diff --git a/curriculum/package.json b/curriculum/package.json
index a0e4ff08295..10b24cdb6a9 100644
--- a/curriculum/package.json
+++ b/curriculum/package.json
@@ -49,6 +49,7 @@
     "@types/js-yaml": "4.0.5",
     "@types/polka": "^0.5.7",
     "@types/string-similarity": "^4.0.2",
+    "@typescript/vfs-1.6.1": "npm:@typescript/vfs@1.6.1",
     "@vitest/ui": "^3.2.4",
     "eslint": "^9.39.1",
     "glob": "8.1.0",
@@ -64,6 +65,7 @@
     "puppeteer": "22.12.1",
     "sirv": "^3.0.2",
     "string-similarity": "4.0.4",
+    "typescript-5.9.2": "npm:typescript@5.9.2",
     "vitest": "^3.2.4"
   }
 }
diff --git a/curriculum/src/test/test-challenges.js b/curriculum/src/test/test-challenges.js
index 1b3d908a15b..1ef99d777f1 100644
--- a/curriculum/src/test/test-challenges.js
+++ b/curriculum/src/test/test-challenges.js
@@ -1,11 +1,8 @@
-import { describe, it, beforeAll, expect } from 'vitest';
+import { describe, it, beforeAll, expect, vi } from 'vitest';
+
 import jsdom from 'jsdom';
 import lodash from 'lodash';
 
-import {
-  buildChallenge,
-  runnerTypes
-} from '../../../client/src/templates/Challenges/utils/build';
 import {
   challengeTypes,
   hasNoSolution
@@ -28,6 +25,32 @@ import { sortChallenges } from './utils/sort-challenges.js';
 
 const { flatten, isEmpty, cloneDeep } = lodash;
 
+vi.mock(
+  '../../../client/src/templates/Challenges/utils/typescript-worker-handler',
+  async importOriginal => {
+    const actual = await importOriginal();
+
+    // ts and tsvfs must match the versions used in the typescript-worker.
+    const tsvfs = await import('@typescript/vfs-1.6.1');
+    const ts = await import('typescript-5.9.2');
+    // use the same TS compiler as the client
+    const tsCompiler = await import(
+      '../../../tools/client-plugins/browser-scripts/modules/typescript-compiler'
+    );
+    const compiler = new tsCompiler.Compiler(ts, tsvfs);
+    await compiler.setup({ useNodeModules: true });
+    return {
+      ...actual,
+      checkTSServiceIsReady: () => Promise.resolve(true),
+      compileTypeScriptCode: code => {
+        const { result, error } = compiler.compile(code, 'index.tsx');
+        if (error) throw error;
+        return result;
+      }
+    };
+  }
+);
+
 const dom = new jsdom.JSDOM('');
 global.document = dom.window.document;
 global.DOMParser = dom.window.DOMParser;
@@ -86,13 +109,13 @@ export async function defineTestsForBlock(testFilter) {
 
   const challengeData = { meta, challenges, lang };
 
-  describe('Check challenges', () => {
+  describe('Check challenges', async () => {
     beforeAll(async () => {
       page = await newPageContext();
       global.Worker = createPseudoWorker(page);
     });
 
-    populateTestsForLang(challengeData, () => page);
+    await populateTestsForLang(challengeData, () => page);
   });
 }
 
@@ -123,7 +146,13 @@ export async function getChallenges(lang, filters) {
   return sortChallenges(challenges);
 }
 
-function populateTestsForLang({ lang, challenges, meta }) {
+async function populateTestsForLang({ lang, challenges, meta }) {
+  // We have to dynamically import this because otherwise it will not be mocked.
+  // Presumably this is because we import from_this file in the generated block
+  // test files and that happens before the mock is applied.
+  const { buildChallenge } = await import(
+    '../../../client/src/templates/Challenges/utils/build'
+  );
   const validateChallenge = challengeSchemaValidator();
 
   describe(`Language: ${lang}`, function () {
@@ -341,6 +370,10 @@ async function createTestRunner(
   buildChallenge,
   solutionFromNext
 ) {
+  const { runnerTypes } = await import(
+    '../../../client/src/templates/Challenges/utils/build'
+  );
+
   const challengeFiles = replaceChallengeFilesContentsWithSolutions(
     challenge.challengeFiles,
     solutionFiles
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 4129a8ba248..cf673e56729 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -121,7 +121,7 @@ importers:
         version: 1.3.1
       '@prisma/client':
         specifier: 6.16.2
-        version: 6.16.2(prisma@6.16.2(typescript@5.8.2))(typescript@5.8.2)
+        version: 6.16.2(prisma@6.16.2(typescript@5.9.3))(typescript@5.9.3)
       '@sentry/node':
         specifier: 9.1.0
         version: 9.1.0
@@ -230,10 +230,10 @@ importers:
         version: 26.1.0
       msw:
         specifier: ^2.7.0
-        version: 2.8.7(@types/node@20.12.8)(typescript@5.8.2)
+        version: 2.8.7(@types/node@20.12.8)(typescript@5.9.3)
       prisma:
         specifier: 6.16.2
-        version: 6.16.2(typescript@5.8.2)
+        version: 6.16.2(typescript@5.9.3)
       supertest:
         specifier: 6.3.3
         version: 6.3.3
@@ -242,7 +242,7 @@ importers:
         version: 4.19.1
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   client:
     dependencies:
@@ -703,6 +703,9 @@ importers:
       '@types/string-similarity':
         specifier: ^4.0.2
         version: 4.0.2
+      '@typescript/vfs-1.6.1':
+        specifier: npm:@typescript/vfs@1.6.1
+        version: '@typescript/vfs@1.6.1(typescript@5.9.3)'
       '@vitest/ui':
         specifier: ^3.2.4
         version: 3.2.4(vitest@3.2.4)
@@ -741,16 +744,19 @@ importers:
         version: 0.5.2
       puppeteer:
         specifier: 22.12.1
-        version: 22.12.1(typescript@5.8.2)
+        version: 22.12.1(typescript@5.9.3)
       sirv:
         specifier: ^3.0.2
         version: 3.0.2
       string-similarity:
         specifier: 4.0.4
         version: 4.0.4
+      typescript-5.9.2:
+        specifier: npm:typescript@5.9.2
+        version: typescript@5.9.2
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   e2e:
     devDependencies:
@@ -834,7 +840,7 @@ importers:
         version: 9.39.1(jiti@2.6.1)
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   tools/challenge-editor/api:
     dependencies:
@@ -1062,13 +1068,13 @@ importers:
         version: 3.0.4
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   tools/client-plugins/browser-scripts:
     dependencies:
       '@freecodecamp/curriculum-helpers':
         specifier: ^7.1.0
-        version: 7.1.0(debug@4.3.4)(typescript@5.7.3)
+        version: 7.1.0(debug@4.3.4)(typescript@5.9.2)
       xterm:
         specifier: ^5.2.1
         version: 5.3.0
@@ -1092,8 +1098,8 @@ importers:
         specifier: ^8.0.1
         version: 8.0.1(webpack-cli@4.10.0)
       '@typescript/vfs':
-        specifier: ^1.6.0
-        version: 1.6.1(typescript@5.7.3)
+        specifier: 1.6.1
+        version: 1.6.1(typescript@5.9.2)
       babel-loader:
         specifier: 8.3.0
         version: 8.3.0(@babel/core@7.28.5)(webpack@5.90.3)
@@ -1112,6 +1118,9 @@ importers:
       sass.js:
         specifier: 0.11.1
         version: 0.11.1
+      typescript:
+        specifier: 5.9.2
+        version: 5.9.2
       util:
         specifier: 0.12.5
         version: 0.12.5
@@ -1177,7 +1186,7 @@ importers:
         version: 9.39.1(jiti@2.6.1)
       vitest:
         specifier: ^3.2.4
-        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+        version: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   tools/scripts/seed:
     devDependencies:
@@ -13091,6 +13100,16 @@ packages:
     engines: {node: '>=14.17'}
     hasBin: true
 
+  typescript@5.9.2:
+    resolution: {integrity: sha512-CWBzXQrc/qOkhidw1OzBTQuYRbfyxDXJMVJ1XNwUHGROVmuaeiEm3OslpZ1RV96d7SKKjZKrSJu3+t/xlw3R9A==}
+    engines: {node: '>=14.17'}
+    hasBin: true
+
+  typescript@5.9.3:
+    resolution: {integrity: sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==}
+    engines: {node: '>=14.17'}
+    hasBin: true
+
   uc.micro@2.0.0:
     resolution: {integrity: sha512-DffL94LsNOccVn4hyfRe5rdKa273swqeA5DJpMOeFmEn1wCDc7nAbbB0gXlgBCL7TNzeTv6G7XVWzan7iJtfig==}
 
@@ -17098,7 +17117,7 @@ snapshots:
       prop-types: 15.8.1
       react: 17.0.2
 
-  '@freecodecamp/curriculum-helpers@7.1.0(debug@4.3.4)(typescript@5.7.3)':
+  '@freecodecamp/curriculum-helpers@7.1.0(debug@4.3.4)(typescript@5.9.2)':
     dependencies:
       '@sinonjs/fake-timers': 14.0.0
       '@types/jquery': 3.5.32
@@ -17111,10 +17130,10 @@ snapshots:
       http-server: 14.1.1(debug@4.3.4)
       jquery: 3.7.1
       process: 0.11.10
-      puppeteer: 24.10.0(typescript@5.7.3)
+      puppeteer: 24.10.0(typescript@5.9.2)
       pyodide: 0.23.3
       util: 0.12.5
-      vitest-environment-puppeteer: 11.0.3(debug@4.3.4)(typescript@5.7.3)
+      vitest-environment-puppeteer: 11.0.3(debug@4.3.4)(typescript@5.9.2)
     transitivePeerDependencies:
       - bare-buffer
       - bufferutil
@@ -17902,10 +17921,10 @@ snapshots:
 
   '@polka/url@1.0.0-next.29': {}
 
-  '@prisma/client@6.16.2(prisma@6.16.2(typescript@5.8.2))(typescript@5.8.2)':
+  '@prisma/client@6.16.2(prisma@6.16.2(typescript@5.9.3))(typescript@5.9.3)':
     optionalDependencies:
-      prisma: 6.16.2(typescript@5.8.2)
-      typescript: 5.8.2
+      prisma: 6.16.2(typescript@5.9.3)
+      typescript: 5.9.3
 
   '@prisma/config@6.16.2':
     dependencies:
@@ -19609,10 +19628,17 @@ snapshots:
       '@typescript-eslint/types': 8.47.0
       eslint-visitor-keys: 4.2.1
 
-  '@typescript/vfs@1.6.1(typescript@5.7.3)':
+  '@typescript/vfs@1.6.1(typescript@5.9.2)':
     dependencies:
       debug: 4.3.4(supports-color@8.1.1)
-      typescript: 5.7.3
+      typescript: 5.9.2
+    transitivePeerDependencies:
+      - supports-color
+
+  '@typescript/vfs@1.6.1(typescript@5.9.3)':
+    dependencies:
+      debug: 4.3.4(supports-color@8.1.1)
+      typescript: 5.9.3
     transitivePeerDependencies:
       - supports-color
 
@@ -19728,13 +19754,13 @@ snapshots:
       msw: 2.8.7(@types/node@20.12.8)(typescript@5.7.3)
       vite: 7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
-  '@vitest/mocker@3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))':
+  '@vitest/mocker@3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))':
     dependencies:
       '@vitest/spy': 3.2.4
       estree-walker: 3.0.3
       magic-string: 0.30.17
     optionalDependencies:
-      msw: 2.8.7(@types/node@20.12.8)(typescript@5.8.2)
+      msw: 2.8.7(@types/node@20.12.8)(typescript@5.9.3)
       vite: 7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   '@vitest/pretty-format@3.2.4':
@@ -19766,7 +19792,7 @@ snapshots:
       sirv: 3.0.2
       tinyglobby: 0.2.14
       tinyrainbow: 2.0.0
-      vitest: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.7.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
+      vitest: 3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1)
 
   '@vitest/utils@3.2.4':
     dependencies:
@@ -21380,14 +21406,23 @@ snapshots:
     optionalDependencies:
       typescript: 5.7.3
 
-  cosmiconfig@9.0.0(typescript@5.8.2):
+  cosmiconfig@9.0.0(typescript@5.9.2):
     dependencies:
       env-paths: 2.2.1
       import-fresh: 3.3.0
       js-yaml: 4.1.0
       parse-json: 5.2.0
     optionalDependencies:
-      typescript: 5.8.2
+      typescript: 5.9.2
+
+  cosmiconfig@9.0.0(typescript@5.9.3):
+    dependencies:
+      env-paths: 2.2.1
+      import-fresh: 3.3.0
+      js-yaml: 4.1.0
+      parse-json: 5.2.0
+    optionalDependencies:
+      typescript: 5.9.3
 
   create-ecdh@4.0.4:
     dependencies:
@@ -22365,7 +22400,7 @@ snapshots:
       confusing-browser-globals: 1.0.11
       eslint: 7.32.0
       eslint-plugin-flowtype: 5.10.0(eslint@7.32.0)
-      eslint-plugin-import: 2.31.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1))
+      eslint-plugin-import: 2.31.0(@typescript-eslint/parser@4.33.0(eslint@9.39.1(jiti@2.6.1))(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-jsx-a11y: 6.10.2(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-react: 7.37.4(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-react-hooks: 4.6.0(eslint@9.39.1(jiti@2.6.1))
@@ -22395,7 +22430,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  eslint-module-utils@2.12.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint-import-resolver-node@0.3.9)(eslint@9.39.1(jiti@2.6.1)):
+  eslint-module-utils@2.12.0(@typescript-eslint/parser@4.33.0(eslint@9.39.1(jiti@2.6.1))(typescript@5.2.2))(eslint-import-resolver-node@0.3.9)(eslint@9.39.1(jiti@2.6.1)):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
@@ -22449,7 +22484,7 @@ snapshots:
       - typescript
       - utf-8-validate
 
-  eslint-plugin-import@2.31.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1)):
+  eslint-plugin-import@2.31.0(@typescript-eslint/parser@4.33.0(eslint@9.39.1(jiti@2.6.1))(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1)):
     dependencies:
       '@rtsao/scc': 1.1.0
       array-includes: 3.1.8
@@ -22460,7 +22495,7 @@ snapshots:
       doctrine: 2.1.0
       eslint: 9.39.1(jiti@2.6.1)
       eslint-import-resolver-node: 0.3.9
-      eslint-module-utils: 2.12.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint-import-resolver-node@0.3.9)(eslint@9.39.1(jiti@2.6.1))
+      eslint-module-utils: 2.12.0(@typescript-eslint/parser@4.33.0(eslint@9.39.1(jiti@2.6.1))(typescript@5.2.2))(eslint-import-resolver-node@0.3.9)(eslint@9.39.1(jiti@2.6.1))
       hasown: 2.0.2
       is-core-module: 2.16.1
       is-glob: 4.0.3
@@ -23683,7 +23718,7 @@ snapshots:
       eslint-config-react-app: 6.0.0(@typescript-eslint/eslint-plugin@4.33.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint@7.32.0)(typescript@5.2.2))(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(babel-eslint@10.1.0(eslint@9.39.1(jiti@2.6.1)))(eslint-plugin-flowtype@5.10.0(eslint@7.32.0))(eslint-plugin-import@2.31.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint@7.32.0))(eslint-plugin-jsx-a11y@6.10.2(eslint@7.32.0))(eslint-plugin-react-hooks@4.6.0(eslint@7.32.0))(eslint-plugin-react@7.37.4(eslint@7.32.0))(eslint@7.32.0)(typescript@5.2.2)
       eslint-plugin-flowtype: 5.10.0(eslint@7.32.0)
       eslint-plugin-graphql: 4.0.0(@types/node@20.12.8)(graphql@15.8.0)(typescript@5.2.2)
-      eslint-plugin-import: 2.31.0(@typescript-eslint/parser@4.33.0(eslint@7.32.0)(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1))
+      eslint-plugin-import: 2.31.0(@typescript-eslint/parser@4.33.0(eslint@9.39.1(jiti@2.6.1))(typescript@5.2.2))(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-jsx-a11y: 6.10.2(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-react: 7.37.4(eslint@9.39.1(jiti@2.6.1))
       eslint-plugin-react-hooks: 4.6.0(eslint@9.39.1(jiti@2.6.1))
@@ -26479,7 +26514,7 @@ snapshots:
       - '@types/node'
     optional: true
 
-  msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2):
+  msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3):
     dependencies:
       '@bundled-es-modules/cookie': 2.0.1
       '@bundled-es-modules/statuses': 1.0.1
@@ -26500,7 +26535,7 @@ snapshots:
       type-fest: 4.37.0
       yargs: 17.7.2
     optionalDependencies:
-      typescript: 5.8.2
+      typescript: 5.9.3
     transitivePeerDependencies:
       - '@types/node'
 
@@ -27449,12 +27484,12 @@ snapshots:
       ansi-styles: 5.2.0
       react-is: 18.2.0
 
-  prisma@6.16.2(typescript@5.8.2):
+  prisma@6.16.2(typescript@5.9.3):
     dependencies:
       '@prisma/config': 6.16.2
       '@prisma/engines': 6.16.2
     optionalDependencies:
-      typescript: 5.8.2
+      typescript: 5.9.3
     transitivePeerDependencies:
       - magicast
 
@@ -27592,10 +27627,10 @@ snapshots:
       - supports-color
       - utf-8-validate
 
-  puppeteer@22.12.1(typescript@5.8.2):
+  puppeteer@22.12.1(typescript@5.9.3):
     dependencies:
       '@puppeteer/browsers': 2.2.3
-      cosmiconfig: 9.0.0(typescript@5.8.2)
+      cosmiconfig: 9.0.0(typescript@5.9.3)
       devtools-protocol: 0.0.1299070
       puppeteer-core: 22.12.1
     transitivePeerDependencies:
@@ -27605,11 +27640,11 @@ snapshots:
       - typescript
       - utf-8-validate
 
-  puppeteer@24.10.0(typescript@5.7.3):
+  puppeteer@24.10.0(typescript@5.9.2):
     dependencies:
       '@puppeteer/browsers': 2.10.5
       chromium-bidi: 5.1.0(devtools-protocol@0.0.1452169)
-      cosmiconfig: 9.0.0(typescript@5.7.3)
+      cosmiconfig: 9.0.0(typescript@5.9.2)
       devtools-protocol: 0.0.1452169
       puppeteer-core: 24.10.0
       typed-query-selector: 2.12.0
@@ -29806,6 +29841,10 @@ snapshots:
 
   typescript@5.8.2: {}
 
+  typescript@5.9.2: {}
+
+  typescript@5.9.3: {}
+
   uc.micro@2.0.0: {}
 
   umd@3.0.3: {}
@@ -30283,21 +30322,21 @@ snapshots:
     transitivePeerDependencies:
       - debug
 
-  vitest-environment-puppeteer@11.0.3(debug@4.3.4)(typescript@5.7.3):
+  vitest-environment-puppeteer@11.0.3(debug@4.3.4)(typescript@5.9.2):
     dependencies:
       chalk: 4.1.2
-      cosmiconfig: 9.0.0(typescript@5.7.3)
+      cosmiconfig: 9.0.0(typescript@5.9.2)
       deepmerge: 4.3.1
       vitest-dev-server: 11.0.3(debug@4.3.4)
     transitivePeerDependencies:
       - debug
       - typescript
 
-  vitest@3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1):
+  vitest@3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@16.7.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1):
     dependencies:
       '@types/chai': 5.2.2
       '@vitest/expect': 3.2.4
-      '@vitest/mocker': 3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))
+      '@vitest/mocker': 3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))
       '@vitest/pretty-format': 3.2.4
       '@vitest/runner': 3.2.4
       '@vitest/snapshot': 3.2.4
@@ -30425,11 +30464,11 @@ snapshots:
       - tsx
       - yaml
 
-  vitest@3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1):
+  vitest@3.2.4(@types/debug@4.1.12)(@types/node@20.12.8)(@vitest/ui@3.2.4)(jiti@2.6.1)(jsdom@26.1.0)(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1):
     dependencies:
       '@types/chai': 5.2.2
       '@vitest/expect': 3.2.4
-      '@vitest/mocker': 3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.8.2))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))
+      '@vitest/mocker': 3.2.4(msw@2.8.7(@types/node@20.12.8)(typescript@5.9.3))(vite@7.1.3(@types/node@20.12.8)(jiti@2.6.1)(terser@5.28.1)(tsx@4.19.1)(yaml@2.8.1))
       '@vitest/pretty-format': 3.2.4
       '@vitest/runner': 3.2.4
       '@vitest/snapshot': 3.2.4
diff --git a/tools/client-plugins/browser-scripts/modules/typescript-compiler.ts b/tools/client-plugins/browser-scripts/modules/typescript-compiler.ts
index ca46cf4cc91..801da2b003e 100644
--- a/tools/client-plugins/browser-scripts/modules/typescript-compiler.ts
+++ b/tools/client-plugins/browser-scripts/modules/typescript-compiler.ts
@@ -11,15 +11,12 @@ export class Compiler {
   tsvfs: TSVFS;
   tsEnv?: VirtualTypeScriptEnvironment;
   compilerHost?: CompilerHost;
-  constructor(
-    ts: typeof import('typescript'),
-    tsvfs: typeof import('@typescript/vfs')
-  ) {
+  constructor(ts: TS, tsvfs: TSVFS) {
     this.ts = ts;
     this.tsvfs = tsvfs;
   }
 
-  async setup() {
+  async setup(opts?: { useNodeModules: boolean }) {
     const ts = this.ts;
     const tsvfs = this.tsvfs;
 
@@ -33,17 +30,21 @@ export class Compiler {
       jsx: ts.JsxEmit.Preserve, // Babel will handle JSX,
       allowUmdGlobalAccess: true // Necessary because React is loaded via a UMD script.
     };
-    const fsMap = await tsvfs.createDefaultMapFromCDN(
-      compilerOptions,
-      ts.version,
-      false, // TODO: cache this. It needs a store that's available to workers and implements https://github.com/microsoft/TypeScript-Website/blob/ac68b8b8e4a621113c4ee45c4051002fd55ede24/packages/typescript-vfs/src/index.ts#L11
-      ts
-    );
+
+    const fsMap = opts?.useNodeModules
+      ? tsvfs.createDefaultMapFromNodeModules(compilerOptions, ts)
+      : await tsvfs.createDefaultMapFromCDN(
+          compilerOptions,
+          ts.version,
+          false, // TODO: cache this. It needs a store that's available to workers and implements https://github.com/microsoft/TypeScript-Website/blob/ac68b8b8e4a621113c4ee45c4051002fd55ede24/packages/typescript-vfs/src/index.ts#L11
+          ts
+        );
 
     // This can be any path, but doing this means import React from 'react' works, if we ever need it.
     const reactTypesPath = `/node_modules/@types/react/index.d.ts`;
 
     // It may be necessary to get all the types (global.d.ts etc)
+
     fsMap.set(reactTypesPath, reactTypes['react-18'] || '');
 
     const system = tsvfs.createSystem(fsMap);
@@ -65,10 +66,14 @@ export class Compiler {
     ).compilerHost;
   }
 
-  compile(code: string, fileName: string) {
+  compile(rawCode: string, fileName: string) {
     if (!this.tsEnv || !this.compilerHost) {
       throw Error('TypeScript environment not set up');
     }
+    // If we try to update or create an empty file, the environment will become
+    // permanently unable to interact with that file. The workaround is to create
+    // a file with a single newline character.
+    const code = rawCode || '\n';
     // TODO: If creating the file fresh each time is too slow, we can try checking
     // if the file exists and updating it if it does.
     this.tsEnv.createFile(fileName, code);
diff --git a/tools/client-plugins/browser-scripts/package.json b/tools/client-plugins/browser-scripts/package.json
index 9c06e97e0f9..56172129ec2 100644
--- a/tools/client-plugins/browser-scripts/package.json
+++ b/tools/client-plugins/browser-scripts/package.json
@@ -32,13 +32,14 @@
     "@babel/preset-typescript": "7.23.3",
     "@freecodecamp/eslint-config": "workspace:*",
     "@types/copy-webpack-plugin": "^8.0.1",
-    "@typescript/vfs": "^1.6.0",
+    "@typescript/vfs": "1.6.1",
     "babel-loader": "8.3.0",
     "copy-webpack-plugin": "9.1.0",
     "eslint": "^9.39.1",
     "process": "0.11.10",
     "pyodide": "^0.23.3",
     "sass.js": "0.11.1",
+    "typescript": "5.9.2",
     "util": "0.12.5",
     "webpack": "5.90.3",
     "webpack-cli": "4.10.0"
diff --git a/tools/client-plugins/browser-scripts/typescript-worker.ts b/tools/client-plugins/browser-scripts/typescript-worker.ts
index d2d13d7610e..255d116c306 100644
--- a/tools/client-plugins/browser-scripts/typescript-worker.ts
+++ b/tools/client-plugins/browser-scripts/typescript-worker.ts
@@ -92,11 +92,7 @@ async function handleCheckIsReadyRequest(port: MessagePort) {
 }
 
 function handleCompileRequest(data: TSCompileEvent['data'], port: MessagePort) {
-  // If we try to update or create an empty file, the environment will become
-  // permanently unable to interact with that file. The workaround is to create
-  // a file with a single newline character.
-  const code = (data.code || '').slice() || '\n';
-  const { result, error } = compiler.compile(code, 'index.tsx');
+  const { result, error } = compiler.compile(data.code, 'index.tsx');
   const message: TSCompiledMessage = {
     type: 'compiled',
     value: result,