diff --git a/docs/providers/anthropic.md b/docs/providers/anthropic.md
index 51bc0f7f14e..d9c3a007ada 100644
--- a/docs/providers/anthropic.md
+++ b/docs/providers/anthropic.md
@@ -260,6 +260,10 @@ OpenClaw supports Anthropic's prompt caching feature for API-key auth.
 
     OpenClaw maps this to `anthropic-beta: context-1m-2025-08-07` on requests.
 
+    `params.context1m: true` also applies to the Claude CLI backend
+    (`claude-cli/*`) for eligible Opus and Sonnet models, expanding the runtime
+    context window for those CLI sessions to match the direct-API behavior.
+
     <Warning>
     Requires long-context access on your Anthropic credential. Legacy token auth (`sk-ant-oat-*`) is rejected for 1M context requests — OpenClaw logs a warning and falls back to the standard context window.
     </Warning>