diff --git a/betaassistant.go b/betaassistant.go
index 2a8f989e..ecaa4610 100644
--- a/betaassistant.go
+++ b/betaassistant.go
@@ -42,6 +42,7 @@ func NewBetaAssistantService(opts ...option.RequestOption) (r *BetaAssistantServ
 // Create an assistant with a model and instructions.
 func (r *BetaAssistantService) New(ctx context.Context, body BetaAssistantNewParams, opts ...option.RequestOption) (res *Assistant, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	path := "assistants"
 	err = requestconfig.ExecuteNewRequest(ctx, http.MethodPost, path, body, &res, opts...)
 	return
@@ -50,6 +51,7 @@ func (r *BetaAssistantService) New(ctx context.Context, body BetaAssistantNewPar
 // Retrieves an assistant.
 func (r *BetaAssistantService) Get(ctx context.Context, assistantID string, opts ...option.RequestOption) (res *Assistant, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if assistantID == "" {
 		err = errors.New("missing required assistant_id parameter")
 		return
@@ -62,6 +64,7 @@ func (r *BetaAssistantService) Get(ctx context.Context, assistantID string, opts
 // Modifies an assistant.
 func (r *BetaAssistantService) Update(ctx context.Context, assistantID string, body BetaAssistantUpdateParams, opts ...option.RequestOption) (res *Assistant, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if assistantID == "" {
 		err = errors.New("missing required assistant_id parameter")
 		return
@@ -75,7 +78,7 @@ func (r *BetaAssistantService) Update(ctx context.Context, assistantID string, b
 func (r *BetaAssistantService) List(ctx context.Context, query BetaAssistantListParams, opts ...option.RequestOption) (res *pagination.CursorPage[Assistant], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	path := "assistants"
 	cfg, err := requestconfig.NewRequestConfig(ctx, http.MethodGet, path, query, &res, opts...)
 	if err != nil {
@@ -97,6 +100,7 @@ func (r *BetaAssistantService) ListAutoPaging(ctx context.Context, query BetaAss
 // Delete an assistant.
 func (r *BetaAssistantService) Delete(ctx context.Context, assistantID string, opts ...option.RequestOption) (res *AssistantDeleted, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if assistantID == "" {
 		err = errors.New("missing required assistant_id parameter")
 		return
diff --git a/betathread.go b/betathread.go
index c192c15b..5a048331 100644
--- a/betathread.go
+++ b/betathread.go
@@ -44,6 +44,7 @@ func NewBetaThreadService(opts ...option.RequestOption) (r *BetaThreadService) {
 // Create a thread.
 func (r *BetaThreadService) New(ctx context.Context, body BetaThreadNewParams, opts ...option.RequestOption) (res *Thread, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	path := "threads"
 	err = requestconfig.ExecuteNewRequest(ctx, http.MethodPost, path, body, &res, opts...)
 	return
@@ -52,6 +53,7 @@ func (r *BetaThreadService) New(ctx context.Context, body BetaThreadNewParams, o
 // Retrieves a thread.
 func (r *BetaThreadService) Get(ctx context.Context, threadID string, opts ...option.RequestOption) (res *Thread, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -64,6 +66,7 @@ func (r *BetaThreadService) Get(ctx context.Context, threadID string, opts ...op
 // Modifies a thread.
 func (r *BetaThreadService) Update(ctx context.Context, threadID string, body BetaThreadUpdateParams, opts ...option.RequestOption) (res *Thread, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -76,6 +79,7 @@ func (r *BetaThreadService) Update(ctx context.Context, threadID string, body Be
 // Delete a thread.
 func (r *BetaThreadService) Delete(ctx context.Context, threadID string, opts ...option.RequestOption) (res *ThreadDeleted, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -88,6 +92,7 @@ func (r *BetaThreadService) Delete(ctx context.Context, threadID string, opts ..
 // Create a thread and run it in one request.
 func (r *BetaThreadService) NewAndRun(ctx context.Context, body BetaThreadNewAndRunParams, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	path := "threads/runs"
 	err = requestconfig.ExecuteNewRequest(ctx, http.MethodPost, path, body, &res, opts...)
 	return
@@ -100,7 +105,7 @@ func (r *BetaThreadService) NewAndRunStreaming(ctx context.Context, body BetaThr
 		err error
 	)
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithJSONSet("stream", true)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithJSONSet("stream", true)}, opts...)
 	path := "threads/runs"
 	err = requestconfig.ExecuteNewRequest(ctx, http.MethodPost, path, body, &raw, opts...)
 	return ssestream.NewStream[AssistantStreamEvent](ssestream.NewDecoder(raw), err)
diff --git a/betathreadmessage.go b/betathreadmessage.go
index eab161ff..c0265b2d 100644
--- a/betathreadmessage.go
+++ b/betathreadmessage.go
@@ -41,6 +41,7 @@ func NewBetaThreadMessageService(opts ...option.RequestOption) (r *BetaThreadMes
 // Create a message.
 func (r *BetaThreadMessageService) New(ctx context.Context, threadID string, body BetaThreadMessageNewParams, opts ...option.RequestOption) (res *Message, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -53,6 +54,7 @@ func (r *BetaThreadMessageService) New(ctx context.Context, threadID string, bod
 // Retrieve a message.
 func (r *BetaThreadMessageService) Get(ctx context.Context, threadID string, messageID string, opts ...option.RequestOption) (res *Message, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -69,6 +71,7 @@ func (r *BetaThreadMessageService) Get(ctx context.Context, threadID string, mes
 // Modifies a message.
 func (r *BetaThreadMessageService) Update(ctx context.Context, threadID string, messageID string, body BetaThreadMessageUpdateParams, opts ...option.RequestOption) (res *Message, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -86,7 +89,7 @@ func (r *BetaThreadMessageService) Update(ctx context.Context, threadID string,
 func (r *BetaThreadMessageService) List(ctx context.Context, threadID string, query BetaThreadMessageListParams, opts ...option.RequestOption) (res *pagination.CursorPage[Message], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -112,6 +115,7 @@ func (r *BetaThreadMessageService) ListAutoPaging(ctx context.Context, threadID
 // Deletes a message.
 func (r *BetaThreadMessageService) Delete(ctx context.Context, threadID string, messageID string, opts ...option.RequestOption) (res *MessageDeleted, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
diff --git a/betathreadrun.go b/betathreadrun.go
index f2f4f40b..6566e486 100644
--- a/betathreadrun.go
+++ b/betathreadrun.go
@@ -42,6 +42,7 @@ func NewBetaThreadRunService(opts ...option.RequestOption) (r *BetaThreadRunServ
 // Create a run.
 func (r *BetaThreadRunService) New(ctx context.Context, threadID string, params BetaThreadRunNewParams, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -58,7 +59,7 @@ func (r *BetaThreadRunService) NewStreaming(ctx context.Context, threadID string
 		err error
 	)
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithJSONSet("stream", true)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithJSONSet("stream", true)}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -71,6 +72,7 @@ func (r *BetaThreadRunService) NewStreaming(ctx context.Context, threadID string
 // Retrieves a run.
 func (r *BetaThreadRunService) Get(ctx context.Context, threadID string, runID string, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -87,6 +89,7 @@ func (r *BetaThreadRunService) Get(ctx context.Context, threadID string, runID s
 // Modifies a run.
 func (r *BetaThreadRunService) Update(ctx context.Context, threadID string, runID string, body BetaThreadRunUpdateParams, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -104,7 +107,7 @@ func (r *BetaThreadRunService) Update(ctx context.Context, threadID string, runI
 func (r *BetaThreadRunService) List(ctx context.Context, threadID string, query BetaThreadRunListParams, opts ...option.RequestOption) (res *pagination.CursorPage[Run], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -130,6 +133,7 @@ func (r *BetaThreadRunService) ListAutoPaging(ctx context.Context, threadID stri
 // Cancels a run that is `in_progress`.
 func (r *BetaThreadRunService) Cancel(ctx context.Context, threadID string, runID string, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -149,6 +153,7 @@ func (r *BetaThreadRunService) Cancel(ctx context.Context, threadID string, runI
 // request.
 func (r *BetaThreadRunService) SubmitToolOutputs(ctx context.Context, threadID string, runID string, body BetaThreadRunSubmitToolOutputsParams, opts ...option.RequestOption) (res *Run, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -172,7 +177,7 @@ func (r *BetaThreadRunService) SubmitToolOutputsStreaming(ctx context.Context, t
 		err error
 	)
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithJSONSet("stream", true)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithJSONSet("stream", true)}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
diff --git a/betathreadrunstep.go b/betathreadrunstep.go
index 28b4c5b5..82fa29de 100644
--- a/betathreadrunstep.go
+++ b/betathreadrunstep.go
@@ -41,6 +41,7 @@ func NewBetaThreadRunStepService(opts ...option.RequestOption) (r *BetaThreadRun
 // Retrieves a run step.
 func (r *BetaThreadRunStepService) Get(ctx context.Context, threadID string, runID string, stepID string, query BetaThreadRunStepGetParams, opts ...option.RequestOption) (res *RunStep, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
@@ -62,7 +63,7 @@ func (r *BetaThreadRunStepService) Get(ctx context.Context, threadID string, run
 func (r *BetaThreadRunStepService) List(ctx context.Context, threadID string, runID string, query BetaThreadRunStepListParams, opts ...option.RequestOption) (res *pagination.CursorPage[RunStep], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	if threadID == "" {
 		err = errors.New("missing required thread_id parameter")
 		return
diff --git a/betavectorstore.go b/betavectorstore.go
index c16d1c37..cbbda291 100644
--- a/betavectorstore.go
+++ b/betavectorstore.go
@@ -45,6 +45,7 @@ func NewBetaVectorStoreService(opts ...option.RequestOption) (r *BetaVectorStore
 // Create a vector store.
 func (r *BetaVectorStoreService) New(ctx context.Context, body BetaVectorStoreNewParams, opts ...option.RequestOption) (res *VectorStore, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	path := "vector_stores"
 	err = requestconfig.ExecuteNewRequest(ctx, http.MethodPost, path, body, &res, opts...)
 	return
@@ -53,6 +54,7 @@ func (r *BetaVectorStoreService) New(ctx context.Context, body BetaVectorStoreNe
 // Retrieves a vector store.
 func (r *BetaVectorStoreService) Get(ctx context.Context, vectorStoreID string, opts ...option.RequestOption) (res *VectorStore, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -65,6 +67,7 @@ func (r *BetaVectorStoreService) Get(ctx context.Context, vectorStoreID string,
 // Modifies a vector store.
 func (r *BetaVectorStoreService) Update(ctx context.Context, vectorStoreID string, body BetaVectorStoreUpdateParams, opts ...option.RequestOption) (res *VectorStore, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -78,7 +81,7 @@ func (r *BetaVectorStoreService) Update(ctx context.Context, vectorStoreID strin
 func (r *BetaVectorStoreService) List(ctx context.Context, query BetaVectorStoreListParams, opts ...option.RequestOption) (res *pagination.CursorPage[VectorStore], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	path := "vector_stores"
 	cfg, err := requestconfig.NewRequestConfig(ctx, http.MethodGet, path, query, &res, opts...)
 	if err != nil {
@@ -100,6 +103,7 @@ func (r *BetaVectorStoreService) ListAutoPaging(ctx context.Context, query BetaV
 // Delete a vector store.
 func (r *BetaVectorStoreService) Delete(ctx context.Context, vectorStoreID string, opts ...option.RequestOption) (res *VectorStoreDeleted, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
diff --git a/betavectorstorefile.go b/betavectorstorefile.go
index de296b1d..8737084e 100644
--- a/betavectorstorefile.go
+++ b/betavectorstorefile.go
@@ -41,6 +41,7 @@ func NewBetaVectorStoreFileService(opts ...option.RequestOption) (r *BetaVectorS
 // [vector store](https://platform.openai.com/docs/api-reference/vector-stores/object).
 func (r *BetaVectorStoreFileService) New(ctx context.Context, vectorStoreID string, body BetaVectorStoreFileNewParams, opts ...option.RequestOption) (res *VectorStoreFile, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -53,6 +54,7 @@ func (r *BetaVectorStoreFileService) New(ctx context.Context, vectorStoreID stri
 // Retrieves a vector store file.
 func (r *BetaVectorStoreFileService) Get(ctx context.Context, vectorStoreID string, fileID string, opts ...option.RequestOption) (res *VectorStoreFile, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -70,7 +72,7 @@ func (r *BetaVectorStoreFileService) Get(ctx context.Context, vectorStoreID stri
 func (r *BetaVectorStoreFileService) List(ctx context.Context, vectorStoreID string, query BetaVectorStoreFileListParams, opts ...option.RequestOption) (res *pagination.CursorPage[VectorStoreFile], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -99,6 +101,7 @@ func (r *BetaVectorStoreFileService) ListAutoPaging(ctx context.Context, vectorS
 // endpoint.
 func (r *BetaVectorStoreFileService) Delete(ctx context.Context, vectorStoreID string, fileID string, opts ...option.RequestOption) (res *VectorStoreFileDeleted, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
diff --git a/betavectorstorefilebatch.go b/betavectorstorefilebatch.go
index 573fed50..dd44c465 100644
--- a/betavectorstorefilebatch.go
+++ b/betavectorstorefilebatch.go
@@ -39,6 +39,7 @@ func NewBetaVectorStoreFileBatchService(opts ...option.RequestOption) (r *BetaVe
 // Create a vector store file batch.
 func (r *BetaVectorStoreFileBatchService) New(ctx context.Context, vectorStoreID string, body BetaVectorStoreFileBatchNewParams, opts ...option.RequestOption) (res *VectorStoreFileBatch, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -51,6 +52,7 @@ func (r *BetaVectorStoreFileBatchService) New(ctx context.Context, vectorStoreID
 // Retrieves a vector store file batch.
 func (r *BetaVectorStoreFileBatchService) Get(ctx context.Context, vectorStoreID string, batchID string, opts ...option.RequestOption) (res *VectorStoreFileBatch, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -68,6 +70,7 @@ func (r *BetaVectorStoreFileBatchService) Get(ctx context.Context, vectorStoreID
 // files in this batch as soon as possible.
 func (r *BetaVectorStoreFileBatchService) Cancel(ctx context.Context, vectorStoreID string, batchID string, opts ...option.RequestOption) (res *VectorStoreFileBatch, err error) {
 	opts = append(r.Options[:], opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2")}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return
@@ -85,7 +88,7 @@ func (r *BetaVectorStoreFileBatchService) Cancel(ctx context.Context, vectorStor
 func (r *BetaVectorStoreFileBatchService) ListFiles(ctx context.Context, vectorStoreID string, batchID string, query BetaVectorStoreFileBatchListFilesParams, opts ...option.RequestOption) (res *pagination.CursorPage[VectorStoreFile], err error) {
 	var raw *http.Response
 	opts = append(r.Options[:], opts...)
-	opts = append([]option.RequestOption{option.WithResponseInto(&raw)}, opts...)
+	opts = append([]option.RequestOption{option.WithHeader("OpenAI-Beta", "assistants=v2"), option.WithResponseInto(&raw)}, opts...)
 	if vectorStoreID == "" {
 		err = errors.New("missing required vector_store_id parameter")
 		return