feat: add model type support for file uploads with automatic resolution and header propagation

internal/httpapi/openai/file_inline_upload_test.go

@@ -94,6 +94,9 @@ func TestPreprocessInlineFileInputsReplacesDataURLAndCollectsRefFileIDs(t *testi
 	if len(ds.uploadCalls) != 1 {
 		t.Fatalf("expected 1 upload, got %d", len(ds.uploadCalls))
 	}
+	if ds.uploadCalls[0].ModelType != "default" {
+		t.Fatalf("expected default model type when request omits model, got %q", ds.uploadCalls[0].ModelType)
+	}
 	if ds.lastCtx != ctx {
 		t.Fatalf("expected upload to use request context")
 	}
@@ -149,7 +152,7 @@ func TestPreprocessInlineFileInputsDeduplicatesIdenticalPayloads(t *testing.T) {
 func TestChatCompletionsUploadsInlineFilesBeforeCompletion(t *testing.T) {
 	ds := &inlineUploadDSStub{}
 	h := &openAITestSurface{Store: mockOpenAIConfig{wideInput: true}, Auth: streamStatusAuthStub{}, DS: ds}
-	reqBody := `{"model":"deepseek-v4-flash","messages":[{"role":"user","content":[{"type":"input_text","text":"hi"},{"type":"image_url","image_url":{"url":"data:image/png;base64,QUJDRA=="}}]}],"stream":false}`
+	reqBody := `{"model":"deepseek-v4-vision","messages":[{"role":"user","content":[{"type":"input_text","text":"hi"},{"type":"image_url","image_url":{"url":"data:image/png;base64,QUJDRA=="}}]}],"stream":false}`
 	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(reqBody))
 	req.Header.Set("Authorization", "Bearer direct-token")
 	req.Header.Set("Content-Type", "application/json")
@@ -163,6 +166,9 @@ func TestChatCompletionsUploadsInlineFilesBeforeCompletion(t *testing.T) {
 	if len(ds.uploadCalls) != 1 {
 		t.Fatalf("expected 1 upload call, got %d", len(ds.uploadCalls))
 	}
+	if ds.uploadCalls[0].ModelType != "vision" {
+		t.Fatalf("expected vision model type for vision request, got %q", ds.uploadCalls[0].ModelType)
+	}
 	if ds.completionReq == nil {
 		t.Fatal("expected completion payload to be captured")
 	}
@@ -177,7 +183,7 @@ func TestResponsesUploadsInlineFilesBeforeCompletion(t *testing.T) {
 	h := &openAITestSurface{Store: mockOpenAIConfig{wideInput: true}, Auth: streamStatusAuthStub{}, DS: ds}
 	r := chi.NewRouter()
 	registerOpenAITestRoutes(r, h)
-	reqBody := `{"model":"deepseek-v4-flash","input":[{"role":"user","content":[{"type":"input_text","text":"hi"},{"type":"input_image","image_url":{"url":"data:image/png;base64,QUJDRA=="}}]}],"stream":false}`
+	reqBody := `{"model":"deepseek-v4-pro","input":[{"role":"user","content":[{"type":"input_text","text":"hi"},{"type":"input_image","image_url":{"url":"data:image/png;base64,QUJDRA=="}}]}],"stream":false}`
 	req := httptest.NewRequest(http.MethodPost, "/v1/responses", strings.NewReader(reqBody))
 	req.Header.Set("Authorization", "Bearer direct-token")
 	req.Header.Set("Content-Type", "application/json")
@@ -191,6 +197,9 @@ func TestResponsesUploadsInlineFilesBeforeCompletion(t *testing.T) {
 	if len(ds.uploadCalls) != 1 {
 		t.Fatalf("expected 1 upload call, got %d", len(ds.uploadCalls))
 	}
+	if ds.uploadCalls[0].ModelType != "expert" {
+		t.Fatalf("expected expert model type for pro request, got %q", ds.uploadCalls[0].ModelType)
+	}
 	refIDs, _ := ds.completionReq["ref_file_ids"].([]any)
 	if len(refIDs) != 1 || refIDs[0] != "file-inline-1" {
 		t.Fatalf("unexpected completion ref_file_ids: %#v", ds.completionReq["ref_file_ids"])

internal/httpapi/openai/files/file_inline_upload.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"ds2api/internal/auth"
+	"ds2api/internal/config"
 	dsclient "ds2api/internal/deepseek/client"
 	"ds2api/internal/httpapi/openai/shared"
 	"ds2api/internal/promptcompat"
@@ -42,6 +43,7 @@ type inlineUploadState struct {
 	ctx             context.Context
 	handler         *Handler
 	auth            *auth.RequestAuth
+	modelType       string
 	uploadedByID    map[string]string
 	uploadCount     int
 	inlineFileBytes int
@@ -58,10 +60,19 @@ func (h *Handler) PreprocessInlineFileInputs(ctx context.Context, a *auth.Reques
 	if h == nil || h.DS == nil || len(req) == 0 {
 		return nil
 	}
+	modelType := "default"
+	if requestedModel, ok := req["model"].(string); ok {
+		if resolvedModel, ok := config.ResolveModel(h.Store, requestedModel); ok {
+			if resolvedType, ok := config.GetModelType(resolvedModel); ok {
+				modelType = resolvedType
+			}
+		}
+	}
 	state := &inlineUploadState{
 		ctx:          ctx,
 		handler:      h,
 		auth:         a,
+		modelType:    modelType,
 		uploadedByID: map[string]string{},
 	}
 	for _, key := range []string{"messages", "input", "attachments"} {
@@ -174,6 +185,7 @@ func (s *inlineUploadState) uploadInlineFile(file inlineDecodedFile) (string, er
 	result, err := s.handler.DS.UploadFile(s.ctx, s.auth, dsclient.UploadFileRequest{
 		Filename:    file.Filename,
 		ContentType: contentType,
+		ModelType:   s.modelType,
 		Data:        file.Data,
 	}, 3)
 	if err != nil {

internal/httpapi/openai/files/handler_files.go

@@ -8,6 +8,7 @@ import (
 
 	"ds2api/internal/auth"
 	"ds2api/internal/chathistory"
+	"ds2api/internal/config"
 	dsclient "ds2api/internal/deepseek/client"
 	"ds2api/internal/httpapi/openai/shared"
 )
@@ -66,10 +67,12 @@ func (h *Handler) UploadFile(w http.ResponseWriter, r *http.Request) {
 	if contentType == "" && len(data) > 0 {
 		contentType = http.DetectContentType(data)
 	}
+	modelType := resolveUploadModelType(h.Store, r)
 	result, err := h.DS.UploadFile(r.Context(), a, dsclient.UploadFileRequest{
 		Filename:    header.Filename,
 		ContentType: contentType,
 		Purpose:     strings.TrimSpace(r.FormValue("purpose")),
+		ModelType:   modelType,
 		Data:        data,
 	}, 3)
 	if err != nil {
@@ -82,6 +85,32 @@ func (h *Handler) UploadFile(w http.ResponseWriter, r *http.Request) {
 	shared.WriteJSON(w, http.StatusOK, buildOpenAIFileObject(result))
 }
 
+func resolveUploadModelType(store shared.ConfigReader, r *http.Request) string {
+	for _, candidate := range []string{r.FormValue("model_type"), r.Header.Get("X-Model-Type")} {
+		if modelType := normalizeUploadModelType(candidate); modelType != "" {
+			return modelType
+		}
+	}
+	requestedModel := strings.TrimSpace(r.FormValue("model"))
+	if requestedModel != "" {
+		if resolvedModel, ok := config.ResolveModel(store, requestedModel); ok {
+			if modelType, ok := config.GetModelType(resolvedModel); ok {
+				return modelType
+			}
+		}
+	}
+	return "default"
+}
+
+func normalizeUploadModelType(raw string) string {
+	switch strings.ToLower(strings.TrimSpace(raw)) {
+	case "default", "expert", "vision":
+		return strings.ToLower(strings.TrimSpace(raw))
+	default:
+		return ""
+	}
+}
+
 func buildOpenAIFileObject(result *dsclient.UploadFileResult) map[string]any {
 	if result == nil {
 		obj := map[string]any{

internal/httpapi/openai/files_route_test.go

@@ -77,7 +77,7 @@ func (m *filesRouteDSStub) DeleteAllSessionsForToken(_ context.Context, _ string
 	return nil
 }
 
-func newMultipartUploadRequest(t *testing.T, purpose string, filename string, data []byte) *http.Request {
+func newMultipartUploadRequest(t *testing.T, purpose string, filename string, data []byte, model string) *http.Request {
 	t.Helper()
 	var body bytes.Buffer
 	writer := multipart.NewWriter(&body)
@@ -86,6 +86,11 @@ func newMultipartUploadRequest(t *testing.T, purpose string, filename string, da
 			t.Fatalf("write purpose failed: %v", err)
 		}
 	}
+	if model != "" {
+		if err := writer.WriteField("model", model); err != nil {
+			t.Fatalf("write model failed: %v", err)
+		}
+	}
 	part, err := writer.CreateFormFile("file", filename)
 	if err != nil {
 		t.Fatalf("create form file failed: %v", err)
@@ -108,7 +113,7 @@ func TestFilesRouteUploadSuccess(t *testing.T) {
 	r := chi.NewRouter()
 	registerOpenAITestRoutes(r, h)
 
-	req := newMultipartUploadRequest(t, "assistants", "notes.txt", []byte("hello world"))
+	req := newMultipartUploadRequest(t, "assistants", "notes.txt", []byte("hello world"), "deepseek-v4-vision")
 	rec := httptest.NewRecorder()
 	r.ServeHTTP(rec, req)
 
@@ -121,6 +126,9 @@ func TestFilesRouteUploadSuccess(t *testing.T) {
 	if ds.lastReq.Purpose != "assistants" {
 		t.Fatalf("expected purpose assistants, got %q", ds.lastReq.Purpose)
 	}
+	if ds.lastReq.ModelType != "vision" {
+		t.Fatalf("expected vision model type, got %q", ds.lastReq.ModelType)
+	}
 	if string(ds.lastReq.Data) != "hello world" {
 		t.Fatalf("unexpected uploaded data: %q", string(ds.lastReq.Data))
 	}
@@ -145,7 +153,7 @@ func TestFilesRouteUploadIncludesAccountIDForManagedAccount(t *testing.T) {
 	r := chi.NewRouter()
 	registerOpenAITestRoutes(r, h)
 
-	req := newMultipartUploadRequest(t, "assistants", "notes.txt", []byte("hello world"))
+	req := newMultipartUploadRequest(t, "assistants", "notes.txt", []byte("hello world"), "deepseek-v4-vision")
 	rec := httptest.NewRecorder()
 	r.ServeHTTP(rec, req)
 

internal/httpapi/openai/history/current_input_file.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"ds2api/internal/auth"
+	"ds2api/internal/config"
 	dsclient "ds2api/internal/deepseek/client"
 	"ds2api/internal/httpapi/openai/shared"
 	"ds2api/internal/promptcompat"
@@ -35,10 +36,15 @@ func (s Service) ApplyCurrentInputFile(ctx context.Context, a *auth.RequestAuth,
 	if strings.TrimSpace(fileText) == "" {
 		return stdReq, errors.New("current user input file produced empty transcript")
 	}
+	modelType := "default"
+	if resolvedType, ok := config.GetModelType(stdReq.ResolvedModel); ok {
+		modelType = resolvedType
+	}
 	result, err := s.DS.UploadFile(ctx, a, dsclient.UploadFileRequest{
 		Filename:    currentInputFilename,
 		ContentType: currentInputContentType,
 		Purpose:     currentInputPurpose,
+		ModelType:   modelType,
 		Data:        []byte(fileText),
 	}, 3)
 	if err != nil {

internal/httpapi/openai/history_split_test.go

@@ -227,7 +227,7 @@ func TestApplyCurrentInputFileDisabledPassThrough(t *testing.T) {
 		DS: ds,
 	}
 	req := map[string]any{
-		"model":    "deepseek-v4-flash",
+		"model":    "deepseek-v4-vision",
 		"messages": historySplitTestMessages(),
 	}
 	stdReq, err := promptcompat.NormalizeOpenAIChatRequest(h.Store, req, "")
@@ -332,7 +332,7 @@ func TestApplyCurrentInputFilePreservesFullContextPromptForTokenCounting(t *test
 		DS: ds,
 	}
 	req := map[string]any{
-		"model":    "deepseek-v4-flash",
+		"model":    "deepseek-v4-vision",
 		"messages": historySplitTestMessages(),
 	}
 	stdReq, err := promptcompat.NormalizeOpenAIChatRequest(h.Store, req, "")
@@ -378,7 +378,7 @@ func TestApplyCurrentInputFileUploadsFullContextFile(t *testing.T) {
 		DS: ds,
 	}
 	req := map[string]any{
-		"model":    "deepseek-v4-flash",
+		"model":    "deepseek-v4-vision",
 		"messages": historySplitTestMessages(),
 	}
 	stdReq, err := promptcompat.NormalizeOpenAIChatRequest(h.Store, req, "")
@@ -400,6 +400,9 @@ func TestApplyCurrentInputFileUploadsFullContextFile(t *testing.T) {
 	if upload.Filename != "DS2API_HISTORY.txt" {
 		t.Fatalf("expected DS2API_HISTORY.txt upload, got %q", upload.Filename)
 	}
+	if upload.ModelType != "vision" {
+		t.Fatalf("expected vision model type for vision request, got %q", upload.ModelType)
+	}
 	uploadedText := string(upload.Data)
 	for _, want := range []string{"# DS2API_HISTORY.txt", "=== 1. SYSTEM ===", "=== 2. USER ===", "=== 3. ASSISTANT ===", "=== 4. TOOL ===", "=== 5. USER ===", "system instructions", "first user turn", "hidden reasoning", "tool result", "latest user turn", promptcompat.ThinkingInjectionMarker} {
 		if !strings.Contains(uploadedText, want) {