diff --git a/packages/base/workspace.gts b/packages/base/workspace.gts
index 04726d6a761..ef946ed2051 100644
--- a/packages/base/workspace.gts
+++ b/packages/base/workspace.gts
@@ -249,6 +249,7 @@ class Isolated extends Component<typeof Workspace> {
   <template>
     <section
       class='card-grid'
+      data-test-workspace-index
       {{this.setupRealmSubscription this.primaryRealm}}
     >
       <header class='frame'>
@@ -256,16 +257,19 @@ class Isolated extends Component<typeof Workspace> {
           <button
             type='button'
             class='tab {{if (eq this.segment "home") "active"}}'
+            data-test-workspace-tab='home'
             {{on 'click' (this.setSegment 'home')}}
           ><HouseIcon class='tab-icon' /> Home</button>
           <button
             type='button'
             class='tab {{if (eq this.segment "library") "active"}}'
+            data-test-workspace-tab='library'
             {{on 'click' (this.setSegment 'library')}}
           ><LayoutGridIcon class='tab-icon' /> Library</button>
           <button
             type='button'
             class='tab {{if (eq this.segment "activity") "active"}}'
+            data-test-workspace-tab='activity'
             {{on 'click' (this.setSegment 'activity')}}
           ><ActivityIcon class='tab-icon' />
             Activity{{#if this.runningJobs.length}}<span
diff --git a/packages/matrix/helpers/index.ts b/packages/matrix/helpers/index.ts
index 00546adc1bf..4184caf7d76 100644
--- a/packages/matrix/helpers/index.ts
+++ b/packages/matrix/helpers/index.ts
@@ -450,12 +450,27 @@ export async function enterWorkspace(
 }
 
 export async function showAllCards(page: Page) {
+  // A realm's index is either the legacy CardsGrid — whose "All Cards" filter
+  // lists every card — or the default Workspace, whose Library tab renders the
+  // same live card grid. `.count()` is point-in-time, so wait for the index to
+  // render one of its browse affordances before deciding; checking right after
+  // a `goto` would otherwise miss both and silently no-op. A bespoke index has
+  // neither — leave it be.
+  let allCardsFilter = page.locator(
+    `[data-test-boxel-filter-list-button="All Cards"]`,
+  );
+  let libraryTab = page.locator(`[data-test-workspace-tab="library"]`);
   try {
-    await page
-      .locator(`[data-test-boxel-filter-list-button="All Cards"]`)
-      .click();
-  } catch (e) {
-    console.warn('all cards filter is not found');
+    await allCardsFilter.or(libraryTab).first().waitFor({ timeout: 30_000 });
+  } catch {
+    return;
+  }
+  if ((await allCardsFilter.count()) > 0) {
+    await allCardsFilter.click();
+    return;
+  }
+  if ((await libraryTab.count()) > 0) {
+    await libraryTab.click();
   }
 }
 
diff --git a/packages/matrix/tests/create-realm.spec.ts b/packages/matrix/tests/create-realm.spec.ts
index b4d131da702..0138391f431 100644
--- a/packages/matrix/tests/create-realm.spec.ts
+++ b/packages/matrix/tests/create-realm.spec.ts
@@ -32,9 +32,8 @@ test.describe('Create Realm via Dashboard', () => {
     await expect(
       page.locator(`[data-test-stack-card="${newRealmURL}index"]`),
     ).toBeVisible();
-    await expect(
-      page.locator(`[data-test-boxel-filter-list-button]`),
-    ).toHaveCount(3);
+    // A newly created realm defaults to a Workspace index card.
+    await expect(page.locator(`[data-test-workspace-index]`)).toBeVisible();
 
     await page.locator('[data-test-submode-switcher] button').click();
     await page.locator('[data-test-boxel-menu-item-text="Host"]').click();
diff --git a/packages/matrix/tests/live-cards.spec.ts b/packages/matrix/tests/live-cards.spec.ts
index 8b6e368b231..886c1d09bdf 100644
--- a/packages/matrix/tests/live-cards.spec.ts
+++ b/packages/matrix/tests/live-cards.spec.ts
@@ -74,9 +74,7 @@ test.describe('Live Cards', () => {
     await page.goto(realmURL);
     await showAllCards(page);
 
-    await expect(
-      page.locator(`[data-test-boxel-filter-list-button="All Cards"]`),
-    ).toHaveCount(1);
+    await expect(page.locator(`[data-test-cards-grid-cards]`)).toBeVisible();
 
     await postCardSource(
       page,
@@ -228,14 +226,15 @@ test.describe('Live Cards', () => {
     const realmURL = new URL(`${username}/${realmName}/`, serverIndexUrl).href;
     await createRealm(page, realmName);
 
-    // Land on the realm's grid so the create-new-card affordance is present.
+    // Open the card chooser via the operator-mode "New" button — an
+    // index-agnostic affordance, so this doesn't depend on whether the realm
+    // index is a CardsGrid or a Workspace. Its "Choose a card type..." item
+    // opens the same chooser CardsGrid's create button did.
     await page.goto(realmURL);
-    await showAllCards(page);
-    await expect(
-      page.locator(`[data-test-boxel-filter-list-button="All Cards"]`),
-    ).toHaveCount(1);
-
-    await page.locator('[data-test-create-new-card-button]').click();
+    await page.locator('[data-test-new-file-button]').click();
+    await page
+      .locator('[data-test-boxel-menu-item-text="Choose a card type..."]')
+      .click();
     await expect(page.locator('[data-test-card-chooser-modal]')).toBeVisible();
     await expect(page.locator('[data-test-item-button]').first()).toBeVisible();
 
diff --git a/packages/matrix/tests/skills.spec.ts b/packages/matrix/tests/skills.spec.ts
index 80527850d3d..a0439b7d01d 100644
--- a/packages/matrix/tests/skills.spec.ts
+++ b/packages/matrix/tests/skills.spec.ts
@@ -363,8 +363,12 @@ test.describe('Skills', () => {
     await page.goto(realmURL);
     await showAllCards(page);
 
-    // create a skill card
-    await page.locator('[data-test-create-new-card-button]').click();
+    // create a skill card — open the chooser via the index-agnostic
+    // operator-mode "New" button rather than the CardsGrid-only + button.
+    await page.locator('[data-test-new-file-button]').click();
+    await page
+      .locator('[data-test-boxel-menu-item-text="Choose a card type..."]')
+      .click();
     await page.locator('[data-test-search-field]').fill('Skill');
     await page
       .locator(
@@ -423,8 +427,10 @@ test.describe('Skills', () => {
       )
       .waitFor();
 
-    // Update the uploaded skill card
-    await page.locator('[data-test-filter-list-item="Skill"]').click();
+    // Update the uploaded skill card — reach the realm's card grid (CardsGrid's
+    // "All Cards" or the Workspace Library) and open the skill directly by its
+    // id, rather than the CardsGrid-only "Skill" type filter.
+    await showAllCards(page);
     await page.locator(`[data-cards-grid-item="${skillCard}"]`).click();
     await page.locator('[data-test-edit-button]').click();
     await page
diff --git a/packages/matrix/tests/tools.spec.ts b/packages/matrix/tests/tools.spec.ts
index 705c535302b..972186ee2df 100644
--- a/packages/matrix/tests/tools.spec.ts
+++ b/packages/matrix/tests/tools.spec.ts
@@ -309,8 +309,12 @@ test.describe('Commands', () => {
     await page.goto(realmURL);
     await showAllCards(page);
 
-    // create a skill card
-    await page.locator('[data-test-create-new-card-button]').click();
+    // create a skill card — open the chooser via the index-agnostic
+    // operator-mode "New" button rather than the CardsGrid-only + button.
+    await page.locator('[data-test-new-file-button]').click();
+    await page
+      .locator('[data-test-boxel-menu-item-text="Choose a card type..."]')
+      .click();
     await page.locator('[data-test-search-field]').fill('Skill');
     await page
       .locator(
diff --git a/packages/realm-server/handlers/create-realm.ts b/packages/realm-server/handlers/create-realm.ts
index 52ffffef77b..7e9ad6822f1 100644
--- a/packages/realm-server/handlers/create-realm.ts
+++ b/packages/realm-server/handlers/create-realm.ts
@@ -187,8 +187,8 @@ export async function createRealm(
         type: 'card',
         meta: {
           adoptsFrom: {
-            module: '@cardstack/base/cards-grid',
-            name: 'CardsGrid',
+            module: '@cardstack/base/workspace',
+            name: 'Workspace',
           },
         },
       },
diff --git a/packages/realm-server/tests/publish-unpublish-realm-test.ts b/packages/realm-server/tests/publish-unpublish-realm-test.ts
index 99e5a1e6469..008a36f3266 100644
--- a/packages/realm-server/tests/publish-unpublish-realm-test.ts
+++ b/packages/realm-server/tests/publish-unpublish-realm-test.ts
@@ -530,7 +530,7 @@ module(basename(import.meta.filename), function () {
         );
       });
 
-      test('publishing a realm with the default CardsGrid index writes includePrerenderedDefaultRealmIndex into the published realm.json', async function (assert) {
+      test('publishing a realm with the default Workspace index writes includePrerenderedDefaultRealmIndex into the published realm.json', async function (assert) {
         let response = await request
           .post('/_publish-realm')
           .set('Accept', 'application/vnd.api+json')
@@ -546,7 +546,7 @@ module(basename(import.meta.filename), function () {
             JSON.stringify({
               sourceRealmURL: sourceRealmUrlString,
               publishedRealmURL:
-                'http://testuser.localhost:4445/cards-grid-default/',
+                'http://testuser.localhost:4445/workspace-default/',
             }),
           );
         assert.strictEqual(response.status, 202, 'HTTP 202 status');
@@ -574,12 +574,12 @@ module(basename(import.meta.filename), function () {
         );
       });
 
-      test('publishing a realm whose index.json is not a CardsGrid leaves the published realm.json untouched', async function (assert) {
+      test('publishing a realm whose index.json is a bespoke card leaves the published realm.json untouched', async function (assert) {
         let sourceRealmPath = new URL(sourceRealmUrlString).pathname;
 
-        // Replace the source realm's default CardsGrid index with a
-        // bespoke CardDef-adopting index so the publish handler should
-        // NOT set the opt-in flag.
+        // Replace the source realm's default index with a bespoke
+        // CardDef-adopting index (neither CardsGrid nor Workspace) so the
+        // publish handler should NOT set the opt-in flag.
         let customIndexResponse = await request
           .post(`${sourceRealmPath}index.json`)
           .set('Accept', 'application/vnd.card+source')
@@ -600,7 +600,7 @@ module(basename(import.meta.filename), function () {
         assert.strictEqual(
           customIndexResponse.status,
           204,
-          'custom non-CardsGrid index.json can be written',
+          'bespoke non-default index.json can be written',
         );
 
         let response = await request
@@ -642,16 +642,17 @@ module(basename(import.meta.filename), function () {
           publishedRealmConfig?.data?.attributes
             ?.includePrerenderedDefaultRealmIndex,
           true,
-          'published realm.json does NOT carry includePrerenderedDefaultRealmIndex when the source index is a non-CardsGrid card',
+          'published realm.json does NOT carry includePrerenderedDefaultRealmIndex when the source index is a bespoke, non-default card',
         );
       });
 
-      test('publishing a realm whose index adopts the default Workspace card writes includePrerenderedDefaultRealmIndex into the published realm.json', async function (assert) {
+      test('publishing a realm whose index adopts the legacy CardsGrid card writes includePrerenderedDefaultRealmIndex into the published realm.json', async function (assert) {
         let sourceRealmPath = new URL(sourceRealmUrlString).pathname;
 
-        // Point the source realm's index at the base Workspace card — the
-        // other recognized default index besides CardsGrid.
-        let workspaceIndexResponse = await request
+        // Workspace is the default index now, so point this realm's index at
+        // the legacy CardsGrid card explicitly — it is still recognized as a
+        // default index alongside Workspace.
+        let cardsGridIndexResponse = await request
           .post(`${sourceRealmPath}index.json`)
           .set('Accept', 'application/vnd.card+source')
           .send(
@@ -661,17 +662,17 @@ module(basename(import.meta.filename), function () {
                 attributes: {},
                 meta: {
                   adoptsFrom: {
-                    module: '@cardstack/base/workspace',
-                    name: 'Workspace',
+                    module: '@cardstack/base/cards-grid',
+                    name: 'CardsGrid',
                   },
                 },
               },
             }),
           );
         assert.strictEqual(
-          workspaceIndexResponse.status,
+          cardsGridIndexResponse.status,
           204,
-          'Workspace index.json can be written',
+          'CardsGrid index.json can be written',
         );
 
         let response = await request
@@ -689,7 +690,7 @@ module(basename(import.meta.filename), function () {
             JSON.stringify({
               sourceRealmURL: sourceRealmUrlString,
               publishedRealmURL:
-                'http://testuser.localhost:4445/workspace-default/',
+                'http://testuser.localhost:4445/cards-grid-legacy/',
             }),
           );
         assert.strictEqual(response.status, 202, 'HTTP 202 status');
@@ -713,7 +714,7 @@ module(basename(import.meta.filename), function () {
         assert.true(
           publishedRealmConfig?.data?.attributes
             ?.includePrerenderedDefaultRealmIndex,
-          'published realm.json carries includePrerenderedDefaultRealmIndex: true for a Workspace index',
+          'published realm.json carries includePrerenderedDefaultRealmIndex: true for a CardsGrid index',
         );
       });
 
diff --git a/packages/realm-server/tests/realm-routing-test.ts b/packages/realm-server/tests/realm-routing-test.ts
index a4856d45ed7..00e440b4498 100644
--- a/packages/realm-server/tests/realm-routing-test.ts
+++ b/packages/realm-server/tests/realm-routing-test.ts
@@ -187,8 +187,9 @@ module(basename(import.meta.filename), function () {
     // realm. ensureMounted publishes the Realm into reconciler.mounted
     // synchronously and then awaits realm.start(). For a brand-new
     // realm, start() awaits the first full index, which prerenders
-    // index.json. The CardsGrid in index.json fires _federated-search
-    // against the new realm. If resolveRealmsForFederatedRequest were
+    // index.json. The Workspace index card in index.json fires
+    // _federated-search against the new realm. If
+    // resolveRealmsForFederatedRequest were
     // to re-enter lookupOrMount() for the same URL, it would find the
     // URL in pendingMounts and await the very start() it is nested
     // inside — deadlocking until the prerender's 90s render timeout
diff --git a/packages/software-factory/src/factory-entrypoint.ts b/packages/software-factory/src/factory-entrypoint.ts
index e93736d877b..3fc36e42a3a 100644
--- a/packages/software-factory/src/factory-entrypoint.ts
+++ b/packages/software-factory/src/factory-entrypoint.ts
@@ -377,9 +377,9 @@ export async function runFactoryEntrypoint(
   let pullTargetRealm = dependencies?.pullTargetRealm ?? defaultPullTargetRealm;
   await pullTargetRealm(client, targetRealm.url, workspaceDir);
 
-  // For a realm the factory just created, replace the default CardsGrid
-  // index page with a RealmDashboard instance so the realm opens to the
-  // factory dashboard. A pre-existing realm keeps its current index page.
+  // For a realm the factory just created, replace the default index page
+  // with a RealmDashboard instance so the realm opens to the factory
+  // dashboard. A pre-existing realm keeps its current index page.
   if (targetRealm.createdRealm) {
     let writeRealmIndex =
       dependencies?.writeRealmIndex ?? writeRealmDashboardCard;
diff --git a/packages/software-factory/src/factory-realm-index.ts b/packages/software-factory/src/factory-realm-index.ts
index 6e82bd5e2ca..6875259b63a 100644
--- a/packages/software-factory/src/factory-realm-index.ts
+++ b/packages/software-factory/src/factory-realm-index.ts
@@ -42,10 +42,10 @@ export function inferRealmDashboardModuleUrl(targetRealm: string): string {
 
 /**
  * Set the realm's index page to a `RealmDashboard` instance, overwriting
- * the default `CardsGrid` index that `create-realm` seeded.
+ * the default index that `create-realm` seeded.
  *
- * Writes two files: a sibling `cards-grid.json` holding the `CardsGrid`
- * instance (the same empty grid `create-realm` would have made), and
+ * Writes two files: a sibling `cards-grid.json` holding a `CardsGrid`
+ * instance (an empty grid), and
  * `index.json` adopting `RealmDashboard` with its `cardsGrid` link
  * pointing at that instance — so the dashboard's catalog tab shows the
  * realm's cards. The `board` link is left for the bootstrap agent to wire