diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 646e0461..272e3f31 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -20,7 +20,7 @@ jobs:
         python-version: [3.9]
         node-version: [18.x]
         tests:
-          - ':lint:python:client:common:smoke:'
+          - ':lint:python:client:common:smoke:stubs:'
           - ':server-1-of-2:'
           - ':server-2-of-2:'
           - ':nbrowser-^[A-G]:'
@@ -73,7 +73,7 @@ jobs:
         run: yarn run build:prod
 
       - name: Install chromedriver
-        if: contains(matrix.tests, ':nbrowser-') || contains(matrix.tests, ':smoke:')
+        if: contains(matrix.tests, ':nbrowser-') || contains(matrix.tests, ':smoke:') || contains(matrix.tests, ':stubs:')
         run: ./node_modules/selenium-webdriver/bin/linux/selenium-manager --driver chromedriver
 
       - name: Run smoke test
@@ -92,6 +92,10 @@ jobs:
         if: contains(matrix.tests, ':common:')
         run: yarn run test:common
 
+      - name: Run stubs tests
+        if: contains(matrix.tests, ':stubs:')
+        run: MOCHA_WEBDRIVER_HEADLESS=1 yarn run test:stubs
+
       - name: Run server tests with minio and redis
         if: contains(matrix.tests, ':server-')
         run: |
diff --git a/app/client/ui/CreateTeamModal.ts b/app/client/ui/CreateTeamModal.ts
new file mode 100644
index 00000000..91ce263c
--- /dev/null
+++ b/app/client/ui/CreateTeamModal.ts
@@ -0,0 +1,362 @@
+import {autoFocus} from 'app/client/lib/domUtils';
+import {ValidationGroup, Validator} from 'app/client/lib/Validator';
+import {AppModel, getHomeUrl} from 'app/client/models/AppModel';
+import {reportError, UserError} from 'app/client/models/errors';
+import {urlState} from 'app/client/models/gristUrlState';
+import {bigBasicButton, bigPrimaryButton, bigPrimaryButtonLink} from 'app/client/ui2018/buttons';
+import {mediaSmall, theme, vars} from 'app/client/ui2018/cssVars';
+import {icon} from 'app/client/ui2018/icons';
+import {IModalControl, modal} from 'app/client/ui2018/modals';
+import {TEAM_PLAN} from 'app/common/Features';
+import {checkSubdomainValidity} from 'app/common/orgNameUtils';
+import {UserAPIImpl} from 'app/common/UserAPI';
+import {
+  Disposable, dom, DomArg, DomContents, DomElementArg, IDisposableOwner, input, makeTestId,
+  Observable, styled
+} from 'grainjs';
+import { makeT } from '../lib/localization';
+
+const t = makeT('CreateTeamModal');
+const testId = makeTestId('test-create-team-');
+
+export function buildNewSiteModal(context: Disposable, options: {
+  planName: string,
+  selectedPlan?: string,
+  onCreate?: () => void
+}) {
+  const { onCreate } = options;
+
+  return showModal(
+    context,
+    (_owner: Disposable, ctrl: IModalControl) => dom.create(NewSiteModalContent, ctrl, onCreate),
+    dom.cls(cssModalIndex.className),
+  );
+}
+
+class NewSiteModalContent extends Disposable {
+  private _page = Observable.create(this, 'createTeam');
+  private _team = Observable.create(this, '');
+  private _domain = Observable.create(this, '');
+  private _ctrl: IModalControl;
+
+  constructor(
+    ctrl: IModalControl,
+    private _onCreate?: (planName: string) => void) {
+    super();
+    this._ctrl = ctrl;
+  }
+
+  public buildDom() {
+    const team = this._team;
+    const domain = this._domain;
+    const ctrl = this._ctrl;
+    return dom.domComputed(this._page, pageValue => {
+
+      switch (pageValue) {
+        case 'createTeam': return buildTeamPage({
+          team,
+          domain,
+          create: () => this._createTeam(),
+          ctrl
+        });
+        case 'teamSuccess': return buildConfirm({domain: domain.get()});
+      }
+    });
+  }
+
+  private async _createTeam() {
+    const api = new UserAPIImpl(getHomeUrl());
+    try {
+      await api.newOrg({name: this._team.get(), domain: this._domain.get()});
+      this._page.set('teamSuccess');
+      if (this._onCreate) {
+        this._onCreate(TEAM_PLAN);
+      }
+    } catch (err) {
+      reportError(err as Error);
+    }
+  }
+}
+
+export function buildUpgradeModal(owner: Disposable, planName: string): void {
+  throw new UserError(t(`Billing is not supported in grist-core`));
+}
+
+export interface UpgradeButton  {
+  showUpgradeCard(...args: DomArg<HTMLElement>[]): DomContents;
+  showUpgradeButton(...args: DomArg<HTMLElement>[]): DomContents;
+}
+
+export function buildUpgradeButton(owner: IDisposableOwner, app: AppModel): UpgradeButton {
+  return {
+    showUpgradeCard: () => null,
+    showUpgradeButton: () => null,
+  };
+}
+
+export function buildConfirm({
+  domain,
+}: {
+  domain: string;
+}) {
+  return cssConfirmWrapper(
+    cssSparks(),
+    hspace('1.5em'),
+    cssHeaderLine(t('Team site created'), testId("confirmation")),
+    hspace('2em'),
+    bigPrimaryButtonLink(
+      urlState().setLinkUrl({org: domain || undefined}), t('Go to your site'), testId("confirmation-link")
+    )
+  );
+}
+
+function buildTeamPage({
+  team,
+  domain,
+  create,
+  ctrl
+}: {
+  team: Observable<string>;
+  domain: Observable<string>;
+  create: () => any;
+  ctrl: IModalControl;
+}) {
+  const disabled = Observable.create(null, false);
+  const group = new ValidationGroup();
+  async function click() {
+    disabled.set(true);
+    try {
+      if (!await group.validate()) {
+        return;
+      }
+      await create();
+    } finally {
+      disabled.set(false);
+    }
+  }
+  const clickOnEnter = dom.onKeyPress({
+    Enter: () => click(),
+  });
+  return cssWide(
+    dom.autoDispose(disabled),
+    cssHeaderLine(t("Work as a Team"), testId("creation-title")),
+    cssSubHeaderLine(t("Choose a name and url for your team site")),
+    hspace('1.5em'),
+    cssColumns(
+      cssSetup(
+        cssLabel(t('Team name')),
+        cssRow(cssField(cssInput(
+          team,
+          {onInput: true},
+          autoFocus(),
+          group.inputReset(),
+          clickOnEnter,
+          testId('name')))),
+        dom.create(Validator, group, t("Team name is required"), () => !!team.get()),
+        hspace('2em'),
+        cssLabel(t('Team url')),
+        cssRow(
+          {style: 'align-items: baseline'},
+          cssField(
+            {style: 'flex: 0 1 0; min-width: auto; margin-right: 5px'},
+            dom.text(`${window.location.origin}/o/`)),
+          cssField(cssInput(
+            domain, {onInput: true}, clickOnEnter, group.inputReset(), testId('domain')
+          )),
+        ),
+        dom.create(Validator, group, t("Domain name is required"), () => !!domain.get()),
+        dom.create(Validator, group, t("Domain name is invalid"), () => checkSubdomainValidity(domain.get())),
+        cssButtonsRow(
+          bigBasicButton(
+            t('Cancel'),
+            dom.on('click', () => ctrl.close()),
+            testId('cancel')),
+          bigPrimaryButton(t("Create site"),
+            dom.on('click', click),
+            dom.prop('disabled', disabled),
+            testId('confirm')
+          ),
+        )
+      )
+    )
+  );
+}
+
+function showModal(
+  context: Disposable,
+  content: (owner: Disposable, ctrl: IModalControl) => DomContents,
+  ...args: DomElementArg[]
+) {
+  let control!: IModalControl;
+  modal((ctrl, modalScope) => {
+    control = ctrl;
+    // When parent is being disposed and we are still visible, close the modal.
+    context.onDispose(() => {
+      // If the modal is already closed (disposed, do nothing)
+      if (modalScope.isDisposed()) {
+        return;
+      }
+      // If not, and parent is going away, close the modal.
+      ctrl.close();
+    });
+    return [
+      cssCreateTeamModal.cls(''),
+      cssCloseButton(testId("close-modal"), cssBigIcon('CrossBig'), dom.on('click', () => ctrl.close())),
+      content(modalScope, ctrl)
+    ];
+  }, {backerDomArgs: args});
+  return control;
+}
+
+function hspace(height: string) {
+  return dom('div', {style: `height: ${height}`});
+}
+
+export const cssCreateTeamModal = styled('div', `
+  position: relative;
+  @media ${mediaSmall} {
+    & {
+      width: 100%;
+      min-width: unset;
+      padding: 24px 16px;
+    }
+  }
+`);
+
+const cssConfirmWrapper = styled('div', `
+  text-align: center;
+`);
+
+const cssSparks = styled('div', `
+  height: 48px;
+  width: 48px;
+  background-image: var(--icon-Sparks);
+  display: inline-block;
+  background-repeat: no-repeat;
+  &-small {
+    height: 20px;
+    width: 20px;
+    background-size: cover;
+  }
+`);
+
+const cssColumns = styled('div', `
+  display: flex;
+  gap: 60px;
+  flex-wrap: wrap;
+`);
+
+const cssSetup = styled('div', `
+  display: flex;
+  flex-direction: column;
+  flex-grow: 1;
+`);
+
+const cssHeaderLine = styled('div', `
+  text-align: center;
+  font-size: 24px;
+  font-weight: 600;
+  margin-bottom: 16px;
+`);
+
+const cssSubHeaderLine = styled('div', `
+  text-align: center;
+  margin-bottom: 7px;
+`);
+
+const cssLabel = styled('label', `
+  font-weight: ${vars.headerControlTextWeight};
+  font-size: ${vars.mediumFontSize};
+  color: ${theme.text};
+  line-height: 1.5em;
+  margin: 0px;
+  margin-bottom: 0.3em;
+`);
+
+
+const cssWide = styled('div', `
+  min-width: 760px;
+  @media ${mediaSmall} {
+    & {
+      min-width: unset;
+    }
+  }
+`);
+
+const cssRow = styled('div', `
+  display: flex;
+`);
+
+const cssField = styled('div', `
+  display: block;
+  flex: 1 1 0;
+  margin: 4px 0;
+  min-width: 120px;
+`);
+
+
+const cssButtonsRow = styled('div', `
+  display: flex;
+  justify-content: flex-end;
+  margin-top: 20px;
+  min-width: 250px;
+  gap: 10px;
+  flex-wrap: wrap;
+  @media ${mediaSmall} {
+    & {
+      margin-top: 60px;
+    }
+  }
+`);
+
+const cssCloseButton = styled('div', `
+  position: absolute;
+  top: 8px;
+  right: 8px;
+  padding: 4px;
+  border-radius: 4px;
+  cursor: pointer;
+  --icon-color: ${theme.modalCloseButtonFg};
+
+  &:hover {
+    background-color: ${theme.hover};
+  }
+`);
+
+const cssBigIcon = styled(icon, `
+  padding: 12px;
+`);
+
+const cssModalIndex = styled('div', `
+  z-index: ${vars.pricingModalZIndex}
+`);
+
+const cssInput = styled(input, `
+  color: ${theme.inputFg};
+  background-color: ${theme.inputBg};
+  font-size: ${vars.mediumFontSize};
+  height: 42px;
+  line-height: 16px;
+  width: 100%;
+  padding: 13px;
+  border: 1px solid ${theme.inputBorder};
+  border-radius: 3px;
+  outline: none;
+
+  &-invalid {
+    color: ${theme.inputInvalid};
+  }
+
+  &[type=number] {
+    -moz-appearance: textfield;
+  }
+  &[type=number]::-webkit-inner-spin-button,
+  &[type=number]::-webkit-outer-spin-button {
+    -webkit-appearance: none;
+    margin: 0;
+  }
+
+  &::placeholder {
+    color: ${theme.inputPlaceholderFg};
+  }
+`);
diff --git a/app/client/ui/HomeIntro.ts b/app/client/ui/HomeIntro.ts
index debe362f..9c2fc296 100644
--- a/app/client/ui/HomeIntro.ts
+++ b/app/client/ui/HomeIntro.ts
@@ -93,7 +93,10 @@ function makeTeamSiteIntro(homeModel: HomeModel) {
     cssIntroLine(t("Get started by inviting your team and creating your first Grist document.")),
     (!isFeatureEnabled('helpCenter') ? null :
       cssIntroLine(
-        'Learn more in our ', helpCenterLink(), ', or find an expert via our ', sproutsProgram, '.',  // TODO i18n
+        t(
+          'Learn more in our {{helpCenterLink}}, or find an expert via our {{sproutsProgram}}.',
+          {helpCenterLink: helpCenterLink(), sproutsProgram}
+        ),
         testId('welcome-text')
       )
     ),
diff --git a/app/client/ui/ProductUpgradesStub.ts b/app/client/ui/ProductUpgradesStub.ts
deleted file mode 100644
index 1e054f68..00000000
--- a/app/client/ui/ProductUpgradesStub.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import type {AppModel} from 'app/client/models/AppModel';
-import {commonUrls} from 'app/common/gristUrls';
-import {Disposable, DomArg, DomContents, IDisposableOwner} from 'grainjs';
-
-export function buildNewSiteModal(context: Disposable, options: {
-  planName: string,
-  selectedPlan?: string,
-  onCreate?: () => void
-}) {
-  window.location.href = commonUrls.plans;
-}
-
-export function buildUpgradeModal(owner: Disposable, planName: string)  {
-  window.location.href = commonUrls.plans;
-}
-
-export function showTeamUpgradeConfirmation(owner: Disposable) {
-}
-
-export interface UpgradeButton  {
-  showUpgradeCard(...args: DomArg<HTMLElement>[]): DomContents;
-  showUpgradeButton(...args: DomArg<HTMLElement>[]): DomContents;
-}
-
-export function buildUpgradeButton(owner: IDisposableOwner, app: AppModel): UpgradeButton {
-  return {
-    showUpgradeCard : () => null,
-    showUpgradeButton : () => null,
-  };
-}
diff --git a/app/client/ui/SupportGristNudge.ts b/app/client/ui/SupportGristNudge.ts
index ae13a0b5..e35d16cf 100644
--- a/app/client/ui/SupportGristNudge.ts
+++ b/app/client/ui/SupportGristNudge.ts
@@ -149,8 +149,8 @@ export class SupportGristNudge extends Disposable {
       cssCenterAlignedHeader(t('Opted In')),
       cssParagraph(
         t(
-          'Thank you! Your trust and support is greatly appreciated. ' +
-          'Opt out any time from the {{link}} in the user menu.',
+          'Thank you! Your trust and support is greatly appreciated.\
+ Opt out any time from the {{link}} in the user menu.',
           {link: adminPanelLink()},
         ),
       ),
diff --git a/package.json b/package.json
index 3abcaac7..371f14a8 100644
--- a/package.json
+++ b/package.json
@@ -13,8 +13,9 @@
     "install:python3": "buildtools/prepare_python3.sh",
     "build:prod": "buildtools/build.sh",
     "start:prod": "sandbox/run.sh",
-    "test": "GRIST_SESSION_COOKIE=grist_test_cookie GRIST_TEST_LOGIN=1 TEST_SUPPORT_API_KEY=api_key_for_support TEST_CLEAN_DATABASE=true LANGUAGE=en_US mocha ${DEBUG:+-b --no-exit} --slow 8000 $([ -z $DEBUG ] && echo --forbid-only) -g \"${GREP_TESTS}\" '_build/test/common/*.js' '_build/test/client/*.js' '_build/test/nbrowser/*.js' '_build/test/server/**/*.js' '_build/test/gen-server/**/*.js'",
+    "test": "GRIST_SESSION_COOKIE=grist_test_cookie GRIST_TEST_LOGIN=1 TEST_SUPPORT_API_KEY=api_key_for_support TEST_CLEAN_DATABASE=true LANGUAGE=en_US mocha ${DEBUG:+-b --no-exit} --slow 8000 $([ -z $DEBUG ] && echo --forbid-only) -g \"${GREP_TESTS}\" '_build/test/common/*.js' '_build/test/client/*.js' '_build/test/nbrowser/*.js' '_build/test/nbrowser_with_stubs/**/*.js' '_build/test/server/**/*.js' '_build/test/gen-server/**/*.js'",
     "test:nbrowser": "TEST_SUITE=nbrowser TEST_SUITE_FOR_TIMINGS=nbrowser TIMINGS_FILE=test/timings/nbrowser.txt GRIST_SESSION_COOKIE=grist_test_cookie GRIST_TEST_LOGIN=1 TEST_SUPPORT_API_KEY=api_key_for_support TEST_CLEAN_DATABASE=true LANGUAGE=en_US mocha ${DEBUG:+-b --no-exit} $([ -z $DEBUG ] && echo --forbid-only) -g \"${GREP_TESTS}\" --slow 8000 -R test/xunit-file '_build/test/nbrowser/**/*.js'",
+    "test:stubs": "GRIST_SESSION_COOKIE=grist_test_cookie GRIST_TEST_LOGIN=1 TEST_SUPPORT_API_KEY=api_key_for_support TEST_CLEAN_DATABASE=true LANGUAGE=en_US mocha ${DEBUG:+-b --no-exit} $([ -z $DEBUG ] && echo --forbid-only) -g \"${GREP_TESTS}\" --slow 8000 -R test/xunit-file '_build/test/nbrowser_with_stubs/**/*.js'",
     "test:client": "GRIST_SESSION_COOKIE=grist_test_cookie mocha ${DEBUG:+'-b'} '_build/test/client/**/*.js'",
     "test:common": "GRIST_SESSION_COOKIE=grist_test_cookie mocha ${DEBUG:+'-b'} '_build/test/common/**/*.js'",
     "test:server": "TEST_CLEAN_DATABASE=true TEST_SUITE=server TEST_SUITE_FOR_TIMINGS=server TIMINGS_FILE=test/timings/server.txt GRIST_SESSION_COOKIE=grist_test_cookie mocha ${DEBUG:+'-b'} -g \"${GREP_TESTS}\" -R test/xunit-file '_build/test/server/**/*.js' '_build/test/gen-server/**/*.js'",
diff --git a/static/locales/en.client.json b/static/locales/en.client.json
index 3376786e..e3570a0d 100644
--- a/static/locales/en.client.json
+++ b/static/locales/en.client.json
@@ -481,7 +481,8 @@
         "Welcome to {{- orgName}}": "Welcome to {{- orgName}}",
         "Sign in": "Sign in",
         "To use Grist, please either sign up or sign in.": "To use Grist, please either sign up or sign in.",
-        "Visit our {{link}} to learn more about Grist.": "Visit our {{link}} to learn more about Grist."
+        "Visit our {{link}} to learn more about Grist.": "Visit our {{link}} to learn more about Grist.",
+        "Learn more in our {{helpCenterLink}}, or find an expert via our {{sproutsProgram}}.": "Learn more in our {{helpCenterLink}}, or find an expert via our {{sproutsProgram}}."
     },
     "HomeLeftPane": {
         "Access Details": "Access Details",
@@ -1294,6 +1295,7 @@
         "Opted In": "Opted In",
         "Support Grist": "Support Grist",
         "Support Grist page": "Support Grist page",
+        "Thank you! Your trust and support is greatly appreciated. Opt out any time from the {{link}} in the user menu.": "Thank you! Your trust and support is greatly appreciated. Opt out any time from the {{link}} in the user menu.",
         "Admin Panel": "Admin Panel"
     },
     "SupportGristPage": {
@@ -1439,6 +1441,20 @@
         "Insert section above": "Insert section above",
         "Insert section below": "Insert section below"
     },
+    "CreateTeamModal": {
+        "Cancel": "Cancel",
+        "Choose a name and url for your team site": "Choose a name and url for your team site",
+        "Create site": "Create site",
+        "Domain name is invalid": "Domain name is invalid",
+        "Domain name is required": "Domain name is required",
+        "Go to your site": "Go to your site",
+        "Team name": "Team name",
+        "Team name is required": "Team name is required",
+        "Team site created": "Team site created",
+        "Team url": "Team url",
+        "Work as a Team": "Work as a Team",
+        "Billing is not supported in grist-core": "Billing is not supported in grist-core"
+    },
     "AdminPanel": {
         "Admin Panel": "Admin Panel",
         "Current": "Current",
diff --git a/stubs/app/client/ui/ProductUpgrades.ts b/stubs/app/client/ui/ProductUpgrades.ts
index 2c583135..839a91d7 100644
--- a/stubs/app/client/ui/ProductUpgrades.ts
+++ b/stubs/app/client/ui/ProductUpgrades.ts
@@ -1 +1 @@
-export * from 'app/client/ui/ProductUpgradesStub';
+export * from 'app/client/ui/CreateTeamModal';
diff --git a/test/nbrowser_with_stubs/CreateTeamSite.ts b/test/nbrowser_with_stubs/CreateTeamSite.ts
new file mode 100644
index 00000000..5c5bdfda
--- /dev/null
+++ b/test/nbrowser_with_stubs/CreateTeamSite.ts
@@ -0,0 +1,62 @@
+import { assert, driver, Key } from 'mocha-webdriver';
+import * as gu from 'test/nbrowser/gristUtils';
+import { cleanupExtraWindows, setupTestSuite } from 'test/nbrowser/testUtils';
+
+describe('Create Team Site', function () {
+  this.timeout(20000);
+  cleanupExtraWindows();
+  const cleanup = setupTestSuite();
+
+  before(async function () {
+    const session = await gu.session().teamSite.login();
+    await session.tempNewDoc(cleanup);
+  });
+
+  async function openCreateTeamModal() {
+    await driver.findWait('.test-dm-org', 500).click();
+    assert.equal(await driver.find('.test-site-switcher-create-new-site').isPresent(), true);
+    await driver.find('.test-site-switcher-create-new-site').click();
+  }
+
+  async function fillCreateTeamModalInputs(name: string, domain: string) {
+    await driver.findWait('.test-create-team-name', 500).click();
+    await gu.sendKeys(name);
+    await gu.sendKeys(Key.TAB);
+    await gu.sendKeys(domain);
+  }
+
+  async function goToNewTeamSite() {
+    await driver.findWait('.test-create-team-confirmation-link', 500).click();
+  }
+
+  async function getTeamSiteName() {
+    return await driver.findWait('.test-dm-orgname', 500).getText();
+  }
+
+  it('should work using the createTeamModal', async () => {
+    assert.equal(await driver.find('.test-dm-org').isPresent(), true);
+    const teamSiteName = await getTeamSiteName();
+    assert.equal(teamSiteName, 'Test Grist');
+    await openCreateTeamModal();
+    assert.equal(await driver.find('.test-create-team-creation-title').isPresent(), true);
+
+    await fillCreateTeamModalInputs("Test Create Team Site", "testteamsite");
+    await gu.sendKeys(Key.ENTER);
+    assert.equal(await driver.findWait('.test-create-team-confirmation', 500).isPresent(), true);
+    await goToNewTeamSite();
+    const newTeamSiteName = await getTeamSiteName();
+    assert.equal(newTeamSiteName, 'Test Create Team Site');
+  });
+
+  it('should work only with unique domain', async () => {
+    await openCreateTeamModal();
+    await fillCreateTeamModalInputs("Test Create Team Site 1", "same-domain");
+    await gu.sendKeys(Key.ENTER);
+    await goToNewTeamSite();
+    await openCreateTeamModal();
+    await fillCreateTeamModalInputs("Test Create Team Site 2", "same-domain");
+    await gu.sendKeys(Key.ENTER);
+    const errorMessage = await driver.findWait('.test-notifier-toast-wrapper ', 500).getText();
+    assert.include(errorMessage, 'Domain already in use');
+  });
+});