From 0bfbe1cb2e6114f8181795bd18f8114269130d1e Mon Sep 17 00:00:00 2001
From: FanouZeng-TT <18280587072@163.com>
Date: Mon, 24 Aug 2026 23:43:20 +0800
Subject: [PATCH] docs: use PostalAddress snake_case attribute

---
 a2a/docs/06-extending.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/a2a/docs/06-extending.md b/a2a/docs/06-extending.md
index ff8cba8b..b5655062 100644
--- a/a2a/docs/06-extending.md
+++ b/a2a/docs/06-extending.md
@@ -57,7 +57,7 @@ tax = int(subtotal * tax_rate)
 
 def _get_tax_rate(self, address: PostalAddress) -> float:
     state_rates = {"CA": 0.0725, "NY": 0.08, "TX": 0.0625}
-    return state_rates.get(address.addressRegion, 0.05)
+    return state_rates.get(address.address_region, 0.05)
 ```
 
 ### Add Minimum Order