From 4ccd20299be94e69d5be02650152565f3f64cc85 Mon Sep 17 00:00:00 2001
From: Danny Kim <temeddix@gmail.com>
Date: Sat, 26 Sep 2026 01:54:31 +0900
Subject: [PATCH] Explain why the session lives in a per-instance slot

---
 src/lib.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 8dc8806..426f1aa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,6 +32,10 @@ struct Session {
   signer: Signer,
 }
 
+// The host creates one component instance per connection and calls into it
+// on a single thread, so this slot holds exactly one connection's session and
+// is not shared state between connections. A WASI component has no other place
+// to keep state between exported calls.
 thread_local! {
   static SESSION: RefCell<Option<Session>> = const { RefCell::new(None) };
 }