diff --git a/shinylive/_main.py b/shinylive/_main.py
index f0fdeec..b7f4521 100644
--- a/shinylive/_main.py
+++ b/shinylive/_main.py
@@ -527,7 +527,7 @@ def url() -> None:
 def encode(
     app: str,
     files: Optional[tuple[str, ...]] = None,
-    mode: str = "editor",
+    mode: Literal["editor", "app"] = "editor",
     language: Optional[str] = None,
     no_header: bool = False,
     view: bool = False,
@@ -551,7 +551,6 @@ def encode(
         import webbrowser
 
         webbrowser.open(url)
-    return
 
 
 @url.command(
@@ -577,7 +576,7 @@ def encode(
     "--json",
     is_flag=True,
     default=False,
-    help="Prints the decoded shinylive bundle as JSON to stdout, ignoring --out.",
+    help="Prints the decoded shinylive bundle as JSON to stdout, ignoring --dir.",
 )
 @click.argument("url", type=str, nargs=1, default="-")
 def decode(url: str, dir: Optional[str] = None, json: bool = False) -> None:
@@ -595,7 +594,7 @@ def decode(url: str, dir: Optional[str] = None, json: bool = False) -> None:
         import os
 
         out_dir = Path(dir)
-        os.makedirs(out_dir, exist_ok=True)
+        out_dir.mkdir(parents=True, exist_ok=True)
         for file in bundle:
             with open(out_dir / file["name"], "w") as f_out:
                 f_out.write(
@@ -610,8 +609,6 @@ def decode(url: str, dir: Optional[str] = None, json: bool = False) -> None:
             print("")
             print(file["content"].encode("utf-8", errors="ignore").decode("utf-8"))
 
-    return
-
 
 # #############################################################################
 # ## Deprecated commands
diff --git a/shinylive/_url.py b/shinylive/_url.py
index e9946cd..82af977 100644
--- a/shinylive/_url.py
+++ b/shinylive/_url.py
@@ -5,7 +5,7 @@
 import os
 import re
 from pathlib import Path
-from typing import List, Literal, Optional, TypedDict, cast
+from typing import Literal, Optional, TypedDict, cast
 
 
 class FileContentJson(TypedDict):
@@ -16,9 +16,9 @@ class FileContentJson(TypedDict):
 
 def encode_shinylive_url(
     app: str | Path,
-    files: Optional[tuple[str | Path, ...]] = None,
-    mode: str = "editor",
-    language: Optional[str] = None,
+    files: Optional[str | Path | Sequence[str | Path]] = None,
+    mode: Literal["editor", "app"] = "editor",
+    language: Optional[Literal["py", "r"]] = None,
     header: bool = True,
 ) -> str:
     """
@@ -35,11 +35,11 @@ def encode_shinylive_url(
         these files will be stored relative to the main `app` file. If an entry in files
         is a directory, then all files in that directory will be included, recursively.
     mode
-        The mode of the application. Defaults to "editor".
+        The mode of the application, either "editor" or "app". Defaults to "editor".
     language
-        The language of the application. Defaults to None.
+        The language of the application, or None to autodetect the language. Defaults to None.
     header
-        Whether to include a header. Defaults to True.
+        Whether to include a header bar in the UI. This is used only if ``mode`` is "app". Defaults to True.
 
     Returns
     -------
@@ -57,7 +57,6 @@ def encode_shinylive_url(
             {
                 "name": f"app.{'py' if language == 'py' else 'R'}",
                 "content": app,
-                "type": "text",
             }
         ]
     else:
@@ -78,11 +77,7 @@ def encode_shinylive_url(
             read_file(file, root_dir) for file in file_list if Path(file) != app_path
         ]
 
-    if language in ["py", "python"]:
-        language = "py"
-    elif language in ["r", "R"]:
-        language = "r"
-    else:
+    if language not in ["py", "r"]:
         raise ValueError(
             f"Language '{language}' is not supported. Please specify one of 'py' or 'r'."
         )
@@ -110,8 +105,7 @@ def detect_app_language(app: str | Path) -> str:
         else:
             raise ValueError(err_not_detected)
 
-    if not isinstance(app, Path):
-        app = Path(app)
+    app = Path(app)
 
     if app.suffix.lower() == ".py":
         return "py"
@@ -171,8 +165,6 @@ def decode_shinylive_url(url: str) -> List[FileContentJson]:
             raise ValueError(
                 f"Invalid shinylive URL: unexpected file type '{file['type']}' in '{file['name']}'."
             )
-        elif "type" not in file:
-            file["type"] = "text"
         if not all(isinstance(value, str) for value in file.values()):  # type: ignore
             raise ValueError(
                 f"Invalid shinylive URL: not all items in '{file['name']}' were strings."