feat(mnp): sharing a folder is decided on the node's machine only (MNP 6.0)

root_add, root_update and group_attach leave MNP: adding a directory and
switching writable/removable go through the loopback API (native dialog in
the desktop app) or the CLI. The operator's Settings tab still lists the
roots from any browser, read-only. The desktop app refuses to sign those
ops; a loopback flag change now reaches open pages (publish_roots).

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

5 files changed, 34 insertions, 51 deletions

diff --git a/packages/meshbay-common/src/meshbay_common/__init__.py b/packages/meshbay-common/src/meshbay_common/__init__.py
index b68e828..c5c04a5 100644
--- a/packages/meshbay-common/src/meshbay_common/__init__.py
+++ b/packages/meshbay-common/src/meshbay_common/__init__.py
@@ -260,5 +260,12 @@ __version__ = "0.17.0"
 # a refusal, across the break. The break is confined to them, so the floor stays
 # at 4.0: everything else a 4.x peer does still works, and nothing is left
 # unsigned on either side — no node accepts the old subjects.
-MNP_VERSION = "5.0"
+#
+# 6.0 (2026-10-02) is a MAJOR — three signed operations are removed: `root_add`,
+# `root_update` and `group_attach`. What of the operator's disk is shared, and
+# whether members may write there, is decided on the node's own machine (the
+# desktop application over loopback, behind a native dialog, or the CLI), never
+# over the wire. A 5.x client that sends one gets no answer, as for any unknown
+# type; everything else it does still works, so the floor stays at 4.0.
+MNP_VERSION = "6.0"
 MHP_VERSION = "0.1"
diff --git a/packages/meshbay-common/src/meshbay_common/adminop.py b/packages/meshbay-common/src/meshbay_common/adminop.py
index 4379519..11100b5 100644
--- a/packages/meshbay-common/src/meshbay_common/adminop.py
+++ b/packages/meshbay-common/src/meshbay_common/adminop.py
@@ -101,7 +101,6 @@ OP_TMDB_REMATCH = "tmdb_rematch"
 # the lesson was already learned once). Signed for the same reason as
 # tmdb_enabled.
 OP_MUSICBRAINZ_ENABLED = "musicbrainz_enabled"
-OP_ROOT_ADD = "root_add"
 OP_ROOT_REMOVE = "root_remove"
 # One op for every application's directories. The subject is
 # "<app>:<comma-joined sorted paths>" so what the operator is shown before
@@ -122,11 +121,16 @@ OP_SEARCH_LISTED = "search_listed"
 # There is no op for *enabling* chat encryption. It is not a setting — MNP 2.0
 # has no plaintext chat to fall back to.
 OP_CHAT_EPOCH = "chat_epoch"
-OP_ROOT_UPDATE = "root_update"
 OP_ROOT_EJECT = "root_eject"
 OP_ROOT_PLUG = "root_plug"
-OP_GROUP_ATTACH = "group_attach"
 OP_GROUP_DETACH = "group_detach"
+# OP_ROOT_ADD, OP_ROOT_UPDATE and OP_GROUP_ATTACH are gone (MNP 6.0). Each one
+# chose what of the operator's disk is shared and who may write there, and a
+# signature proves only that the operator's key signed — in a browser, through
+# code the hub serves; on the desktop, through a renderer that parses content
+# from nodes. Sharing a folder, hosting a group and opening a folder to writes
+# are done on the node's own machine (loopback, behind a native dialog) or with
+# the CLI, and a message that does not exist cannot be mis-authorized.
 # OP_GEK_BUNDLE_STORE is gone. Members no longer hand the node key material at
 # all: the node holds the GEK and wraps it itself, for a key the recipient proved
 # they hold (see `join.py` and docs/MESHBAY_DESIGN.md §3.4). The operation existed
@@ -159,17 +163,6 @@ def secret_digest(value: str | None) -> str | None:
     return "sha256:" + hashlib.sha256(value.encode()).hexdigest()
 
 
-def root_add_subject(path: str, name: str, kind: str, writable: bool,
-                     removable: bool) -> str:
-    return structured_subject({"path": path, "name": name, "kind": kind,
-                               "writable": writable, "removable": removable})
-
-
-def group_attach_subject(name: str, shared_dir: str, writable: bool) -> str:
-    return structured_subject({"name": name, "shared_dir": shared_dir,
-                               "writable": writable})
-
-
 def invite_create_subject(user_id: str, username: str) -> str:
     return structured_subject({"user_id": user_id, "username": username})
 
diff --git a/packages/meshbay-common/src/meshbay_common/protocol.py b/packages/meshbay-common/src/meshbay_common/protocol.py
index af2d93b..2c7e301 100644
--- a/packages/meshbay-common/src/meshbay_common/protocol.py
+++ b/packages/meshbay-common/src/meshbay_common/protocol.py
@@ -224,8 +224,6 @@ class MNP:
     INVITE_LINK_RESULT   = "invite_link_result"    # node → operator: link code + handle, once
     NODE_STATUS          = "node_status"           # operator → node: list all groups + roots
     NODE_STATUS_ACK      = "node_status_ack"       # node → operator: full status
-    ROOT_ADD             = "root_add"              # operator → node: add a directory to a group
-    ROOT_ADD_ACK         = "root_add_ack"          # node → operator: confirmed
     ROOT_REMOVE          = "root_remove"           # operator → node: remove a root from a group
     ROOT_REMOVE_ACK      = "root_remove_ack"       # node → operator: confirmed
     # One message for every application's directories, keyed by the app's own
@@ -256,8 +254,6 @@ class MNP:
     # key without having to reconnect.
     CHAT_EPOCH            = "chat_epoch"
     CHAT_EPOCH_ACK        = "chat_epoch_ack"
-    ROOT_UPDATE          = "root_update"           # operator → node: a root's flags
-    ROOT_UPDATE_ACK      = "root_update_ack"
     ROOT_EJECT           = "root_eject"            # operator → node: mark removable root as ejected
     ROOT_EJECT_ACK       = "root_eject_ack"
     ROOT_PLUG            = "root_plug"             # operator → node: re-enable an ejected root
@@ -276,8 +272,6 @@ class MNP:
     DENYLIST_READ_ACK    = "denylist_read_ack"
     DENYLIST_CLEAR       = "denylist_clear"         # operator → node: remove denylist entry(ies)
     DENYLIST_CLEAR_ACK   = "denylist_clear_ack"
-    GROUP_ATTACH         = "group_attach"           # operator → node: host a new group
-    GROUP_ATTACH_ACK     = "group_attach_ack"
     GROUP_DETACH         = "group_detach"           # operator → node: stop hosting a group
     GROUP_DETACH_ACK     = "group_detach_ack"
     NODE_SETTINGS_SET    = "node_settings_set"      # operator → node: change daemon settings
diff --git a/packages/meshbay-common/tests/test_admin_subject_parity.py b/packages/meshbay-common/tests/test_admin_subject_parity.py
index 7a229a9..59deaab 100644
--- a/packages/meshbay-common/tests/test_admin_subject_parity.py
+++ b/packages/meshbay-common/tests/test_admin_subject_parity.py
@@ -18,9 +18,7 @@ from pathlib import Path
 
 import pytest
 from meshbay_common.adminop import (
-    group_attach_subject,
     invite_create_subject,
-    root_add_subject,
     secret_digest,
     structured_subject,
     tmdb_config_subject,
@@ -34,16 +32,13 @@ pytestmark = pytest.mark.skipif(
     reason="node or crypto.js unavailable — parity cannot be checked",
 )
 
-ROOT_ADD = [
-    ("/srv/Films", "", "generic", False, False),
-    ("/srv/Films", "Films", "video", True, True),
-    ("C:\\Users\\me\\Share", "Partagé", "photo", True, False),
-    ('/srv/a "quoted", odd:name|x', "名前", "audio", False, True),
-    ("/srv/tab\there\nnewline\x01ctl", "é", "generic", True, False),
-]
-GROUP_ATTACH = [
-    ("photos", "/srv/photos", True),
-    ("famille-été", "/mnt/disque externe/Photos", False),
+# The canonical JSON itself, on the values that are hard to get identical:
+# separators, quotes, control characters, non-ASCII, and null/""/false.
+STRUCTURED = [
+    {"path": "/srv/Films", "name": "", "writable": False, "n": None},
+    {"path": "C:\\Users\\me\\Share", "name": "Partagé", "kind": "photo"},
+    {"path": '/srv/a "quoted", odd:name|x', "name": "名前", "removable": True},
+    {"path": "/srv/tab\there\nnewline\x01ctl", "name": "é", "z": "", "a": 0},
 ]
 INVITE_CREATE = [
     ("0f8fad5b-d9cb-469f-a165-70867728950e", ""),
@@ -59,13 +54,12 @@ _HARNESS = r"""
 const fs = require('fs');
 globalThis.window = {};
 const src = fs.readFileSync(process.argv[2], 'utf8');
-const M = new Function(src + '\nreturn { rootAddSubject, groupAttachSubject, '
+const M = new Function(src + '\nreturn { adminSubject, '
                            + 'inviteCreateSubject, tmdbConfigSubject };')();
 const v = JSON.parse(fs.readFileSync(process.argv[3], 'utf8'));
 (async () => {
   const out = {
-    root_add: v.root_add.map((a) => M.rootAddSubject(...a)),
-    group_attach: v.group_attach.map((a) => M.groupAttachSubject(...a)),
+    structured: v.structured.map((f) => M.adminSubject(f)),
     invite_create: v.invite_create.map((a) => M.inviteCreateSubject(...a)),
     tmdb_config: [],
   };
@@ -80,7 +74,7 @@ def js(tmp_path_factory):
     d = tmp_path_factory.mktemp("subject-parity")
     (d / "harness.js").write_text(_HARNESS, encoding="utf-8")
     (d / "vectors.json").write_text(json.dumps({
-        "root_add": ROOT_ADD, "group_attach": GROUP_ATTACH,
+        "structured": STRUCTURED,
         "invite_create": INVITE_CREATE, "tmdb_config": TMDB_CONFIG,
     }), encoding="utf-8")
     proc = subprocess.run(
@@ -95,14 +89,9 @@ def _bytes(s: str) -> bytes:
     return s.encode("utf-8")
 
 
-@pytest.mark.parametrize("i,args", list(enumerate(ROOT_ADD)))
-def test_root_add_subject_parity(i, args, js):
-    assert _bytes(js["root_add"][i]) == _bytes(root_add_subject(*args))
-
-
-@pytest.mark.parametrize("i,args", list(enumerate(GROUP_ATTACH)))
-def test_group_attach_subject_parity(i, args, js):
-    assert _bytes(js["group_attach"][i]) == _bytes(group_attach_subject(*args))
+@pytest.mark.parametrize("i,fields", list(enumerate(STRUCTURED)))
+def test_structured_subject_parity(i, fields, js):
+    assert _bytes(js["structured"][i]) == _bytes(structured_subject(fields))
 
 
 @pytest.mark.parametrize("i,args", list(enumerate(INVITE_CREATE)))
@@ -116,13 +105,13 @@ def test_tmdb_config_subject_parity(i, args, js):
 
 
 def test_every_value_changes_the_subject():
-    base = ("/srv/Films", "Films", "video", False, False)
-    variants = {root_add_subject(*base)}
-    for i, other in enumerate(("/srv/Other", "Other", "audio", True, True)):
+    base = ("0f8fad5b-d9cb-469f-a165-70867728950e", "Someone")
+    variants = {invite_create_subject(*base)}
+    for i, other in enumerate(("6a2f41a3-c54c-fce8-32d2-0324e1c32e22", "Somebody")):
         args = list(base)
         args[i] = other
-        variants.add(root_add_subject(*args))
-    assert len(variants) == 6
+        variants.add(invite_create_subject(*args))
+    assert len(variants) == 3
 
 
 def test_unchanged_cleared_and_set_are_three_subjects():
diff --git a/packages/meshbay-common/tests/test_js_python_parity.py b/packages/meshbay-common/tests/test_js_python_parity.py
index f75d60a..bb52742 100644
--- a/packages/meshbay-common/tests/test_js_python_parity.py
+++ b/packages/meshbay-common/tests/test_js_python_parity.py
@@ -668,7 +668,7 @@ _KIND_FIELDS = {
     "chat": {"groupId": "g" * 32, "epoch": 4,
              "nonce": base64.b64encode(b"\x01" * 12).decode(),
              "ct": base64.b64encode(b"ciphertext").decode()},
-    "admin": {"op": "root_add", "nodePk": "Tk9ERVBL", "groupId": "g" * 32,
+    "admin": {"op": "root_remove", "nodePk": "Tk9ERVBL", "groupId": "g" * 32,
               "subject": '{"path":"/café"}', "nonce": _NONCE, "ts": 1_700_000_000},
 }