diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 509abc6f1f..a25f0a9b1c 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "6.37.0"
+  ".": "6.38.0"
 }
diff --git a/.stats.yml b/.stats.yml
index ff6b893527..6359ad0608 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 232
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai/openai-371f497afe4d6070f6e252e5febbe8f453c7058a8dff0c26a01b4d88442a4ac2.yml
-openapi_spec_hash: d39f46e8fda45f77096448105efd175a
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai/openai-50d816559ef0935e64d07789ff936a2b762e26ab0714a2fa6bc06d06d4484294.yml
+openapi_spec_hash: c5d8f37edbf66c1fef627d787b4c54fd
 config_hash: b64135fff1fe9cf4069b9ecf59ae8b07
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f940b22a14..8f3c742da8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 6.38.0 (2026-05-13)
+
+Full Changelog: [v6.37.0...v6.38.0](https://github.com/openai/openai-node/compare/v6.37.0...v6.38.0)
+
+### Features
+
+* **api:** add service_tier parameter to responses compact method ([423e838](https://github.com/openai/openai-node/commit/423e838c498bd1b77f3b732cfc43c54fc5d261df))
+
 ## 6.37.0 (2026-05-07)
 
 Full Changelog: [v6.36.0...v6.37.0](https://github.com/openai/openai-node/compare/v6.36.0...v6.37.0)
diff --git a/README.md b/README.md
index 26b0dfa9eb..68cebbcb32 100644
--- a/README.md
+++ b/README.md
@@ -75,6 +75,8 @@ For secure, automated environments like cloud-managed Kubernetes, Azure, and GCP
 
 The `workloadIdentity` parameter is mutually exclusive with `apiKey`.
 
+The required fields are `identityProviderId`, `serviceAccountId`, and `provider`.
+
 ### Kubernetes (service account tokens)
 
 ```ts
@@ -83,7 +85,6 @@ import { k8sServiceAccountTokenProvider } from 'openai/auth';
 
 const client = new OpenAI({
   workloadIdentity: {
-    clientId: 'your-client-id',
     identityProviderId: 'idp-123',
     serviceAccountId: 'sa-456',
     provider: k8sServiceAccountTokenProvider('/var/run/secrets/kubernetes.io/serviceaccount/token'),
@@ -104,7 +105,6 @@ import { azureManagedIdentityTokenProvider } from 'openai/auth';
 
 const client = new OpenAI({
   workloadIdentity: {
-    clientId: 'your-client-id',
     identityProviderId: 'idp-123',
     serviceAccountId: 'sa-456',
     provider: azureManagedIdentityTokenProvider(),
@@ -120,7 +120,6 @@ import { gcpIDTokenProvider } from 'openai/auth';
 
 const client = new OpenAI({
   workloadIdentity: {
-    clientId: 'your-client-id',
     identityProviderId: 'idp-123',
     serviceAccountId: 'sa-456',
     provider: gcpIDTokenProvider(),
@@ -135,7 +134,6 @@ import OpenAI from 'openai';
 
 const client = new OpenAI({
   workloadIdentity: {
-    clientId: 'your-client-id',
     identityProviderId: 'idp-123',
     serviceAccountId: 'sa-456',
     provider: {
@@ -156,7 +154,6 @@ import { k8sServiceAccountTokenProvider } from 'openai/auth';
 
 const client = new OpenAI({
   workloadIdentity: {
-    clientId: 'your-client-id',
     identityProviderId: 'idp-123',
     serviceAccountId: 'sa-456',
     provider: k8sServiceAccountTokenProvider('/var/token'),
diff --git a/jsr.json b/jsr.json
index 2939a44dc6..5ba8b00e38 100644
--- a/jsr.json
+++ b/jsr.json
@@ -1,6 +1,6 @@
 {
   "name": "@openai/openai",
-  "version": "6.37.0",
+  "version": "6.38.0",
   "exports": {
     ".": "./index.ts",
     "./helpers/zod": "./helpers/zod.ts",
diff --git a/package.json b/package.json
index a6afab3fa7..b6eee5755b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "openai",
-  "version": "6.37.0",
+  "version": "6.38.0",
   "description": "The official TypeScript library for the OpenAI API",
   "author": "OpenAI <support@openai.com>",
   "types": "dist/index.d.ts",
diff --git a/src/auth/types.ts b/src/auth/types.ts
index b94e062730..05dbd90ea5 100644
--- a/src/auth/types.ts
+++ b/src/auth/types.ts
@@ -4,8 +4,8 @@ export interface SubjectTokenProvider {
 }
 
 export interface WorkloadIdentity {
-  /**A unique string that identifies the client.*/
-  clientId: string;
+  /**Optional client identifier for token exchange compatibility.*/
+  clientId?: string;
 
   /**Identity provider resource id in WIFAPI.*/
   identityProviderId: string;
diff --git a/src/auth/workload-identity-auth.ts b/src/auth/workload-identity-auth.ts
index 31946709f9..a1a78502af 100644
--- a/src/auth/workload-identity-auth.ts
+++ b/src/auth/workload-identity-auth.ts
@@ -8,7 +8,7 @@ interface CachedToken {
   expiresAt: number;
 }
 
-const SUBJECT_TOKEN_TYPES: Record<string, string> = {
+const SUBJECT_TOKEN_TYPES: Record<WorkloadIdentity['provider']['tokenType'], string> = {
   jwt: 'urn:ietf:params:oauth:token-type:jwt',
   id: 'urn:ietf:params:oauth:token-type:id_token',
 };
@@ -54,20 +54,24 @@ export class WorkloadIdentityAuth {
 
   private async refreshToken(): Promise<string> {
     const subjectToken = await this.config.provider.getToken();
+    const body: Record<string, string> = {
+      grant_type: TOKEN_EXCHANGE_GRANT_TYPE,
+      subject_token: subjectToken,
+      subject_token_type: SUBJECT_TOKEN_TYPES[this.config.provider.tokenType],
+      identity_provider_id: this.config.identityProviderId,
+      service_account_id: this.config.serviceAccountId,
+    };
+
+    if (this.config.clientId) {
+      body['client_id'] = this.config.clientId;
+    }
 
     const response = await this.fetch(this.tokenExchangeUrl, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/json',
       },
-      body: JSON.stringify({
-        grant_type: TOKEN_EXCHANGE_GRANT_TYPE,
-        client_id: this.config.clientId,
-        subject_token: subjectToken,
-        subject_token_type: SUBJECT_TOKEN_TYPES[this.config.provider.tokenType],
-        identity_provider_id: this.config.identityProviderId,
-        service_account_id: this.config.serviceAccountId,
-      }),
+      body: JSON.stringify(body),
     });
 
     if (!response.ok) {
diff --git a/src/resources/responses/responses.ts b/src/resources/responses/responses.ts
index 937f10f7cd..6de563e0b3 100644
--- a/src/resources/responses/responses.ts
+++ b/src/resources/responses/responses.ts
@@ -8035,6 +8035,11 @@ export interface ResponseCompactParams {
    * How long to retain a prompt cache entry created by this request.
    */
   prompt_cache_retention?: 'in_memory' | '24h' | null;
+
+  /**
+   * The service tier to use for this request.
+   */
+  service_tier?: 'auto' | 'default' | 'flex' | 'priority' | null;
 }
 
 Responses.InputItems = InputItems;
diff --git a/src/version.ts b/src/version.ts
index b381c68ffd..1422fd54f2 100644
--- a/src/version.ts
+++ b/src/version.ts
@@ -1 +1 @@
-export const VERSION = '6.37.0'; // x-release-please-version
+export const VERSION = '6.38.0'; // x-release-please-version
diff --git a/tests/api-resources/responses/responses.test.ts b/tests/api-resources/responses/responses.test.ts
index f9162f41ae..aeee41b717 100644
--- a/tests/api-resources/responses/responses.test.ts
+++ b/tests/api-resources/responses/responses.test.ts
@@ -94,6 +94,7 @@ describe('resource responses', () => {
       previous_response_id: 'resp_123',
       prompt_cache_key: 'prompt_cache_key',
       prompt_cache_retention: 'in_memory',
+      service_tier: 'auto',
     });
   });
 });
diff --git a/tests/auth/workload-identity-auth.test.ts b/tests/auth/workload-identity-auth.test.ts
index 8048454648..b479b81eab 100644
--- a/tests/auth/workload-identity-auth.test.ts
+++ b/tests/auth/workload-identity-auth.test.ts
@@ -18,7 +18,6 @@ describe('WorkloadIdentityAuth', () => {
     let fetchCallCount = 0;
 
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -59,7 +58,6 @@ describe('WorkloadIdentityAuth', () => {
     let fetchCallCount = 0;
 
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -102,7 +100,6 @@ describe('WorkloadIdentityAuth', () => {
     let fetchCallCount = 0;
 
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -142,7 +139,6 @@ describe('WorkloadIdentityAuth', () => {
 
   test('sends correct OAuth2 token exchange request', async () => {
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -179,7 +175,7 @@ describe('WorkloadIdentityAuth', () => {
 
     const body = JSON.parse(capturedRequest!.body);
     expect(body.grant_type).toBe('urn:ietf:params:oauth:grant-type:token-exchange');
-    expect(body.client_id).toBe('test-client-id');
+    expect(body).not.toHaveProperty('client_id');
     expect(body.subject_token).toBe('subject-token');
     expect(body.subject_token_type).toBe('urn:ietf:params:oauth:token-type:jwt');
     expect(body.identity_provider_id).toBe('test-identity-provider-id');
@@ -188,7 +184,6 @@ describe('WorkloadIdentityAuth', () => {
 
   test('includes all required fields in token exchange', async () => {
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -219,12 +214,12 @@ describe('WorkloadIdentityAuth', () => {
     const body = JSON.parse(capturedBody!);
     expect(body.grant_type).toBe('urn:ietf:params:oauth:grant-type:token-exchange');
     expect(body.subject_token_type).toBe('urn:ietf:params:oauth:token-type:jwt');
-    expect(body.client_id).toBe('test-client-id');
+    expect(body).not.toHaveProperty('client_id');
     expect(body.identity_provider_id).toBe('test-identity-provider-id');
     expect(body.service_account_id).toBe('test-service-account-id');
   });
 
-  test('throws OAuthError on failed token exchange', async () => {
+  test('includes client_id when clientId is provided', async () => {
     const config: WorkloadIdentity = {
       clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
@@ -235,6 +230,39 @@ describe('WorkloadIdentityAuth', () => {
       },
     };
 
+    let capturedBody: string | null = null;
+
+    global.fetch = jest.fn(async (url: string, init?: RequestInit) => {
+      capturedBody = init?.body?.toString() || '';
+
+      return new Response(
+        JSON.stringify({
+          access_token: 'access-token',
+          issued_token_type: 'urn:ietf:params:oauth:token-type:id_token',
+          token_type: 'Bearer',
+          expires_in: 3600,
+        }),
+        { status: 200 },
+      );
+    }) as typeof fetch;
+
+    const auth = new WorkloadIdentityAuth(config);
+    await auth.getToken();
+
+    const body = JSON.parse(capturedBody!);
+    expect(body.client_id).toBe('test-client-id');
+  });
+
+  test('throws OAuthError on failed token exchange', async () => {
+    const config: WorkloadIdentity = {
+      identityProviderId: 'test-identity-provider-id',
+      serviceAccountId: 'test-service-account-id',
+      provider: {
+        tokenType: 'jwt',
+        getToken: async () => 'subject-token',
+      },
+    };
+
     global.fetch = jest.fn(async () => {
       return new Response(
         JSON.stringify({
@@ -253,7 +281,6 @@ describe('WorkloadIdentityAuth', () => {
 
   test('defaults to 3600 seconds when expires_in is missing', async () => {
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -283,7 +310,6 @@ describe('WorkloadIdentityAuth', () => {
     let fetchCallCount = 0;
 
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
@@ -319,7 +345,6 @@ describe('WorkloadIdentityAuth', () => {
 
   test('uses the configured fetch implementation for token exchange', async () => {
     const config: WorkloadIdentity = {
-      clientId: 'test-client-id',
       identityProviderId: 'test-identity-provider-id',
       serviceAccountId: 'test-service-account-id',
       provider: {
diff --git a/tests/lib/workload-identity.test.ts b/tests/lib/workload-identity.test.ts
index 15b770227b..c46514c952 100644
--- a/tests/lib/workload-identity.test.ts
+++ b/tests/lib/workload-identity.test.ts
@@ -5,7 +5,6 @@ import { OAuthError, SubjectTokenProviderError } from 'openai';
 const originalFetch = global.fetch;
 
 const createTestWorkloadIdentity = () => ({
-  clientId: 'test-client-id',
   identityProviderId: 'test-identity-provider-id',
   serviceAccountId: 'test-service-account-id',
   provider: {
@@ -272,7 +271,6 @@ describe('OpenAI with Workload Identity', () => {
   test('propagates SubjectTokenProviderError', async () => {
     const client = new OpenAI({
       workloadIdentity: {
-        clientId: 'test-client-id',
         identityProviderId: 'test-identity-provider-id',
         serviceAccountId: 'test-service-account-id',
         provider: {
@@ -407,7 +405,6 @@ describe('OpenAI with Workload Identity', () => {
 
     const client = new OpenAI({
       workloadIdentity: {
-        clientId: 'test-client-id',
         identityProviderId: 'test-identity-provider-id',
         serviceAccountId: 'test-service-account-id',
         provider: {