fix: add protected resource metadata + GET /token for Claude Desktop

Claude Desktop needs:
- /.well-known/oauth-protected-resource (RFC 9728)
- GET method on /token endpoint (sends params via query string)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mcp_bridge/__main__.py

@@ -24,6 +24,7 @@ logger = logging.getLogger("mcp_bridge")
 # Paths that don't require auth
 PUBLIC_PATHS = {
     "/.well-known/oauth-authorization-server",
+    "/.well-known/oauth-protected-resource",
     "/authorize",
     "/token",
     "/api/health",

mcp_bridge/auth.py

@@ -132,12 +132,15 @@ async def token_endpoint(request: Request) -> JSONResponse:
     - grant_type=client_credentials (direct)
     """
     try:
-        content_type = request.headers.get("content-type", "")
-        if "application/json" in content_type:
-            data = await request.json()
+        if request.method == "GET":
+            data = dict(request.query_params)
         else:
-            form = await request.form()
-            data = dict(form)
+            content_type = request.headers.get("content-type", "")
+            if "application/json" in content_type:
+                data = await request.json()
+            else:
+                form = await request.form()
+                data = dict(form)
     except Exception:
         return JSONResponse(
             {"error": "invalid_request", "error_description": "Could not parse request body"},
@@ -253,9 +256,21 @@ async def oauth_metadata(request: Request) -> JSONResponse:
     })
 
 
+async def protected_resource_metadata(request: Request) -> JSONResponse:
+    """OAuth 2.0 Protected Resource Metadata (RFC 9728)."""
+    base = str(request.base_url).rstrip("/")
+    return JSONResponse({
+        "resource": base,
+        "authorization_servers": [base],
+        "scopes_supported": ["mcp"],
+        "bearer_methods_supported": ["header"],
+    })
+
+
 # Routes to add to the app
 auth_routes = [
     Route("/.well-known/oauth-authorization-server", oauth_metadata, methods=["GET"]),
+    Route("/.well-known/oauth-protected-resource", protected_resource_metadata, methods=["GET"]),
     Route("/authorize", authorize_endpoint, methods=["GET"]),
-    Route("/token", token_endpoint, methods=["POST"]),
+    Route("/token", token_endpoint, methods=["GET", "POST"]),
 ]