diff --git a/src/fastapi_cloud_cli/commands/apps/create.py b/src/fastapi_cloud_cli/commands/apps/create.py
index 00c93c4b..fa4f3df8 100644
--- a/src/fastapi_cloud_cli/commands/apps/create.py
+++ b/src/fastapi_cloud_cli/commands/apps/create.py
@@ -75,7 +75,10 @@ def create_app(
         str | None,
         typer.Option(
             "--directory",
-            help="Directory containing the app's pyproject.toml.",
+            help=(
+                "Relative app directory containing the pyproject.toml "
+                "(for example: src or backend)."
+            ),
         ),
     ] = None,
     link: Annotated[
@@ -146,7 +149,17 @@ def create_app(
                 )
                 toolkit.print_line()
 
-            directory = validate_app_directory(directory)
+            try:
+                directory = validate_app_directory(directory)
+            except ValueError as e:
+                toolkit.fail(
+                    "invalid_input",
+                    f"Invalid app directory: {e}",
+                    hint=(
+                        "Pass a relative app directory such as `src` or `backend`; "
+                        "use --path with --link to choose a local filesystem path."
+                    ),
+                )
 
             with toolkit.progress(
                 title="Creating app",
diff --git a/tests/test_cli_apps.py b/tests/test_cli_apps.py
index 47a4cad2..770c3a96 100644
--- a/tests/test_cli_apps.py
+++ b/tests/test_cli_apps.py
@@ -322,6 +322,36 @@ def test_creates_app_json_rejects_path_without_link(
     assert result.stderr == ""
 
 
+def test_creates_app_json_rejects_invalid_directory(logged_in_cli: None) -> None:
+    result = runner.invoke(
+        app,
+        [
+            "apps",
+            "create",
+            "--team-id",
+            "00000000-0000-4000-8000-000000000001",
+            "--name",
+            "API",
+            "--directory",
+            "/tmp/api",
+            "--json",
+        ],
+    )
+
+    assert result.exit_code == 1
+    assert json.loads(result.stdout) == {
+        "error": {
+            "code": "invalid_input",
+            "message": ("Invalid app directory: must be a relative path, not absolute"),
+            "hint": (
+                "Pass a relative app directory such as `src` or `backend`; "
+                "use --path with --link to choose a local filesystem path."
+            ),
+        }
+    }
+    assert result.stderr == ""
+
+
 @pytest.mark.respx
 def test_links_existing_app_to_path_as_json(
     logged_in_cli: None,