diff --git a/packages/core-api/src/apis/ApiProvider.test.tsx b/packages/core-api/src/apis/ApiProvider.test.tsx
index 255b35a0d2..ac64aca3a7 100644
--- a/packages/core-api/src/apis/ApiProvider.test.tsx
+++ b/packages/core-api/src/apis/ApiProvider.test.tsx
@@ -51,6 +51,35 @@ describe('ApiProvider', () => {
     renderedHoc.getByText('hoc message: hello');
   });
 
+  it('should provide nested access to apis', () => {
+    const aRef = createApiRef<string>({ id: 'a', description: '' });
+    const bRef = createApiRef<string>({ id: 'b', description: '' });
+
+    const MyComponent = () => {
+      const a = useApi(aRef);
+      const b = useApi(bRef);
+      return (
+        <div>
+          a={a} b={b}
+        </div>
+      );
+    };
+
+    const renderedHook = render(
+      <ApiProvider
+        apis={ApiRegistry.from([
+          [aRef, 'x'],
+          [bRef, 'y'],
+        ])}
+      >
+        <ApiProvider apis={ApiRegistry.from([[aRef, 'z']])}>
+          <MyComponent />
+        </ApiProvider>
+      </ApiProvider>,
+    );
+    renderedHook.getByText('a=z b=y');
+  });
+
   it('should ignore deps in prototype', () => {
     // 100% coverage + happy typescript = hasOwnProperty + this atrocity
     const xRef = createApiRef<number>({ id: 'x', description: '' });
diff --git a/packages/core-api/src/apis/ApiProvider.tsx b/packages/core-api/src/apis/ApiProvider.tsx
index 1c5abf1c56..e157782024 100644
--- a/packages/core-api/src/apis/ApiProvider.tsx
+++ b/packages/core-api/src/apis/ApiProvider.tsx
@@ -18,16 +18,20 @@ import React, { FC, createContext, useContext, ReactNode } from 'react';
 import PropTypes from 'prop-types';
 import { ApiRef } from './ApiRef';
 import { ApiHolder, TypesToApiRefs } from './types';
+import { ApiAggregator } from './ApiAggregator';
 
-type Props = {
+type ApiProviderProps = {
   apis: ApiHolder;
   children: ReactNode;
 };
 
 const Context = createContext<ApiHolder | undefined>(undefined);
 
-export const ApiProvider: FC<Props> = ({ apis, children }) => {
-  return <Context.Provider value={apis} children={children} />;
+export const ApiProvider: FC<ApiProviderProps> = ({ apis, children }) => {
+  const parentHolder = useContext(Context);
+  const holder = parentHolder ? new ApiAggregator(apis, parentHolder) : apis;
+
+  return <Context.Provider value={holder} children={children} />;
 };
 
 ApiProvider.propTypes = {
diff --git a/packages/core-api/src/apis/ApiRegistry.test.ts b/packages/core-api/src/apis/ApiRegistry.test.ts
index 2971397e7a..a859d51004 100644
--- a/packages/core-api/src/apis/ApiRegistry.test.ts
+++ b/packages/core-api/src/apis/ApiRegistry.test.ts
@@ -49,4 +49,20 @@ describe('ApiRegistry', () => {
     expect(registry.get(x1Ref)).toBe(3);
     expect(registry.get(x2Ref)).toBe('y');
   });
+
+  it('should be created with API', () => {
+    const reg1 = ApiRegistry.with(x1Ref, 3);
+    const reg2 = reg1.with(x2Ref, 'y');
+    const reg3 = reg2.with(x2Ref, 'z');
+    const reg4 = reg3.with(x1Ref, 2);
+
+    expect(reg1.get(x1Ref)).toBe(3);
+    expect(reg1.get(x2Ref)).toBe(undefined);
+    expect(reg2.get(x1Ref)).toBe(3);
+    expect(reg2.get(x2Ref)).toBe('y');
+    expect(reg3.get(x1Ref)).toBe(3);
+    expect(reg3.get(x2Ref)).toBe('z');
+    expect(reg4.get(x1Ref)).toBe(2);
+    expect(reg4.get(x2Ref)).toBe('z');
+  });
 });
diff --git a/packages/core-api/src/apis/ApiRegistry.ts b/packages/core-api/src/apis/ApiRegistry.ts
index 0a9d14a4e7..64d97ba234 100644
--- a/packages/core-api/src/apis/ApiRegistry.ts
+++ b/packages/core-api/src/apis/ApiRegistry.ts
@@ -42,8 +42,28 @@ export class ApiRegistry implements ApiHolder {
     return new ApiRegistry(new Map(apis));
   }
 
+  /**
+   * Creates a new ApiRegistry with a single API implementation.
+   *
+   * @param api ApiRef for the API to add
+   * @param impl Implementation of the API to add
+   */
+  static with<T>(api: ApiRef<T>, impl: T): ApiRegistry {
+    return new ApiRegistry(new Map([[api, impl]]));
+  }
+
   constructor(private readonly apis: Map<ApiRef<unknown>, unknown>) {}
 
+  /**
+   * Returns a new ApiRegistry with the provided API added to the existing ones.
+   *
+   * @param api ApiRef for the API to add
+   * @param impl Implementation of the API to add
+   */
+  with<T>(api: ApiRef<T>, impl: T): ApiRegistry {
+    return new ApiRegistry(new Map([...this.apis, [api, impl]]));
+  }
+
   get<T>(api: ApiRef<T>): T | undefined {
     return this.apis.get(api) as T | undefined;
   }
diff --git a/packages/test-utils/src/testUtils/appWrappers.test.tsx b/packages/test-utils/src/testUtils/appWrappers.test.tsx
index e46b6a95ce..a30e8f9823 100644
--- a/packages/test-utils/src/testUtils/appWrappers.test.tsx
+++ b/packages/test-utils/src/testUtils/appWrappers.test.tsx
@@ -14,22 +14,59 @@
  * limitations under the License.
  */
 
-import React from 'react';
+import React, { FC } from 'react';
 import { render } from '@testing-library/react';
-import { wrapInTestApp } from './appWrappers';
+import { wrapInTestApp, renderInTestApp } from './appWrappers';
 import { Route } from 'react-router';
+import { withLogCollector } from '@backstage/test-utils-core';
 
 describe('wrapInTestApp', () => {
-  it('should provide routing', () => {
-    const rendered = render(
-      wrapInTestApp(
-        <>
-          <Route path="/route1">Route 1</Route>
-          <Route path="/route2">Route 2</Route>
-        </>,
-        { routeEntries: ['/route2'] },
+  it('should provide routing and warn about missing act()', async () => {
+    const { error } = await withLogCollector(['error'], async () => {
+      const rendered = render(
+        wrapInTestApp(
+          <>
+            <Route path="/route1">Route 1</Route>
+            <Route path="/route2">Route 2</Route>
+          </>,
+          { routeEntries: ['/route2'] },
+        ),
+      );
+      expect(rendered.getByText('Route 2')).toBeInTheDocument();
+
+      // Wait for async actions to trigger the act() warnings that we assert below
+      await Promise.resolve();
+    });
+
+    expect(error).toEqual([
+      expect.stringMatching(
+        /^Warning: An update to %s inside a test was not wrapped in act\(...\)/,
       ),
-    );
-    expect(rendered.getByText('Route 2')).toBeInTheDocument();
+      expect.stringMatching(
+        /^Warning: An update to %s inside a test was not wrapped in act\(...\)/,
+      ),
+    ]);
+  });
+
+  it('should render a component in a test app without warning about missing act()', async () => {
+    const { error } = await withLogCollector(['error'], async () => {
+      const Foo: FC<{}> = () => {
+        return <p>foo</p>;
+      };
+
+      const rendered = await renderInTestApp(Foo);
+      expect(rendered.getByText('foo')).toBeInTheDocument();
+    });
+
+    expect(error).toEqual([]);
+  });
+
+  it('should render a node in a test app', async () => {
+    const Foo: FC<{}> = () => {
+      return <p>foo</p>;
+    };
+
+    const rendered = await renderInTestApp(<Foo />);
+    expect(rendered.getByText('foo')).toBeInTheDocument();
   });
 });
diff --git a/packages/test-utils/src/testUtils/appWrappers.tsx b/packages/test-utils/src/testUtils/appWrappers.tsx
index 6fa6f62d8c..f191f955a3 100644
--- a/packages/test-utils/src/testUtils/appWrappers.tsx
+++ b/packages/test-utils/src/testUtils/appWrappers.tsx
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import React, { ComponentType, ReactNode, FunctionComponent, FC } from 'react';
+import React, { ComponentType, ReactNode, FC, ReactElement } from 'react';
 import { MemoryRouter } from 'react-router';
 import { Route } from 'react-router-dom';
 import { lightTheme } from '@backstage/theme';
@@ -23,6 +23,8 @@ import privateExports, {
   ApiTestRegistry,
   BootErrorPageProps,
 } from '@backstage/core-api';
+import { RenderResult } from '@testing-library/react';
+import { renderWithEffects } from '@backstage/test-utils-core';
 const { PrivateAppImpl } = privateExports;
 
 const NotFoundErrorPage = () => {
@@ -43,10 +45,17 @@ type TestAppOptions = {
   routeEntries?: string[];
 };
 
+/**
+ * Wraps a component inside a Backstage test app, providing a mocked theme
+ * and app context, along with mocked APIs.
+ *
+ * @param Component - A component or react node to render inside the test app.
+ * @param options - Additional options for the rendering.
+ */
 export function wrapInTestApp(
   Component: ComponentType | ReactNode,
   options: TestAppOptions = {},
-) {
+): ReactElement {
   const { routeEntries = ['/'] } = options;
 
   const app = new PrivateAppImpl({
@@ -75,7 +84,7 @@ export function wrapInTestApp(
   if (Component instanceof Function) {
     Wrapper = Component;
   } else {
-    Wrapper = (() => Component) as FunctionComponent;
+    Wrapper = (() => Component) as FC;
   }
 
   const AppProvider = app.getProvider();
@@ -86,3 +95,20 @@ export function wrapInTestApp(
     </AppProvider>
   );
 }
+
+/**
+ * Renders a component inside a Backstage test app, providing a mocked theme
+ * and app context, along with mocked APIs.
+ *
+ * The render executes async effects similar to `renderWithEffects`. To avoid this
+ * behavior, use a regular `render()` + `wrapInTestApp()` instead.
+ *
+ * @param Component - A component or react node to render inside the test app.
+ * @param options - Additional options for the rendering.
+ */
+export async function renderInTestApp(
+  Component: ComponentType | ReactNode,
+  options: TestAppOptions = {},
+): Promise<RenderResult> {
+  return renderWithEffects(wrapInTestApp(Component, options));
+}
diff --git a/packages/test-utils/src/testUtils/index.tsx b/packages/test-utils/src/testUtils/index.tsx
index ea33de2f31..302bdb405f 100644
--- a/packages/test-utils/src/testUtils/index.tsx
+++ b/packages/test-utils/src/testUtils/index.tsx
@@ -15,4 +15,4 @@
  */
 
 export { default as mockBreakpoint } from './mockBreakpoint';
-export * from './appWrappers';
+export { wrapInTestApp, renderInTestApp } from './appWrappers';