From 7dbf8a26eaa3e61b70d3213ff28ac127e10a6c89 Mon Sep 17 00:00:00 2001
From: Kewe63 <Kewe63@users.noreply.github.com>
Date: Sun, 23 Aug 2026 17:39:31 +0300
Subject: [PATCH 1/2] fix(ack-id): return reply nonce for response handshakes

---
 packages/ack-id/src/a2a/sign-message.test.ts | 14 ++++++++++++++
 packages/ack-id/src/a2a/sign-message.ts      |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/packages/ack-id/src/a2a/sign-message.test.ts b/packages/ack-id/src/a2a/sign-message.test.ts
index fed6068d..f630928d 100644
--- a/packages/ack-id/src/a2a/sign-message.test.ts
+++ b/packages/ack-id/src/a2a/sign-message.test.ts
@@ -138,6 +138,20 @@ describe("createA2AHandshakeMessage", () => {
     expect(result.message.role).toBe("agent")
   })
 
+  it("returns the fresh reply nonce when responding to a handshake", async () => {
+    const result = await createA2AHandshakeMessage(
+      "agent",
+      {
+        recipient: userDid,
+        vc: testCredential,
+        requestNonce: "original-nonce",
+      },
+      { did: agentDid, jwtSigner },
+    )
+
+    expect(result.nonce).toBe("test-nonce-1234")
+  })
+
   it("returns the signed JWT in the message data part", async () => {
     const result = await createA2AHandshakeMessage(
       "agent",
diff --git a/packages/ack-id/src/a2a/sign-message.ts b/packages/ack-id/src/a2a/sign-message.ts
index a4a041bc..f3e26ba4 100644
--- a/packages/ack-id/src/a2a/sign-message.ts
+++ b/packages/ack-id/src/a2a/sign-message.ts
@@ -122,7 +122,7 @@ export async function createA2AHandshakeMessage(
   return {
     sig: jwt,
     jti,
-    nonce: payload.nonce,
+    nonce: payload.replyNonce ?? payload.nonce,
     message,
   }
 }

From 134d3ae12b19b03d8191fc9cca4157d6f2f55c94 Mon Sep 17 00:00:00 2001
From: Kewe63 <Kewe63@users.noreply.github.com>
Date: Tue, 1 Sep 2026 15:56:43 +0300
Subject: [PATCH 2/2] chore: add changeset for ack-id nonce fix

---
 .changeset/fresh-reply-nonce.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/fresh-reply-nonce.md

diff --git a/.changeset/fresh-reply-nonce.md b/.changeset/fresh-reply-nonce.md
new file mode 100644
index 00000000..e0d678d2
--- /dev/null
+++ b/.changeset/fresh-reply-nonce.md
@@ -0,0 +1,5 @@
+---
+"@agentcommercekit/ack-id": patch
+---
+
+Return the fresh reply nonce from A2A response handshakes so callers can correlate the next handshake leg.