Integrate mcp security guards into agentgateway

Author: APuzik-devpulse

crates/agentgateway/src/mcp/handler.rs

@@ -59,6 +59,8 @@ pub enum Error {
 	ForwardLegacySse(String),
 	#[error("failed to create SSE url: {0}")]
 	CreateSseUrl(String),
+	#[error("security guard rejected: {1} - {2}")]
+	SecurityGuard(RequestId, String, String),
 }
 
 impl From<Error> for ProxyError {

crates/agentgateway/src/mcp/mod.rs

@@ -105,10 +105,16 @@ impl App {
 				.collect::<Result<Vec<_>, _>>()?;
 
 			McpBackendGroup {
+				name: format!(
+					"{}/{}",
+					backend_group_name.namespace, backend_group_name.name
+				),
 				targets: nt,
 				stateful: backend.stateful,
+				security_guards: backend.security_guards.clone(),
 			}
 		};
+		let guard_registry = self.state.guard_registry.clone();
 		let sm = self.session.clone();
 		let client = PolicyClient { inputs: pi.clone() };
 		let authorization_policies = backend_policies
@@ -178,12 +184,14 @@ impl App {
 		match (req.uri().path(), req.method(), authn) {
 			("/sse", _, _) => {
 				// Assume this is streamable HTTP otherwise
+				let guard_registry_clone = guard_registry.clone();
 				let sse = LegacySSEService::new(
 					move || {
 						Relay::new(
 							backends.clone(),
 							authorization_policies.clone(),
 							client.clone(),
+							guard_registry_clone.clone(),
 						)
 						.map_err(|e| Error::new(e.to_string()))
 					},
@@ -226,6 +234,7 @@ impl App {
 							backends.clone(),
 							authorization_policies.clone(),
 							client.clone(),
+							guard_registry.clone(),
 						)
 						.map_err(|e| Error::new(e.to_string()))
 					},
@@ -247,8 +256,10 @@ impl App {
 
 #[derive(Debug, Clone)]
 pub struct McpBackendGroup {
+	pub name: String,
 	pub targets: Vec<Arc<McpTarget>>,
 	pub stateful: bool,
+	pub security_guards: Vec<crate::mcp::security::McpSecurityGuard>,
 }
 
 #[derive(Debug)]