fix: preserve OpenAI image edit reference fields (#4646)

* fix: preserve OpenAI image edit reference fields

* feat: support json image edit requests

dto/openai_image.go

@@ -27,6 +27,9 @@ type ImageRequest struct {
 	OutputCompression json.RawMessage `json:"output_compression,omitempty"`
 	PartialImages     json.RawMessage `json:"partial_images,omitempty"`
 	// Stream            bool            `json:"stream,omitempty"`
+	Images        json.RawMessage `json:"images,omitempty"`
+	Mask          json.RawMessage `json:"mask,omitempty"`
+	InputFidelity json.RawMessage `json:"input_fidelity,omitempty"`
 	Watermark     *bool           `json:"watermark,omitempty"`
 	// zhipu 4v
 	WatermarkEnabled json.RawMessage `json:"watermark_enabled,omitempty"`

relay/channel/openai/adaptor.go

@@ -426,6 +426,9 @@ func (a *Adaptor) ConvertAudioRequest(c *gin.Context, info *relaycommon.RelayInf
 func (a *Adaptor) ConvertImageRequest(c *gin.Context, info *relaycommon.RelayInfo, request dto.ImageRequest) (any, error) {
 	switch info.RelayMode {
 	case relayconstant.RelayModeImagesEdits:
+		if isJSONRequest(c) {
+			return request, nil
+		}
 
 		var requestBody bytes.Buffer
 		writer := multipart.NewWriter(&requestBody)
@@ -551,6 +554,13 @@ func (a *Adaptor) ConvertImageRequest(c *gin.Context, info *relaycommon.RelayInf
 	}
 }
 
+func isJSONRequest(c *gin.Context) bool {
+	if c == nil || c.Request == nil {
+		return false
+	}
+	return strings.HasPrefix(c.Request.Header.Get("Content-Type"), "application/json")
+}
+
 // detectImageMimeType determines the MIME type based on the file extension
 func detectImageMimeType(filename string) string {
 	ext := strings.ToLower(filepath.Ext(filename))
@@ -593,7 +603,7 @@ func (a *Adaptor) ConvertOpenAIResponsesRequest(c *gin.Context, info *relaycommo
 func (a *Adaptor) DoRequest(c *gin.Context, info *relaycommon.RelayInfo, requestBody io.Reader) (any, error) {
 	if info.RelayMode == relayconstant.RelayModeAudioTranscription ||
 		info.RelayMode == relayconstant.RelayModeAudioTranslation ||
-		info.RelayMode == relayconstant.RelayModeImagesEdits {
+		(info.RelayMode == relayconstant.RelayModeImagesEdits && !isJSONRequest(c)) {
 		return channel.DoFormRequest(a, c, info, requestBody)
 	} else if info.RelayMode == relayconstant.RelayModeRealtime {
 		return channel.DoWssRequest(a, c, info, requestBody)

relay/helper/valid_request.go

 package helper
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"math"
@@ -156,7 +155,7 @@ func GetAndValidOpenAIImageRequest(c *gin.Context, relayMode int) (*dto.ImageReq
 			imageRequest.Quality = formData.Get("quality")
 			imageRequest.Size = formData.Get("size")
 			if imageValue := formData.Get("image"); imageValue != "" {
-				imageRequest.Image, _ = json.Marshal(imageValue)
+				imageRequest.Image, _ = common.Marshal(imageValue)
 			}
 
 			if imageRequest.Model == "gpt-image-1" {