+      { queryParams: { credential_store_id: credentialStoreId } }
+    ) => credentials.where({ credentialStoreId })
+  );
   this.get('/credentials/:id');
+  this.post('/credentials', function ({ credentialStores, credentials }) {
+    const attrs = this.normalizedRequestAttrs();
+    const credentialStore = credentialStores.find(attrs.credentialStoreId);
+    attrs.scopeId = credentialStore.scope.id;
+    return credentials.create(attrs);
+  });
 
   // managed-groups
   this.get(
diff --git a/addons/api/mirage/serializers/credential.js b/addons/api/mirage/serializers/credential.js
index 7afcc7965..f028e0a86 100644
--- a/addons/api/mirage/serializers/credential.js
+++ b/addons/api/mirage/serializers/credential.js
@@ -10,9 +10,9 @@ export default ApplicationSerializer.extend({
     );
     json.credential_store_id = model.credentialStoreId;
 
-    // in a real API, the following field is set-only and returned
-    // as an associated HMAC field
-    delete json.attributes?.password_hmac;
+    // in a real API, the password field is not returned
+    // so we delete it from the response
+    delete json.attributes?.password;
 
     return json;
   },