Summary

The codebase uses two different patterns to access the application's root path:

1. request.scope.get("root_path", "") - ~80 occurrences
2. settings.app_root_path - ~15 occurrences

While both approaches currently return the same value (FastAPI sets scope["root_path"] from its root_path parameter in __call__), the codebase should use a consistent pattern.

Related PR

This issue was identified during the review of #1547, which fixed the root redirect in main.py to use settings.app_root_path instead of request.scope.get("root_path", "").

Technical Analysis

Why both work the same:

FastAPI's __call__ method (in fastapi/applications.py:1131-1134) sets the scope's root_path:

async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
    if self.root_path:
        scope["root_path"] = self.root_path
    await super().__call__(scope, receive, send)

Since mcpgateway initializes FastAPI with root_path=settings.app_root_path (in main.py:617), both patterns return the same value.

Why standardization matters:

1. Consistency: Reduces cognitive load when reading/maintaining code
2. Clarity: settings.app_root_path is explicit about the source
3. Future-proofing: Doesn't depend on FastAPI's internal behavior
4. Testability: settings.app_root_path can be easily mocked without request context

Files Affected

Using request.scope.get("root_path", "") (~80 occurrences):

• mcpgateway/admin.py - 75 occurrences (redirects, template contexts)
• mcpgateway/utils/verify_credentials.py - 3 occurrences
• mcpgateway/routers/sso.py - 1 occurrence
• mcpgateway/routers/oauth_router.py - 1 occurrence

Already using settings.app_root_path (~15 occurrences):

• mcpgateway/main.py - Fixed in fix: root redirect uses app_root_path with trailing slash #1547
• mcpgateway/admin.py - Some template contexts (lines 2646, 2718, 2766, etc.)
• Various other locations

Additional Finding: Missing Trailing Slashes

Some redirects use /admin instead of /admin/, which causes an unnecessary 307 redirect when FastAPI normalizes the trailing slash. Example from admin.py:2764:

return RedirectResponse(url=f"{root_path}/admin", status_code=303)

Should be:

return RedirectResponse(url=f"{root_path}/admin/", status_code=303)

Proposed Solution

1. Replace all request.scope.get("root_path", "") with settings.app_root_path
2. Add trailing slashes to redirect URLs where appropriate
3. Consider creating a helper function for consistent redirect URL generation

Acceptance Criteria

• All occurrences of request.scope.get("root_path", "") replaced with settings.app_root_path
• Redirect URLs use consistent trailing slash pattern
• All existing tests pass
• No functional changes to behavior