6 files changed, 35 insertions, 0 deletions
diff --git a/src/api/schema.rs b/src/api/schema.rs
index 074cd4ed..ba9f0c3a 100644
--- a/src/api/schema.rs
+++ b/src/api/schema.rs
@@ -69,6 +69,8 @@ pub enum Method {
     ClientWindowTitleSet(ClientWindowTitleSetParams),
     #[serde(rename = "client.window_title.clear")]
     ClientWindowTitleClear(EmptyParams),
+    #[serde(rename = "client_shell.surface.set")]
+    ClientShellSurfaceSet(ClientShellSurfaceSetParams),
     #[serde(rename = "session.snapshot")]
     SessionSnapshot(EmptyParams),
     #[serde(rename = "workspace.create")]
diff --git a/src/api/schema/common.rs b/src/api/schema/common.rs
index 15f56e6c..bf0d7caf 100644
--- a/src/api/schema/common.rs
+++ b/src/api/schema/common.rs
@@ -61,6 +61,12 @@ pub struct ClientWindowTitleSetParams {
     pub title: String,
 }
 
+/// Updates whether the requesting client shell receives and controls pane presentation.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, schemars::JsonSchema)]
+pub struct ClientShellSurfaceSetParams {
+    pub active: bool,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, schemars::JsonSchema)]
 #[serde(rename_all = "snake_case")]
 pub enum SplitDirection {
diff --git a/src/api/schema/response.rs b/src/api/schema/response.rs
index 180d6645..e6d4de4d 100644
--- a/src/api/schema/response.rs
+++ b/src/api/schema/response.rs
@@ -295,6 +295,12 @@ pub enum ResponseResult {
         status: crate::config::ConfigReloadStatus,
         diagnostics: Vec<String>,
     },
+    /// Acknowledgement for the client-shell surface interest lease. This method is new on the
+    /// endpoint protocol, so its revision-bearing result can establish an activation floor.
+    ClientShellSurfaceSet {
+        active: bool,
+        projection_revision: u64,
+    },
     Ok {},
 }
 
diff --git a/src/api/schema/server.rs b/src/api/schema/server.rs
index 96e51564..b274bc95 100644
--- a/src/api/schema/server.rs
+++ b/src/api/schema/server.rs
@@ -21,4 +21,10 @@ pub struct ServerCapabilities {
     /// Stable client-owned endpoint generation supported by this server.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub endpoint_protocol_generation: Option<u32>,
+    /// Whether this server supports explicit client-shell surface interest.
+    #[serde(default)]
+    pub surface_interest: bool,
+    /// Whether this server supports endpoint health probes.
+    #[serde(default)]
+    pub health_check: bool,
 }
diff --git a/src/api/schema/tests.rs b/src/api/schema/tests.rs
index 693f0e85..b566e8f6 100644
--- a/src/api/schema/tests.rs
+++ b/src/api/schema/tests.rs
@@ -725,6 +725,8 @@ fn success_response_round_trips() {
                 live_handoff: true,
                 detached_server_daemon: true,
                 endpoint_protocol_generation: Some(1),
+                surface_interest: true,
+                health_check: true,
             }),
         },
     };
diff --git a/src/api/server.rs b/src/api/server.rs
index 655d89c5..b8ef7c38 100644
--- a/src/api/server.rs
+++ b/src/api/server.rs
@@ -69,6 +69,8 @@ fn default_capabilities() -> Option<ServerCapabilities> {
         live_handoff: crate::platform::capabilities().live_handoff,
         detached_server_daemon: crate::platform::current_process_is_detached_server_daemon(),
         endpoint_protocol_generation: Some(crate::protocol::endpoint::ENDPOINT_PROTOCOL_GENERATION),
+        surface_interest: true,
+        health_check: true,
     })
 }
 
@@ -352,6 +354,14 @@ fn handle_request(
         });
     }
 
+    if matches!(&request.method, Method::ClientShellSurfaceSet(_)) {
+        return error_response_json(
+            request.id,
+            "connection_local_only",
+            "client_shell.surface.set is only available through a client shell endpoint".into(),
+        );
+    }
+
     if matches!(&request.method, Method::ServerStop(_)) {
         if let Some(server_stop) = server_stop {
             server_stop.store(true, Ordering::Release);
@@ -386,6 +396,7 @@ pub(crate) fn api_method_name(method: &Method) -> &'static str {
         Method::CommandInvoke(_) => "command.invoke",
         Method::ClientWindowTitleSet(_) => "client.window_title.set",
         Method::ClientWindowTitleClear(_) => "client.window_title.clear",
+        Method::ClientShellSurfaceSet(_) => "client_shell.surface.set",
         Method::SessionSnapshot(_) => "session.snapshot",
         Method::WorkspaceCreate(_) => "workspace.create",
         Method::WorkspaceList(_) => "workspace.list",
@@ -1136,6 +1147,8 @@ mod tests {
                 endpoint_protocol_generation: Some(
                     crate::protocol::endpoint::ENDPOINT_PROTOCOL_GENERATION,
                 ),
+                surface_interest: true,
+                health_check: true,
             }),
             None,
             None,