diff --git a/tools/md_to_html.py b/tools/md_to_html.py
new file mode 100644
index 0000000..ad905bb
--- /dev/null
+++ b/tools/md_to_html.py
@@ -0,0 +1,200 @@
+#!/usr/bin/env python3
+"""
+md_to_html.py
+
+Convert a Markdown file (.md) to an HTML file (.html) wrapped in a specific
+template including base target, styles, archive header, and title.
+
+Usage:
+  python wiki/tools/md_to_html.py INPUT.md [-o OUTPUT.html]
+      [--title TITLE] [--archived YYYY-MM] [--source SOURCE]
+      [--no-extract-title] [--base-target _blank]
+
+Defaults:
+  - title: first H1 in the markdown (or filename stem if none)
+  - archived: current UTC year-month (YYYY-MM)
+  - source: ""
+  - base-target: _blank
+
+Requires the 'Markdown' package:
+  pip install markdown
+"""
+
+from __future__ import annotations
+
+import argparse
+import datetime as _dt
+import html as _html
+import sys
+from pathlib import Path
+from textwrap import indent as _indent
+
+try:
+    import markdown as _md
+except Exception as exc:  # pragma: no cover
+    print(
+        "Error: Python package 'markdown' is required. Install with: pip install markdown",
+        file=sys.stderr,
+    )
+    raise
+
+
+CSS_BLOCK = (
+    """
+    body{font-family:system-ui,sans-serif;max-width:50rem;margin:2rem auto;line-height:1.6;padding:1rem}
+    img,iframe{max-width:100%}
+    .post-content{background:#f9f9f9;padding:1rem;border-radius:5px;margin:1rem 0}
+    .archive-header{background:#f0f8ff;border:1px solid #e0e0e0;border-radius:5px;padding:0.75rem;margin-bottom:1rem;font-size:0.9rem}
+    .archive-info{margin-bottom:0.5rem;color:#666}
+    .archive-source{color:#666}
+    .archive-header a{color:#007acc;text-decoration:none}
+    .archive-header a:hover{text-decoration:underline}
+    @media (prefers-color-scheme: dark) {
+        .archive-header{background:#1a1a2e;border-color:#333;color:#e0e0e0}
+        .archive-info, .archive-source{color:#ccc}
+        .archive-header a{color:#66b3ff}
+    }
+    """
+    .strip()
+)
+
+
+def _read_text(path: Path) -> str:
+    return path.read_text(encoding="utf-8")
+
+
+def _write_text(path: Path, text: str) -> None:
+    path.write_text(text, encoding="utf-8", newline="\n")
+
+
+def extract_title(markdown_text: str) -> tuple[str | None, str]:
+    """Return (title, remaining_markdown).
+
+    Finds the first ATX-style H1 (lines starting with '# ') and removes that
+    line from the markdown body. If none found, returns (None, original).
+    """
+    lines = markdown_text.splitlines()
+    for idx, line in enumerate(lines):
+        stripped = line.lstrip()
+        if stripped.startswith("# "):
+            title = stripped[2:].strip()
+            remaining = lines[:idx] + lines[idx + 1 :]
+            # Drop one following blank line if present
+            if idx < len(remaining) and remaining[idx : idx + 1] == [""]:
+                remaining = remaining[:idx] + remaining[idx + 1 :]
+            return title, "\n".join(remaining)
+    return None, markdown_text
+
+
+def render_markdown_to_html(markdown_text: str) -> str:
+    # Keep extensions minimal to avoid extra dependencies
+    return _md.markdown(markdown_text, extensions=["extra", "sane_lists", "smarty"])
+
+
+def build_html_document(*, title: str, archived: str, source: str, base_target: str, body_html: str) -> str:
+    safe_title = _html.escape(title)
+    safe_archived = _html.escape(archived)
+    safe_source = _html.escape(source)
+
+    # Indent rendered HTML for readability inside the container
+    indented_body = _indent(body_html.strip(), " " * 8)
+
+    return (
+        "<!DOCTYPE html>\n"
+        "<html lang=\"en\">\n"
+        "<head>\n"
+        "    <meta charset=\"utf-8\">\n"
+        f"    <base target=\"{_html.escape(base_target)}\">\n"
+        "    <style>\n"
+        + _indent(CSS_BLOCK, " " * 8)
+        + "\n    </style>\n"
+        "</head>\n"
+        "<body>\n\n"
+        "<div class=\"archive-header\">\n"
+        "    <div class=\"archive-info\">\n"
+        f"        <strong>📄 Archived:</strong> {safe_archived}\n"
+        "    </div>\n"
+        "    <div class=\"archive-source\">\n"
+        f"        <strong>🔗 Source:</strong> {safe_source}\n"
+        "    </div>\n"
+        "</div>\n\n"
+        f"<h1>{safe_title}</h1>\n\n"
+        "<div class='post-content'>\n\n"
+        "    <div class=\"md\">\n\n"
+        f"{indented_body}\n\n"
+        "    </div>\n"
+        "</div>\n\n"
+        "</body>\n"
+        "</html>\n"
+    )
+
+
+def parse_args(argv: list[str]) -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="Convert Markdown to templated HTML")
+    parser.add_argument("input", type=Path, help="Input .md file path or '-' for stdin")
+    parser.add_argument("-o", "--output", type=Path, help="Output .html file path")
+    parser.add_argument("--title", type=str, default=None, help="Title for <h1> (defaults to first H1 or filename)")
+    parser.add_argument(
+        "--archived",
+        type=str,
+        default=_dt.datetime.utcnow().strftime("%Y-%m"),
+        help="Archive period like YYYY-MM (default: current UTC year-month)",
+    )
+    parser.add_argument("--source", type=str, default="", help="Source label (e.g., 'ChatGPT o3')")
+    parser.add_argument("--base-target", type=str, default="_blank", help="Value for <base target>")
+    parser.add_argument(
+        "--no-extract-title",
+        action="store_true",
+        help="Do not detect/remove first H1 from markdown when inferring title",
+    )
+    return parser.parse_args(argv)
+
+
+def main(argv: list[str] | None = None) -> int:
+    ns = parse_args(argv or sys.argv[1:])
+
+    if str(ns.input) == "-":
+        md_text = sys.stdin.read()
+        input_stem = "stdin"
+    else:
+        md_path = ns.input
+        if not md_path.exists():
+            print(f"Error: input file not found: {md_path}", file=sys.stderr)
+            return 2
+        md_text = _read_text(md_path)
+        input_stem = md_path.stem
+
+    title: str | None = ns.title
+    body_md = md_text
+    if title is None and not ns.no_extract_title:
+        found_title, body_md = extract_title(md_text)
+        title = found_title
+    if title is None:
+        title = input_stem
+
+    body_html = render_markdown_to_html(body_md)
+    html_doc = build_html_document(
+        title=title,
+        archived=ns.archived,
+        source=ns.source,
+        base_target=ns.base_target,
+        body_html=body_html,
+    )
+
+    if ns.output:
+        out_path = ns.output
+    else:
+        if str(ns.input) == "-":
+            out_path = Path(f"{input_stem}.html")
+        else:
+            out_path = md_path.with_suffix(".html")  # type: ignore[name-defined]
+
+    _write_text(out_path, html_doc)
+    print(str(out_path))
+    return 0
+
+
+if __name__ == "__main__":  # pragma: no cover
+    raise SystemExit(main())
+
+
