diff --git a/docs/src/pages/configurations/composition/index.md b/docs/src/pages/configurations/composition/index.md
index e17f6436c78..2c51d1aad25 100644
--- a/docs/src/pages/configurations/composition/index.md
+++ b/docs/src/pages/configurations/composition/index.md
@@ -77,11 +77,11 @@ For an example what this file should look like, see: [here](https://next--storyb
 If you have some authentication layer on your hosted storybook, the composing the storybook will fail. Storybook will show a message in the sidebar if that happens.
 
 
-You can assist the user by creating a `metadata.json` file with a `authUrl` field, and ensure this file **is** loadable (even in the user is not authenticated):
+You can assist the user by creating a `metadata.json` file with a `loginUrl` field, and ensure this file **is** loadable (even in the user is not authenticated):
 
 ```json
 {
-  "authUrl": "https://example.com"
+  "loginUrl": "https://example.com"
 }
 ```
 
diff --git a/lib/api/src/modules/refs.ts b/lib/api/src/modules/refs.ts
index cd7138c2f93..00595d930ed 100644
--- a/lib/api/src/modules/refs.ts
+++ b/lib/api/src/modules/refs.ts
@@ -15,9 +15,11 @@ export interface SubState {
 
 type Versions = Record<string, string>;
 
-export type SetRefData = Omit<ComposedRef, 'stories'> & {
-  stories?: StoriesRaw;
-};
+export type SetRefData = Partial<
+  Omit<ComposedRef, 'stories'> & {
+    stories?: StoriesRaw;
+  }
+>;
 
 export interface SubAPI {
   findRef: (source: string) => ComposedRef;
@@ -36,7 +38,7 @@ export interface ComposedRef {
   type?: 'auto-inject' | 'unknown' | 'lazy';
   stories: StoriesHash;
   versions?: Versions;
-  authUrl?: string;
+  loginUrl?: string;
   ready?: boolean;
   error?: any;
 }
@@ -48,12 +50,12 @@ export type RefUrl = string;
 // eslint-disable-next-line no-useless-escape
 const findFilename = /(\/((?:[^\/]+?)\.[^\/]+?)|\/)$/;
 
-const allSettled = (promises: Promise<any>[]) =>
+const allSettled = (promises: Promise<Response>[]): Promise<(Response | false)[]> =>
   Promise.all(
-    promises.map((promise, i) =>
+    promises.map((promise) =>
       promise.then(
-        (r) => (r.ok ? r : false),
-        () => false
+        (r) => (r.ok ? r : (false as const)),
+        () => false as const
       )
     )
   );
@@ -98,7 +100,7 @@ const map = (
   return input;
 };
 
-export const init: ModuleFn = ({ store, provider, fullAPI }) => {
+export const init: ModuleFn = ({ store, provider, fullAPI }, { runCheck = true } = {}) => {
   const api: SubAPI = {
     findRef: (source) => {
       const refs = api.getRefs();
@@ -123,7 +125,7 @@ export const init: ModuleFn = ({ store, provider, fullAPI }) => {
     checkRef: async (ref) => {
       const { id, url } = ref;
 
-      const loadedData: { error?: Error; stories?: StoriesRaw } = {};
+      const loadedData: { error?: Error; stories?: StoriesRaw; loginUrl?: string } = {};
 
       const [included, omitted, iframe] = await allSettled([
         fetch(`${url}/stories.json`, {
@@ -144,7 +146,7 @@ export const init: ModuleFn = ({ store, provider, fullAPI }) => {
         }),
       ]);
 
-      const handle = async (request: Promise<Response> | false) => {
+      const handle = async (request: Response | false): Promise<SetRefData> => {
         if (request) {
           return Promise.resolve(request)
             .then((response) => (response.ok ? response.json() : {}))
@@ -168,10 +170,10 @@ export const init: ModuleFn = ({ store, provider, fullAPI }) => {
           `,
         } as Error;
       } else if (omitted || included) {
-        const credentials = !omitted ? 'include' : 'omit';
+        const credentials = included ? 'include' : 'omit';
 
         const [stories, metadata] = await Promise.all([
-          handle(omitted || included),
+          included ? handle(included) : handle(omitted),
           handle(
             fetch(`${url}/metadata.json`, {
               headers: {
@@ -179,14 +181,14 @@ export const init: ModuleFn = ({ store, provider, fullAPI }) => {
               },
               credentials,
               cache: 'no-cache',
-            })
+            }).catch(() => false)
           ),
         ]);
 
         Object.assign(loadedData, { ...stories, ...metadata });
       }
 
-      api.setRef(id, {
+      await api.setRef(id, {
         id,
         url,
         ...loadedData,
@@ -230,9 +232,11 @@ export const init: ModuleFn = ({ store, provider, fullAPI }) => {
     r.type = 'unknown';
   });
 
-  Object.entries(refs).forEach(([k, v]) => {
-    api.checkRef(v as SetRefData);
-  });
+  if (runCheck) {
+    Object.entries(refs).forEach(([k, v]) => {
+      api.checkRef(v as SetRefData);
+    });
+  }
 
   return {
     api,
diff --git a/lib/api/src/tests/ref-mockdata.login-required.json b/lib/api/src/tests/ref-mockdata.login-required.json
index 784e17e77ba..64c19b486fc 100644
--- a/lib/api/src/tests/ref-mockdata.login-required.json
+++ b/lib/api/src/tests/ref-mockdata.login-required.json
@@ -1,3 +1,3 @@
 {
-  "authUrl": "https://example.com"
+  "loginUrl": "https://example.com"
 }
\ No newline at end of file
diff --git a/lib/api/src/tests/refs.test.js b/lib/api/src/tests/refs.test.js
index 930e65c135b..1c54af75597 100644
--- a/lib/api/src/tests/refs.test.js
+++ b/lib/api/src/tests/refs.test.js
@@ -1,7 +1,10 @@
-import { getSourceType } from '../modules/refs';
+import { fetch } from 'global';
+import { getSourceType, init as initRefs } from '../modules/refs';
 
 jest.mock('global', () => {
-  const globalMock = {};
+  const globalMock = {
+    fetch: jest.fn(() => Promise.resolve({})),
+  };
   // Change global.location value to handle edge cases
   // Add additional variations of global.location mock return values in this array.
   // NOTE: The order must match the order that global.location is called in the unit tests.
@@ -20,7 +23,80 @@ jest.mock('global', () => {
   return globalMock;
 });
 
-describe('refs', () => {
+const provider = {
+  getConfig: () => ({
+    refs: {
+      fake: {
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      },
+    },
+  }),
+};
+
+const store = {
+  getState: () => ({
+    refs: {
+      fake: {
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      },
+    },
+  }),
+  setState: jest.fn(() => {}),
+};
+
+const emptyResponse = Promise.resolve({
+  ok: true,
+  json: async () => ({}),
+});
+
+const setupResponses = (
+  a = emptyResponse,
+  b = emptyResponse,
+  c = emptyResponse,
+  d = emptyResponse
+) => {
+  fetch.mockClear();
+  store.setState.mockClear();
+
+  fetch.mockImplementation((l, o) => {
+    if (l.includes('stories') && o.credentials === 'omit') {
+      return Promise.resolve({
+        ok: a.ok,
+        json: a.response,
+      });
+    }
+    if (l.includes('stories') && o.credentials === 'include') {
+      return Promise.resolve({
+        ok: b.ok,
+        json: b.response,
+      });
+    }
+    if (l.includes('iframe')) {
+      return Promise.resolve({
+        ok: c.ok,
+        json: c.response,
+      });
+    }
+    if (l.includes('metadata')) {
+      return Promise.resolve({
+        ok: d.ok,
+        json: d.response,
+      });
+    }
+    return Promise.resolve({
+      ok: false,
+      json: () => {
+        throw new Error('not ok');
+      },
+    });
+  });
+};
+
+describe('Refs API', () => {
   describe('getSourceType(source)', () => {
     // These tests must be run first and in correct order.
     // The order matches the "edgecaseLocations" order in the 'global' mock function above.
@@ -53,4 +129,490 @@ describe('refs', () => {
       ]);
     });
   });
+
+  describe('checkRef', () => {
+    it('on initialization it checks refs', async () => {
+      // given
+      initRefs({ provider, store });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+        ]
+      `);
+    });
+
+    it('checks refs (all fail)', async () => {
+      // given
+      const { api } = initRefs({ provider, store }, { runCheck: false });
+
+      setupResponses(
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('Failed to fetch');
+          },
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('Failed to fetch');
+          },
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        }
+      );
+
+      await api.checkRef({
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+        ]
+      `);
+
+      expect(store.setState.mock.calls[0][0]).toMatchInlineSnapshot(`
+        Object {
+          "refs": Object {
+            "fake": Object {
+              "error": Object {
+                "message": "Error: Loading of ref failed
+          at fetch (lib/api/src/modules/refs.ts)
+
+        URL: https://example.com
+
+        We weren't able to load the above URL,
+        it's possible a CORS error happened.
+
+        Please check your dev-tools network tab.",
+              },
+              "id": "fake",
+              "ready": false,
+              "stories": undefined,
+              "title": "Fake",
+              "type": "auto-inject",
+              "url": "https://example.com",
+            },
+          },
+        }
+      `);
+    });
+
+    it('checks refs (success)', async () => {
+      // given
+      const { api } = initRefs({ provider, store }, { runCheck: false });
+
+      setupResponses(
+        {
+          ok: true,
+          response: async () => ({ stories: {} }),
+        },
+        {
+          ok: true,
+          response: async () => ({ stories: {} }),
+        },
+        {
+          ok: true,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        },
+        {
+          ok: true,
+          response: async () => ({
+            versions: {},
+          }),
+        }
+      );
+
+      await api.checkRef({
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+          Array [
+            "https://example.com/metadata.json",
+            Object {
+              "cache": "no-cache",
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+        ]
+      `);
+
+      expect(store.setState.mock.calls[0][0]).toMatchInlineSnapshot(`
+        Object {
+          "refs": Object {
+            "fake": Object {
+              "id": "fake",
+              "ready": false,
+              "stories": Object {},
+              "title": "Fake",
+              "type": "lazy",
+              "url": "https://example.com",
+              "versions": Object {},
+            },
+          },
+        }
+      `);
+    });
+
+    it('checks refs (auth)', async () => {
+      // given
+      const { api } = initRefs({ provider, store }, { runCheck: false });
+
+      setupResponses(
+        {
+          ok: true,
+          response: async () => ({ loginUrl: 'https://example.com/login' }),
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        },
+        {
+          ok: true,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        }
+      );
+
+      await api.checkRef({
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+          Array [
+            "https://example.com/metadata.json",
+            Object {
+              "cache": "no-cache",
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+        ]
+      `);
+
+      expect(store.setState.mock.calls[0][0]).toMatchInlineSnapshot(`
+        Object {
+          "refs": Object {
+            "fake": Object {
+              "id": "fake",
+              "loginUrl": "https://example.com/login",
+              "ready": false,
+              "stories": undefined,
+              "title": "Fake",
+              "type": "auto-inject",
+              "url": "https://example.com",
+            },
+          },
+        }
+      `);
+    });
+
+    it('checks refs (mixed)', async () => {
+      // given
+      const { api } = initRefs({ provider, store }, { runCheck: false });
+
+      fetch.mockClear();
+      store.setState.mockClear();
+
+      setupResponses(
+        {
+          ok: true,
+          response: async () => ({ loginUrl: 'https://example.com/login' }),
+        },
+        {
+          ok: true,
+          response: async () => ({ stories: {} }),
+        },
+        {
+          ok: true,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        },
+        {
+          ok: true,
+          response: async () => ({
+            versions: { '1.0.0': 'https://example.com/v1', '2.0.0': 'https://example.com' },
+          }),
+        }
+      );
+
+      await api.checkRef({
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+          Array [
+            "https://example.com/metadata.json",
+            Object {
+              "cache": "no-cache",
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+        ]
+      `);
+
+      expect(store.setState.mock.calls[0][0]).toMatchInlineSnapshot(`
+        Object {
+          "refs": Object {
+            "fake": Object {
+              "id": "fake",
+              "ready": false,
+              "stories": Object {},
+              "title": "Fake",
+              "type": "lazy",
+              "url": "https://example.com",
+              "versions": Object {
+                "1.0.0": "https://example.com/v1",
+                "2.0.0": "https://example.com",
+              },
+            },
+          },
+        }
+      `);
+    });
+
+    it('checks refs (cors)', async () => {
+      // given
+      const { api } = initRefs({ provider, store }, { runCheck: false });
+
+      setupResponses(
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('Failed to fetch');
+          },
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('Failed to fetch');
+          },
+        },
+        {
+          ok: true,
+          response: async () => {
+            throw new Error('not ok');
+          },
+        },
+        {
+          ok: false,
+          response: async () => {
+            throw new Error('Failed to fetch');
+          },
+        }
+      );
+
+      await api.checkRef({
+        id: 'fake',
+        url: 'https://example.com',
+        title: 'Fake',
+      });
+
+      expect(fetch.mock.calls).toMatchInlineSnapshot(`
+        Array [
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "include",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/stories.json",
+            Object {
+              "credentials": "omit",
+              "headers": Object {
+                "Accept": "application/json",
+              },
+            },
+          ],
+          Array [
+            "https://example.com/iframe.html",
+            Object {
+              "cors": "no-cors",
+              "credentials": "omit",
+            },
+          ],
+        ]
+      `);
+
+      expect(store.setState.mock.calls[0][0]).toMatchInlineSnapshot(`
+        Object {
+          "refs": Object {
+            "fake": Object {
+              "id": "fake",
+              "ready": false,
+              "stories": undefined,
+              "title": "Fake",
+              "type": "auto-inject",
+              "url": "https://example.com",
+            },
+          },
+        }
+      `);
+    });
+  });
 });
diff --git a/lib/api/src/version.ts b/lib/api/src/version.ts
index 42fcc6ce797..2a55a8b9514 100644
--- a/lib/api/src/version.ts
+++ b/lib/api/src/version.ts
@@ -1 +1 @@
-export const version = '6.0.0-beta.31';
\ No newline at end of file
+export const version = '6.0.0-beta.31';
diff --git a/lib/ui/src/components/sidebar/RefBlocks.tsx b/lib/ui/src/components/sidebar/RefBlocks.tsx
index 22bf7bf9dfe..abd36d1f1ac 100644
--- a/lib/ui/src/components/sidebar/RefBlocks.tsx
+++ b/lib/ui/src/components/sidebar/RefBlocks.tsx
@@ -160,7 +160,10 @@ const ErrorFormatter: FunctionComponent<{ error: Error }> = ({ error }) => {
   );
 };
 
-export const AuthBlock: FunctionComponent<{ authUrl: string; id: string }> = ({ authUrl, id }) => {
+export const AuthBlock: FunctionComponent<{ loginUrl: string; id: string }> = ({
+  loginUrl,
+  id,
+}) => {
   const [isAuthAttempted, setAuthAttempted] = useState(false);
 
   const refresh = useCallback(() => {
@@ -169,12 +172,12 @@ export const AuthBlock: FunctionComponent<{ authUrl: string; id: string }> = ({
 
   const open = useCallback((e) => {
     e.preventDefault();
-    const childWindow = window.open(authUrl, `storybook_auth_${id}`, 'resizable,scrollbars');
+    const childWindow = window.open(loginUrl, `storybook_auth_${id}`, 'resizable,scrollbars');
 
     // poll for window to close
     const timer = setInterval(() => {
       if (!childWindow) {
-        logger.error('unable to access authUrl window');
+        logger.error('unable to access loginUrl window');
         clearInterval(timer);
       } else if (childWindow.closed) {
         clearInterval(timer);
@@ -189,8 +192,8 @@ export const AuthBlock: FunctionComponent<{ authUrl: string; id: string }> = ({
         {isAuthAttempted ? (
           <Fragment>
             <Text>
-              Authentication on <strong>{authUrl}</strong> seems to have concluded, refresh the page
-              to fetch this storybook
+              Authentication on <strong>{loginUrl}</strong> seems to have concluded, refresh the
+              page to fetch this storybook
             </Text>
             <div>
               <Button small gray onClick={refresh}>
diff --git a/lib/ui/src/components/sidebar/Refs.tsx b/lib/ui/src/components/sidebar/Refs.tsx
index ab790800064..ed83ea7a7d1 100644
--- a/lib/ui/src/components/sidebar/Refs.tsx
+++ b/lib/ui/src/components/sidebar/Refs.tsx
@@ -54,7 +54,7 @@ export const Ref: FunctionComponent<RefType & RefProps> = (ref) => {
   const [isExpanded, setIsExpanded] = useState(true);
   const indicatorRef = useRef<HTMLElement>(null);
 
-  const { stories, id: key, title = key, storyId, filter, isHidden = false, authUrl, error } = ref;
+  const { stories, id: key, title = key, storyId, filter, isHidden = false, loginUrl, error } = ref;
   const { dataSet, expandedSet, length, others, roots, setExpanded, selectedSet } = useDataset(
     stories,
     filter,
@@ -77,7 +77,7 @@ export const Ref: FunctionComponent<RefType & RefProps> = (ref) => {
   const isLoading = isLoadingMain || isLoadingInjected || ref.type === 'unknown';
   const isError = !!error;
   const isEmpty = !isLoading && length === 0;
-  const isAuthRequired = !!authUrl;
+  const isAuthRequired = !!loginUrl && length === 0;
 
   const state = getStateType(isLoading, isAuthRequired, isError, isEmpty);
 
@@ -97,7 +97,7 @@ export const Ref: FunctionComponent<RefType & RefProps> = (ref) => {
       )}
       {isExpanded && (
         <Wrapper data-title={title} isMain={isMain}>
-          {state === 'auth' && <AuthBlock id={ref.id} authUrl={authUrl} />}
+          {state === 'auth' && <AuthBlock id={ref.id} loginUrl={loginUrl} />}
           {state === 'error' && <ErrorBlock error={error} />}
           {state === 'loading' && <LoaderBlock isMain={isMain} />}
           {state === 'empty' && <EmptyBlock isMain={isMain} />}
diff --git a/lib/ui/src/components/sidebar/Sidebar.stories.tsx b/lib/ui/src/components/sidebar/Sidebar.stories.tsx
index c1ecabf0032..f5319ebe62c 100644
--- a/lib/ui/src/components/sidebar/Sidebar.stories.tsx
+++ b/lib/ui/src/components/sidebar/Sidebar.stories.tsx
@@ -88,7 +88,7 @@ const refs: Record<string, RefType> = {
     url: 'https://example.com',
     type: 'lazy',
     stories: {},
-    authUrl: 'https://example.com',
+    loginUrl: 'https://example.com',
   },
   long: {
     id: 'long',