diff --git a/ch6-web/ch6-15-extend.md b/ch6-web/ch6-15-extend.md
index 2b39566..0a1e093 100644
--- a/ch6-web/ch6-15-extend.md
+++ b/ch6-web/ch6-15-extend.md
@@ -1 +1 @@
-服务准入、业务线级限流、压测谬论
+服务准入、业务线级限流、压测谬论、api 文档化