diff --git a/lib/ai/providers/openai-image.ts b/lib/ai/providers/openai-image.ts
index 4aed6225a..ff4c0d4c1 100644
--- a/lib/ai/providers/openai-image.ts
+++ b/lib/ai/providers/openai-image.ts
@@ -87,6 +87,15 @@ function normalizeImageSizeLabel(imageSize?: string): "1K" | "2K" | "4K" {
   return DEFAULT_IMAGE_SIZE;
 }
 
+function inferImageSizeFromModelId(modelId?: string): "1K" | "2K" | "4K" | undefined {
+  const normalized = String(modelId || "").trim().toLowerCase();
+  const explicitBucket = normalized.match(/(?:^|[-_\s])([124])k(?:$|[-_\s])/);
+  if (explicitBucket?.[1] === "1") return "1K";
+  if (explicitBucket?.[1] === "2") return "2K";
+  if (explicitBucket?.[1] === "4") return "4K";
+  return undefined;
+}
+
 function normalizeAspectRatio(value?: string) {
   const normalized = String(value || "").trim();
   if (!normalized || normalized.toLowerCase() === "auto") return "auto";
@@ -591,10 +600,16 @@ export function createOpenAIImage({ apiKey, baseURL }: OpenAIImageConfig) {
           normalizedAspectRatio === "auto"
             ? promptAspectRatio || (await inferAspectRatioFromImageUrl(imageUrls[0] || ""))
             : normalizedAspectRatio;
-        const imageSize = normalizeImageSizeLabel(options.imageParams?.imageSize);
+        const requestedImageSize = normalizeImageSizeLabel(options.imageParams?.imageSize);
+        const modelImageSize = isComflyBaseURL(baseURL)
+          ? inferImageSizeFromModelId(activeModelId)
+          : undefined;
+        const imageSize = modelImageSize || requestedImageSize;
         const size =
-          options.imageParams?.size ||
-          (aspectRatio ? resolveProviderImageSize(baseURL, aspectRatio, imageSize) : undefined);
+          modelImageSize && aspectRatio
+            ? resolveProviderImageSize(baseURL, aspectRatio, imageSize)
+            : options.imageParams?.size ||
+              (aspectRatio ? resolveProviderImageSize(baseURL, aspectRatio, imageSize) : undefined);
         const quality = normalizeQuality(options.imageParams?.quality);
         const background = normalizeBackground(options.imageParams?.background);
         const outputFormat = normalizeOutputFormat(options.imageParams?.outputFormat);
@@ -605,6 +620,8 @@ export function createOpenAIImage({ apiKey, baseURL }: OpenAIImageConfig) {
           aspectRatio: aspectRatio || "auto",
           promptAspectRatio: promptAspectRatio || undefined,
           imageSize,
+          requestedImageSize,
+          modelImageSize,
           resolutionMode: isComflyBaseURL(baseURL) ? "longest-edge" : "pixel-area",
           timeoutMs: resolveRequestTimeoutMs(baseURL, imageSize, activeModelId),
           useBltcyImageCompatParams: shouldUseBltcyImageCompatParams(baseURL),