mcp: throttle rapid stream session polls

2026-05-01 16:36:50 +00:00
parent 8ac55ebcc2
commit 4cd5d5b132
3 changed files with 182 additions and 1 deletions
@@ -811,7 +811,7 @@ async fn handle_session_start_call(
                    batch_size,
                }),
                expires_at,
-                last_poll_at: Some(now),
+                last_poll_at: None,
                created_at: now,
                closed_at: None,
            };
@@ -996,6 +996,24 @@ async fn handle_session_poll_call(
        );
    }

+    let poll_after_ms = streaming.poll_interval_ms.unwrap_or(1_000);
+    let remaining_delay_ms = loaded.remaining_poll_delay_ms(now, poll_after_ms);
+    if remaining_delay_ms > 0 {
+        return tool_error_response(
+            message,
+            response_mode,
+            &session.protocol_version,
+            "stream_session_poll_rate_limited",
+            format!(
+                "stream session {} must wait before the next poll",
+                control.session_id
+            ),
+            Some(json!({
+                "poll_after_ms": remaining_delay_ms
+            })),
+        );
+    }
+
    let mut state_payload: StoredSessionState = match serde_json::from_value(loaded.state.clone()) {
        Ok(value) => value,
        Err(error) => {