diff --git a/skills/baoyu-url-to-markdown/SKILL.md b/skills/baoyu-url-to-markdown/SKILL.md
index 86eaf59..c8c929d 100644
--- a/skills/baoyu-url-to-markdown/SKILL.md
+++ b/skills/baoyu-url-to-markdown/SKILL.md
@@ -82,8 +82,14 @@ Full reference: [references/config/first-time-setup.md](references/config/first-
 | `download_media` | `ask` | `ask` / `1` / `0` | `ask` = prompt each time, `1` = always download, `0` = never |
 | `default_output_dir` | empty | path or empty | Default output directory (empty = `./url-to-markdown/`) |
 
+**EXTEND.md → CLI mapping**:
+| EXTEND.md key | CLI argument | Notes |
+|---------------|-------------|-------|
+| `download_media: 1` | `--download-media` | |
+| `default_output_dir: ./posts/` | `--output-dir ./posts/` | Directory path. Do NOT pass to `-o` (which expects a file path) |
+
 **Value priority**:
-1. CLI arguments (`--download-media`, `-o`)
+1. CLI arguments (`--download-media`, `-o`, `--output-dir`)
 2. EXTEND.md
 3. Skill defaults
 
@@ -107,6 +113,9 @@ ${BUN_X} ${SKILL_DIR}/scripts/main.ts <url> --wait
 # Save to specific file
 ${BUN_X} ${SKILL_DIR}/scripts/main.ts <url> -o output.md
 
+# Save to a custom output directory (auto-generates filename)
+${BUN_X} ${SKILL_DIR}/scripts/main.ts <url> --output-dir ./posts/
+
 # Download images and videos to local directories
 ${BUN_X} ${SKILL_DIR}/scripts/main.ts <url> --download-media
 ```
@@ -116,7 +125,8 @@ ${BUN_X} ${SKILL_DIR}/scripts/main.ts <url> --download-media
 | Option | Description |
 |--------|-------------|
 | `<url>` | URL to fetch |
-| `-o <path>` | Output file path (default: auto-generated) |
+| `-o <path>` | Output file path — must be a **file** path, not directory (default: auto-generated) |
+| `--output-dir <dir>` | Base output directory — auto-generates `{dir}/{domain}/{slug}.md` (default: `./url-to-markdown/`) |
 | `--wait` | Wait for user signal before capturing |
 | `--timeout <ms>` | Page load timeout (default: 30000) |
 | `--download-media` | Download image/video assets to local `imgs/` and `videos/`, and rewrite markdown links to local relative paths |
@@ -139,9 +149,8 @@ YAML front matter with `url`, `title`, `description`, `author`, `published`, `ca
 
 ## Output Directory
 
-```
-url-to-markdown/<domain>/<slug>.md
-```
+Default: `url-to-markdown/<domain>/<slug>.md`
+With `--output-dir ./posts/`: `./posts/<domain>/<slug>.md`
 
 - `<slug>`: From page title or URL path (kebab-case, 2-6 words)
 - Conflict resolution: Append timestamp `<slug>-YYYYMMDD-HHMMSS.md`
diff --git a/skills/baoyu-url-to-markdown/scripts/main.ts b/skills/baoyu-url-to-markdown/scripts/main.ts
index 3bd5b32..c48a6b9 100644
--- a/skills/baoyu-url-to-markdown/scripts/main.ts
+++ b/skills/baoyu-url-to-markdown/scripts/main.ts
@@ -25,6 +25,7 @@ async function fileExists(filePath: string): Promise<boolean> {
 interface Args {
   url: string;
   output?: string;
+  outputDir?: string;
   wait: boolean;
   timeout: number;
   downloadMedia: boolean;
@@ -40,6 +41,8 @@ function parseArgs(argv: string[]): Args {
       args.output = argv[++i];
     } else if (arg === "--timeout" || arg === "-t") {
       args.timeout = parseInt(argv[++i], 10) || DEFAULT_TIMEOUT_MS;
+    } else if (arg === "--output-dir") {
+      args.outputDir = argv[++i];
     } else if (arg === "--download-media") {
       args.downloadMedia = true;
     } else if (!arg.startsWith("-") && !args.url) {
@@ -66,10 +69,10 @@ function formatTimestamp(): string {
   return `${now.getFullYear()}${pad(now.getMonth() + 1)}${pad(now.getDate())}-${pad(now.getHours())}${pad(now.getMinutes())}${pad(now.getSeconds())}`;
 }
 
-async function generateOutputPath(url: string, title: string): Promise<string> {
+async function generateOutputPath(url: string, title: string, outputDir?: string): Promise<string> {
   const domain = new URL(url).hostname.replace(/^www\./, "");
   const slug = generateSlug(title, url);
-  const dataDir = resolveUrlToMarkdownDataDir();
+  const dataDir = outputDir ? path.resolve(outputDir) : resolveUrlToMarkdownDataDir();
   const basePath = path.join(dataDir, domain, `${slug}.md`);
 
   if (!(await fileExists(basePath))) {
@@ -149,11 +152,19 @@ async function main(): Promise<void> {
     process.exit(1);
   }
 
+  if (args.output) {
+    const stat = await import("node:fs").then(fs => fs.statSync(args.output!, { throwIfNoEntry: false }));
+    if (stat?.isDirectory()) {
+      console.error(`Error: -o path is a directory, not a file: ${args.output}`);
+      process.exit(1);
+    }
+  }
+
   console.log(`Fetching: ${args.url}`);
   console.log(`Mode: ${args.wait ? "wait" : "auto"}`);
 
   const result = await captureUrl(args);
-  const outputPath = args.output || await generateOutputPath(args.url, result.metadata.title);
+  const outputPath = args.output || await generateOutputPath(args.url, result.metadata.title, args.outputDir);
   const outputDir = path.dirname(outputPath);
   await mkdir(outputDir, { recursive: true });