fix: force HTTPS for image downloads and add base64 response format

- Auto-convert HTTP to HTTPS in downloadFile() to work around
  Alibaba Cloud OSS CDN blocking HTTP traffic from certain regions
- Add --response-format <url|base64> flag for image generation
- Add retry logic (3 attempts, exponential backoff) for download failures
- Fixes image download failures with 'Network request failed' error

Related: MiniMax API returns http:// URLs but OSS CDN requires https://

Author: nguyenngothuong

src/commands/image/generate.ts

@@ -8,15 +8,15 @@ import { formatOutput, detectOutputFormat } from '../../output/formatter';
 import type { Config } from '../../config/schema';
 import type { GlobalFlags } from '../../types/flags';
 import type { ImageRequest, ImageResponse } from '../../types/api';
-import { mkdirSync, existsSync, readFileSync } from 'fs';
+import { mkdirSync, existsSync, readFileSync, writeFileSync } from 'fs';
 import { join, resolve, extname } from 'path';
+import { isInteractive } from '../../utils/env';
+import { promptText, failIfMissing } from '../../utils/prompt';
 
 const MIME_TYPES: Record<string, string> = {
   '.jpg': 'image/jpeg', '.jpeg': 'image/jpeg',
   '.png': 'image/png', '.webp': 'image/webp',
 };
-import { isInteractive } from '../../utils/env';
-import { promptText, failIfMissing } from '../../utils/prompt';
 
 export default defineCommand({
   name: 'image generate',
@@ -33,6 +33,7 @@ export default defineCommand({
     { flag: '--prompt-optimizer', description: 'Automatically optimize the prompt before generation for better results.' },
     { flag: '--aigc-watermark', description: 'Embed AI-generated content watermark in the output image.' },
     { flag: '--subject-ref <params>', description: 'Subject reference for character consistency. Format: type=character,image=path-or-url' },
+    { flag: '--response-format <format>', description: 'Response format: url (download), base64 (embed). Default: url' },
     { flag: '--out-dir <dir>', description: 'Download images to directory' },
     { flag: '--out-prefix <prefix>', description: 'Filename prefix (default: image)' },
   ],
@@ -46,6 +47,8 @@ export default defineCommand({
     'mmx image generate --prompt "Wide landscape" --width 1920 --height 1080',
     '# Optimized prompt with watermark',
     'mmx image generate --prompt "sunset" --prompt-optimizer --aigc-watermark',
+    '# Base64 response (bypasses CDN, useful when image URLs are unreachable)',
+    'mmx image generate --prompt "A cat" --response-format base64',
   ],
   async run(config: Config, flags: GlobalFlags) {
     let prompt = (flags.prompt ?? (flags._positional as string[]|undefined)?.[0]) as string | undefined;
@@ -88,6 +91,8 @@ export default defineCommand({
       validateSize('height', height);
     }
 
+    const responseFormat = (flags.responseFormat as 'url' | 'base64' | undefined) || 'url';
+
     const body: ImageRequest = {
       model: 'image-01',
       prompt,
@@ -98,6 +103,7 @@ export default defineCommand({
       height: height,
       prompt_optimizer: flags.promptOptimizer === true || undefined,
       aigc_watermark: flags.aigcWatermark === true || undefined,
+      response_format: responseFormat,
     };
 
     if (flags.subjectRef) {
@@ -143,8 +149,6 @@ export default defineCommand({
       body,
     });
 
-    const imageUrls = response.data.image_urls || [];
-
     if (!config.quiet) {
       process.stderr.write('[Model: image-01]\n');
     }
@@ -155,11 +159,22 @@ export default defineCommand({
     const prefix = (flags.outPrefix as string) || 'image';
     const saved: string[] = [];
 
-    for (let i = 0; i < imageUrls.length; i++) {
-      const filename = `${prefix}_${String(i + 1).padStart(3, '0')}.jpg`;
-      const destPath = join(outDir, filename);
-      await downloadFile(imageUrls[i]!, destPath, { quiet: config.quiet });
-      saved.push(destPath);
+    if (responseFormat === 'base64') {
+      const images = response.data.image_base64 || [];
+      for (let i = 0; i < images.length; i++) {
+        const filename = `${prefix}_${String(i + 1).padStart(3, '0')}.jpg`;
+        const destPath = join(outDir, filename);
+        writeFileSync(destPath, images[i]!, 'base64');
+        saved.push(destPath);
+      }
+    } else {
+      const imageUrls = response.data.image_urls || [];
+      for (let i = 0; i < imageUrls.length; i++) {
+        const filename = `${prefix}_${String(i + 1).padStart(3, '0')}.jpg`;
+        const destPath = join(outDir, filename);
+        await downloadFile(imageUrls[i]!, destPath, { quiet: config.quiet });
+        saved.push(destPath);
+      }
     }
 
     if (config.quiet) {

src/files/download.ts

@@ -3,64 +3,100 @@ import { createProgressBar } from '../output/progress';
 import { CLIError } from '../errors/base';
 import { ExitCode } from '../errors/codes';
 
+export interface DownloadOpts {
+  quiet?: boolean;
+  retries?: number;
+  retryDelayMs?: number;
+}
+
 export async function downloadFile(
   url: string,
   destPath: string,
-  opts?: { quiet?: boolean },
+  opts?: DownloadOpts,
 ): Promise<{ size: number }> {
-  const res = await fetch(url);
+  // Fix: Alibaba Cloud OSS US East blocks HTTP from certain regions.
+  // Force HTTPS to ensure reliable downloads.
+  const downloadUrl = url.startsWith('http://') ? url.replace('http://', 'https://') : url;
+  const maxRetries = opts?.retries ?? 3;
+  const baseDelay = opts?.retryDelayMs ?? 1000;
+  let lastError: Error | undefined;
 
-  if (!res.ok) {
-    throw new CLIError(`Download failed: HTTP ${res.status}`, ExitCode.GENERAL);
-  }
+  for (let attempt = 0; attempt <= maxRetries; attempt++) {
+    try {
+      if (attempt > 0) {
+        const delay = baseDelay * Math.pow(2, attempt - 1);
+        if (!opts?.quiet) {
+          process.stderr.write(`\n  Retry ${attempt}/${maxRetries} in ${delay}ms...\n`);
+        }
+        await new Promise(r => setTimeout(r, delay));
+      }
 
-  const contentLength = Number(res.headers.get('content-length') || 0);
-  const reader = res.body?.getReader();
-  if (!reader) throw new CLIError('No response body', ExitCode.GENERAL);
+      const res = await fetch(downloadUrl);
 
-  const writer = createWriteStream(destPath);
-  const progress = contentLength > 0 && !opts?.quiet
-    ? createProgressBar(contentLength, 'Downloading')
-    : null;
+      if (!res.ok) {
+        throw new CLIError(`Download failed: HTTP ${res.status}`, ExitCode.GENERAL);
+      }
 
-  let received = 0;
-  let completed = false;
+      const contentLength = Number(res.headers.get('content-length') || 0);
+      const reader = res.body?.getReader();
+      if (!reader) throw new CLIError('No response body', ExitCode.GENERAL);
 
-  try {
-    const writeError = new Promise<never>((_, reject) => {
-      writer.on('error', reject);
-    });
+      const writer = createWriteStream(destPath);
+      const progress = contentLength > 0 && !opts?.quiet
+        ? createProgressBar(contentLength, 'Downloading')
+        : null;
 
-    while (true) {
-      const { done, value } = await Promise.race([
-        reader.read(),
-        writeError,
-      ]) as ReadableStreamReadResult<Uint8Array>;
-      if (done) break;
+      let received = 0;
+      let completed = false;
 
-      const ok = writer.write(value);
-      if (!ok) await new Promise(r => writer.once('drain', r));
+      try {
+        const writeError = new Promise<never>((_, reject) => {
+          writer.on('error', reject);
+        });
 
-      received += value.byteLength;
-      progress?.update(received);
-    }
-    completed = true;
-  } finally {
-    reader.releaseLock();
-    progress?.finish();
-
-    await new Promise<void>((resolve, reject) => {
-      writer.on('finish', resolve);
-      writer.on('error', reject);
-      writer.end();
-    });
-
-    if (!completed) {
-      try { unlinkSync(destPath); } catch { /* best effort */ }
+        while (true) {
+          const { done, value } = await Promise.race([
+            reader.read(),
+            writeError,
+          ]) as ReadableStreamReadResult<Uint8Array>;
+          if (done) break;
+
+          const ok = writer.write(value);
+          if (!ok) await new Promise(r => writer.once('drain', r));
+
+          received += value.byteLength;
+          progress?.update(received);
+        }
+        completed = true;
+      } finally {
+        reader.releaseLock();
+        progress?.finish();
+
+        await new Promise<void>((resolve, reject) => {
+          writer.on('finish', resolve);
+          writer.on('error', reject);
+          writer.end();
+        });
+
+        if (!completed) {
+          try { unlinkSync(destPath); } catch { /* best effort */ }
+        }
+      }
+
+      return { size: received };
+    } catch (err) {
+      lastError = err instanceof Error ? err : new Error(String(err));
+      if (!opts?.quiet) {
+        process.stderr.write(`\n  Download attempt ${attempt + 1} failed: ${lastError.message}\n`);
+      }
     }
   }
 
-  return { size: received };
+  throw new CLIError(
+    `Download failed after ${maxRetries + 1} attempts: ${lastError?.message}`,
+    ExitCode.NETWORK,
+    'Check your network connection and proxy settings.',
+  );
 }
 
 export function formatBytes(bytes: number): string {

src/types/api.ts

@@ -162,6 +162,7 @@ export interface ImageRequest {
   height?: number;
   prompt_optimizer?: boolean;
   aigc_watermark?: boolean;
+  response_format?: 'url' | 'base64';
   subject_reference?: Array<{
     type: string;
     image_url?: string;
@@ -172,7 +173,8 @@ export interface ImageRequest {
 export interface ImageResponse {
   base_resp: BaseResp;
   data: {
-    image_urls: string[];
+    image_urls?: string[];
+    image_base64?: string[];
     task_id: string;
     success_count: number;
     failed_count: number;