diff --git a/.agents/skills/deploy-app-sd/SKILL.md b/.agents/skills/deploy-app-sd/SKILL.md
index a9eecf3..0789f2f 100644
--- a/.agents/skills/deploy-app-sd/SKILL.md
+++ b/.agents/skills/deploy-app-sd/SKILL.md
@@ -22,7 +22,7 @@ The CrossPoint Reader web server exposes:
 3. Upload the app directory to `/.apps/<AppId>`:
 
    ```sh
-   .pi/skills/deploy-app-sd/upload-app.sh <device-ip> <AppId>
+   .agents/skills/deploy-app-sd/upload-app.sh <device-ip> <AppId>
    ```
 
-The script creates `/.apps`, replaces `/.apps/<AppId>`, recreates any subdirectories, and uploads every file under `apps/<AppId>/` except `README.md`.
+The script creates `/.apps`, clears `/.apps/<AppId>` recursively, recreates any subdirectories, and uploads every file under `apps/<AppId>/` except `README.md`.
diff --git a/.agents/skills/deploy-app-sd/upload-app.sh b/.agents/skills/deploy-app-sd/upload-app.sh
index e74db6f..ff9eacd 100755
--- a/.agents/skills/deploy-app-sd/upload-app.sh
+++ b/.agents/skills/deploy-app-sd/upload-app.sh
@@ -1,59 +1,145 @@
-#!/usr/bin/env bash
-# Usage: upload-app.sh <device-ip> <AppId>
-set -euo pipefail
+#!/usr/bin/env -S uv run --script
+# /// script
+# requires-python = ">=3.11"
+# dependencies = []
+# ///
+"""Usage: upload-app.sh <device-ip> <AppId>"""
 
-IP="${1:?usage: upload-app.sh <device-ip> <AppId>}"
-APP="${2:?usage: upload-app.sh <device-ip> <AppId>}"
+import json
+import mimetypes
+import re
+import subprocess
+import sys
+from pathlib import Path
+from urllib.error import HTTPError, URLError
+from urllib.parse import quote, urlencode
+from urllib.request import Request, urlopen
 
-[[ "$APP" =~ ^[A-Za-z0-9_-]+$ ]] || { echo "bad AppId: $APP" >&2; exit 1; }
-APP_DIR="apps/$APP"
-[ -d "$APP_DIR" ] || { echo "not found: $APP_DIR" >&2; exit 1; }
-[ -f "$APP_DIR/main.lua" ] || { echo "not found: $APP_DIR/main.lua" >&2; exit 1; }
+TIMEOUT = 20
 
-if [ -x scripts/update-manifests.py ]; then
-  scripts/update-manifests.py
-else
-  python3 scripts/update-manifests.py
-fi
 
-urlenc() {
-  python3 -c 'import sys, urllib.parse; print(urllib.parse.quote(sys.argv[1], safe=""))' "$1"
-}
+def fail(message: str) -> None:
+    print(message, file=sys.stderr)
+    raise SystemExit(1)
 
-mkdir_remote() {
-  local parent="$1" name="$2"
-  curl -sS -X POST "http://$IP/mkdir" \
-    --data-urlencode "path=$parent" \
-    --data-urlencode "name=$name" \
-    -o /dev/null || true
-}
 
-upload_file() {
-  local src="$1" rel="${1#"$APP_DIR"/}" dir remote_dir
-  dir="$(dirname "$rel")"
-  remote_dir="/.apps/$APP"
-  [ "$dir" = "." ] || remote_dir="$remote_dir/$dir"
+def request(ip: str, method: str, path: str, *, data: bytes | None = None, headers: dict[str, str] | None = None) -> tuple[int, bytes]:
+    req = Request(f"http://{ip}{path}", data=data, headers=headers or {}, method=method)
+    try:
+        with urlopen(req, timeout=TIMEOUT) as res:
+            return res.status, res.read()
+    except HTTPError as e:
+        return e.code, e.read()
+    except URLError as e:
+        fail(f"request failed: {e.reason}")
 
-  curl -fsS \
-    -F "file=@$src;filename=$(basename "$src")" \
-    "http://$IP/upload?path=$(urlenc "$remote_dir")" >/dev/null
-  echo "uploaded: $rel"
-}
 
-mkdir_remote "/" ".apps"
-curl -sS -X POST "http://$IP/delete" --data-urlencode "path=/.apps/$APP" -o /dev/null || true
-mkdir_remote "/.apps" "$APP"
+def post_form(ip: str, path: str, fields: dict[str, str]) -> tuple[int, bytes]:
+    return request(
+        ip,
+        "POST",
+        path,
+        data=urlencode(fields).encode(),
+        headers={"Content-Type": "application/x-www-form-urlencoded"},
+    )
 
-while IFS= read -r -d '' dir; do
-  rel="${dir#"$APP_DIR"/}"
-  parent="/.apps/$APP"
-  [ "$(dirname "$rel")" = "." ] || parent="$parent/$(dirname "$rel")"
-  mkdir_remote "$parent" "$(basename "$rel")"
-done < <(find "$APP_DIR" -mindepth 1 -type d -print0 | sort -z)
 
-while IFS= read -r -d '' file; do
-  [ -s "$file" ] || { echo "empty file rejected: $file" >&2; exit 1; }
-  upload_file "$file"
-done < <(find "$APP_DIR" -type f ! -name README.md -print0 | sort -z)
+def mkdir_remote(ip: str, parent: str, name: str) -> None:
+    status, body = post_form(ip, "/mkdir", {"path": parent, "name": name})
+    if status not in (200, 400):
+        fail(f"mkdir failed for {parent}/{name}: HTTP {status} {body.decode(errors='replace')}")
 
-echo "App uploaded successfully: $APP"
+
+def delete_remote(ip: str, path: str, *, missing_ok: bool = True) -> None:
+    status, body = post_form(ip, "/delete", {"path": path})
+    text = body.decode(errors="replace")
+    if status == 200 or (missing_ok and "not found" in text.lower()):
+        return
+    fail(f"delete failed for {path}: HTTP {status} {text}")
+
+
+def list_remote(ip: str, path: str) -> list[dict]:
+    status, body = request(ip, "GET", f"/api/files?path={quote(path, safe='')}")
+    if status == 404:
+        return []
+    if status != 200:
+        fail(f"list failed for {path}: HTTP {status} {body.decode(errors='replace')}")
+    return json.loads(body)
+
+
+def delete_tree_contents(ip: str, path: str) -> None:
+    dirs: list[str] = []
+    for entry in list_remote(ip, path):
+        child = f"{path.rstrip('/')}/{entry['name']}"
+        if entry.get("isDirectory"):
+            delete_tree_contents(ip, child)
+            dirs.append(child)
+        else:
+            delete_remote(ip, child)
+    for child in dirs:
+        delete_remote(ip, child)
+
+
+def upload_file(ip: str, remote_dir: str, src: Path, rel: Path) -> None:
+    boundary = "----xteink-app-upload"
+    filename = src.name
+    content_type = mimetypes.guess_type(filename)[0] or "application/octet-stream"
+    body = b"".join(
+        [
+            f"--{boundary}\r\n".encode(),
+            f'Content-Disposition: form-data; name="file"; filename="{filename}"\r\n'.encode(),
+            f"Content-Type: {content_type}\r\n\r\n".encode(),
+            src.read_bytes(),
+            f"\r\n--{boundary}--\r\n".encode(),
+        ]
+    )
+    status, response = request(
+        ip,
+        "POST",
+        f"/upload?path={quote(remote_dir, safe='')}",
+        data=body,
+        headers={"Content-Type": f"multipart/form-data; boundary={boundary}"},
+    )
+    if not 200 <= status < 300:
+        fail(f"upload failed for {rel}: HTTP {status} {response.decode(errors='replace')}")
+    print(f"uploaded: {rel}")
+
+
+def main() -> None:
+    if len(sys.argv) != 3:
+        fail(__doc__ or "usage error")
+
+    ip, app = sys.argv[1:]
+    if not re.fullmatch(r"[A-Za-z0-9_-]+", app):
+        fail(f"bad AppId: {app}")
+
+    app_dir = Path("apps") / app
+    if not app_dir.is_dir():
+        fail(f"not found: {app_dir}")
+    if not (app_dir / "main.lua").is_file():
+        fail(f"not found: {app_dir / 'main.lua'}")
+
+    subprocess.run(["scripts/update-manifests.py"], check=True)
+
+    mkdir_remote(ip, "/", ".apps")
+    remote_app = f"/.apps/{app}"
+    mkdir_remote(ip, "/.apps", app)
+    delete_tree_contents(ip, remote_app)
+
+    for local_dir in sorted(p for p in app_dir.rglob("*") if p.is_dir()):
+        rel = local_dir.relative_to(app_dir)
+        parent = remote_app if rel.parent == Path(".") else f"{remote_app}/{rel.parent.as_posix()}"
+        mkdir_remote(ip, parent, rel.name)
+
+    for src in sorted(p for p in app_dir.rglob("*") if p.is_file() and p.name != "README.md"):
+        if src.stat().st_size == 0:
+            fail(f"empty file rejected: {src}")
+        rel = src.relative_to(app_dir)
+        remote_dir = remote_app if rel.parent == Path(".") else f"{remote_app}/{rel.parent.as_posix()}"
+        upload_file(ip, remote_dir, src, rel)
+
+    print(f"App uploaded successfully: {app}")
+
+
+if __name__ == "__main__":
+    main()