diff --git a/config.yaml b/config.yaml
index 3ab36c8..a62f9c6 100644
--- a/config.yaml
+++ b/config.yaml
@@ -11,6 +11,11 @@
 #   glm-5-3-flash:       $0.40 in / $1.25 out / $0.10 cached per 1M
 # Without these, LiteLLM can't price these custom models, so spend shows $0.00
 # and the team budget cap is not enforced.
+#
+# SYNC: the per-model pricing here must mirror the user-facing model list in
+# co-op/docs/models.md (and vice-versa). When a rate changes, update BOTH this
+# file and models.md — this config is the authoritative source of the numbers;
+# models.md is the member-facing mirror.
 
 model_list:
   # DeepSeek V4.1 Flash — default model (replaces V4 Flash, deprecated 2026-09-15)