diff --git a/skills/baoyu-image-gen/scripts/providers/openrouter.test.ts b/skills/baoyu-image-gen/scripts/providers/openrouter.test.ts
index eda5437..415122e 100644
--- a/skills/baoyu-image-gen/scripts/providers/openrouter.test.ts
+++ b/skills/baoyu-image-gen/scripts/providers/openrouter.test.ts
@@ -12,7 +12,9 @@ import {
 } from "./openrouter.ts";
 
 const GEMINI_MODEL = "google/gemini-3.1-flash-image-preview";
-const GEMINI_25_MODEL = "google/gemini-2.5-flash-image-preview";
+const GEMINI_25_MODEL = "google/gemini-2.5-flash-image";
+const GPT_5_IMAGE_MODEL = "openai/gpt-5-image";
+const OPENROUTER_AUTO_MODEL = "openrouter/auto";
 const FLUX_MODEL = "black-forest-labs/flux.2-pro";
 
 function makeArgs(overrides: Partial<CliArgs> = {}): CliArgs {
@@ -52,7 +54,36 @@ test("OpenRouter request body uses image_config and string content for text-only
   assert.equal(body.messages[0].content, "hello");
 });
 
-test("OpenRouter request body omits image_config and provider guard when no image options are requested", () => {
+test("OpenRouter request body keeps text+image modalities for current text+image models", () => {
+  for (const model of [GEMINI_MODEL, GEMINI_25_MODEL, GPT_5_IMAGE_MODEL, OPENROUTER_AUTO_MODEL]) {
+    const body = buildRequestBody("hello", model, makeArgs({ quality: "2k" }), []);
+
+    assert.deepEqual(body.image_config, {
+      image_size: "2K",
+    });
+    assert.deepEqual(body.provider, {
+      require_parameters: true,
+    });
+    assert.deepEqual(body.modalities, ["image", "text"]);
+    assert.equal(body.messages[0].content, "hello");
+  }
+});
+
+test("OpenRouter request body uses image-only modalities for image-only models under CLI defaults", () => {
+  const body = buildRequestBody("hello", FLUX_MODEL, makeArgs({ quality: "2k" }), []);
+
+  assert.deepEqual(body.image_config, {
+    image_size: "2K",
+  });
+  assert.deepEqual(body.provider, {
+    require_parameters: true,
+  });
+  assert.deepEqual(body.modalities, ["image"]);
+  assert.equal(body.stream, false);
+  assert.equal(body.messages[0].content, "hello");
+});
+
+test("OpenRouter helper omits image_config when no size or quality is passed", () => {
   const body = buildRequestBody("hello", FLUX_MODEL, makeArgs(), []);
 
   assert.equal(body.image_config, undefined);
@@ -72,21 +103,23 @@ test("OpenRouter request body keeps multimodal array content when references are
   });
 });
 
-test("OpenRouter size and aspect helpers infer expected defaults", () => {
+test("OpenRouter size and aspect helpers infer supported values", () => {
   assert.equal(getImageSize(makeArgs()), null);
   assert.equal(getImageSize(makeArgs({ quality: "normal" })), "1K");
   assert.equal(getImageSize(makeArgs({ size: "2048x1024" })), "2K");
-  assert.equal(getAspectRatio(GEMINI_MODEL, makeArgs({ size: "2048x1024" })), null);
   assert.equal(getAspectRatio(GEMINI_MODEL, makeArgs({ size: "1600x900" })), "16:9");
   assert.equal(getAspectRatio(GEMINI_MODEL, makeArgs({ size: "1024x4096" })), "1:4");
-  assert.equal(getAspectRatio(GEMINI_25_MODEL, makeArgs({ size: "1024x4096" })), null);
+  assert.equal(getAspectRatio(GEMINI_25_MODEL, makeArgs({ size: "1600x900" })), "16:9");
   assert.equal(getAspectRatio(FLUX_MODEL, makeArgs({ size: "1024x4096" })), null);
 });
 
-test("OpenRouter validates explicit aspect ratios against model support", () => {
+test("OpenRouter validates explicit aspect ratios and inferred size ratios against model support", () => {
   assert.doesNotThrow(() =>
     validateArgs(GEMINI_MODEL, makeArgs({ aspectRatio: "1:4" })),
   );
+  assert.doesNotThrow(() =>
+    validateArgs(GEMINI_MODEL, makeArgs({ size: "1024x4096" })),
+  );
   assert.throws(
     () => validateArgs(GEMINI_25_MODEL, makeArgs({ aspectRatio: "1:4" })),
     /does not support aspect ratio 1:4/,
@@ -95,6 +128,10 @@ test("OpenRouter validates explicit aspect ratios against model support", () =>
     () => validateArgs(FLUX_MODEL, makeArgs({ aspectRatio: "1:4" })),
     /does not support aspect ratio 1:4/,
   );
+  assert.throws(
+    () => validateArgs(GEMINI_MODEL, makeArgs({ size: "2048x1024" })),
+    /does not support size 2048x1024 \(aspect ratio 2:1\)/,
+  );
 });
 
 test("OpenRouter response extraction supports inline image data and finish_reason errors", async () => {
diff --git a/skills/baoyu-image-gen/scripts/providers/openrouter.ts b/skills/baoyu-image-gen/scripts/providers/openrouter.ts
index 86e0db7..79bb57f 100644
--- a/skills/baoyu-image-gen/scripts/providers/openrouter.ts
+++ b/skills/baoyu-image-gen/scripts/providers/openrouter.ts
@@ -48,9 +48,21 @@ function normalizeModelId(model: string): string {
   return model.trim().toLowerCase().split(":")[0]!;
 }
 
-export function isGeminiImageModel(model: string): boolean {
+function isTextAndImageModel(model: string): boolean {
   const normalized = normalizeModelId(model);
-  return normalized.startsWith("google/gemini-") && normalized.includes("image-preview");
+  if (normalized === "openrouter/auto") {
+    return true;
+  }
+
+  if (normalized.startsWith("google/gemini-") && normalized.includes("image")) {
+    return true;
+  }
+
+  if (normalized.startsWith("openai/gpt-") && normalized.includes("image")) {
+    return true;
+  }
+
+  return false;
 }
 
 function getSupportedAspectRatios(model: string): Set<string> {
@@ -159,21 +171,26 @@ export function getAspectRatio(model: string, args: CliArgs): string | null {
 }
 
 function getModalities(model: string): string[] {
-  return isGeminiImageModel(model) ? ["image", "text"] : ["image"];
+  return isTextAndImageModel(model) ? ["image", "text"] : ["image"];
 }
 
 export function validateArgs(model: string, args: CliArgs): void {
-  if (!args.aspectRatio) {
+  const requestedAspectRatio = args.aspectRatio || inferAspectRatio(args.size);
+  if (!requestedAspectRatio) {
     return;
   }
 
   const supported = getSupportedAspectRatios(model);
-  if (supported.has(args.aspectRatio)) {
+  if (supported.has(requestedAspectRatio)) {
     return;
   }
 
+  const requestedValue = args.aspectRatio
+    ? `aspect ratio ${requestedAspectRatio}`
+    : `size ${args.size} (aspect ratio ${requestedAspectRatio})`;
+
   throw new Error(
-    `OpenRouter model ${model} does not support aspect ratio ${args.aspectRatio}. Supported values: ${Array.from(supported).join(", ")}`
+    `OpenRouter model ${model} does not support ${requestedValue}. Supported values: ${Array.from(supported).join(", ")}`
   );
 }
 
@@ -276,6 +293,8 @@ export function buildRequestBody(
   args: CliArgs,
   referenceImages: string[],
 ): Record<string, unknown> {
+  validateArgs(model, args);
+
   const imageConfig: Record<string, string> = {};
 
   const imageSize = getImageSize(args);