diff --git a/.memory/worklog.json b/.memory/worklog.json
index 9398246..756298c 100644
--- a/.memory/worklog.json
+++ b/.memory/worklog.json
@@ -484,6 +484,19 @@
       "message": "auto-save 2026-05-19 10:40 (+1, ~3)",
       "hash": "12159ca",
       "files_changed": 4
+    },
+    {
+      "ts": "2026-05-19T10:43:58+08:00",
+      "type": "commit",
+      "message": "feat: add upload replicate mode",
+      "hash": "a9b1250",
+      "files_changed": 3
+    },
+    {
+      "ts": "2026-05-19T02:50:00Z",
+      "type": "session-heartbeat",
+      "message": "Codex 会话活跃 · 最近命令：codex · 分支 master · 1 项未提交变更 · 最近提交：feat: add upload replicate mode",
+      "files_changed": 1
     }
   ]
 }
diff --git a/src/lib/providers.ts b/src/lib/providers.ts
index dfa81b5..45fb5a4 100644
--- a/src/lib/providers.ts
+++ b/src/lib/providers.ts
@@ -44,12 +44,19 @@ export async function generateMock(opts: {
   });
 }
 
-function readImageBase64(payload: unknown): string {
+async function imageResponseToDataUrl(payload: unknown): Promise<string> {
   const data = payload as { data?: Array<{ b64_json?: string; url?: string }> };
   const first = data.data?.[0];
   if (!first) throw new Error('GPT image response missing data');
-  if (first.b64_json) return first.b64_json;
-  throw new Error('GPT image response missing b64_json');
+  if (first.b64_json) return `data:image/png;base64,${first.b64_json}`;
+  if (first.url) {
+    const res = await fetch(first.url);
+    if (!res.ok) throw new Error(`GPT image URL fetch ${res.status}: ${await res.text()}`);
+    const type = res.headers.get('content-type')?.split(';')[0] || 'image/png';
+    const buf = Buffer.from(await res.arrayBuffer());
+    return `data:${type};base64,${buf.toString('base64')}`;
+  }
+  throw new Error('GPT image response missing b64_json or url');
 }
 
 export async function generateGptImages(opts: {
@@ -77,14 +84,13 @@ export async function generateGptImages(opts: {
         prompt: `${opts.prompt}${refHint}`,
         n: 1,
         size: '1024x1024',
-        response_format: 'b64_json',
       }),
     });
     if (!res.ok) throw new Error(`GPT image ${res.status}: ${await res.text()}`);
     const data = await res.json();
     return {
       id: `img_${opts.sessionId}_${i}`,
-      url: `data:image/png;base64,${readImageBase64(data)}`,
+      url: await imageResponseToDataUrl(data),
       prompt: opts.prompt,
       status: 'pending' as const,
       meta: { provider: 'gpt', model: GPT_IMAGE_MODEL, index: i },
@@ -94,14 +100,6 @@ export async function generateGptImages(opts: {
   return Promise.all(calls);
 }
 
-function readEditImageBase64(payload: unknown): string {
-  return readImageBase64(payload);
-}
-
-function dataUrlFromImageResponse(payload: unknown): string {
-  return `data:image/png;base64,${readEditImageBase64(payload)}`;
-}
-
 function readResponseText(data: {
   output_text?: string;
   output?: Array<{ content?: Array<{ text?: string }> }>;
@@ -136,7 +134,6 @@ export async function generateGptImageEdit(opts: {
   form.set('model', process.env.GPT_IMAGE_EDIT_MODEL || GPT_IMAGE_MODEL);
   form.set('prompt', opts.prompt);
   form.set('size', opts.size || '1024x1024');
-  form.set('response_format', 'b64_json');
   const imageBytes = source.buf.buffer.slice(source.buf.byteOffset, source.buf.byteOffset + source.buf.byteLength) as ArrayBuffer;
   form.set('image', new Blob([imageBytes], { type: source.type }), source.filename);
 
@@ -149,7 +146,7 @@ export async function generateGptImageEdit(opts: {
   const data = await res.json();
   return {
     id: `img_${opts.sessionId}_edit`,
-    url: dataUrlFromImageResponse(data),
+    url: await imageResponseToDataUrl(data),
     prompt: opts.prompt,
     status: 'pending',
     meta: { provider: 'gpt', model: process.env.GPT_IMAGE_EDIT_MODEL || GPT_IMAGE_MODEL, edit: true },