diff --git a/backend/internal/service/openai_codex_transform.go b/backend/internal/service/openai_codex_transform.go
index 457309d3..a68c9b67 100644
--- a/backend/internal/service/openai_codex_transform.go
+++ b/backend/internal/service/openai_codex_transform.go
@@ -187,9 +187,13 @@ func applyCodexOAuthTransform(reqBody map[string]any, isCodexCLI bool, isCompact
 }
 
 func normalizeCodexModel(model string) string {
+	model = strings.TrimSpace(model)
 	if model == "" {
 		return "gpt-5.4"
 	}
+	if isOpenAIImageGenerationModel(model) {
+		return model
+	}
 
 	modelID := model
 	if strings.Contains(modelID, "/") {
@@ -231,6 +235,78 @@ func normalizeCodexModel(model string) string {
 	return "gpt-5.4"
 }
 
+func hasOpenAIImageGenerationTool(reqBody map[string]any) bool {
+	rawTools, ok := reqBody["tools"]
+	if !ok || rawTools == nil {
+		return false
+	}
+	tools, ok := rawTools.([]any)
+	if !ok {
+		return false
+	}
+	for _, rawTool := range tools {
+		toolMap, ok := rawTool.(map[string]any)
+		if !ok {
+			continue
+		}
+		if strings.TrimSpace(firstNonEmptyString(toolMap["type"])) == "image_generation" {
+			return true
+		}
+	}
+	return false
+}
+
+func normalizeOpenAIResponsesImageGenerationTools(reqBody map[string]any) bool {
+	rawTools, ok := reqBody["tools"]
+	if !ok || rawTools == nil {
+		return false
+	}
+	tools, ok := rawTools.([]any)
+	if !ok {
+		return false
+	}
+
+	modified := false
+	for _, rawTool := range tools {
+		toolMap, ok := rawTool.(map[string]any)
+		if !ok || strings.TrimSpace(firstNonEmptyString(toolMap["type"])) != "image_generation" {
+			continue
+		}
+		if _, ok := toolMap["output_format"]; !ok {
+			if value := strings.TrimSpace(firstNonEmptyString(toolMap["format"])); value != "" {
+				toolMap["output_format"] = value
+				modified = true
+			}
+		}
+		if _, ok := toolMap["output_compression"]; !ok {
+			if value, exists := toolMap["compression"]; exists && value != nil {
+				toolMap["output_compression"] = value
+				modified = true
+			}
+		}
+		if _, ok := toolMap["format"]; ok {
+			delete(toolMap, "format")
+			modified = true
+		}
+		if _, ok := toolMap["compression"]; ok {
+			delete(toolMap, "compression")
+			modified = true
+		}
+	}
+	return modified
+}
+
+func validateOpenAIResponsesImageModel(reqBody map[string]any, model string) error {
+	if !hasOpenAIImageGenerationTool(reqBody) {
+		return nil
+	}
+	model = strings.TrimSpace(model)
+	if !isOpenAIImageGenerationModel(model) {
+		return nil
+	}
+	return fmt.Errorf("/v1/responses image_generation requests require a Responses-capable text model; image-only model %q is not allowed", model)
+}
+
 func normalizeOpenAIModelForUpstream(account *Account, model string) string {
 	if account == nil || account.Type == AccountTypeOAuth {
 		return normalizeCodexModel(model)
diff --git a/backend/internal/service/openai_codex_transform_test.go b/backend/internal/service/openai_codex_transform_test.go
index 22264f5e..f08e4b15 100644
--- a/backend/internal/service/openai_codex_transform_test.go
+++ b/backend/internal/service/openai_codex_transform_test.go
@@ -217,6 +217,42 @@ func TestApplyCodexOAuthTransform_NormalizeCodexTools_PreservesResponsesFunction
 	require.Equal(t, "bash", first["name"])
 }
 
+func TestNormalizeOpenAIResponsesImageGenerationTools_RewritesLegacyFields(t *testing.T) {
+	reqBody := map[string]any{
+		"tools": []any{
+			map[string]any{
+				"type":        "image_generation",
+				"format":      "png",
+				"compression": 60,
+			},
+		},
+	}
+
+	modified := normalizeOpenAIResponsesImageGenerationTools(reqBody)
+	require.True(t, modified)
+
+	tools, ok := reqBody["tools"].([]any)
+	require.True(t, ok)
+	first, ok := tools[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "png", first["output_format"])
+	require.Equal(t, 60, first["output_compression"])
+	_, hasFormat := first["format"]
+	require.False(t, hasFormat)
+	_, hasCompression := first["compression"]
+	require.False(t, hasCompression)
+}
+
+func TestValidateOpenAIResponsesImageModel_RejectsImageOnlyModel(t *testing.T) {
+	err := validateOpenAIResponsesImageModel(map[string]any{
+		"tools": []any{
+			map[string]any{"type": "image_generation"},
+		},
+	}, "gpt-image-2")
+
+	require.ErrorContains(t, err, `/v1/responses image_generation requests require a Responses-capable text model`)
+}
+
 func TestApplyCodexOAuthTransform_EmptyInput(t *testing.T) {
 	// 空 input 应保持为空且不触发异常。
 
diff --git a/backend/internal/service/openai_gateway_service.go b/backend/internal/service/openai_gateway_service.go
index a4a7ff1b..534ffeee 100644
--- a/backend/internal/service/openai_gateway_service.go
+++ b/backend/internal/service/openai_gateway_service.go
@@ -1935,6 +1935,12 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		markPatchSet("instructions", "You are a helpful coding assistant.")
 	}
 
+	if normalizeOpenAIResponsesImageGenerationTools(reqBody) {
+		bodyModified = true
+		disablePatch()
+		logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Normalized /responses image_generation tool payload")
+	}
+
 	// 对所有请求执行模型映射（包含 Codex CLI）。
 	billingModel := account.GetMappedModel(reqModel)
 	if billingModel != reqModel {
@@ -1944,6 +1950,26 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 		markPatchSet("model", billingModel)
 	}
 	upstreamModel := billingModel
+	if err := validateOpenAIResponsesImageModel(reqBody, upstreamModel); err != nil {
+		setOpsUpstreamError(c, http.StatusBadRequest, err.Error(), "")
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error": gin.H{
+				"type":    "invalid_request_error",
+				"message": err.Error(),
+				"param":   "model",
+			},
+		})
+		return nil, err
+	}
+	if hasOpenAIImageGenerationTool(reqBody) {
+		logger.LegacyPrintf(
+			"service.openai_gateway",
+			"[OpenAI] /responses image_generation request inbound_model=%s mapped_model=%s account_type=%s",
+			reqModel,
+			upstreamModel,
+			account.Type,
+		)
+	}
 
 	// OpenAI OAuth 账号走 ChatGPT internal Codex endpoint，需要将模型名规范化为
 	// 上游可识别的 Codex/GPT 系列。API Key 账号则应保留原始/映射后的模型名，
diff --git a/backend/internal/service/openai_images.go b/backend/internal/service/openai_images.go
index fb6bdc7f..f11a2278 100644
--- a/backend/internal/service/openai_images.go
+++ b/backend/internal/service/openai_images.go
@@ -47,6 +47,7 @@ const (
 
 	openAIImageBackendUserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36"
 	openAIImageRequirementsDiff = "0fffff"
+	openAIImageLifecycleTimeout = 2 * time.Minute
 )
 
 type OpenAIImagesCapability string
@@ -148,6 +149,9 @@ func (s *OpenAIGatewayService) ParseOpenAIImagesRequest(c *gin.Context, body []b
 	}
 
 	applyOpenAIImagesDefaults(req)
+	if err := validateOpenAIImagesModel(req.Model); err != nil {
+		return nil, err
+	}
 	req.SizeTier = normalizeOpenAIImageSizeTier(req.Size)
 	req.RequiredCapability = classifyOpenAIImagesCapability(req)
 	return req, nil
@@ -295,6 +299,21 @@ func applyOpenAIImagesDefaults(req *OpenAIImagesRequest) {
 	req.Model = "gpt-image-2"
 }
 
+func isOpenAIImageGenerationModel(model string) bool {
+	return strings.HasPrefix(strings.ToLower(strings.TrimSpace(model)), "gpt-image-")
+}
+
+func validateOpenAIImagesModel(model string) error {
+	model = strings.TrimSpace(model)
+	if isOpenAIImageGenerationModel(model) {
+		return nil
+	}
+	if model == "" {
+		return fmt.Errorf("images endpoint requires an image model")
+	}
+	return fmt.Errorf("images endpoint requires an image model, got %q", model)
+}
+
 func normalizeOpenAIImagesEndpointPath(path string) string {
 	trimmed := strings.TrimSpace(path)
 	switch {
@@ -400,7 +419,21 @@ func (s *OpenAIGatewayService) forwardOpenAIImagesAPIKey(
 	if mapped := strings.TrimSpace(channelMappedModel); mapped != "" {
 		requestModel = mapped
 	}
+	if err := validateOpenAIImagesModel(requestModel); err != nil {
+		return nil, err
+	}
 	upstreamModel := account.GetMappedModel(requestModel)
+	if err := validateOpenAIImagesModel(upstreamModel); err != nil {
+		return nil, err
+	}
+	logger.LegacyPrintf(
+		"service.openai_gateway",
+		"[OpenAI] Images request routing request_model=%s upstream_model=%s endpoint=%s account_type=%s",
+		strings.TrimSpace(parsed.Model),
+		upstreamModel,
+		parsed.Endpoint,
+		account.Type,
+	)
 	forwardBody, forwardContentType, err := rewriteOpenAIImagesModel(body, parsed.ContentType, upstreamModel)
 	if err != nil {
 		return nil, err
@@ -759,6 +792,17 @@ func (s *OpenAIGatewayService) forwardOpenAIImagesOAuth(
 	if mapped := strings.TrimSpace(channelMappedModel); mapped != "" {
 		requestModel = mapped
 	}
+	if err := validateOpenAIImagesModel(requestModel); err != nil {
+		return nil, err
+	}
+	logger.LegacyPrintf(
+		"service.openai_gateway",
+		"[OpenAI] Images request routing request_model=%s endpoint=%s account_type=%s uploads=%d",
+		requestModel,
+		parsed.Endpoint,
+		account.Type,
+		len(parsed.Uploads),
+	)
 
 	token, _, err := s.GetAccessToken(ctx, account)
 	if err != nil {
@@ -844,8 +888,18 @@ func (s *OpenAIGatewayService) forwardOpenAIImagesOAuth(
 		return nil, err
 	}
 	pointerInfos = mergeOpenAIImagePointerInfos(pointerInfos, nil)
+	logger.LegacyPrintf(
+		"service.openai_gateway",
+		"[OpenAI] Image extraction stream conversation_id=%s total_assets=%d file_service_assets=%d direct_assets=%d",
+		conversationID,
+		len(pointerInfos),
+		countOpenAIFileServicePointerInfos(pointerInfos),
+		countOpenAIDirectImageAssets(pointerInfos),
+	)
+	lifecycleCtx, releaseLifecycleCtx := detachOpenAIImageLifecycleContext(ctx, openAIImageLifecycleTimeout)
+	defer releaseLifecycleCtx()
 	if conversationID != "" && !hasOpenAIFileServicePointerInfos(pointerInfos) {
-		polledPointers, pollErr := pollOpenAIImageConversation(ctx, client, headers, conversationID)
+		polledPointers, pollErr := pollOpenAIImageConversation(lifecycleCtx, client, headers, conversationID)
 		if pollErr != nil {
 			return nil, s.wrapOpenAIImageBackendError(ctx, c, account, pollErr)
 		}
@@ -853,10 +907,11 @@ func (s *OpenAIGatewayService) forwardOpenAIImagesOAuth(
 	}
 	pointerInfos = preferOpenAIFileServicePointerInfos(pointerInfos)
 	if len(pointerInfos) == 0 {
+		logger.LegacyPrintf("service.openai_gateway", "[OpenAI] Image extraction yielded no assets conversation_id=%s", conversationID)
 		return nil, fmt.Errorf("openai image conversation returned no downloadable images")
 	}
 
-	responseBody, imageCount, err := buildOpenAIImageResponse(ctx, client, headers, conversationID, pointerInfos)
+	responseBody, imageCount, err := buildOpenAIImageResponse(lifecycleCtx, client, headers, conversationID, pointerInfos)
 	if err != nil {
 		return nil, s.wrapOpenAIImageBackendError(ctx, c, account, err)
 	}
@@ -1283,8 +1338,11 @@ func buildOpenAIImageConversationRequest(parsed *OpenAIImagesRequest, parentMess
 }
 
 type openAIImagePointerInfo struct {
-	Pointer string
-	Prompt  string
+	Pointer     string
+	DownloadURL string
+	B64JSON     string
+	MimeType    string
+	Prompt      string
 }
 
 type openAIImageToolMessage struct {
@@ -1336,10 +1394,6 @@ func collectOpenAIImagePointers(body []byte) []openAIImagePointerInfo {
 	if len(body) == 0 {
 		return nil
 	}
-	matches := openAIImagePointerMatches(body)
-	if len(matches) == 0 {
-		return nil
-	}
 	prompt := ""
 	for _, path := range []string{
 		"message.metadata.dalle.prompt",
@@ -1351,11 +1405,12 @@ func collectOpenAIImagePointers(body []byte) []openAIImagePointerInfo {
 			break
 		}
 	}
+	matches := openAIImagePointerMatches(body)
 	out := make([]openAIImagePointerInfo, 0, len(matches))
 	for _, pointer := range matches {
 		out = append(out, openAIImagePointerInfo{Pointer: pointer, Prompt: prompt})
 	}
-	return out
+	return mergeOpenAIImagePointerInfos(out, collectOpenAIImageInlineAssets(body, prompt))
 }
 
 func openAIImagePointerMatches(body []byte) []string {
@@ -1394,27 +1449,72 @@ func mergeOpenAIImagePointerInfos(existing []openAIImagePointerInfo, next []open
 	seen := make(map[string]openAIImagePointerInfo, len(existing)+len(next))
 	out := make([]openAIImagePointerInfo, 0, len(existing)+len(next))
 	for _, item := range existing {
-		seen[item.Pointer] = item
+		if key := item.identityKey(); key != "" {
+			seen[key] = item
+		}
 		out = append(out, item)
 	}
 	for _, item := range next {
-		if existingItem, ok := seen[item.Pointer]; ok {
-			if existingItem.Prompt == "" && item.Prompt != "" {
+		key := item.identityKey()
+		if key == "" {
+			continue
+		}
+		if existingItem, ok := seen[key]; ok {
+			merged := mergeOpenAIImagePointerInfo(existingItem, item)
+			if merged != existingItem {
 				for i := range out {
-					if out[i].Pointer == item.Pointer {
-						out[i].Prompt = item.Prompt
+					if out[i].identityKey() == key {
+						out[i] = merged
 						break
 					}
 				}
+				seen[key] = merged
 			}
 			continue
 		}
-		seen[item.Pointer] = item
+		seen[key] = item
 		out = append(out, item)
 	}
 	return out
 }
 
+func (i openAIImagePointerInfo) identityKey() string {
+	switch {
+	case strings.TrimSpace(i.Pointer) != "":
+		return "pointer:" + strings.TrimSpace(i.Pointer)
+	case strings.TrimSpace(i.DownloadURL) != "":
+		return "download:" + strings.TrimSpace(i.DownloadURL)
+	case strings.TrimSpace(i.B64JSON) != "":
+		b64 := strings.TrimSpace(i.B64JSON)
+		if len(b64) > 64 {
+			b64 = b64[:64]
+		}
+		return "b64:" + b64
+	default:
+		return ""
+	}
+}
+
+func mergeOpenAIImagePointerInfo(existing, next openAIImagePointerInfo) openAIImagePointerInfo {
+	merged := existing
+	if strings.TrimSpace(merged.Pointer) == "" {
+		merged.Pointer = next.Pointer
+	}
+	if strings.TrimSpace(merged.DownloadURL) == "" {
+		merged.DownloadURL = next.DownloadURL
+	}
+	if strings.TrimSpace(merged.B64JSON) == "" {
+		merged.B64JSON = next.B64JSON
+	}
+	if strings.TrimSpace(merged.MimeType) == "" {
+		merged.MimeType = next.MimeType
+	}
+	if strings.TrimSpace(merged.Prompt) == "" {
+		merged.Prompt = next.Prompt
+	}
+	return merged
+}
+
 func hasOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) bool {
 	for _, item := range items {
 		if strings.HasPrefix(item.Pointer, "file-service://") {
@@ -1424,6 +1524,26 @@ func hasOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) bool {
 	return false
 }
 
+func countOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) int {
+	count := 0
+	for _, item := range items {
+		if strings.HasPrefix(item.Pointer, "file-service://") {
+			count++
+		}
+	}
+	return count
+}
+
+func countOpenAIDirectImageAssets(items []openAIImagePointerInfo) int {
+	count := 0
+	for _, item := range items {
+		if strings.TrimSpace(item.DownloadURL) != "" || strings.TrimSpace(item.B64JSON) != "" {
+			count++
+		}
+	}
+	return count
+}
+
 func preferOpenAIFileServicePointerInfos(items []openAIImagePointerInfo) []openAIImagePointerInfo {
 	if !hasOpenAIFileServicePointerInfos(items) {
 		return items
@@ -1591,11 +1711,7 @@ func buildOpenAIImageResponse(
 	}
 	items := make([]responseItem, 0, len(pointers))
 	for _, pointer := range pointers {
-		downloadURL, err := fetchOpenAIImageDownloadURL(ctx, client, headers, conversationID, pointer.Pointer)
-		if err != nil {
-			return nil, 0, err
-		}
-		data, err := downloadOpenAIImageBytes(ctx, client, headers, downloadURL)
+		data, err := resolveOpenAIImageBytes(ctx, client, headers, conversationID, pointer)
 		if err != nil {
 			return nil, 0, err
 		}
@@ -1615,6 +1731,136 @@ func buildOpenAIImageResponse(
 	return body, len(items), nil
 }
 
+func resolveOpenAIImageBytes(
+	ctx context.Context,
+	client *req.Client,
+	headers http.Header,
+	conversationID string,
+	pointer openAIImagePointerInfo,
+) ([]byte, error) {
+	if normalized := normalizeOpenAIImageBase64(pointer.B64JSON); normalized != "" {
+		return base64.StdEncoding.DecodeString(normalized)
+	}
+	if downloadURL := strings.TrimSpace(pointer.DownloadURL); downloadURL != "" {
+		return downloadOpenAIImageBytes(ctx, client, headers, downloadURL)
+	}
+	if strings.TrimSpace(pointer.Pointer) == "" {
+		return nil, fmt.Errorf("image asset is missing pointer, url, and base64 data")
+	}
+	downloadURL, err := fetchOpenAIImageDownloadURL(ctx, client, headers, conversationID, pointer.Pointer)
+	if err != nil {
+		return nil, err
+	}
+	return downloadOpenAIImageBytes(ctx, client, headers, downloadURL)
+}
+
+func normalizeOpenAIImageBase64(raw string) string {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return ""
+	}
+	if strings.HasPrefix(strings.ToLower(raw), "data:") {
+		if idx := strings.Index(raw, ","); idx >= 0 && idx+1 < len(raw) {
+			raw = raw[idx+1:]
+		}
+	}
+	raw = strings.TrimSpace(raw)
+	raw = strings.TrimRight(raw, "=") + strings.Repeat("=", (4-len(raw)%4)%4)
+	if raw == "" {
+		return ""
+	}
+	if _, err := base64.StdEncoding.DecodeString(raw); err != nil {
+		return ""
+	}
+	return raw
+}
+
+func collectOpenAIImageInlineAssets(body []byte, fallbackPrompt string) []openAIImagePointerInfo {
+	if len(body) == 0 || !gjson.ValidBytes(body) {
+		return nil
+	}
+	var decoded any
+	if err := json.Unmarshal(body, &decoded); err != nil {
+		return nil
+	}
+	var out []openAIImagePointerInfo
+	walkOpenAIImageInlineAssets(decoded, strings.TrimSpace(fallbackPrompt), &out)
+	return out
+}
+
+func walkOpenAIImageInlineAssets(node any, prompt string, out *[]openAIImagePointerInfo) {
+	switch value := node.(type) {
+	case map[string]any:
+		localPrompt := prompt
+		for _, key := range []string{"revised_prompt", "image_gen_title", "prompt"} {
+			if v, ok := value[key].(string); ok && strings.TrimSpace(v) != "" {
+				localPrompt = strings.TrimSpace(v)
+				break
+			}
+		}
+		item := openAIImagePointerInfo{
+			Prompt:      localPrompt,
+			Pointer:     firstNonEmptyString(value["asset_pointer"], value["pointer"]),
+			DownloadURL: firstNonEmptyString(value["download_url"], value["url"], value["image_url"]),
+			B64JSON:     firstNonEmptyString(value["b64_json"], value["base64"], value["image_base64"]),
+			MimeType:    firstNonEmptyString(value["mime_type"], value["mimeType"], value["content_type"]),
+		}
+		switch {
+		case strings.HasPrefix(strings.TrimSpace(item.Pointer), "file-service://"),
+			strings.HasPrefix(strings.TrimSpace(item.Pointer), "sediment://"),
+			isLikelyOpenAIImageDownloadURL(item.DownloadURL),
+			normalizeOpenAIImageBase64(item.B64JSON) != "":
+			*out = append(*out, item)
+		}
+		for _, child := range value {
+			walkOpenAIImageInlineAssets(child, localPrompt, out)
+		}
+	case []any:
+		for _, child := range value {
+			walkOpenAIImageInlineAssets(child, prompt, out)
+		}
+	}
+}
+
+func firstNonEmptyString(values ...any) string {
+	for _, value := range values {
+		if s, ok := value.(string); ok && strings.TrimSpace(s) != "" {
+			return strings.TrimSpace(s)
+		}
+	}
+	return ""
+}
+
+func isLikelyOpenAIImageDownloadURL(raw string) bool {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return false
+	}
+	if strings.HasPrefix(strings.ToLower(raw), "data:image/") {
+		return true
+	}
+	if !strings.HasPrefix(strings.ToLower(raw), "http://") && !strings.HasPrefix(strings.ToLower(raw), "https://") {
+		return false
+	}
+	lower := strings.ToLower(raw)
+	return strings.Contains(lower, "/download") ||
+		strings.Contains(lower, ".png") ||
+		strings.Contains(lower, ".jpg") ||
+		strings.Contains(lower, ".jpeg") ||
+		strings.Contains(lower, ".webp")
+}
+
+func detachOpenAIImageLifecycleContext(ctx context.Context, timeout time.Duration) (context.Context, context.CancelFunc) {
+	base := context.Background()
+	if ctx != nil {
+		base = context.WithoutCancel(ctx)
+	}
+	if timeout <= 0 {
+		return base, func() {}
+	}
+	return context.WithTimeout(base, timeout)
+}
+
 func fetchOpenAIImageDownloadURL(
 	ctx context.Context,
 	client *req.Client,
diff --git a/backend/internal/service/openai_images_test.go b/backend/internal/service/openai_images_test.go
index 173d69ba..6aa1d5e5 100644
--- a/backend/internal/service/openai_images_test.go
+++ b/backend/internal/service/openai_images_test.go
@@ -2,6 +2,7 @@ package service
 
 import (
 	"bytes"
+	"context"
 	"mime/multipart"
 	"net/http"
 	"net/http/httptest"
@@ -103,3 +104,56 @@ func TestOpenAIGatewayServiceParseOpenAIImagesRequest_ExplicitSizeRequiresNative
 	require.NotNil(t, parsed)
 	require.Equal(t, OpenAIImagesCapabilityNative, parsed.RequiredCapability)
 }
+
+func TestOpenAIGatewayServiceParseOpenAIImagesRequest_RejectsNonImageModel(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"model":"gpt-5.4","prompt":"draw a cat"}`)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/images/generations", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	rec := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(rec)
+	c.Request = req
+
+	svc := &OpenAIGatewayService{}
+	parsed, err := svc.ParseOpenAIImagesRequest(c, body)
+	require.Nil(t, parsed)
+	require.ErrorContains(t, err, `images endpoint requires an image model, got "gpt-5.4"`)
+}
+
+func TestCollectOpenAIImagePointers_RecognizesDirectAssets(t *testing.T) {
+	items := collectOpenAIImagePointers([]byte(`{
+		"revised_prompt": "cat astronaut",
+		"parts": [
+			{"b64_json":"QUJD"},
+			{"download_url":"https://files.example.com/image.png?sig=1"},
+			{"asset_pointer":"file-service://file_123"}
+		]
+	}`))
+
+	require.Len(t, items, 3)
+	var sawBase64, sawURL, sawPointer bool
+	for _, item := range items {
+		if item.B64JSON == "QUJD" {
+			sawBase64 = true
+			require.Equal(t, "cat astronaut", item.Prompt)
+		}
+		if item.DownloadURL == "https://files.example.com/image.png?sig=1" {
+			sawURL = true
+		}
+		if item.Pointer == "file-service://file_123" {
+			sawPointer = true
+		}
+	}
+	require.True(t, sawBase64)
+	require.True(t, sawURL)
+	require.True(t, sawPointer)
+}
+
+func TestResolveOpenAIImageBytes_PrefersInlineBase64(t *testing.T) {
+	data, err := resolveOpenAIImageBytes(context.Background(), nil, nil, "", openAIImagePointerInfo{
+		B64JSON: "data:image/png;base64,QUJD",
+	})
+	require.NoError(t, err)
+	require.Equal(t, []byte("ABC"), data)
+}
diff --git a/backend/internal/service/openai_model_mapping_test.go b/backend/internal/service/openai_model_mapping_test.go
index 35e7c250..f25863a8 100644
--- a/backend/internal/service/openai_model_mapping_test.go
+++ b/backend/internal/service/openai_model_mapping_test.go
@@ -91,6 +91,7 @@ func TestNormalizeCodexModel(t *testing.T) {
 		"gpt-5.3-codex-spark-high":  "gpt-5.3-codex-spark",
 		"gpt-5.3-codex-spark-xhigh": "gpt-5.3-codex-spark",
 		"gpt-5.3":                   "gpt-5.3-codex",
+		"gpt-image-2":               "gpt-image-2",
 	}
 
 	for input, expected := range cases {
diff --git a/backend/internal/service/pricing_service.go b/backend/internal/service/pricing_service.go
index 2bf48702..106ec9f7 100644
--- a/backend/internal/service/pricing_service.go
+++ b/backend/internal/service/pricing_service.go
@@ -812,6 +812,16 @@ func (s *PricingService) matchOpenAIModel(model string) *LiteLLMModelPricing {
 		return openAIGPT54FallbackPricing
 	}
 
+	if isOpenAIImageGenerationModel(model) {
+		for _, candidate := range []string{"gpt-image-2", "gpt-image-1.5", "gpt-image-1"} {
+			if pricing, ok := s.pricingData[candidate]; ok {
+				logger.LegacyPrintf("service.pricing", "[Pricing] OpenAI image fallback matched %s -> %s", model, candidate)
+				return pricing
+			}
+		}
+		return nil
+	}
+
 	// 最终回退到 DefaultTestModel
 	defaultModel := strings.ToLower(openai.DefaultTestModel)
 	if pricing, ok := s.pricingData[defaultModel]; ok {
diff --git a/backend/internal/service/pricing_service_test.go b/backend/internal/service/pricing_service_test.go
index 13a5c70c..e2bd7cf3 100644
--- a/backend/internal/service/pricing_service_test.go
+++ b/backend/internal/service/pricing_service_test.go
@@ -128,6 +128,21 @@ func TestGetModelPricing_Gpt54NanoUsesDedicatedStaticFallbackWhenRemoteMissing(t
 	require.Zero(t, got.LongContextInputTokenThreshold)
 }
 
+func TestGetModelPricing_ImageModelDoesNotFallbackToTextModel(t *testing.T) {
+	imagePricing := &LiteLLMModelPricing{InputCostPerToken: 3}
+	textPricing := &LiteLLMModelPricing{InputCostPerToken: 9}
+
+	svc := &PricingService{
+		pricingData: map[string]*LiteLLMModelPricing{
+			"gpt-image-2": imagePricing,
+			"gpt-5.4":     textPricing,
+		},
+	}
+
+	got := svc.GetModelPricing("gpt-image-3")
+	require.Same(t, imagePricing, got)
+}
+
 func TestParsePricingData_PreservesPriorityAndServiceTierFields(t *testing.T) {
 	raw := map[string]any{
 		"gpt-5.4": map[string]any{