diff --git a/modeling-cmds/src/session.rs b/modeling-cmds/src/session.rs
index 968fc63a..167aa7b3 100644
--- a/modeling-cmds/src/session.rs
+++ b/modeling-cmds/src/session.rs
@@ -29,6 +29,8 @@ pub struct EngineParams {
     /// the session will be written out to this filename.
     /// For debugging.
     pub replay: Option<String>,
+    /// API Call ID for distributed tracing
+    pub api_call_id: Option<String>,
 }
 
 impl Default for EngineParams {
@@ -43,6 +45,7 @@ impl Default for EngineParams {
             pool: None,
             show_grid: false,
             replay: None,
+            api_call_id: None,
         }
     }
 }
diff --git a/modeling-cmds/src/websocket.rs b/modeling-cmds/src/websocket.rs
index e8f2ec4d..d1cd6bfb 100644
--- a/modeling-cmds/src/websocket.rs
+++ b/modeling-cmds/src/websocket.rs
@@ -97,6 +97,9 @@ pub enum WebSocketRequest {
         metrics: Box<ClientMetrics>,
     },
 
+    /// Return information about the connected instance
+    Debug {},
+
     /// Authentication header request.
     Headers {
         /// The authentication header.
@@ -208,6 +211,12 @@ pub enum OkWebSocketResponseData {
 
     /// Pong response to a Ping message.
     Pong {},
+
+    /// Information about the connected instance
+    Debug {
+        /// Instance name. This may or may not mean something.
+        name: String,
+    },
 }
 
 /// Successful Websocket response.