diff --git a/.changeset/eight-suns-tan.md b/.changeset/eight-suns-tan.md
new file mode 100644
index 0000000000..4b8634a9e1
--- /dev/null
+++ b/.changeset/eight-suns-tan.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-plugin-api': minor
+---
+
+Extension attachment point is now configured via `attachTo: { id, input }` instead of `at: 'id/input'`.
diff --git a/.changeset/plenty-toys-cheer.md b/.changeset/plenty-toys-cheer.md
new file mode 100644
index 0000000000..3c16002632
--- /dev/null
+++ b/.changeset/plenty-toys-cheer.md
@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-search-react': patch
+'@backstage/plugin-graphiql': patch
+---
+
+Updated `/alpha` exports to use new `attachTo` option.
diff --git a/.changeset/small-books-deliver.md b/.changeset/small-books-deliver.md
new file mode 100644
index 0000000000..0d09f7ae1c
--- /dev/null
+++ b/.changeset/small-books-deliver.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-app-api': patch
+---
+
+Updates for `at` -> `attachTo` refactor.
diff --git a/packages/frontend-app-api/src/extensions/Core.tsx b/packages/frontend-app-api/src/extensions/Core.tsx
index 4cb21a8702..4a66afe38d 100644
--- a/packages/frontend-app-api/src/extensions/Core.tsx
+++ b/packages/frontend-app-api/src/extensions/Core.tsx
@@ -22,7 +22,7 @@ import {
 
 export const Core = createExtension({
   id: 'core',
-  at: 'root',
+  attachTo: { id: 'root', input: 'default' },
   inputs: {
     apis: createExtensionInput({
       api: coreExtensionData.apiFactory,
diff --git a/packages/frontend-app-api/src/extensions/CoreLayout.tsx b/packages/frontend-app-api/src/extensions/CoreLayout.tsx
index 0c5c0446fc..9b0b8b25d1 100644
--- a/packages/frontend-app-api/src/extensions/CoreLayout.tsx
+++ b/packages/frontend-app-api/src/extensions/CoreLayout.tsx
@@ -24,7 +24,7 @@ import { SidebarPage } from '@backstage/core-components';
 
 export const CoreLayout = createExtension({
   id: 'core.layout',
-  at: 'root',
+  attachTo: { id: 'root', input: 'default' },
   inputs: {
     nav: createExtensionInput(
       {
diff --git a/packages/frontend-app-api/src/extensions/CoreNav.tsx b/packages/frontend-app-api/src/extensions/CoreNav.tsx
index 71ab71a6aa..8e8aa638c0 100644
--- a/packages/frontend-app-api/src/extensions/CoreNav.tsx
+++ b/packages/frontend-app-api/src/extensions/CoreNav.tsx
@@ -73,7 +73,7 @@ const SidebarNavItem = (props: NavTarget) => {
 
 export const CoreNav = createExtension({
   id: 'core.nav',
-  at: 'core.layout/nav',
+  attachTo: { id: 'core.layout', input: 'nav' },
   inputs: {
     items: createExtensionInput({
       target: coreExtensionData.navTarget,
diff --git a/packages/frontend-app-api/src/extensions/CoreRoutes.tsx b/packages/frontend-app-api/src/extensions/CoreRoutes.tsx
index 5c79b56f43..5006a87cac 100644
--- a/packages/frontend-app-api/src/extensions/CoreRoutes.tsx
+++ b/packages/frontend-app-api/src/extensions/CoreRoutes.tsx
@@ -24,7 +24,7 @@ import { useRoutes } from 'react-router-dom';
 
 export const CoreRoutes = createExtension({
   id: 'core.routes',
-  at: 'core.layout/content',
+  attachTo: { id: 'core.layout', input: 'content' },
   inputs: {
     routes: createExtensionInput({
       path: coreExtensionData.routePath,
diff --git a/packages/frontend-app-api/src/routing/extractRouteInfoFromInstanceTree.test.ts b/packages/frontend-app-api/src/routing/extractRouteInfoFromInstanceTree.test.ts
index c64dc7a3b9..a510adf1b7 100644
--- a/packages/frontend-app-api/src/routing/extractRouteInfoFromInstanceTree.test.ts
+++ b/packages/frontend-app-api/src/routing/extractRouteInfoFromInstanceTree.test.ts
@@ -40,13 +40,15 @@ const refOrder = [ref1, ref2, ref3, ref4, ref5];
 
 function createTestExtension(options: {
   id: string;
-  at?: string;
+  parent?: string;
   path?: string;
   routeRef?: RouteRef;
 }) {
   return createExtension({
     id: options.id,
-    at: options.at ?? 'core.routes/children',
+    attachTo: options.parent
+      ? { id: options.parent, input: 'children' }
+      : { id: 'core.routes', input: 'children' },
     output: {
       element: coreExtensionData.reactElement,
       path: coreExtensionData.routePath.optional(),
@@ -126,13 +128,13 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page2',
-        at: 'page1/children',
+        parent: 'page1',
         path: 'bar/:id',
         routeRef: ref2,
       }),
       createTestExtension({
         id: 'page3',
-        at: 'page2/children',
+        parent: 'page2',
         path: 'baz',
         routeRef: ref3,
       }),
@@ -143,7 +145,7 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page5',
-        at: 'page1/children',
+        parent: 'page1',
         path: 'blop',
         routeRef: ref5,
       }),
@@ -194,7 +196,7 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page2',
-        at: 'page1/children',
+        parent: 'page1',
         path: 'bar/:id',
         routeRef: ref2,
       }),
@@ -205,13 +207,13 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page4',
-        at: 'page3/children',
+        parent: 'page3',
         path: 'divsoup',
         routeRef: ref4,
       }),
       createTestExtension({
         id: 'page5',
-        at: 'page3/children',
+        parent: 'page3',
         path: 'blop',
         routeRef: ref5,
       }),
@@ -242,7 +244,7 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page2',
-        at: 'page1/children',
+        parent: 'page1',
         path: '/bar/:id',
         routeRef: ref2,
       }),
@@ -253,13 +255,13 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page4',
-        at: 'page3/children',
+        parent: 'page3',
         path: '/divsoup',
         routeRef: ref4,
       }),
       createTestExtension({
         id: 'page5',
-        at: 'page3/children',
+        parent: 'page3',
         path: '/blop',
         routeRef: ref5,
       }),
@@ -289,16 +291,16 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page1',
-        at: 'foo/children',
+        parent: 'foo',
         routeRef: ref1,
       }),
       createTestExtension({
         id: 'fooChild',
-        at: 'foo/children',
+        parent: 'foo',
       }),
       createTestExtension({
         id: 'page2',
-        at: 'fooChild/children',
+        parent: 'fooChild',
         routeRef: ref2,
       }),
       createTestExtension({
@@ -311,17 +313,17 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page3Child',
-        at: 'page3/children',
+        parent: 'page3',
         path: '',
       }),
       createTestExtension({
         id: 'page4',
-        at: 'page3Child/children',
+        parent: 'page3Child',
         routeRef: ref4,
       }),
       createTestExtension({
         id: 'page5',
-        at: 'page4/children',
+        parent: 'page4',
         routeRef: ref5,
       }),
     ]);
@@ -361,29 +363,29 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page1Child',
-        at: 'page1/children',
+        parent: 'page1',
         path: 'bar',
       }),
       createTestExtension({
         id: 'page2',
-        at: 'page1Child/children',
+        parent: 'page1Child',
         routeRef: ref2,
       }),
       createTestExtension({
         id: 'page3',
-        at: 'page2/children',
+        parent: 'page2',
         path: 'baz',
         routeRef: ref3,
       }),
       createTestExtension({
         id: 'page4',
-        at: 'page3/children',
+        parent: 'page3',
         path: '/blop',
         routeRef: ref4,
       }),
       createTestExtension({
         id: 'page5',
-        at: 'page2/children',
+        parent: 'page2',
         routeRef: ref5,
       }),
     ]);
@@ -445,30 +447,30 @@ describe('discovery', () => {
       }),
       createTestExtension({
         id: 'page1',
-        at: 'r/children',
+        parent: 'r',
         path: 'x',
         routeRef: ref1,
       }),
       createTestExtension({
         id: 'y',
         path: 'y',
-        at: 'r/children',
+        parent: 'r',
       }),
       createTestExtension({
         id: 'page2',
-        at: 'y/children',
+        parent: 'y',
         path: '1',
         routeRef: ref2,
       }),
       createTestExtension({
         id: 'page3',
-        at: 'page2/children',
+        parent: 'page2',
         path: 'a',
         routeRef: ref3,
       }),
       createTestExtension({
         id: 'page4',
-        at: 'page2/children',
+        parent: 'page2',
         path: 'b',
         routeRef: ref4,
       }),
diff --git a/packages/frontend-app-api/src/wiring/createApp.test.tsx b/packages/frontend-app-api/src/wiring/createApp.test.tsx
index f6172f5a4b..14e52af469 100644
--- a/packages/frontend-app-api/src/wiring/createApp.test.tsx
+++ b/packages/frontend-app-api/src/wiring/createApp.test.tsx
@@ -32,9 +32,7 @@ describe('createInstances', () => {
       app: {
         extensions: [
           {
-            root: {
-              at: '',
-            },
+            root: {},
           },
         ],
       },
@@ -58,7 +56,7 @@ describe('createInstances', () => {
         extensions: [
           createExtension({
             id: 'root',
-            at: 'core.routes/route',
+            attachTo: { id: 'core.routes', input: 'route' },
             inputs: {},
             output: {},
             factory() {},
diff --git a/packages/frontend-app-api/src/wiring/createApp.tsx b/packages/frontend-app-api/src/wiring/createApp.tsx
index 540b47849f..e40c943e23 100644
--- a/packages/frontend-app-api/src/wiring/createApp.tsx
+++ b/packages/frontend-app-api/src/wiring/createApp.tsx
@@ -202,8 +202,8 @@ export function createInstances(options: {
     Map<string, ExtensionInstanceParameters[]>
   >();
   for (const instanceParams of extensionParams) {
-    const [extensionId, pointId = 'default'] = instanceParams.at.split('/');
-
+    const extensionId = instanceParams.attachTo.id;
+    const pointId = instanceParams.attachTo.input;
     let pointMap = attachmentMap.get(extensionId);
     if (!pointMap) {
       pointMap = new Map();
diff --git a/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts b/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
index 12e109874a..6550d76608 100644
--- a/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
+++ b/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
@@ -28,7 +28,7 @@ const inputMirrorDataRef = createExtensionDataRef<unknown>('mirror');
 
 const simpleExtension = createExtension({
   id: 'core.test',
-  at: 'ignored',
+  attachTo: { id: 'ignored', input: 'ignored' },
   output: {
     test: testDataRef,
     other: otherDataRef.optional(),
@@ -101,7 +101,7 @@ describe('createExtensionInstance', () => {
       config: undefined,
       extension: createExtension({
         id: 'core.test',
-        at: 'ignored',
+        attachTo: { id: 'ignored', input: 'ignored' },
         inputs: {
           optionalSingletonPresent: createExtensionInput(
             {
@@ -166,7 +166,7 @@ describe('createExtensionInstance', () => {
         config: { other: 'not-a-number' },
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           output: {},
           factory() {
             const error = new Error('NOPE');
@@ -188,7 +188,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           output: {
             test1: testDataRef,
             test2: testDataRef,
@@ -211,7 +211,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           output: {
             test: testDataRef,
           },
@@ -232,7 +232,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           inputs: {
             singleton: createExtensionInput(
               {
@@ -273,7 +273,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           inputs: {
             singleton: createExtensionInput(
               {
@@ -314,7 +314,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           inputs: {
             singleton: createExtensionInput(
               {
@@ -350,7 +350,7 @@ describe('createExtensionInstance', () => {
         config: undefined,
         extension: createExtension({
           id: 'core.test',
-          at: 'ignored',
+          attachTo: { id: 'ignored', input: 'ignored' },
           inputs: {
             singleton: createExtensionInput(
               {
diff --git a/packages/frontend-app-api/src/wiring/parameters.test.ts b/packages/frontend-app-api/src/wiring/parameters.test.ts
index 10b0e2fc6f..97ae941744 100644
--- a/packages/frontend-app-api/src/wiring/parameters.test.ts
+++ b/packages/frontend-app-api/src/wiring/parameters.test.ts
@@ -26,7 +26,7 @@ import {
 function makeExt(id: string, status: 'disabled' | 'enabled' = 'enabled') {
   return {
     id,
-    at: 'root',
+    attachTo: { id: 'root', input: 'default' },
     disabled: status === 'disabled',
   } as Extension<unknown>;
 }
@@ -52,8 +52,8 @@ describe('mergeExtensionParameters', () => {
         parameters: [],
       }),
     ).toEqual([
-      { extension: a, at: 'root' },
-      { extension: b, at: 'root' },
+      { extension: a, attachTo: { id: 'root', input: 'default' } },
+      { extension: b, attachTo: { id: 'root', input: 'default' } },
     ]);
   });
 
@@ -68,13 +68,17 @@ describe('mergeExtensionParameters', () => {
         parameters: [
           {
             id: 'b',
-            at: 'derp',
+            attachTo: { id: 'derp', input: 'default' },
           },
         ],
       }),
     ).toEqual([
-      { extension: a, at: 'root', source: pluginA },
-      { extension: b, at: 'derp' },
+      {
+        extension: a,
+        attachTo: { id: 'root', input: 'default' },
+        source: pluginA,
+      },
+      { extension: b, attachTo: { id: 'derp', input: 'default' } },
     ]);
   });
 
@@ -102,8 +106,18 @@ describe('mergeExtensionParameters', () => {
         ],
       }),
     ).toEqual([
-      { extension: a, at: 'root', source: plugin, config: { foo: { bar: 1 } } },
-      { extension: b, at: 'root', source: plugin, config: { foo: { qux: 3 } } },
+      {
+        extension: a,
+        attachTo: { id: 'root', input: 'default' },
+        source: plugin,
+        config: { foo: { bar: 1 } },
+      },
+      {
+        extension: b,
+        attachTo: { id: 'root', input: 'default' },
+        source: plugin,
+        config: { foo: { qux: 3 } },
+      },
     ]);
   });
 
@@ -126,8 +140,8 @@ describe('mergeExtensionParameters', () => {
         ],
       }),
     ).toEqual([
-      { extension: b, at: 'root' },
-      { extension: a, at: 'root' },
+      { extension: b, attachTo: { id: 'root', input: 'default' } },
+      { extension: a, attachTo: { id: 'root', input: 'default' } },
     ]);
   });
 });
@@ -315,14 +329,18 @@ describe('expandShorthandExtensionParameters', () => {
     expect(() =>
       run({ 'core.router': { id: 'some.id' } }),
     ).toThrowErrorMatchingInlineSnapshot(
-      `"Invalid extension configuration at app.extensions[1][core.router].id, unknown parameter; expected one of 'at', 'disabled', 'config'"`,
+      `"Invalid extension configuration at app.extensions[1][core.router].id, unknown parameter; expected one of 'attachTo', 'disabled', 'config'"`,
     );
   });
 
-  it('supports object at', () => {
-    expect(run({ 'core.router': { at: 'other.root/inputs' } })).toEqual({
+  it('supports object attachTo', () => {
+    expect(
+      run({
+        'core.router': { attachTo: { id: 'other.root', input: 'inputs' } },
+      }),
+    ).toEqual({
       id: 'core.router',
-      at: 'other.root/inputs',
+      attachTo: { id: 'other.root', input: 'inputs' },
     });
     expect(() =>
       run({
@@ -331,7 +349,7 @@ describe('expandShorthandExtensionParameters', () => {
         },
       }),
     ).toThrowErrorMatchingInlineSnapshot(
-      `"Invalid extension configuration at app.extensions[1][core.router].id, unknown parameter; expected one of 'at', 'disabled', 'config'"`,
+      `"Invalid extension configuration at app.extensions[1][core.router].id, unknown parameter; expected one of 'attachTo', 'disabled', 'config'"`,
     );
   });
 
@@ -369,7 +387,7 @@ describe('expandShorthandExtensionParameters', () => {
     expect(() =>
       run({ 'core.router': { foo: { settings: true } } }),
     ).toThrowErrorMatchingInlineSnapshot(
-      `"Invalid extension configuration at app.extensions[1][core.router].foo, unknown parameter; expected one of 'at', 'disabled', 'config'"`,
+      `"Invalid extension configuration at app.extensions[1][core.router].foo, unknown parameter; expected one of 'attachTo', 'disabled', 'config'"`,
     );
   });
 });
diff --git a/packages/frontend-app-api/src/wiring/parameters.ts b/packages/frontend-app-api/src/wiring/parameters.ts
index efe0fbf678..9474a01d79 100644
--- a/packages/frontend-app-api/src/wiring/parameters.ts
+++ b/packages/frontend-app-api/src/wiring/parameters.ts
@@ -20,12 +20,12 @@ import { JsonValue } from '@backstage/types';
 
 export interface ExtensionParameters {
   id: string;
-  at?: string;
+  attachTo?: { id: string; input: string };
   disabled?: boolean;
   config?: unknown;
 }
 
-const knownExtensionParameters = ['at', 'disabled', 'config'];
+const knownExtensionParameters = ['attachTo', 'disabled', 'config'];
 
 // Since we'll never merge arrays in config the config reader context
 // isn't too much of a help. Fall back to manual config reading logic
@@ -143,15 +143,33 @@ export function expandShorthandExtensionParameters(
     throw new Error(errorMsg('value must be a boolean or object', id));
   }
 
-  const at = value.at;
+  const attachTo = value.attachTo as { id: string; input: string } | undefined;
   const disabled = value.disabled;
   const config = value.config;
 
-  if (at !== undefined && typeof at !== 'string') {
-    throw new Error(errorMsg('must be a string', id, 'at'));
-  } else if (disabled !== undefined && typeof disabled !== 'boolean') {
+  if (attachTo !== undefined) {
+    if (
+      attachTo === null ||
+      typeof attachTo !== 'object' ||
+      Array.isArray(attachTo)
+    ) {
+      throw new Error(errorMsg('must be an object', id, 'attachTo'));
+    }
+    if (typeof attachTo.id !== 'string' || attachTo.id === '') {
+      throw new Error(
+        errorMsg('must be a non-empty string', id, 'attachTo.id'),
+      );
+    }
+    if (typeof attachTo.input !== 'string' || attachTo.input === '') {
+      throw new Error(
+        errorMsg('must be a non-empty string', id, 'attachTo.input'),
+      );
+    }
+  }
+  if (disabled !== undefined && typeof disabled !== 'boolean') {
     throw new Error(errorMsg('must be a boolean', id, 'disabled'));
-  } else if (
+  }
+  if (
     config !== undefined &&
     (typeof config !== 'object' || config === null || Array.isArray(config))
   ) {
@@ -175,7 +193,7 @@ export function expandShorthandExtensionParameters(
 
   return {
     id,
-    at,
+    attachTo,
     disabled,
     config,
   };
@@ -184,7 +202,7 @@ export function expandShorthandExtensionParameters(
 export interface ExtensionInstanceParameters {
   extension: Extension<unknown>;
   source?: BackstagePlugin;
-  at: string;
+  attachTo: { id: string; input: string };
   config?: unknown;
 }
 
@@ -217,7 +235,7 @@ export function mergeExtensionParameters(options: {
       extension,
       params: {
         source,
-        at: extension.at,
+        attachTo: extension.attachTo,
         disabled: extension.disabled,
         config: undefined as unknown,
       },
@@ -226,7 +244,7 @@ export function mergeExtensionParameters(options: {
       extension,
       params: {
         source: undefined,
-        at: extension.at,
+        attachTo: extension.attachTo,
         disabled: extension.disabled,
         config: undefined as unknown,
       },
@@ -283,8 +301,8 @@ export function mergeExtensionParameters(options: {
     );
     if (existingIndex !== -1) {
       const existing = overrides[existingIndex];
-      if (overrideParam.at) {
-        existing.params.at = overrideParam.at;
+      if (overrideParam.attachTo) {
+        existing.params.attachTo = overrideParam.attachTo;
       }
       if (overrideParam.config) {
         // TODO: merge config?
@@ -309,7 +327,7 @@ export function mergeExtensionParameters(options: {
     .filter(override => !override.params.disabled)
     .map(param => ({
       extension: param.extension,
-      at: param.params.at,
+      attachTo: param.params.attachTo,
       source: param.params.source,
       config: param.params.config,
     }));
diff --git a/packages/frontend-plugin-api/api-report.md b/packages/frontend-plugin-api/api-report.md
index e28d7d5993..f6781be290 100644
--- a/packages/frontend-plugin-api/api-report.md
+++ b/packages/frontend-plugin-api/api-report.md
@@ -136,7 +136,10 @@ export interface CreateExtensionOptions<
   TConfig,
 > {
   // (undocumented)
-  at: string;
+  attachTo: {
+    id: string;
+    input: string;
+  };
   // (undocumented)
   configSchema?: PortableSchema<TConfig>;
   // (undocumented)
@@ -182,7 +185,10 @@ export function createPageExtension<
       }
   ) & {
     id: string;
-    at?: string;
+    attachTo?: {
+      id: string;
+      input: string;
+    };
     disabled?: boolean;
     inputs?: TInputs;
     routeRef?: RouteRef;
@@ -209,7 +215,10 @@ export interface Extension<TConfig> {
   // (undocumented)
   $$type: '@backstage/Extension';
   // (undocumented)
-  at: string;
+  attachTo: {
+    id: string;
+    input: string;
+  };
   // (undocumented)
   configSchema?: PortableSchema<TConfig>;
   // (undocumented)
diff --git a/packages/frontend-plugin-api/src/extensions/createApiExtension.test.ts b/packages/frontend-plugin-api/src/extensions/createApiExtension.test.ts
index 7426edb766..e90c0b6b85 100644
--- a/packages/frontend-plugin-api/src/extensions/createApiExtension.test.ts
+++ b/packages/frontend-plugin-api/src/extensions/createApiExtension.test.ts
@@ -33,7 +33,7 @@ describe('createApiExtension', () => {
     expect(extension).toEqual({
       $$type: '@backstage/Extension',
       id: 'apis.test',
-      at: 'core/apis',
+      attachTo: { id: 'core', input: 'apis' },
       disabled: false,
       configSchema: undefined,
       inputs: {},
@@ -67,7 +67,7 @@ describe('createApiExtension', () => {
     expect(extension).toEqual({
       $$type: '@backstage/Extension',
       id: 'apis.test',
-      at: 'core/apis',
+      attachTo: { id: 'core', input: 'apis' },
       disabled: false,
       configSchema: undefined,
       inputs: {},
diff --git a/packages/frontend-plugin-api/src/extensions/createApiExtension.ts b/packages/frontend-plugin-api/src/extensions/createApiExtension.ts
index a142a5af61..8e5a9e9f33 100644
--- a/packages/frontend-plugin-api/src/extensions/createApiExtension.ts
+++ b/packages/frontend-plugin-api/src/extensions/createApiExtension.ts
@@ -51,7 +51,7 @@ export function createApiExtension<
 
   return createExtension({
     id: `apis.${apiRef.id}`,
-    at: 'core/apis',
+    attachTo: { id: 'core', input: 'apis' },
     inputs: extensionInputs,
     configSchema,
     output: {
diff --git a/packages/frontend-plugin-api/src/extensions/createNavItemExtension.tsx b/packages/frontend-plugin-api/src/extensions/createNavItemExtension.tsx
index 8c55531866..f208c975b7 100644
--- a/packages/frontend-plugin-api/src/extensions/createNavItemExtension.tsx
+++ b/packages/frontend-plugin-api/src/extensions/createNavItemExtension.tsx
@@ -31,7 +31,7 @@ export function createNavItemExtension(options: {
   const { id, routeRef, title, icon } = options;
   return createExtension({
     id,
-    at: 'core.nav/items',
+    attachTo: { id: 'core.nav', input: 'items' },
     configSchema: createSchemaFromZod(z =>
       z.object({
         title: z.string().default(title),
diff --git a/packages/frontend-plugin-api/src/extensions/createPageExtension.test.tsx b/packages/frontend-plugin-api/src/extensions/createPageExtension.test.tsx
index 7de6ee3253..125bf3495d 100644
--- a/packages/frontend-plugin-api/src/extensions/createPageExtension.test.tsx
+++ b/packages/frontend-plugin-api/src/extensions/createPageExtension.test.tsx
@@ -35,7 +35,7 @@ describe('createPageExtension', () => {
     ).toEqual({
       $$type: '@backstage/Extension',
       id: 'test',
-      at: 'core.routes/routes',
+      attachTo: { id: 'core.routes', input: 'routes' },
       configSchema: expect.anything(),
       disabled: false,
       inputs: {},
@@ -50,7 +50,7 @@ describe('createPageExtension', () => {
     expect(
       createPageExtension({
         id: 'test',
-        at: 'other/place',
+        attachTo: { id: 'other', input: 'place' },
         disabled: true,
         configSchema,
         inputs: {
@@ -63,7 +63,7 @@ describe('createPageExtension', () => {
     ).toEqual({
       $$type: '@backstage/Extension',
       id: 'test',
-      at: 'other/place',
+      attachTo: { id: 'other', input: 'place' },
       configSchema: expect.anything(),
       disabled: true,
       inputs: {
@@ -88,7 +88,7 @@ describe('createPageExtension', () => {
     ).toEqual({
       $$type: '@backstage/Extension',
       id: 'test',
-      at: 'core.routes/routes',
+      attachTo: { id: 'core.routes', input: 'routes' },
       configSchema: expect.anything(),
       disabled: false,
       inputs: {},
diff --git a/packages/frontend-plugin-api/src/extensions/createPageExtension.tsx b/packages/frontend-plugin-api/src/extensions/createPageExtension.tsx
index 5460fb518d..712c55f896 100644
--- a/packages/frontend-plugin-api/src/extensions/createPageExtension.tsx
+++ b/packages/frontend-plugin-api/src/extensions/createPageExtension.tsx
@@ -44,7 +44,7 @@ export function createPageExtension<
       }
   ) & {
     id: string;
-    at?: string;
+    attachTo?: { id: string; input: string };
     disabled?: boolean;
     inputs?: TInputs;
     routeRef?: RouteRef;
@@ -63,7 +63,7 @@ export function createPageExtension<
 
   return createExtension({
     id: options.id,
-    at: options.at ?? 'core.routes/routes',
+    attachTo: options.attachTo ?? { id: 'core.routes', input: 'routes' },
     disabled: options.disabled,
     output: {
       element: coreExtensionData.reactElement,
diff --git a/packages/frontend-plugin-api/src/extensions/createThemeExtension.ts b/packages/frontend-plugin-api/src/extensions/createThemeExtension.ts
index 5c13dd199e..38763688a4 100644
--- a/packages/frontend-plugin-api/src/extensions/createThemeExtension.ts
+++ b/packages/frontend-plugin-api/src/extensions/createThemeExtension.ts
@@ -21,7 +21,7 @@ import { AppTheme } from '@backstage/core-plugin-api';
 export function createThemeExtension(theme: AppTheme) {
   return createExtension({
     id: `themes.${theme.id}`,
-    at: 'core/themes',
+    attachTo: { id: 'core', input: 'themes' },
     output: {
       theme: coreExtensionData.theme,
     },
diff --git a/packages/frontend-plugin-api/src/wiring/createExtension.test.ts b/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
index 6f4a21399d..757bcd7e3d 100644
--- a/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
+++ b/packages/frontend-plugin-api/src/wiring/createExtension.test.ts
@@ -26,7 +26,7 @@ describe('createExtension', () => {
   it('should create an extension with a simple output', () => {
     const extension = createExtension({
       id: 'test',
-      at: 'root',
+      attachTo: { id: 'root', input: 'default' },
       output: {
         foo: stringData,
       },
@@ -56,7 +56,7 @@ describe('createExtension', () => {
   it('should create an extension with a some optional output', () => {
     const extension = createExtension({
       id: 'test',
-      at: 'root',
+      attachTo: { id: 'root', input: 'default' },
       output: {
         foo: stringData,
         bar: stringData.optional(),
@@ -94,7 +94,7 @@ describe('createExtension', () => {
   it('should create an extension with input', () => {
     const extension = createExtension({
       id: 'test',
-      at: 'root',
+      attachTo: { id: 'root', input: 'default' },
       inputs: {
         mixed: createExtensionInput({
           required: stringData,
diff --git a/packages/frontend-plugin-api/src/wiring/createExtension.ts b/packages/frontend-plugin-api/src/wiring/createExtension.ts
index dd365a87d8..01d4962965 100644
--- a/packages/frontend-plugin-api/src/wiring/createExtension.ts
+++ b/packages/frontend-plugin-api/src/wiring/createExtension.ts
@@ -80,7 +80,7 @@ export interface CreateExtensionOptions<
   TConfig,
 > {
   id: string;
-  at: string;
+  attachTo: { id: string; input: string };
   disabled?: boolean;
   inputs?: TInputs;
   output: TOutput;
@@ -97,7 +97,7 @@ export interface CreateExtensionOptions<
 export interface Extension<TConfig> {
   $$type: '@backstage/Extension';
   id: string;
-  at: string;
+  attachTo: { id: string; input: string };
   disabled: boolean;
   inputs: AnyExtensionInputMap;
   output: AnyExtensionDataMap;
diff --git a/packages/frontend-plugin-api/src/wiring/createPlugin.test.ts b/packages/frontend-plugin-api/src/wiring/createPlugin.test.ts
index b14838c17a..589ac59d75 100644
--- a/packages/frontend-plugin-api/src/wiring/createPlugin.test.ts
+++ b/packages/frontend-plugin-api/src/wiring/createPlugin.test.ts
@@ -30,7 +30,7 @@ const nameExtensionDataRef = createExtensionDataRef<string>('name');
 
 const TechRadarPage = createExtension({
   id: 'plugin.techradar.page',
-  at: 'test.output/names',
+  attachTo: { id: 'test.output', input: 'names' },
   output: {
     name: nameExtensionDataRef,
   },
@@ -41,7 +41,7 @@ const TechRadarPage = createExtension({
 
 const CatalogPage = createExtension({
   id: 'plugin.catalog.page',
-  at: 'test.output/names',
+  attachTo: { id: 'test.output', input: 'names' },
   output: {
     name: nameExtensionDataRef,
   },
@@ -55,7 +55,7 @@ const CatalogPage = createExtension({
 
 const TechDocsAddon = createExtension({
   id: 'plugin.techdocs.addon.example',
-  at: 'plugin.techdocs.page/addons',
+  attachTo: { id: 'plugin.techdocs.page', input: 'addons' },
   output: {
     name: nameExtensionDataRef,
   },
@@ -69,7 +69,7 @@ const TechDocsAddon = createExtension({
 
 const TechDocsPage = createExtension({
   id: 'plugin.techdocs.page',
-  at: 'test.output/names',
+  attachTo: { id: 'test.output', input: 'names' },
   inputs: {
     addons: createExtensionInput({
       name: nameExtensionDataRef,
@@ -85,7 +85,7 @@ const TechDocsPage = createExtension({
 
 const outputExtension = createExtension({
   id: 'test.output',
-  at: 'root',
+  attachTo: { id: 'root', input: 'default' },
   inputs: {
     names: createExtensionInput({
       name: nameExtensionDataRef,
diff --git a/plugins/graphiql/src/alpha.tsx b/plugins/graphiql/src/alpha.tsx
index 9cd956fc1a..08950b9072 100644
--- a/plugins/graphiql/src/alpha.tsx
+++ b/plugins/graphiql/src/alpha.tsx
@@ -86,7 +86,7 @@ export function createEndpointExtension<TConfig extends {}>(options: {
 }) {
   return createExtension({
     id: `apis.plugin.graphiql.browse.${options.id}`,
-    at: 'apis.plugin.graphiql.browse/endpoints',
+    attachTo: { id: 'apis.plugin.graphiql.browse', input: 'endpoints' },
     configSchema: options.configSchema,
     disabled: options.disabled ?? false,
     output: {
diff --git a/plugins/search-react/alpha-api-report.md b/plugins/search-react/alpha-api-report.md
index d62a0f1f0e..9c1248b536 100644
--- a/plugins/search-react/alpha-api-report.md
+++ b/plugins/search-react/alpha-api-report.md
@@ -48,7 +48,10 @@ export type SearchResultItemExtensionOptions<
   },
 > = {
   id: string;
-  at?: string;
+  attachTo?: {
+    id: string;
+    input: string;
+  };
   configSchema?: PortableSchema<TConfig>;
   component: (options: {
     config: TConfig;
diff --git a/plugins/search-react/src/alpha.test.tsx b/plugins/search-react/src/alpha.test.tsx
index b61a400832..8a88c9cc5d 100644
--- a/plugins/search-react/src/alpha.test.tsx
+++ b/plugins/search-react/src/alpha.test.tsx
@@ -58,7 +58,7 @@ describe('createSearchResultListItemExtension', () => {
     const TechDocsSearchResultItemExtension =
       createSearchResultListItemExtension({
         id: 'techdocs',
-        at: 'plugin.search.page/items',
+        attachTo: { id: 'plugin.search.page', input: 'items' },
         configSchema: createSchemaFromZod(z =>
           z.object({
             noTrack: z.boolean().default(true),
@@ -79,7 +79,7 @@ describe('createSearchResultListItemExtension', () => {
     const ExploreSearchResultItemExtension =
       createSearchResultListItemExtension({
         id: 'explore',
-        at: 'plugin.search.page/items',
+        attachTo: { id: 'plugin.search.page', input: 'items' },
         predicate: result => result.type === 'explore',
         component: async () => ExploreSearchResultItemComponent,
       });
diff --git a/plugins/search-react/src/alpha.tsx b/plugins/search-react/src/alpha.tsx
index 5b44a7bbb5..366112c95e 100644
--- a/plugins/search-react/src/alpha.tsx
+++ b/plugins/search-react/src/alpha.tsx
@@ -65,7 +65,7 @@ export type SearchResultItemExtensionOptions<
   /**
    * The extension attachment point (e.g., search modal or page).
    */
-  at?: string;
+  attachTo?: { id: string; input: string };
   /**
    * Optional extension config schema.
    */
@@ -97,7 +97,7 @@ export function createSearchResultListItemExtension<
         ) as PortableSchema<TConfig>);
   return createExtension({
     id: `plugin.search.result.item.${options.id}`,
-    at: options.at ?? 'plugin.search.page/items',
+    attachTo: options.attachTo ?? { id: 'plugin.search.page', input: 'items' },
     configSchema,
     output: {
       item: searchResultItemExtensionData,