1 files changed, 9 insertions, 10 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index 27edc4e..f3683eb 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -305,16 +305,15 @@ window.addEventListener('hashchange', () => {
 // The `v: '0.1'` on every other message in this file is the historical value
 // and is read by nothing; it is left alone deliberately. The range is
 // negotiated once, at the start, not restated per message.
-const MNP_V = '3.1';
-// **Not** raised with it, and that is the whole difference between 3.0 and 3.1.
-// 3.0 was a flag day because a node older than it cannot grant the lease this
-// client opens for every download and upload, so talking to one would mean
-// every transfer failing for a reason the person cannot act on. 3.1 only adds
-// `user_blob_*`: a 3.0 node answers "unknown message type" and the client
-// stores its playlists on the next node it reaches, keeping its own copy
-// meanwhile (docs/playlists.md §6.4). Refusing every 3.0 node over a feature
-// that degrades this quietly would be the flag day nobody needed.
-const MNP_V_MIN = '3.0';
+const MNP_V = '4.0';
+// Raised with it: 4.0 is a flag day. A member now presents a short-lived
+// MNP-audience token in the handshake, not its hub session token — a node
+// older than 4.0 expected the session token, and one newer refuses it, so the
+// two cannot authenticate across the break. This is the C6 rule: no
+// compatibility branch, or the old path (a hub credential handed to a node)
+// stays reachable. The desktop client is gated by client.minimum before it
+// even connects; the browser picks up this build on reload.
+const MNP_V_MIN = '4.0';
 
 // Codes a NODE sends us, in its own vocabulary (meshbay_common/handshake.py's
 // check_version): `version_too_old` means *we* are too old for it,