diff --git a/fern/pages/integrations/x402.mdx b/fern/pages/integrations/x402.mdx
index 0230afd..f55df1c 100644
--- a/fern/pages/integrations/x402.mdx
+++ b/fern/pages/integrations/x402.mdx
@@ -11,6 +11,8 @@ description: AgentMail's x402 integration for HTTP-native payments
 
 ### Base URLs
 
+To authenticate with x402 instead of an API key, you must use the x402-specific base URLs below. These replace the default AgentMail base URLs and route requests through the x402 payment layer.
+
 | Protocol | URL |
 |---|---|
 | HTTP | `x402.api.agentmail.to` |