diff --git a/docs/architecture/c4/l2-containers.puml b/docs/architecture/c4/l2-containers.puml
index 8d66a614..5bfd6799 100644
--- a/docs/architecture/c4/l2-containers.puml
+++ b/docs/architecture/c4/l2-containers.puml
@@ -48,6 +48,7 @@ Rel(prometheus, ocr, "Scrapes OCR + http_* metrics", "HTTP 8000 /metrics")
 Rel(grafana, prometheus, "Queries metrics", "HTTP 9090")
 Rel(grafana, loki, "Queries logs", "HTTP 3100")
 Rel(grafana, tempo, "Queries traces", "HTTP 3200")
+Rel(grafana, db, "Read-only dashboard queries via grafana_reader role", "PostgreSQL / archiv-net")
 Rel(glitchtip, db, "Stores error events in glitchtip DB", "PostgreSQL / archiv-net")
 Rel(obs_glitchtip_worker, obs_redis, "Processes Celery tasks", "Redis / obs-net")