[ai-proxy] vertex image edits & variations (#3536)

plugins/wasm-go/extensions/ai-proxy/main.go

@@ -225,9 +225,9 @@ func onHttpRequestHeader(ctx wrapper.HttpContext, pluginConfig config.PluginConf
 		}
 	}
 
-	if contentType, _ := proxywasm.GetHttpRequestHeader(util.HeaderContentType); contentType != "" && !strings.Contains(contentType, util.MimeTypeApplicationJson) {
+	if contentType, _ := proxywasm.GetHttpRequestHeader(util.HeaderContentType); contentType != "" && !isSupportedRequestContentType(apiName, contentType) {
 		ctx.DontReadRequestBody()
-		log.Debugf("[onHttpRequestHeader] unsupported content type: %s, will not process the request body", contentType)
+		log.Debugf("[onHttpRequestHeader] unsupported content type for api %s: %s, will not process the request body", apiName, contentType)
 	}
 
 	if apiName == "" {
@@ -306,6 +306,7 @@ func onHttpRequestBody(ctx wrapper.HttpContext, pluginConfig config.PluginConfig
 		if err == nil {
 			return action
 		}
+		log.Errorf("[onHttpRequestBody] failed to process request body, apiName=%s, err=%v", apiName, err)
 		_ = util.ErrorHandler("ai-proxy.proc_req_body_failed", fmt.Errorf("failed to process request body: %v", err))
 	}
 	return types.ActionContinue
@@ -594,3 +595,14 @@ func getApiName(path string) provider.ApiName {
 
 	return ""
 }
+
+func isSupportedRequestContentType(apiName provider.ApiName, contentType string) bool {
+	if strings.Contains(contentType, util.MimeTypeApplicationJson) {
+		return true
+	}
+	contentType = strings.ToLower(contentType)
+	if strings.HasPrefix(contentType, "multipart/form-data") {
+		return apiName == provider.ApiNameImageEdit || apiName == provider.ApiNameImageVariation
+	}
+	return false
+}

plugins/wasm-go/extensions/ai-proxy/main_test.go

@@ -63,6 +63,54 @@ func Test_getApiName(t *testing.T) {
 	}
 }
 
+func Test_isSupportedRequestContentType(t *testing.T) {
+	tests := []struct {
+		name        string
+		apiName     provider.ApiName
+		contentType string
+		want        bool
+	}{
+		{
+			name:        "json chat completion",
+			apiName:     provider.ApiNameChatCompletion,
+			contentType: "application/json",
+			want:        true,
+		},
+		{
+			name:        "multipart image edit",
+			apiName:     provider.ApiNameImageEdit,
+			contentType: "multipart/form-data; boundary=----boundary",
+			want:        true,
+		},
+		{
+			name:        "multipart image variation",
+			apiName:     provider.ApiNameImageVariation,
+			contentType: "multipart/form-data; boundary=----boundary",
+			want:        true,
+		},
+		{
+			name:        "multipart chat completion",
+			apiName:     provider.ApiNameChatCompletion,
+			contentType: "multipart/form-data; boundary=----boundary",
+			want:        false,
+		},
+		{
+			name:        "text plain image edit",
+			apiName:     provider.ApiNameImageEdit,
+			contentType: "text/plain",
+			want:        false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := isSupportedRequestContentType(tt.apiName, tt.contentType)
+			if got != tt.want {
+				t.Errorf("isSupportedRequestContentType(%v, %q) = %v, want %v", tt.apiName, tt.contentType, got, tt.want)
+			}
+		})
+	}
+}
+
 func TestAi360(t *testing.T) {
 	test.RunAi360ParseConfigTests(t)
 	test.RunAi360OnHttpRequestHeadersTests(t)
@@ -137,6 +185,8 @@ func TestVertex(t *testing.T) {
 	test.RunVertexExpressModeOnStreamingResponseBodyTests(t)
 	test.RunVertexExpressModeImageGenerationRequestBodyTests(t)
 	test.RunVertexExpressModeImageGenerationResponseBodyTests(t)
+	test.RunVertexExpressModeImageEditVariationRequestBodyTests(t)
+	test.RunVertexExpressModeImageEditVariationResponseBodyTests(t)
 	// Vertex Raw 模式测试
 	test.RunVertexRawModeOnHttpRequestHeadersTests(t)
 	test.RunVertexRawModeOnHttpRequestBodyTests(t)

plugins/wasm-go/extensions/ai-proxy/provider/model.go

@@ -1,6 +1,7 @@
 package provider
 
 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 
@@ -461,6 +462,122 @@ type imageGenerationRequest struct {
 	Size              string `json:"size,omitempty"`
 }
 
+type imageInputURL struct {
+	URL      string                      `json:"url,omitempty"`
+	ImageURL *chatMessageContentImageUrl `json:"image_url,omitempty"`
+}
+
+func (i *imageInputURL) UnmarshalJSON(data []byte) error {
+	// Support a plain string payload, e.g. "data:image/png;base64,..."
+	var rawURL string
+	if err := json.Unmarshal(data, &rawURL); err == nil {
+		i.URL = rawURL
+		i.ImageURL = nil
+		return nil
+	}
+
+	type alias imageInputURL
+	var value alias
+	if err := json.Unmarshal(data, &value); err != nil {
+		return err
+	}
+	*i = imageInputURL(value)
+	return nil
+}
+
+func (i *imageInputURL) GetURL() string {
+	if i == nil {
+		return ""
+	}
+	if i.ImageURL != nil && i.ImageURL.Url != "" {
+		return i.ImageURL.Url
+	}
+	return i.URL
+}
+
+type imageEditRequest struct {
+	Model             string          `json:"model"`
+	Prompt            string          `json:"prompt"`
+	Image             *imageInputURL  `json:"image,omitempty"`
+	Images            []imageInputURL `json:"images,omitempty"`
+	ImageURL          *imageInputURL  `json:"image_url,omitempty"`
+	Mask              *imageInputURL  `json:"mask,omitempty"`
+	MaskURL           *imageInputURL  `json:"mask_url,omitempty"`
+	Background        string          `json:"background,omitempty"`
+	Moderation        string          `json:"moderation,omitempty"`
+	OutputCompression int             `json:"output_compression,omitempty"`
+	OutputFormat      string          `json:"output_format,omitempty"`
+	Quality           string          `json:"quality,omitempty"`
+	ResponseFormat    string          `json:"response_format,omitempty"`
+	Style             string          `json:"style,omitempty"`
+	N                 int             `json:"n,omitempty"`
+	Size              string          `json:"size,omitempty"`
+}
+
+func (r *imageEditRequest) GetImageURLs() []string {
+	urls := make([]string, 0, len(r.Images)+2)
+	for _, image := range r.Images {
+		if url := image.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	if r.Image != nil {
+		if url := r.Image.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	if r.ImageURL != nil {
+		if url := r.ImageURL.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	return urls
+}
+
+func (r *imageEditRequest) HasMask() bool {
+	if r.Mask != nil && r.Mask.GetURL() != "" {
+		return true
+	}
+	return r.MaskURL != nil && r.MaskURL.GetURL() != ""
+}
+
+type imageVariationRequest struct {
+	Model             string          `json:"model"`
+	Prompt            string          `json:"prompt,omitempty"`
+	Image             *imageInputURL  `json:"image,omitempty"`
+	Images            []imageInputURL `json:"images,omitempty"`
+	ImageURL          *imageInputURL  `json:"image_url,omitempty"`
+	Background        string          `json:"background,omitempty"`
+	Moderation        string          `json:"moderation,omitempty"`
+	OutputCompression int             `json:"output_compression,omitempty"`
+	OutputFormat      string          `json:"output_format,omitempty"`
+	Quality           string          `json:"quality,omitempty"`
+	ResponseFormat    string          `json:"response_format,omitempty"`
+	Style             string          `json:"style,omitempty"`
+	N                 int             `json:"n,omitempty"`
+	Size              string          `json:"size,omitempty"`
+}
+
+func (r *imageVariationRequest) GetImageURLs() []string {
+	urls := make([]string, 0, len(r.Images)+2)
+	for _, image := range r.Images {
+		if url := image.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	if r.Image != nil {
+		if url := r.Image.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	if r.ImageURL != nil {
+		if url := r.ImageURL.GetURL(); url != "" {
+			urls = append(urls, url)
+		}
+	}
+	return urls
+}
+
 type imageGenerationData struct {
 	URL           string `json:"url,omitempty"`
 	B64           string `json:"b64_json,omitempty"`

plugins/wasm-go/extensions/ai-proxy/provider/multipart_helper.go

@@ -0,0 +1,156 @@
+package provider
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+type multipartImageRequest struct {
+	Model        string
+	Prompt       string
+	Size         string
+	OutputFormat string
+	N            int
+	ImageURLs    []string
+	HasMask      bool
+}
+
+func isMultipartFormData(contentType string) bool {
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return false
+	}
+	return strings.EqualFold(mediaType, "multipart/form-data")
+}
+
+func parseMultipartImageRequest(body []byte, contentType string) (*multipartImageRequest, error) {
+	_, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse content-type: %v", err)
+	}
+	boundary := params["boundary"]
+	if boundary == "" {
+		return nil, fmt.Errorf("missing multipart boundary")
+	}
+
+	req := &multipartImageRequest{
+		ImageURLs: make([]string, 0),
+	}
+	reader := multipart.NewReader(bytes.NewReader(body), boundary)
+	for {
+		part, err := reader.NextPart()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, fmt.Errorf("unable to read multipart part: %v", err)
+		}
+		fieldName := part.FormName()
+		if fieldName == "" {
+			_ = part.Close()
+			continue
+		}
+		partContentType := strings.TrimSpace(part.Header.Get("Content-Type"))
+
+		partData, err := io.ReadAll(part)
+		_ = part.Close()
+		if err != nil {
+			return nil, fmt.Errorf("unable to read multipart field %s: %v", fieldName, err)
+		}
+
+		value := strings.TrimSpace(string(partData))
+		switch fieldName {
+		case "model":
+			req.Model = value
+			continue
+		case "prompt":
+			req.Prompt = value
+			continue
+		case "size":
+			req.Size = value
+			continue
+		case "output_format":
+			req.OutputFormat = value
+			continue
+		case "n":
+			if value != "" {
+				if parsed, err := strconv.Atoi(value); err == nil {
+					req.N = parsed
+				}
+			}
+			continue
+		}
+
+		if isMultipartImageField(fieldName) {
+			if isMultipartImageURLValue(value) {
+				req.ImageURLs = append(req.ImageURLs, value)
+				continue
+			}
+			if len(partData) == 0 {
+				continue
+			}
+			imageURL := buildMultipartDataURL(partContentType, partData)
+			req.ImageURLs = append(req.ImageURLs, imageURL)
+			continue
+		}
+		if isMultipartMaskField(fieldName) {
+			if len(partData) > 0 || value != "" {
+				req.HasMask = true
+			}
+			continue
+		}
+	}
+
+	return req, nil
+}
+
+func isMultipartImageField(fieldName string) bool {
+	return fieldName == "image" || fieldName == "image[]" || strings.HasPrefix(fieldName, "image[")
+}
+
+func isMultipartMaskField(fieldName string) bool {
+	return fieldName == "mask" || fieldName == "mask[]" || strings.HasPrefix(fieldName, "mask[")
+}
+
+func isMultipartImageURLValue(value string) bool {
+	if value == "" {
+		return false
+	}
+	loweredValue := strings.ToLower(value)
+	return strings.HasPrefix(loweredValue, "data:") || strings.HasPrefix(loweredValue, "http://") || strings.HasPrefix(loweredValue, "https://")
+}
+
+func buildMultipartDataURL(contentType string, data []byte) string {
+	mimeType := strings.TrimSpace(contentType)
+	if mimeType == "" || strings.EqualFold(mimeType, "application/octet-stream") {
+		mimeType = http.DetectContentType(data)
+	}
+	mimeType = normalizeMultipartMimeType(mimeType)
+	if mimeType == "" {
+		mimeType = "application/octet-stream"
+	}
+	encoded := base64.StdEncoding.EncodeToString(data)
+	return fmt.Sprintf("data:%s;base64,%s", mimeType, encoded)
+}
+
+func normalizeMultipartMimeType(contentType string) string {
+	contentType = strings.TrimSpace(contentType)
+	if contentType == "" {
+		return ""
+	}
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err == nil && mediaType != "" {
+		return strings.TrimSpace(mediaType)
+	}
+	if idx := strings.Index(contentType, ";"); idx > 0 {
+		return strings.TrimSpace(contentType[:idx])
+	}
+	return contentType
+}

plugins/wasm-go/extensions/ai-proxy/provider/provider.go

@@ -763,19 +763,19 @@ func (c *ProviderConfig) GetRandomToken() string {
 func isStatefulAPI(apiName string) bool {
 	// These APIs maintain session state and should be routed to the same provider consistently
 	statefulAPIs := map[string]bool{
-		string(ApiNameResponses):                 true, // Response API - uses previous_response_id
-		string(ApiNameFiles):                     true, // Files API - maintains file state
-		string(ApiNameRetrieveFile):              true, // File retrieval - depends on file upload
-		string(ApiNameRetrieveFileContent):       true, // File content - depends on file upload
-		string(ApiNameBatches):                   true, // Batch API - maintains batch state
-		string(ApiNameRetrieveBatch):             true, // Batch status - depends on batch creation
-		string(ApiNameCancelBatch):               true, // Batch operations - depends on batch state
-		string(ApiNameFineTuningJobs):            true, // Fine-tuning - maintains job state
-		string(ApiNameRetrieveFineTuningJob):     true, // Fine-tuning job status
-		string(ApiNameFineTuningJobEvents):       true, // Fine-tuning events
-		string(ApiNameFineTuningJobCheckpoints):  true, // Fine-tuning checkpoints
-		string(ApiNameCancelFineTuningJob):       true, // Cancel fine-tuning job
-		string(ApiNameResumeFineTuningJob):       true, // Resume fine-tuning job
+		string(ApiNameResponses):                true, // Response API - uses previous_response_id
+		string(ApiNameFiles):                    true, // Files API - maintains file state
+		string(ApiNameRetrieveFile):             true, // File retrieval - depends on file upload
+		string(ApiNameRetrieveFileContent):      true, // File content - depends on file upload
+		string(ApiNameBatches):                  true, // Batch API - maintains batch state
+		string(ApiNameRetrieveBatch):            true, // Batch status - depends on batch creation
+		string(ApiNameCancelBatch):              true, // Batch operations - depends on batch state
+		string(ApiNameFineTuningJobs):           true, // Fine-tuning - maintains job state
+		string(ApiNameRetrieveFineTuningJob):    true, // Fine-tuning job status
+		string(ApiNameFineTuningJobEvents):      true, // Fine-tuning events
+		string(ApiNameFineTuningJobCheckpoints): true, // Fine-tuning checkpoints
+		string(ApiNameCancelFineTuningJob):      true, // Cancel fine-tuning job
+		string(ApiNameResumeFineTuningJob):      true, // Resume fine-tuning job
 	}
 	return statefulAPIs[apiName]
 }
@@ -845,6 +845,16 @@ func (c *ProviderConfig) parseRequestAndMapModel(ctx wrapper.HttpContext, reques
 			return err
 		}
 		return c.setRequestModel(ctx, req)
+	case *imageEditRequest:
+		if err := decodeImageEditRequest(body, req); err != nil {
+			return err
+		}
+		return c.setRequestModel(ctx, req)
+	case *imageVariationRequest:
+		if err := decodeImageVariationRequest(body, req); err != nil {
+			return err
+		}
+		return c.setRequestModel(ctx, req)
 	default:
 		return errors.New("unsupported request type")
 	}
@@ -860,6 +870,10 @@ func (c *ProviderConfig) setRequestModel(ctx wrapper.HttpContext, request interf
 		model = &req.Model
 	case *imageGenerationRequest:
 		model = &req.Model
+	case *imageEditRequest:
+		model = &req.Model
+	case *imageVariationRequest:
+		model = &req.Model
 	default:
 		return errors.New("unsupported request type")
 	}

plugins/wasm-go/extensions/ai-proxy/provider/request_helper.go

@@ -4,8 +4,8 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/higress-group/wasm-go/pkg/log"
 	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/wasm-go/pkg/log"
 )
 
 func decodeChatCompletionRequest(body []byte, request *chatCompletionRequest) error {
@@ -32,6 +32,20 @@ func decodeImageGenerationRequest(body []byte, request *imageGenerationRequest)
 	return nil
 }
 
+func decodeImageEditRequest(body []byte, request *imageEditRequest) error {
+	if err := json.Unmarshal(body, request); err != nil {
+		return fmt.Errorf("unable to unmarshal request: %v", err)
+	}
+	return nil
+}
+
+func decodeImageVariationRequest(body []byte, request *imageVariationRequest) error {
+	if err := json.Unmarshal(body, request); err != nil {
+		return fmt.Errorf("unable to unmarshal request: %v", err)
+	}
+	return nil
+}
+
 func replaceJsonRequestBody(request interface{}) error {
 	body, err := json.Marshal(request)
 	if err != nil {

plugins/wasm-go/extensions/ai-proxy/provider/vertex.go

@@ -46,6 +46,7 @@ const (
 	contextOpenAICompatibleMarker      = "isOpenAICompatibleRequest"
 	contextVertexRawMarker             = "isVertexRawRequest"
 	vertexAnthropicVersion             = "vertex-2023-10-16"
+	vertexImageVariationDefaultPrompt  = "Create variations of the provided image."
 )
 
 // vertexRawPathRegex 匹配原生 Vertex AI REST API 路径
@@ -98,6 +99,8 @@ func (v *vertexProviderInitializer) DefaultCapabilities() map[string]string {
 		string(ApiNameChatCompletion):  vertexPathTemplate,
 		string(ApiNameEmbeddings):      vertexPathTemplate,
 		string(ApiNameImageGeneration): vertexPathTemplate,
+		string(ApiNameImageEdit):       vertexPathTemplate,
+		string(ApiNameImageVariation):  vertexPathTemplate,
 		string(ApiNameVertexRaw):       "", // 空字符串表示保持原路径，不做路径转换
 	}
 }
@@ -307,6 +310,10 @@ func (v *vertexProvider) TransformRequestBodyHeaders(ctx wrapper.HttpContext, ap
 		return v.onEmbeddingsRequestBody(ctx, body, headers)
 	case ApiNameImageGeneration:
 		return v.onImageGenerationRequestBody(ctx, body, headers)
+	case ApiNameImageEdit:
+		return v.onImageEditRequestBody(ctx, body, headers)
+	case ApiNameImageVariation:
+		return v.onImageVariationRequestBody(ctx, body, headers)
 	default:
 		return body, nil
 	}
@@ -387,11 +394,108 @@ func (v *vertexProvider) onImageGenerationRequestBody(ctx wrapper.HttpContext, b
 	path := v.getRequestPath(ApiNameImageGeneration, request.Model, false)
 	util.OverwriteRequestPathHeader(headers, path)
 
-	vertexRequest := v.buildVertexImageGenerationRequest(request)
+	vertexRequest, err := v.buildVertexImageGenerationRequest(request)
+	if err != nil {
+		return nil, err
+	}
 	return json.Marshal(vertexRequest)
 }
 
-func (v *vertexProvider) buildVertexImageGenerationRequest(request *imageGenerationRequest) *vertexChatRequest {
+func (v *vertexProvider) onImageEditRequestBody(ctx wrapper.HttpContext, body []byte, headers http.Header) ([]byte, error) {
+	request := &imageEditRequest{}
+	imageURLs := make([]string, 0)
+	contentType := headers.Get("Content-Type")
+	if isMultipartFormData(contentType) {
+		parsedRequest, err := parseMultipartImageRequest(body, contentType)
+		if err != nil {
+			return nil, err
+		}
+		request.Model = parsedRequest.Model
+		request.Prompt = parsedRequest.Prompt
+		request.Size = parsedRequest.Size
+		request.OutputFormat = parsedRequest.OutputFormat
+		request.N = parsedRequest.N
+		imageURLs = parsedRequest.ImageURLs
+		if err := v.config.mapModel(ctx, &request.Model); err != nil {
+			return nil, err
+		}
+		if parsedRequest.HasMask {
+			return nil, fmt.Errorf("mask is not supported for vertex image edits yet")
+		}
+	} else {
+		if err := v.config.parseRequestAndMapModel(ctx, request, body); err != nil {
+			return nil, err
+		}
+		if request.HasMask() {
+			return nil, fmt.Errorf("mask is not supported for vertex image edits yet")
+		}
+		imageURLs = request.GetImageURLs()
+	}
+	if len(imageURLs) == 0 {
+		return nil, fmt.Errorf("missing image_url in request")
+	}
+	if request.Prompt == "" {
+		return nil, fmt.Errorf("missing prompt in request")
+	}
+
+	path := v.getRequestPath(ApiNameImageEdit, request.Model, false)
+	util.OverwriteRequestPathHeader(headers, path)
+	headers.Set("Content-Type", util.MimeTypeApplicationJson)
+	vertexRequest, err := v.buildVertexImageRequest(request.Prompt, request.Size, request.OutputFormat, imageURLs)
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(vertexRequest)
+}
+
+func (v *vertexProvider) onImageVariationRequestBody(ctx wrapper.HttpContext, body []byte, headers http.Header) ([]byte, error) {
+	request := &imageVariationRequest{}
+	imageURLs := make([]string, 0)
+	contentType := headers.Get("Content-Type")
+	if isMultipartFormData(contentType) {
+		parsedRequest, err := parseMultipartImageRequest(body, contentType)
+		if err != nil {
+			return nil, err
+		}
+		request.Model = parsedRequest.Model
+		request.Prompt = parsedRequest.Prompt
+		request.Size = parsedRequest.Size
+		request.OutputFormat = parsedRequest.OutputFormat
+		request.N = parsedRequest.N
+		imageURLs = parsedRequest.ImageURLs
+		if err := v.config.mapModel(ctx, &request.Model); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := v.config.parseRequestAndMapModel(ctx, request, body); err != nil {
+			return nil, err
+		}
+		imageURLs = request.GetImageURLs()
+	}
+	if len(imageURLs) == 0 {
+		return nil, fmt.Errorf("missing image_url in request")
+	}
+
+	prompt := request.Prompt
+	if prompt == "" {
+		prompt = vertexImageVariationDefaultPrompt
+	}
+
+	path := v.getRequestPath(ApiNameImageVariation, request.Model, false)
+	util.OverwriteRequestPathHeader(headers, path)
+	headers.Set("Content-Type", util.MimeTypeApplicationJson)
+	vertexRequest, err := v.buildVertexImageRequest(prompt, request.Size, request.OutputFormat, imageURLs)
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(vertexRequest)
+}
+
+func (v *vertexProvider) buildVertexImageGenerationRequest(request *imageGenerationRequest) (*vertexChatRequest, error) {
+	return v.buildVertexImageRequest(request.Prompt, request.Size, request.OutputFormat, nil)
+}
+
+func (v *vertexProvider) buildVertexImageRequest(prompt string, size string, outputFormat string, imageURLs []string) (*vertexChatRequest, error) {
 	// 构建安全设置
 	safetySettings := make([]vertexChatSafetySetting, 0)
 	for category, threshold := range v.config.geminiSafetySetting {
@@ -402,12 +506,12 @@ func (v *vertexProvider) buildVertexImageGenerationRequest(request *imageGenerat
 	}
 
 	// 解析尺寸参数
-	aspectRatio, imageSize := v.parseImageSize(request.Size)
+	aspectRatio, imageSize := v.parseImageSize(size)
 
 	// 确定输出 MIME 类型
 	mimeType := "image/png"
-	if request.OutputFormat != "" {
-		switch request.OutputFormat {
+	if outputFormat != "" {
+		switch outputFormat {
 		case "jpeg", "jpg":
 			mimeType = "image/jpeg"
 		case "webp":
@@ -417,12 +521,27 @@ func (v *vertexProvider) buildVertexImageGenerationRequest(request *imageGenerat
 		}
 	}
 
+	parts := make([]vertexPart, 0, len(imageURLs)+1)
+	for _, imageURL := range imageURLs {
+		part, err := convertMediaContent(imageURL)
+		if err != nil {
+			return nil, err
+		}
+		parts = append(parts, part)
+	}
+	if prompt != "" {
+		parts = append(parts, vertexPart{
+			Text: prompt,
+		})
+	}
+	if len(parts) == 0 {
+		return nil, fmt.Errorf("missing prompt and image_url in request")
+	}
+
 	vertexRequest := &vertexChatRequest{
 		Contents: []vertexChatContent{{
-			Role: roleUser,
-			Parts: []vertexPart{{
-				Text: request.Prompt,
-			}},
+			Role:  roleUser,
+			Parts: parts,
 		}},
 		SafetySettings: safetySettings,
 		GenerationConfig: vertexChatGenerationConfig{
@@ -440,7 +559,7 @@ func (v *vertexProvider) buildVertexImageGenerationRequest(request *imageGenerat
 		},
 	}
 
-	return vertexRequest
+	return vertexRequest, nil
 }
 
 // parseImageSize 解析 OpenAI 格式的尺寸字符串（如 "1024x1024"）为 Vertex AI 的 aspectRatio 和 imageSize
@@ -553,7 +672,7 @@ func (v *vertexProvider) TransformResponseBody(ctx wrapper.HttpContext, apiName
 		return v.onChatCompletionResponseBody(ctx, body)
 	case ApiNameEmbeddings:
 		return v.onEmbeddingsResponseBody(ctx, body)
-	case ApiNameImageGeneration:
+	case ApiNameImageGeneration, ApiNameImageEdit, ApiNameImageVariation:
 		return v.onImageGenerationResponseBody(ctx, body)
 	default:
 		return body, nil
@@ -784,7 +903,7 @@ func (v *vertexProvider) getRequestPath(apiName ApiName, modelId string, stream
 	switch apiName {
 	case ApiNameEmbeddings:
 		action = vertexEmbeddingAction
-	case ApiNameImageGeneration:
+	case ApiNameImageGeneration, ApiNameImageEdit, ApiNameImageVariation:
 		// 图片生成使用非流式端点，需要完整响应
 		action = vertexChatCompletionAction
 	default:

plugins/wasm-go/extensions/ai-proxy/test/vertex.go

@@ -1,7 +1,9 @@
 package test
 
 import (
+	"bytes"
 	"encoding/json"
+	"mime/multipart"
 	"strings"
 	"testing"
 
@@ -1273,6 +1275,324 @@ func RunVertexExpressModeImageGenerationResponseBodyTests(t *testing.T) {
 	})
 }
 
+func buildMultipartRequestBody(t *testing.T, fields map[string]string, files map[string][]byte) ([]byte, string) {
+	var buffer bytes.Buffer
+	writer := multipart.NewWriter(&buffer)
+
+	for key, value := range fields {
+		require.NoError(t, writer.WriteField(key, value))
+	}
+
+	for fieldName, data := range files {
+		part, err := writer.CreateFormFile(fieldName, "upload-image.png")
+		require.NoError(t, err)
+		_, err = part.Write(data)
+		require.NoError(t, err)
+	}
+
+	require.NoError(t, writer.Close())
+	return buffer.Bytes(), writer.FormDataContentType()
+}
+
+func RunVertexExpressModeImageEditVariationRequestBodyTests(t *testing.T) {
+	test.RunTest(t, func(t *testing.T) {
+		const testDataURL = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
+
+		t.Run("vertex express mode image edit request body with image_url", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/edits"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gemini-2.0-flash-exp","prompt":"Add sunglasses to the cat","image":{"image_url":{"url":"` + testDataURL + `"}},"size":"1024x1024"}`
+			action := host.CallOnHttpRequestBody([]byte(requestBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			processedBody := host.GetRequestBody()
+			require.NotNil(t, processedBody)
+
+			bodyStr := string(processedBody)
+			require.Contains(t, bodyStr, "inlineData", "Request should contain inlineData converted from image_url")
+			require.Contains(t, bodyStr, "Add sunglasses to the cat", "Prompt text should be preserved")
+			require.NotContains(t, bodyStr, "image_url", "OpenAI image_url field should be converted to Vertex format")
+
+			requestHeaders := host.GetRequestHeaders()
+			pathHeader := ""
+			for _, header := range requestHeaders {
+				if header[0] == ":path" {
+					pathHeader = header[1]
+					break
+				}
+			}
+			require.Contains(t, pathHeader, "generateContent", "Image edit should use generateContent action")
+			require.Contains(t, pathHeader, "key=test-api-key-123456789", "Path should contain API key")
+		})
+
+		t.Run("vertex express mode image edit request body with image string", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/edits"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gemini-2.0-flash-exp","prompt":"Add sunglasses to the cat","image":"` + testDataURL + `","size":"1024x1024"}`
+			action := host.CallOnHttpRequestBody([]byte(requestBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			processedBody := host.GetRequestBody()
+			require.NotNil(t, processedBody)
+
+			bodyStr := string(processedBody)
+			require.Contains(t, bodyStr, "inlineData", "Request should contain inlineData converted from image string")
+			require.Contains(t, bodyStr, "Add sunglasses to the cat", "Prompt text should be preserved")
+		})
+
+		t.Run("vertex express mode image edit multipart request body", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			body, contentType := buildMultipartRequestBody(t, map[string]string{
+				"model":  "gemini-2.0-flash-exp",
+				"prompt": "Add sunglasses to the cat",
+				"size":   "1024x1024",
+			}, map[string][]byte{
+				"image": []byte("fake-image-content"),
+			})
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/edits"},
+				{":method", "POST"},
+				{"Content-Type", contentType},
+			})
+
+			action := host.CallOnHttpRequestBody(body)
+			require.Equal(t, types.ActionContinue, action)
+
+			processedBody := host.GetRequestBody()
+			require.NotNil(t, processedBody)
+			bodyStr := string(processedBody)
+			require.Contains(t, bodyStr, "inlineData", "Multipart image should be converted to inlineData")
+			require.Contains(t, bodyStr, "Add sunglasses to the cat", "Prompt text should be preserved")
+
+			requestHeaders := host.GetRequestHeaders()
+			require.True(t, test.HasHeaderWithValue(requestHeaders, "Content-Type", "application/json"), "Content-Type should be rewritten to application/json")
+		})
+
+		t.Run("vertex express mode image variation multipart request body", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			body, contentType := buildMultipartRequestBody(t, map[string]string{
+				"model": "gemini-2.0-flash-exp",
+				"size":  "1024x1024",
+			}, map[string][]byte{
+				"image": []byte("fake-image-content"),
+			})
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/variations"},
+				{":method", "POST"},
+				{"Content-Type", contentType},
+			})
+
+			action := host.CallOnHttpRequestBody(body)
+			require.Equal(t, types.ActionContinue, action)
+
+			processedBody := host.GetRequestBody()
+			require.NotNil(t, processedBody)
+			bodyStr := string(processedBody)
+			require.Contains(t, bodyStr, "inlineData", "Multipart image should be converted to inlineData")
+			require.Contains(t, bodyStr, "Create variations of the provided image.", "Variation request should inject a default prompt")
+
+			requestHeaders := host.GetRequestHeaders()
+			require.True(t, test.HasHeaderWithValue(requestHeaders, "Content-Type", "application/json"), "Content-Type should be rewritten to application/json")
+		})
+
+		t.Run("vertex express mode image edit with model mapping", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeWithModelMappingConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/edits"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gpt-4","prompt":"Turn it into watercolor","image_url":{"url":"` + testDataURL + `"}}`
+			action := host.CallOnHttpRequestBody([]byte(requestBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			requestHeaders := host.GetRequestHeaders()
+			pathHeader := ""
+			for _, header := range requestHeaders {
+				if header[0] == ":path" {
+					pathHeader = header[1]
+					break
+				}
+			}
+			require.Contains(t, pathHeader, "gemini-2.5-flash", "Path should contain mapped model name")
+		})
+
+		t.Run("vertex express mode image variation request body with image_url", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/variations"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gemini-2.0-flash-exp","image_url":{"url":"` + testDataURL + `"}}`
+			action := host.CallOnHttpRequestBody([]byte(requestBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			processedBody := host.GetRequestBody()
+			require.NotNil(t, processedBody)
+
+			bodyStr := string(processedBody)
+			require.Contains(t, bodyStr, "inlineData", "Request should contain inlineData converted from image_url")
+			require.Contains(t, bodyStr, "Create variations of the provided image.", "Variation request should inject a default prompt")
+
+			requestHeaders := host.GetRequestHeaders()
+			pathHeader := ""
+			for _, header := range requestHeaders {
+				if header[0] == ":path" {
+					pathHeader = header[1]
+					break
+				}
+			}
+			require.Contains(t, pathHeader, "generateContent", "Image variation should use generateContent action")
+			require.Contains(t, pathHeader, "key=test-api-key-123456789", "Path should contain API key")
+		})
+	})
+}
+
+func RunVertexExpressModeImageEditVariationResponseBodyTests(t *testing.T) {
+	test.RunTest(t, func(t *testing.T) {
+		const testDataURL = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
+
+		t.Run("vertex express mode image edit response body", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/edits"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gemini-2.0-flash-exp","prompt":"Add glasses","image_url":{"url":"` + testDataURL + `"}}`
+			host.CallOnHttpRequestBody([]byte(requestBody))
+
+			host.SetProperty([]string{"response", "code_details"}, []byte("via_upstream"))
+			host.CallOnHttpResponseHeaders([][2]string{
+				{":status", "200"},
+				{"Content-Type", "application/json"},
+			})
+
+			responseBody := `{
+				"candidates": [{
+					"content": {
+						"role": "model",
+						"parts": [{
+							"inlineData": {
+								"mimeType": "image/png",
+								"data": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
+							}
+						}]
+					}
+				}],
+				"usageMetadata": {
+					"promptTokenCount": 12,
+					"candidatesTokenCount": 1024,
+					"totalTokenCount": 1036
+				}
+			}`
+			action := host.CallOnHttpResponseBody([]byte(responseBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			processedResponseBody := host.GetResponseBody()
+			require.NotNil(t, processedResponseBody)
+
+			responseStr := string(processedResponseBody)
+			require.Contains(t, responseStr, "b64_json", "Response should contain b64_json field")
+			require.Contains(t, responseStr, "usage", "Response should contain usage field")
+		})
+
+		t.Run("vertex express mode image variation response body", func(t *testing.T) {
+			host, status := test.NewTestHost(vertexExpressModeConfig)
+			defer host.Reset()
+			require.Equal(t, types.OnPluginStartStatusOK, status)
+
+			host.CallOnHttpRequestHeaders([][2]string{
+				{":authority", "example.com"},
+				{":path", "/v1/images/variations"},
+				{":method", "POST"},
+				{"Content-Type", "application/json"},
+			})
+
+			requestBody := `{"model":"gemini-2.0-flash-exp","image_url":{"url":"` + testDataURL + `"}}`
+			host.CallOnHttpRequestBody([]byte(requestBody))
+
+			host.SetProperty([]string{"response", "code_details"}, []byte("via_upstream"))
+			host.CallOnHttpResponseHeaders([][2]string{
+				{":status", "200"},
+				{"Content-Type", "application/json"},
+			})
+
+			responseBody := `{
+				"candidates": [{
+					"content": {
+						"role": "model",
+						"parts": [{
+							"inlineData": {
+								"mimeType": "image/png",
+								"data": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
+							}
+						}]
+					}
+				}],
+				"usageMetadata": {
+					"promptTokenCount": 8,
+					"candidatesTokenCount": 768,
+					"totalTokenCount": 776
+				}
+			}`
+			action := host.CallOnHttpResponseBody([]byte(responseBody))
+			require.Equal(t, types.ActionContinue, action)
+
+			processedResponseBody := host.GetResponseBody()
+			require.NotNil(t, processedResponseBody)
+
+			responseStr := string(processedResponseBody)
+			require.Contains(t, responseStr, "b64_json", "Response should contain b64_json field")
+			require.Contains(t, responseStr, "usage", "Response should contain usage field")
+		})
+	})
+}
+
 // ==================== Vertex Raw 模式测试 ====================
 
 func RunVertexRawModeOnHttpRequestHeadersTests(t *testing.T) {