fix: FastMCP 2.12+ auth import compatibility

asgi_app.py

@@ -55,43 +55,61 @@ logger = logging.getLogger(__name__)
 # Configure CORS and Auth middleware
 cors_origins = os.getenv("ALLOWED_ORIGINS", "*").split(",")
 
-# Import FastMCP Bearer Auth Provider
-from fastmcp.server.auth import BearerAuthProvider
-from fastmcp.server.auth.providers.bearer import RSAKeyPair
-
-# Import Clerk SDK at module level for performance
-try:
-    from clerk_backend_api import Clerk
-    CLERK_SDK_AVAILABLE = True
-except ImportError:
-    CLERK_SDK_AVAILABLE = False
-    logger.warning("Clerk SDK not available - falling back to development mode")
-
 # Configure Bearer token authentication based on ENABLE_AUTH
 auth_enabled = os.getenv("ENABLE_AUTH", "false").lower() == "true"
 bearer_auth = None
 
-if CLERK_SECRET_KEY and CLERK_ISSUER:
+# Only import and configure auth if enabled
+if auth_enabled:
+    # Import FastMCP JWT Verifier (handles both old and new FastMCP versions)
+    try:
+        # FastMCP 2.12+ uses JWTVerifier
+        from fastmcp.server.auth.providers.jwt import JWTVerifier, RSAKeyPair
+        AuthProviderClass = JWTVerifier
+    except ImportError:
+        try:
+            # Older FastMCP versions used BearerAuthProvider
+            from fastmcp.server.auth import BearerAuthProvider
+            from fastmcp.server.auth.providers.bearer import RSAKeyPair
+            AuthProviderClass = BearerAuthProvider
+        except ImportError:
+            logger.error("No compatible auth provider found in FastMCP")
+            AuthProviderClass = None
+            RSAKeyPair = None
+
+    # Import Clerk SDK at module level for performance
+    try:
+        from clerk_backend_api import Clerk
+        CLERK_SDK_AVAILABLE = True
+    except ImportError:
+        CLERK_SDK_AVAILABLE = False
+        logger.warning("Clerk SDK not available - falling back to development mode")
+
+    if AuthProviderClass:
+        if CLERK_SECRET_KEY and CLERK_ISSUER:
             # Production: Use Clerk JWKS endpoint for token validation
-    bearer_auth = BearerAuthProvider(
+            bearer_auth = AuthProviderClass(
                 jwks_uri=f"{CLERK_ISSUER}/.well-known/jwks.json",
                 issuer=None,
                 algorithm="RS256",
                 audience=None,
                 required_scopes=[]
             )
-else:
+        elif RSAKeyPair:
             # Development: Generate RSA key pair for testing
             dev_key_pair = RSAKeyPair.generate()
-    bearer_auth = BearerAuthProvider(
+            bearer_auth = AuthProviderClass(
                 public_key=dev_key_pair.public_key,
                 issuer="https://dev.yargimcp.com",
                 audience="dev-mcp-server",
                 required_scopes=["yargi.read"]
             )
+else:
+    CLERK_SDK_AVAILABLE = False
+    logger.info("Authentication disabled (ENABLE_AUTH=false)")
 
-# Create MCP app with Bearer authentication
+# Create MCP app with Bearer authentication (None if auth disabled)
-mcp_server = create_app(auth=bearer_auth if auth_enabled else None)
+mcp_server = create_app(auth=bearer_auth)
 
 # Create MCP Starlette sub-application with root path - mount will add /mcp prefix
 mcp_app = mcp_server.http_app(path="/")