diff --git a/docs/docs/cloud/reference/env_var.md b/docs/docs/cloud/reference/env_var.md
index e15157cac..e82778248 100644
--- a/docs/docs/cloud/reference/env_var.md
+++ b/docs/docs/cloud/reference/env_var.md
@@ -89,3 +89,12 @@ Database Connectivity:
     Custom Redis instances are only available for [Self-Hosted Data Plane](../../concepts/langgraph_self_hosted_data_plane.md) and [Self-Hosted Control Plane](../../concepts/langgraph_self_hosted_control_plane.md) deployments.
 
 Specify `REDIS_URI_CUSTOM` to use a custom Redis instance. The value of `REDIS_URI_CUSTOM` must be a valid [Redis connection URI](https://redis-py.readthedocs.io/en/stable/connections.html#redis.Redis.from_url).
+
+## `REDIS_KEY_PREFIX`
+
+!!! info "Available in API Server version 0.1.9+"
+    This environment variable is supported in API Server version 0.1.9 and above.
+
+Specify a prefix for Redis keys. This allows multiple LangGraph Server instances to share the same Redis instance by using different key prefixes. 
+
+Defaults to `''`.