✨ Add basic embedded app

spylib/oauth/fastapi.py

@@ -4,20 +4,27 @@
 from spylib.exceptions import FastAPIImportError
 
 try:
-    from fastapi import APIRouter, Depends, HTTPException, Query  # type: ignore
+    from fastapi import (  # type: ignore
+        APIRouter,
+        Depends,
+        HTTPException,
+        Query,
+        Request,
+        Response,
+    )
 except ImportError as e:
     raise FastAPIImportError(
         'The oauth router is a fastapi router and fastapi is not installed. '
         'Run `pip install spylib[fastapi]` to be able to use the oauth router.'
     ) from e
 
-from starlette.requests import Request
 from starlette.responses import RedirectResponse
 
 from ..utils import store_domain
 from .callback import process_callback
 from .models import OfflineTokenModel, OnlineTokenModel
 from .redirects import app_redirect, oauth_init_url
+from .validations import validate_hmac
 
 
 @dataclass
@@ -41,6 +48,7 @@ def init_oauth_router(
     install_init_path='/shopify/auth',
     callback_path='/callback',
     path_prefix: str = '',
+    initial_path: Optional[str] = '/'
 ) -> APIRouter:
     router = APIRouter()
 
@@ -120,4 +128,15 @@ async def shopify_callback(request: Request, shop: str, args: Callback = Depends
             )
         )
 
+    if initial_path:
+        @router.get(initial_path, include_in_schema=False)
+        async def default_root(
+            request: Request,
+            hmac: str,
+            session: str = None,
+        ):
+            validate_hmac(request=request, hmac=hmac)
+            if session:
+                return Response('App Installed')
+
     return router