From 49eba18b371c9f99edd6949d9fcae5b828c64b73 Mon Sep 17 00:00:00 2001
From: Eitan Yarmush <eitan.yarmush@solo.io>
Date: Tue, 29 Apr 2025 15:16:29 +0000
Subject: [PATCH] stderr-notification-handler

---
 crates/rmcp/src/handler/client.rs | 9 +++++++++
 crates/rmcp/src/model.rs          | 9 +++++++++
 crates/rmcp/src/model/meta.rs     | 1 +
 3 files changed, 19 insertions(+)

diff --git a/crates/rmcp/src/handler/client.rs b/crates/rmcp/src/handler/client.rs
index 13bd9677..2f051599 100644
--- a/crates/rmcp/src/handler/client.rs
+++ b/crates/rmcp/src/handler/client.rs
@@ -28,6 +28,9 @@ impl<H: ClientHandler> Service<RoleClient> for H {
         notification: <RoleClient as ServiceRole>::PeerNot,
     ) -> Result<(), McpError> {
         match notification {
+            ServerNotification::StderrNotification(notification) => {
+                self.on_stderr(notification.params).await
+            }
             ServerNotification::CancelledNotification(notification) => {
                 self.on_cancelled(notification.params).await
             }
@@ -98,6 +101,12 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
     ) -> impl Future<Output = ()> + Send + '_ {
         std::future::ready(())
     }
+    fn on_stderr(
+        &self,
+        params: StderrNotificationParam,
+    ) -> impl Future<Output = ()> + Send + '_ {
+        std::future::ready(())
+    }
     fn on_progress(
         &self,
         params: ProgressNotificationParam,
diff --git a/crates/rmcp/src/model.rs b/crates/rmcp/src/model.rs
index 7ff035ee..d1cd6585 100644
--- a/crates/rmcp/src/model.rs
+++ b/crates/rmcp/src/model.rs
@@ -569,6 +569,14 @@ pub struct PaginatedRequestParam {
 const_string!(PingRequestMethod = "ping");
 pub type PingRequest = RequestNoParam<PingRequestMethod>;
 
+const_string!(StderrNotificationMethod = "notifications/stderr");
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct StderrNotificationParam {
+    pub content: String,
+}
+pub type StderrNotification = Notification<StderrNotificationMethod, StderrNotificationParam>;
+
 const_string!(ProgressNotificationMethod = "notifications/progress");
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
 #[serde(rename_all = "camelCase")]
@@ -981,6 +989,7 @@ ts_union!(
     | ResourceUpdatedNotification
     | ResourceListChangedNotification
     | ToolListChangedNotification
+    | StderrNotification
     | PromptListChangedNotification;
 );
 
diff --git a/crates/rmcp/src/model/meta.rs b/crates/rmcp/src/model/meta.rs
index 010dd8ca..5bfcd08b 100644
--- a/crates/rmcp/src/model/meta.rs
+++ b/crates/rmcp/src/model/meta.rs
@@ -95,6 +95,7 @@ variant_extension! {
         ResourceListChangedNotification
         ToolListChangedNotification
         PromptListChangedNotification
+        StderrNotification
     }
 }
 #[derive(Debug, Serialize, Deserialize, Clone, Default)]