Preserve proxy image API resolution sizes

src/lib/image-api-templates/openai-compatible.ts

@@ -27,6 +27,21 @@ function normalizeGptImageSize(size: string | undefined): string | undefined {
   return '1024x1024';
 }
 
+function isOfficialOpenAIEndpoint(apiUrl: string | undefined): boolean {
+  try {
+    return new URL(apiUrl || '').hostname.toLowerCase() === 'api.openai.com';
+  } catch {
+    return false;
+  }
+}
+
+function preserveRequestedImageSize(size: string | undefined): string | undefined {
+  if (!size) return undefined;
+  const normalized = size.trim().toLowerCase();
+  if (normalized === 'auto') return 'auto';
+  return /^\d{2,5}x\d{2,5}$/i.test(normalized) ? normalized : undefined;
+}
+
 function normalizeDallE3Size(size: string | undefined): string {
   const normalized = (size || '').trim().toLowerCase();
   if (['1024x1024', '1792x1024', '1024x1792'].includes(normalized)) return normalized;
@@ -46,9 +61,16 @@ function normalizeDallE2Size(size: string | undefined): string {
   return '1024x1024';
 }
 
-export function normalizeOpenAICompatibleImageSize(modelName: string | undefined, size: string | undefined): string {
+export function normalizeOpenAICompatibleImageSize(
+  modelName: string | undefined,
+  size: string | undefined,
+  options: { apiUrl?: string } = {},
+): string {
   if (isDallE3Model(modelName)) return normalizeDallE3Size(size);
   if (isDallE2Model(modelName)) return normalizeDallE2Size(size);
+  if (isGptImageModel(modelName) && !isOfficialOpenAIEndpoint(options.apiUrl)) {
+    return preserveRequestedImageSize(size) || 'auto';
+  }
   return normalizeGptImageSize(size) || 'auto';
 }
 
@@ -118,7 +140,7 @@ export const openAICompatibleImageTemplate: ImageApiTemplate = {
   matches: isOpenAICompatibleImageApi,
   buildTextToImageRequest(input) {
     const requestCount = normalizeOpenAICompatibleImageCount(input.modelName, input.count);
-    const requestSize = normalizeOpenAICompatibleImageSize(input.modelName, input.size);
+    const requestSize = normalizeOpenAICompatibleImageSize(input.modelName, input.size, { apiUrl: input.apiUrl });
     const prompt = input.negativePrompt
       ? `${input.prompt}\n\nNegative prompt: ${input.negativePrompt}`
       : input.prompt;
@@ -148,7 +170,7 @@ export const openAICompatibleImageTemplate: ImageApiTemplate = {
   },
   buildImageToImageRequest(input) {
     const requestCount = normalizeOpenAICompatibleImageCount(input.modelName, input.count);
-    const requestSize = normalizeOpenAICompatibleImageSize(input.modelName, input.size);
+    const requestSize = normalizeOpenAICompatibleImageSize(input.modelName, input.size, { apiUrl: input.apiUrl });
     const denoisingStrength = input.strength ?? 0.5;
     const formFields = buildOpenAICompatibleImageEditFields(input, requestCount, requestSize);
     const chatBody: Record<string, unknown> = {