diff --git a/agent/nix_builder_autoscaler/logging.py b/agent/nix_builder_autoscaler/logging.py
index 0036be2..23fabf9 100644
--- a/agent/nix_builder_autoscaler/logging.py
+++ b/agent/nix_builder_autoscaler/logging.py
@@ -12,7 +12,7 @@ from typing import Any
 class JSONFormatter(logging.Formatter):
     """Format log records as single-line JSON."""
 
-    EXTRA_FIELDS = ("slot_id", "reservation_id", "instance_id", "request_id")
+    EXTRA_FIELDS = ("slot_id", "reservation_id", "instance_id", "request_id", "error", "category", "count", "ids", "idle_seconds")
 
     def format(self, record: logging.LogRecord) -> str:
         """Format a log record as JSON."""