fix(openai): omit Azure image deployment model body

extensions/openai/image-generation-provider.test.ts

@@ -1181,6 +1181,38 @@ describe("openai image generation provider", () => {
       );
     });
 
+    it("omits model from Azure generation body because deployment is URL-scoped", async () => {
+      mockGeneratedPngResponse();
+
+      const provider = buildOpenAIImageGenerationProvider();
+      await provider.generateImage({
+        provider: "openai",
+        model: "gpt-image-2-1",
+        prompt: "Azure cat",
+        cfg: {
+          models: {
+            providers: {
+              openai: {
+                baseUrl: "https://myresource.openai.azure.com/openai/v1",
+                models: [],
+              },
+            },
+          },
+        },
+      });
+
+      expect(postJsonRequestMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          url: "https://myresource.openai.azure.com/openai/deployments/gpt-image-2-1/images/generations?api-version=2024-12-01-preview",
+          body: {
+            prompt: "Azure cat",
+            n: 1,
+            size: "1024x1024",
+          },
+        }),
+      );
+    });
+
     it("uses api-key header and deployment-scoped URL for .cognitiveservices.azure.com hosts", async () => {
       mockGeneratedPngResponse();
 
@@ -1308,6 +1340,41 @@ describe("openai image generation provider", () => {
       );
     });
 
+    it("omits model from Azure edit form because deployment is URL-scoped", async () => {
+      mockGeneratedPngResponse();
+
+      const provider = buildOpenAIImageGenerationProvider();
+      await provider.generateImage({
+        provider: "openai",
+        model: "gpt-image-2-1",
+        prompt: "Change background",
+        cfg: {
+          models: {
+            providers: {
+              openai: {
+                baseUrl: "https://myresource.openai.azure.com/openai/v1",
+                models: [],
+              },
+            },
+          },
+        },
+        inputImages: [
+          {
+            buffer: Buffer.from("png-bytes"),
+            mimeType: "image/png",
+            fileName: "reference.png",
+          },
+        ],
+      });
+
+      const editCallArgs = postMultipartRequestMock.mock.calls[0]?.[0] as {
+        body: FormData;
+      };
+      expect(editCallArgs.body.has("model")).toBe(false);
+      expect(editCallArgs.body.get("prompt")).toBe("Change background");
+      expect(editCallArgs.body.get("size")).toBe("1024x1024");
+    });
+
     it("strips trailing /v1 from Azure base URL", async () => {
       mockGeneratedPngResponse();
 

extensions/openai/image-generation-provider.ts

@@ -721,7 +721,9 @@ export function buildOpenAIImageGenerationProvider(): ImageGenerationProvider {
       const requestResult = isEdit
         ? await (() => {
             const form = new FormData();
-            form.set("model", model);
+            if (!isAzure) {
+              form.set("model", model);
+            }
             form.set("prompt", req.prompt);
             form.set("n", String(count));
             form.set("size", size);
@@ -755,11 +757,13 @@ export function buildOpenAIImageGenerationProvider(): ImageGenerationProvider {
             const jsonHeaders = new Headers(headers);
             jsonHeaders.set("Content-Type", "application/json");
             const body: Record<string, unknown> = {
-              model,
               prompt: req.prompt,
               n: count,
               size,
             };
+            if (!isAzure) {
+              body.model = model;
+            }
             appendOpenAIImageOptions(body, req);
             return postJsonRequest({
               url,