diff --git a/src/monitor_service/logging.py b/src/monitor_service/logging.py
new file mode 100644
index 0000000..5d86e0c
--- /dev/null
+++ b/src/monitor_service/logging.py
@@ -0,0 +1,22 @@
+import json
+import logging
+from urllib.parse import urlsplit, urlunsplit
+
+
+def redact_url(url: str) -> str:
+    parts = urlsplit(url)
+    host = parts.hostname or ""
+    if ":" in host and not host.startswith("["):
+        host = f"[{host}]"
+    if parts.port is not None:
+        host = f"{host}:{parts.port}"
+    return urlunsplit((parts.scheme, host, parts.path, "", ""))
+
+
+def log_event(logger: logging.Logger, event: str, **fields: object) -> None:
+    safe = {key: redact_url(str(value)) if key == "url" else value for key, value in fields.items()}
+    logger.info(json.dumps({"event": event, **safe}, default=str, sort_keys=True))
+
+
+def configure_logging(level: str) -> None:
+    logging.basicConfig(level=level.upper(), format="%(message)s")