feat(registry, executor, util): add support for gemini-2.5-flash-image-preview and improve aspect ratio handling

- Introduced `gemini-2.5-flash-image-preview` model to the registry with updated definitions.
- Enhanced Gemini CLI and API executors to handle image aspect ratio adjustments for the new model.
- Added utility function to create base64 white image placeholders based on aspect ratio configurations.

internal/registry/model_definitions.go

@@ -104,6 +104,34 @@ func GetGeminiModels() []*ModelInfo {
 			OutputTokenLimit:           65536,
 			SupportedGenerationMethods: []string{"generateContent", "countTokens", "createCachedContent", "batchGenerateContent"},
 		},
+		{
+			ID:                         "gemini-2.5-flash-image-preview",
+			Object:                     "model",
+			Created:                    time.Now().Unix(),
+			OwnedBy:                    "google",
+			Type:                       "gemini",
+			Name:                       "models/gemini-2.5-flash-image-preview",
+			Version:                    "2.5",
+			DisplayName:                "Gemini 2.5 Flash Image Preview",
+			Description:                "State-of-the-art image generation and editing model.",
+			InputTokenLimit:            1048576,
+			OutputTokenLimit:           8192,
+			SupportedGenerationMethods: []string{"generateContent", "countTokens", "createCachedContent", "batchGenerateContent"},
+		},
+		{
+			ID:                         "gemini-2.5-flash-image",
+			Object:                     "model",
+			Created:                    time.Now().Unix(),
+			OwnedBy:                    "google",
+			Type:                       "gemini",
+			Name:                       "models/gemini-2.5-flash-image",
+			Version:                    "2.5",
+			DisplayName:                "Gemini 2.5 Flash Image",
+			Description:                "State-of-the-art image generation and editing model.",
+			InputTokenLimit:            1048576,
+			OutputTokenLimit:           8192,
+			SupportedGenerationMethods: []string{"generateContent", "countTokens", "createCachedContent", "batchGenerateContent"},
+		},
 	}
 }
 

internal/runtime/executor/gemini_cli_executor.go

@@ -14,6 +14,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/misc"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
 	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
 	sdktranslator "github.com/router-for-me/CLIProxyAPI/v6/sdk/translator"
@@ -60,6 +61,7 @@ func (e *GeminiCLIExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini-cli")
 	basePayload := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
+	basePayload = fixGeminiCLIImageAspectRatio(req.Model, basePayload)
 
 	action := "generateContent"
 	if req.Metadata != nil {
@@ -148,6 +150,7 @@ func (e *GeminiCLIExecutor) ExecuteStream(ctx context.Context, auth *cliproxyaut
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("gemini-cli")
 	basePayload := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
+	basePayload = fixGeminiCLIImageAspectRatio(req.Model, basePayload)
 
 	projectID := strings.TrimSpace(stringValue(auth.Metadata, "project_id"))
 
@@ -294,6 +297,7 @@ func (e *GeminiCLIExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.
 		payload = deleteJSONField(payload, "project")
 		payload = deleteJSONField(payload, "model")
 		payload = disableGeminiThinkingConfig(payload, attemptModel)
+		payload = fixGeminiCLIImageAspectRatio(attemptModel, payload)
 
 		tok, errTok := tokenSource.Token()
 		if errTok != nil {
@@ -549,3 +553,45 @@ func deleteJSONField(body []byte, key string) []byte {
 	}
 	return updated
 }
+
+func fixGeminiCLIImageAspectRatio(modelName string, rawJSON []byte) []byte {
+	if modelName == "gemini-2.5-flash-image-preview" {
+		aspectRatioResult := gjson.GetBytes(rawJSON, "request.generationConfig.imageConfig.aspectRatio")
+		if aspectRatioResult.Exists() {
+			contents := gjson.GetBytes(rawJSON, "request.contents")
+			contentArray := contents.Array()
+			if len(contentArray) > 0 {
+				hasInlineData := false
+			loopContent:
+				for i := 0; i < len(contentArray); i++ {
+					parts := contentArray[i].Get("parts").Array()
+					for j := 0; j < len(parts); j++ {
+						if parts[j].Get("inlineData").Exists() {
+							hasInlineData = true
+							break loopContent
+						}
+					}
+				}
+
+				if !hasInlineData {
+					emptyImageBase64ed, _ := util.CreateWhiteImageBase64(aspectRatioResult.String())
+					emptyImagePart := `{"inlineData":{"mime_type":"image/png","data":""}}`
+					emptyImagePart, _ = sjson.Set(emptyImagePart, "inlineData.data", emptyImageBase64ed)
+					newPartsJson := `[]`
+					newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", `{"text": "Based on the following requirements, create an image within the uploaded picture. The new content *MUST* completely cover the entire area of the original picture, maintaining its exact proportions, and *NO* blank areas should appear."}`)
+					newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", emptyImagePart)
+
+					parts := contentArray[0].Get("parts").Array()
+					for j := 0; j < len(parts); j++ {
+						newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", parts[j].Raw)
+					}
+
+					rawJSON, _ = sjson.SetRawBytes(rawJSON, "request.contents.0.parts", []byte(newPartsJson))
+					rawJSON, _ = sjson.SetRawBytes(rawJSON, "request.generationConfig.responseModalities", []byte(`["Image", "Text"]`))
+				}
+			}
+			rawJSON, _ = sjson.DeleteBytes(rawJSON, "request.generationConfig.imageConfig")
+		}
+	}
+	return rawJSON
+}

internal/runtime/executor/gemini_executor.go

@@ -78,6 +78,7 @@ func (e *GeminiExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
 	body = disableGeminiThinkingConfig(body, req.Model)
+	body = fixGeminiImageAspectRatio(req.Model, body)
 
 	action := "generateContent"
 	if req.Metadata != nil {
@@ -136,6 +137,7 @@ func (e *GeminiExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	to := sdktranslator.FromString("gemini")
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), true)
 	body = disableGeminiThinkingConfig(body, req.Model)
+	body = fixGeminiImageAspectRatio(req.Model, body)
 
 	url := fmt.Sprintf("%s/%s/models/%s:%s", glEndpoint, glAPIVersion, req.Model, "streamGenerateContent")
 	if opts.Alt == "" {
@@ -207,6 +209,7 @@ func (e *GeminiExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Aut
 	to := sdktranslator.FromString("gemini")
 	translatedReq := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), false)
 	translatedReq = disableGeminiThinkingConfig(translatedReq, req.Model)
+	translatedReq = fixGeminiImageAspectRatio(req.Model, translatedReq)
 	respCtx := context.WithValue(ctx, "alt", opts.Alt)
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "tools")
 	translatedReq, _ = sjson.DeleteBytes(translatedReq, "generationConfig")
@@ -374,3 +377,45 @@ func geminiCreds(a *cliproxyauth.Auth) (apiKey, bearer string) {
 	}
 	return
 }
+
+func fixGeminiImageAspectRatio(modelName string, rawJSON []byte) []byte {
+	if modelName == "gemini-2.5-flash-image-preview" {
+		aspectRatioResult := gjson.GetBytes(rawJSON, "generationConfig.imageConfig.aspectRatio")
+		if aspectRatioResult.Exists() {
+			contents := gjson.GetBytes(rawJSON, "contents")
+			contentArray := contents.Array()
+			if len(contentArray) > 0 {
+				hasInlineData := false
+			loopContent:
+				for i := 0; i < len(contentArray); i++ {
+					parts := contentArray[i].Get("parts").Array()
+					for j := 0; j < len(parts); j++ {
+						if parts[j].Get("inlineData").Exists() {
+							hasInlineData = true
+							break loopContent
+						}
+					}
+				}
+
+				if !hasInlineData {
+					emptyImageBase64ed, _ := util.CreateWhiteImageBase64(aspectRatioResult.String())
+					emptyImagePart := `{"inlineData":{"mime_type":"image/png","data":""}}`
+					emptyImagePart, _ = sjson.Set(emptyImagePart, "inlineData.data", emptyImageBase64ed)
+					newPartsJson := `[]`
+					newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", `{"text": "Based on the following requirements, create an image within the uploaded picture. The new content *MUST* completely cover the entire area of the original picture, maintaining its exact proportions, and *NO* blank areas should appear."}`)
+					newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", emptyImagePart)
+
+					parts := contentArray[0].Get("parts").Array()
+					for j := 0; j < len(parts); j++ {
+						newPartsJson, _ = sjson.SetRaw(newPartsJson, "-1", parts[j].Raw)
+					}
+
+					rawJSON, _ = sjson.SetRawBytes(rawJSON, "contents.0.parts", []byte(newPartsJson))
+					rawJSON, _ = sjson.SetRawBytes(rawJSON, "generationConfig.responseModalities", []byte(`["Image", "Text"]`))
+				}
+			}
+			rawJSON, _ = sjson.DeleteBytes(rawJSON, "generationConfig.imageConfig")
+		}
+	}
+	return rawJSON
+}

internal/util/image.go

@@ -0,0 +1,59 @@
+package util
+
+import (
+	"bytes"
+	"encoding/base64"
+	"image"
+	"image/draw"
+	"image/png"
+)
+
+func CreateWhiteImageBase64(aspectRatio string) (string, error) {
+	width := 1024
+	height := 1024
+
+	switch aspectRatio {
+	case "1:1":
+		width = 1024
+		height = 1024
+	case "2:3":
+		width = 832
+		height = 1248
+	case "3:2":
+		width = 1248
+		height = 832
+	case "3:4":
+		width = 864
+		height = 1184
+	case "4:3":
+		width = 1184
+		height = 864
+	case "4:5":
+		width = 896
+		height = 1152
+	case "5:4":
+		width = 1152
+		height = 896
+	case "9:16":
+		width = 768
+		height = 1344
+	case "16:9":
+		width = 1344
+		height = 768
+	case "21:9":
+		width = 1536
+		height = 672
+	}
+
+	img := image.NewRGBA(image.Rect(0, 0, width, height))
+	draw.Draw(img, img.Bounds(), image.White, image.Point{}, draw.Src)
+
+	var buf bytes.Buffer
+
+	if err := png.Encode(&buf, img); err != nil {
+		return "", err
+	}
+
+	base64String := base64.StdEncoding.EncodeToString(buf.Bytes())
+	return base64String, nil
+}