refactor: drop the unread transfer_limits field from the handshake ack

The interface reads a member's cap from transfer_state and never read the
copy on the ack. The transfer probe reads it from transfer_state too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 17 insertions, 35 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index 7f1b232..98d010e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -500,11 +500,6 @@ class MeshBayTransport {
     this._inFlightUploads = new Set();
     // tr → Lease. A transfer's slot on the node, from the client's side.
     this._leases = new Map();
-    // Set from the handshake ack: a node that answers with `transfer_limits`
-    // speaks transfer slots. Used instead of a timeout, because "no answer
-    // yet" and "this node will never answer" are indistinguishable in time and
-    // guessing wrong either stalls every download or defeats the cap.
-    this._transferLimits = null;
     // Set once close() runs — stops the automatic reconnect from firing on a
     // connection the caller tore down on purpose (leaving the group, page
     // unload), which would otherwise race back in right as everything else
@@ -573,9 +568,6 @@ class MeshBayTransport {
   set onIndexDelta(fn) { this._onIndexDelta = fn; }
   set onRootsChanged(fn) { this._onRootsChanged = fn; }
 
-  /** This member's own caps in this group, or null when the node said nothing. */
-  get transferLimits() { return this._transferLimits; }
-
   set onAppsEnabled(fn) { this._onAppsEnabled = fn; }
   set onAppDirectories(fn) { this._onAppDirectories = fn; }
   set onChatDirectory(fn) { this._onChatDirectory = fn; }
@@ -1157,7 +1149,6 @@ class MeshBayTransport {
       delete ack.nonce;
       delete ack.ct;
       Object.assign(ack, config);
-      this._transferLimits = ack.transfer_limits || null;
 
       // From the *sealed* part of the ack: a forged epoch would have this
       // client sealing under a key the group has retired.
diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc/handshake.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc/handshake.py
index eceb2b4..f701072 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/webrtc/handshake.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc/handshake.py
@@ -24,7 +24,6 @@ from meshbay_common.handshake import (
 )
 from meshbay_common.protocol import MNP
 
-from meshbay_node import transfers as transfers_mod
 from meshbay_node.indexer.indexer import DirectoryIndexer
 from meshbay_node.transport.webrtc.channel import _extract_dtls_fingerprint, _get_remote_ip
 from meshbay_node.transport.webrtc.limits import MAX_MSG
@@ -266,19 +265,6 @@ class HandshakeMixin:
             # No `chat_encrypted` beside it: there is no switch. A peer that
             # reached this point speaks MNP 2.0, and 2.0 has no plaintext chat.
             "chat_epoch": int(self._group_ctx().get("chat_epoch", 0) or 0),
-            # This member's own transfer caps in this group, so the interface
-            # can say "2 of 2 of your slots are busy" rather than draw a bare
-            # spinner. Absent reads as "no limit known" and the hint is simply
-            # not drawn — never as "unlimited", which would have the interface
-            # contradicting the node.
-            "transfer_limits": {
-                "download": self._slots().member_cap(
-                    transfers_mod.DOWNLOAD,
-                    (self._group_id or "", self._user_id or "")),
-                "upload": self._slots().member_cap(
-                    transfers_mod.UPLOAD,
-                    (self._group_id or "", self._user_id or "")),
-            },
             # So a client that connects mid-scan shows the indexing state
             # immediately, instead of waiting for the next periodic
             # INDEX_PROGRESS push. Never a path or filename — see
diff --git a/packages/meshbay-node/tests/transfer_probe.py b/packages/meshbay-node/tests/transfer_probe.py
index 7aa4902..6666960 100755
--- a/packages/meshbay-node/tests/transfer_probe.py
+++ b/packages/meshbay-node/tests/transfer_probe.py
@@ -274,7 +274,14 @@ async def operator_checks(client, ack, group, node_id) -> int:
     import re as _re
 
     failures = 0
-    member_cap = int((ack.get("transfer_limits") or {}).get("download") or 0)
+    # This member's own cap, as the node states it on every `transfer_state`.
+    probe_tr, probe_state = await _open_transfer(client)
+    member_cap = int(probe_state.get("cap") or 0)
+    client.send({"type": "transfer_close", "v": "0.1", "tr": probe_tr, "reason": "done"})
+    while True:   # closed before anything below counts what is in use
+        reply = await client.recv_type("transfer_state", timeout=15)
+        if reply.get("tr") == probe_tr and reply.get("state") == "closed":
+            break
 
     # The queue has to be held by the *node* cap, not by this member's own.
     #
@@ -446,16 +453,6 @@ async def probe(args) -> int:
 
         ack = await alice.connect(http, group["id"], node_id)
 
-        limits = ack.get("transfer_limits")
-        if limits is None:
-            print("This node does not hand out transfer slots — it predates "
-                  "them, or the handshake ack lost the field. Nothing below "
-                  "can be measured.")
-            await alice.close()
-            return 1
-        cap = int(limits.get("download") or 0)
-        print(f"node reports this member may run {cap} download(s) at once\n")
-
         if args.operator:
             return await operator_checks(alice, ack, group, node_id)
 
@@ -472,9 +469,17 @@ async def probe(args) -> int:
         # held. So the first reply is read for what the node says is already
         # in use, and the run stops rather than measuring against a moving
         # floor.
-        want = args.want or (cap + 2)
         opened = [await _open_transfer(alice)]
         first = opened[0][1]
+        # This member's cap, as the node states it on every `transfer_state`.
+        cap = int(first.get("cap") or 0)
+        if not cap:
+            print("This node does not state a transfer cap — nothing below can "
+                  "be measured.")
+            await alice.close()
+            return 1
+        print(f"node reports this member may run {cap} download(s) at once\n")
+        want = args.want or (cap + 2)
         if first.get("state") != "granted" or first.get("used", 1) != 1:
             print(f"this node is not idle: it reports {first.get('used')} of "
                   f"{first.get('cap')} slots already used by this member, and "