diff --git a/.github/scripts/setup-vars.js b/.github/scripts/setup-vars.js
index c78c2f2f63..d538128ca3 100644
--- a/.github/scripts/setup-vars.js
+++ b/.github/scripts/setup-vars.js
@@ -14,11 +14,12 @@
  limitations under the License.
  */
 
-export default function setupVars({projectId, core, setup}, runId = null) {
+export default function setupVars({projectId, core, setup, serviceAccount, idToken}, runId = null) {
   // Define automatic variables plus custom variables.
   const vars = {
     PROJECT_ID: projectId,
     RUN_ID: runId || uniqueId(),
+    SERVICE_ACCOUNT: serviceAccount,
     ...(setup.env || {}),
   };
 
@@ -45,6 +46,16 @@ export default function setupVars({projectId, core, setup}, runId = null) {
     console.log(`  ${key}: ${setup.secrets[key]}`);
   }
 
+  // Set global secret for the Service Account identity token
+  // Use in place of 'gcloud auth print-identity-token' or auth.getIdTokenClient
+  // usage: curl -H 'Bearer: $ID_TOKEN' https://
+
+  idToken = (idToken || '').toString() // debug
+  core.exportVariable('ID_TOKEN', idToken)
+  core.setSecret(idToken)
+  // For logging, show the source of the ID_TOKEN
+  console.log(`  ID_TOKEN: steps.auth.outputs.id_token (from GitHub Action)`);
+
   // Return env and secrets to use for further steps.
   return {
     env: env,
diff --git a/.github/scripts/setup-vars.test.js b/.github/scripts/setup-vars.test.js
index 86524856b4..e1f4b47b90 100644
--- a/.github/scripts/setup-vars.test.js
+++ b/.github/scripts/setup-vars.test.js
@@ -19,52 +19,54 @@ import setupVars from './setup-vars.js';
 import {substituteVars, uniqueId} from './setup-vars.js';
 
 const projectId = 'my-test-project';
+const serviceAccount = "my-sa@my-project.iam.gserviceaccount.com"
 const core = {
   exportVariable: (_key, _value) => null,
+  setSecret: (_key) => null,
 };
 
-const autovars = {PROJECT_ID: projectId, RUN_ID: 'run-id'};
+const autovars = {PROJECT_ID: projectId, RUN_ID: 'run-id', SERVICE_ACCOUNT: serviceAccount};
 
 describe('setupVars', () => {
   describe('env', () => {
     it('empty', () => {
       const setup = {};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = autovars;
       deepStrictEqual(vars.env, expected);
     });
 
     it('zero vars', () => {
       const setup = {env: {}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = autovars;
       deepStrictEqual(vars.env, expected);
     });
 
     it('one var', () => {
       const setup = {env: {A: 'x'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = {...autovars, A: 'x'};
       deepStrictEqual(vars.env, expected);
     });
 
     it('three vars', () => {
       const setup = {env: {A: 'x', B: 'y', C: 'z'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = {...autovars, A: 'x', B: 'y', C: 'z'};
       deepStrictEqual(vars.env, expected);
     });
 
     it('should override automatic variables', () => {
-      const setup = {env: {PROJECT_ID: 'custom-value'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
-      const expected = {PROJECT_ID: 'custom-value', RUN_ID: 'run-id'};
+      const setup = {env: {PROJECT_ID: 'custom-value', SERVICE_ACCOUNT: 'baz@foo.com'}};
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
+      const expected = {PROJECT_ID: 'custom-value', RUN_ID: 'run-id', SERVICE_ACCOUNT: 'baz@foo.com'};
       deepStrictEqual(vars.env, expected);
     });
 
     it('should interpolate variables', () => {
       const setup = {env: {A: 'x', B: 'y', C: '$A/${B}'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = {...autovars, A: 'x', B: 'y', C: 'x/y'};
       deepStrictEqual(vars.env, expected);
     });
@@ -74,7 +76,7 @@ describe('setupVars', () => {
         env: {C: '$x/$y'},
         secrets: {A: 'x', B: 'y'},
       };
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = {...autovars, C: '$x/$y'};
       deepStrictEqual(vars.env, expected);
     });
@@ -83,20 +85,20 @@ describe('setupVars', () => {
   describe('secrets', () => {
     it('zero secrets', () => {
       const setup = {secrets: {}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       deepStrictEqual(vars.secrets, '');
     });
 
     it('one secret', () => {
       const setup = {secrets: {A: 'x'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = 'A:x';
       deepStrictEqual(vars.secrets, expected);
     });
 
     it('three secrets', () => {
       const setup = {secrets: {A: 'x', B: 'y', C: 'z'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = 'A:x\nB:y\nC:z';
       deepStrictEqual(vars.secrets, expected);
     });
@@ -106,14 +108,14 @@ describe('setupVars', () => {
         env: {A: 'x', B: 'y'},
         secrets: {C: '$A/$B'},
       };
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = 'C:$A/$B';
       deepStrictEqual(vars.secrets, expected);
     });
 
     it('should not interpolate secrets', () => {
       const setup = {secrets: {A: 'x', B: 'y', C: '$A/$B'}};
-      const vars = setupVars({projectId, core, setup}, 'run-id');
+      const vars = setupVars({projectId, core, setup, serviceAccount}, 'run-id');
       const expected = 'A:x\nB:y\nC:$A/$B';
       deepStrictEqual(vars.secrets, expected);
     });
diff --git a/.github/workflows/ci-dev.yaml b/.github/workflows/ci-dev.yaml
index 79fda5a6fd..48eec185d2 100644
--- a/.github/workflows/ci-dev.yaml
+++ b/.github/workflows/ci-dev.yaml
@@ -73,6 +73,7 @@ jobs:
         path: ${{ fromJson(github.event_name == 'pull_request' && needs.affected.outputs.nodejs-paths || '[]') }}
     env:
       GOOGLE_SAMPLES_PROJECT: long-door-651
+      GOOGLE_SERVICE_ACCOUNT: kokoro-system-test@long-door-651.iam.gserviceaccount.com
       CI_SETUP: ${{ toJson(fromJson(needs.affected.outputs.nodejs-setups)[matrix.path])}}
     steps:
       - name: CI Setup
@@ -84,20 +85,26 @@ jobs:
         with:
           node-version: ${{ fromJson(env.CI_SETUP).node-version }}
       - uses: google-github-actions/auth@6fc4af4b145ae7821d527454aa9bd537d1f2dc5f # v2
+        id: auth
         with:
           project_id: ${{ env.GOOGLE_SAMPLES_PROJECT }}
           workload_identity_provider: projects/1046198160504/locations/global/workloadIdentityPools/github-actions-pool/providers/github-actions-provider
-          service_account: kokoro-system-test@long-door-651.iam.gserviceaccount.com
+          service_account: ${{ env.GOOGLE_SERVICE_ACCOUNT }}
           access_token_lifetime: 600s # 10 minutes
+          token_format: 'id_token'
+          id_token_audience: 'https://action.test/' # service must have this custom audience
+          id_token_include_email: true
       - name: Export environment variables
         uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
         id: vars
         with:
           script: |
-            const { default: setupVars } = await import('${{ github.workspace }}/.github/scripts/setup-vars.js')
+            const { default: setupVars } = await import('${{ github.workspace }}/.github/scripts/setup-vars.js');
             const projectId = '${{ env.GOOGLE_SAMPLES_PROJECT }}';
             const setup = JSON.parse(process.env.CI_SETUP);
-            return await setupVars({projectId, core, setup})
+            const serviceAccount = '${{ env.GOOGLE_SERVICE_ACCOUNT }}';
+            const idToken = '${{ steps.auth.outputs.id_token }}';
+            return await setupVars({projectId, core, setup, serviceAccount, idToken})
       - uses: google-github-actions/get-secretmanager-secrets@e5bb06c2ca53b244f978d33348d18317a7f263ce # v2
         if: ${{ fromJson(steps.vars.outputs.result).secrets }}
         with:
diff --git a/.github/workflows/ci-prod.yaml b/.github/workflows/ci-prod.yaml
index 1aea6ef23e..3448fc7c40 100644
--- a/.github/workflows/ci-prod.yaml
+++ b/.github/workflows/ci-prod.yaml
@@ -85,6 +85,7 @@ jobs:
         path: ${{ fromJson(github.event_name == 'pull_request' && needs.affected.outputs.nodejs-paths || '[]') }}
     env:
       GOOGLE_SAMPLES_PROJECT: long-door-651
+      GOOGLE_SERVICE_ACCOUNT: kokoro-system-test@long-door-651.iam.gserviceaccount.com
       CI_SETUP: ${{ toJson(fromJson(needs.affected.outputs.nodejs-setups)[matrix.path])}}
     steps:
       - name: CI Setup
@@ -96,20 +97,26 @@ jobs:
         with:
           node-version: ${{ fromJson(env.CI_SETUP).node-version }}
       - uses: google-github-actions/auth@6fc4af4b145ae7821d527454aa9bd537d1f2dc5f # v2
+        id: auth
         with:
           project_id: ${{ env.GOOGLE_SAMPLES_PROJECT }}
           workload_identity_provider: projects/1046198160504/locations/global/workloadIdentityPools/github-actions-pool/providers/github-actions-provider
-          service_account: kokoro-system-test@long-door-651.iam.gserviceaccount.com
+          service_account: ${{ env.GOOGLE_SERVICE_ACCOUNT }}
           access_token_lifetime: 600s # 10 minutes
+          token_format: 'id_token'
+          id_token_audience: 'https://action.test/' # service must have this custom audience
+          id_token_include_email: true
       - name: Export environment variables
         uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
         id: vars
         with:
           script: |
-            const { default: setupVars } = await import('${{ github.workspace }}/.github/scripts/setup-vars.js')
+            const { default: setupVars } = await import('${{ github.workspace }}/.github/scripts/setup-vars.js');
             const projectId = '${{ env.GOOGLE_SAMPLES_PROJECT }}';
             const setup = JSON.parse(process.env.CI_SETUP);
-            return await setupVars({projectId, core, setup})
+            const serviceAccount = '${{ env.GOOGLE_SERVICE_ACCOUNT }}';
+            const idToken = '${{ steps.auth.outputs.id_token }}';
+            return await setupVars({projectId, core, setup, serviceAccount, idToken})
       - uses: google-github-actions/get-secretmanager-secrets@e5bb06c2ca53b244f978d33348d18317a7f263ce # v2
         if: ${{ fromJson(steps.vars.outputs.result).secrets }}
         with:
diff --git a/run/helloworld/ci-setup.json b/run/helloworld/ci-setup.json
new file mode 100644
index 0000000000..94233e215c
--- /dev/null
+++ b/run/helloworld/ci-setup.json
@@ -0,0 +1,5 @@
+{
+    "env": {
+        "SERVICE_NAME": "run-helloworld-$RUN_ID"
+    }
+}
diff --git a/run/helloworld/package.json b/run/helloworld/package.json
index c380d70ab2..62cccf4d37 100644
--- a/run/helloworld/package.json
+++ b/run/helloworld/package.json
@@ -6,7 +6,9 @@
   "main": "index.js",
   "scripts": {
     "start": "node index.js",
-    "test": "c8 mocha -p -j 2 test/index.test.js --exit",
+    "test": "npm -- run all-test",
+    "all-test": "npm run unit-test && npm run system-test",
+    "unit-test": "c8 mocha -p -j 2 test/index.test.js --exit",
     "system-test": "NAME=Cloud c8 mocha -p -j 2 test/system.test.js --timeout=180000"
   },
   "type": "module",
diff --git a/run/helloworld/test/e2e_test_cleanup.yaml b/run/helloworld/test/e2e_test_cleanup.yaml
index a82fd25c06..47434239a9 100644
--- a/run/helloworld/test/e2e_test_cleanup.yaml
+++ b/run/helloworld/test/e2e_test_cleanup.yaml
@@ -17,3 +17,9 @@ substitutions:
   _VERSION: manual
   _REGION: us-central1
   _PLATFORM: managed
+  _SERVICE_ACCOUNT: ${PROJECT_NUMBER}@cloudbuild.gserviceaccount.com
+
+serviceAccount: 'projects/${PROJECT_ID}/serviceAccounts/${_SERVICE_ACCOUNT}'
+options:
+    logging: CLOUD_LOGGING_ONLY
+    dynamicSubstitutions: true
diff --git a/run/helloworld/test/e2e_test_setup.yaml b/run/helloworld/test/e2e_test_setup.yaml
index b354bca091..b8405f85f8 100644
--- a/run/helloworld/test/e2e_test_setup.yaml
+++ b/run/helloworld/test/e2e_test_setup.yaml
@@ -27,8 +27,8 @@ steps:
       --no-allow-unauthenticated \
       --region ${_REGION} \
       --platform ${_PLATFORM} \
-      --set-env-vars NAME=${_NAME}"
-
+      --set-env-vars NAME=${_NAME} \
+      --add-custom-audiences 'https://action.test/'"
 
 images:
 - gcr.io/${PROJECT_ID}/${_SERVICE}:${_VERSION}
@@ -39,3 +39,9 @@ substitutions:
   _REGION: us-central1
   _PLATFORM: managed
   _NAME: Cloud
+  _SERVICE_ACCOUNT: ${PROJECT_NUMBER}@cloudbuild.gserviceaccount.com
+
+serviceAccount: 'projects/${PROJECT_ID}/serviceAccounts/${_SERVICE_ACCOUNT}'
+options:
+    logging: CLOUD_LOGGING_ONLY
+    dynamicSubstitutions: true
diff --git a/run/helloworld/test/system.test.js b/run/helloworld/test/system.test.js
index 3980f27031..4089f21501 100644
--- a/run/helloworld/test/system.test.js
+++ b/run/helloworld/test/system.test.js
@@ -15,8 +15,6 @@
 import assert from 'assert';
 import {execSync} from 'child_process';
 import request from 'got';
-import {GoogleAuth} from 'google-auth-library';
-const auth = new GoogleAuth();
 
 const get = (route, base_url) => {
   if (!ID_TOKEN) {
@@ -25,7 +23,7 @@ const get = (route, base_url) => {
 
   return request(new URL(route, base_url.trim()), {
     headers: {
-      Authorization: `${ID_TOKEN.trim()}`,
+      Authorization: `Bearer ${ID_TOKEN}`,
     },
     throwHttpErrors: false,
   });
@@ -44,12 +42,17 @@ describe('End-to-End Tests', () => {
       `"SERVICE_NAME" env var not found. Defaulting to "${SERVICE_NAME}"`
     );
   }
+  const {SERVICE_ACCOUNT} = process.env;
   let {NAME} = process.env;
   if (!NAME) {
     NAME = 'Cloud';
     console.log(`"NAME" env var not found. Defaulting to "${NAME}"`);
   }
   const {SAMPLE_VERSION} = process.env;
+  ID_TOKEN = process.env;
+  if (!ID_TOKEN) {
+    throw Error('"ID_TOKEN" env var not found.');
+  }
   const PLATFORM = 'managed';
   const REGION = 'us-central1';
   before(async () => {
@@ -60,6 +63,7 @@ describe('End-to-End Tests', () => {
       `--substitutions _SERVICE=${SERVICE_NAME},_PLATFORM=${PLATFORM},_REGION=${REGION}` +
       `,_NAME=${NAME}`;
     if (SAMPLE_VERSION) buildCmd += `,_VERSION=${SAMPLE_VERSION}`;
+    if (SERVICE_ACCOUNT) buildCmd += `,_SERVICE_ACCOUNT=${SERVICE_ACCOUNT}`;
 
     console.log('Starting Cloud Build...');
     execSync(buildCmd, {timeout: 240000}); // timeout at 4 mins
@@ -75,9 +79,8 @@ describe('End-to-End Tests', () => {
     if (!BASE_URL) throw Error('Cloud Run service URL not found');
 
     // Retrieve ID token for testing
-    const client = await auth.getIdTokenClient(BASE_URL);
-    const clientHeaders = await client.getRequestHeaders();
-    ID_TOKEN = clientHeaders['Authorization'].trim();
+    //const client = await auth.getIdTokenClient(BASE_URL);
+    //const clientHeaders = await client.getRequestHeaders();
     if (!ID_TOKEN) throw Error('Unable to acquire an ID token.');
   });
 
@@ -87,6 +90,7 @@ describe('End-to-End Tests', () => {
       '--config ./test/e2e_test_cleanup.yaml ' +
       `--substitutions _SERVICE=${SERVICE_NAME},_PLATFORM=${PLATFORM},_REGION=${REGION}`;
     if (SAMPLE_VERSION) cleanUpCmd += `,_VERSION=${SAMPLE_VERSION}`;
+    if (SERVICE_ACCOUNT) cleanUpCmd += `,_SERVICE_ACCOUNT=${SERVICE_ACCOUNT}`;
 
     execSync(cleanUpCmd);
   });