Add the interim `/tipc/` maddr grammar

`mk_maddr()`/`parse_maddr()` learn,

    /tipc/<stype>/<instance>/<scope>

mirroring how `uds` maps onto the spec-legal `/unix`.

XXX `str`-ONLY for now: there is no registered `/tipc` proto
in the multiaddr table (upstream track gh #483 +
multiformats/py-multiaddr#107) and `Multiaddr()` rejects an
unregistered name outright. `MsgTransport.maddr`s return type
is already `Multiaddr|str` (and `MsgpackUDSStream` already
exercises the `str` branch), so this fits — but it IS why gh

`parse_maddr()` therefore special-cases the `/tipc/` prefix
BEFORE handing anything to `Multiaddr()`.

Also drive the maddr mapping-table tests off `_address_types`
instead of a hardcoded len/dict so the next backend can't
fail them for the wrong reason.

(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))

tests/discovery/test_multiaddr.py

@@ -19,7 +19,10 @@ from tractor.discovery._multiaddr import (
     _tpt_proto_to_maddr,
     _maddr_to_tpt_proto,
 )
-from tractor.discovery._addr import wrap_address
+from tractor.discovery._addr import (
+    wrap_address,
+    _address_types,
+)
 
 
 def test_tpt_proto_to_maddr_mapping():
@@ -30,7 +33,12 @@ def test_tpt_proto_to_maddr_mapping():
     '''
     assert _tpt_proto_to_maddr['tcp'] == 'tcp'
     assert _tpt_proto_to_maddr['uds'] == 'unix'
-    assert len(_tpt_proto_to_maddr) == 2
+    assert _tpt_proto_to_maddr['tipc'] == 'tipc'
+
+    # NOTE, drive the expected set off the registration table
+    # (per the "drive-the-set-from-the-`Literal`" pattern) so
+    # adding a backend can't fail this for the wrong reason.
+    assert set(_tpt_proto_to_maddr) == set(_address_types)
 
 
 def test_mk_maddr_tcp_ipv4():
@@ -153,9 +161,12 @@ def test_maddr_to_tpt_proto_mapping():
 
     '''
     assert _maddr_to_tpt_proto == {
-        'tcp': 'tcp',
-        'unix': 'uds',
+        maddr_proto: proto_key
+        for proto_key, maddr_proto in _tpt_proto_to_maddr.items()
     }
+    assert _maddr_to_tpt_proto['tcp'] == 'tcp'
+    assert _maddr_to_tpt_proto['unix'] == 'uds'
+    assert _maddr_to_tpt_proto['tipc'] == 'tipc'
 
 
 def test_parse_maddr_tcp_ipv4():

tests/ipc/test_tipc.py

@@ -19,6 +19,12 @@ import pytest
 import trio
 
 from tractor.msg.types import Aid
+from tractor.discovery import _addr
+from tractor.discovery._addr import wrap_address
+from tractor.discovery._multiaddr import (
+    mk_maddr,
+    parse_maddr,
+)
 from tractor.ipc import _tipc
 from tractor.ipc._tipc import (
     AF_TIPC,
@@ -206,6 +212,48 @@ def test_get_random_honors_bindspace():
     assert addr.bindspace == TIPC_NODE_SCOPE == addr._scope
 
 
+def test_wrap_address_dispatches_on_the_proto_key():
+    '''
+    The proto-keyed unwrapped form must round-trip through the
+    *global* `wrap_address()` — and NOT get stolen by `tcp`s
+    `(str(), int())` case nor `uds`s `(_, str())` one.
+
+    '''
+    addr: TIPCAddress = TIPCAddress.get_random()
+    assert wrap_address(addr.unwrap()) == addr
+    # ..and via the `list` form `msgpack` decodes to
+    assert wrap_address(list(addr.unwrap())) == addr
+
+    assert _addr._address_types['tipc'] is TIPCAddress
+    assert _addr.get_address_cls('tipc') is TIPCAddress
+
+    # the host-singleton registrar default is import-time cheap
+    # (no kernel module, no I/O) and mirrors the `1616` idiom
+    assert _addr._default_lo_addrs['tipc'] == (
+        'tipc', TRACTOR_STYPE, 1616, TIPC_CLUSTER_SCOPE,
+    )
+
+
+def test_maddr_roundtrip():
+    '''
+    Interim `str`-only `/tipc/` maddr grammar (there's no
+    registered `/tipc` multiaddr proto yet, gh #483), which
+    `parse_maddr()` special-cases before `Multiaddr()` ever sees
+    the string.
+
+    '''
+    addr: TIPCAddress = TIPCAddress.get_random()
+    maddr: str = mk_maddr(addr)
+
+    assert isinstance(maddr, str)
+    assert maddr == (
+        f'/tipc/{addr._stype}/{addr._instance}/{addr._scope}'
+    )
+    assert parse_maddr(maddr) == addr
+    # ..and through the generic entrypoint
+    assert wrap_address(maddr) == addr
+
+
 def test_eafnosupport_is_actionable_connerr(
     monkeypatch: pytest.MonkeyPatch,
 ):

tractor/discovery/_multiaddr.py

@@ -38,8 +38,23 @@ if TYPE_CHECKING:
 _tpt_proto_to_maddr: dict[str, str] = {
     'tcp': 'tcp',
     'uds': 'unix',
+    'tipc': 'tipc',
 }
 
+# XXX, there is NO `/tipc` in the multiaddr protocol table yet
+# (upstream track: gh #483 + multiformats/py-multiaddr#107), and
+# `Multiaddr()` rejects an unregistered proto name outright.
+#
+# So until that lands `tipc` maddrs stay **`str`**-only — which
+# `MsgTransport.maddr`s `Multiaddr|str` return type already
+# allows and `MsgpackUDSStream.maddr` already exercises — and
+# `parse_maddr()` special-cases the prefix BEFORE handing
+# anything to `Multiaddr()`.
+#
+# This is also why gh #443's "always return `Multiaddr`" item
+# stays blocked.
+_tipc_maddr_prefix: str = '/tipc/'
+
 # reverse mapping: multiaddr protocol name -> tractor proto_key
 _maddr_to_tpt_proto: dict[str, str] = {
     v: k for k, v in _tpt_proto_to_maddr.items()
@@ -49,7 +64,7 @@ _maddr_to_tpt_proto: dict[str, str] = {
 
 def mk_maddr(
     addr: 'Address',
-) -> Multiaddr:
+) -> Multiaddr|str:
     '''
     Construct a `Multiaddr` from a tractor `Address` instance,
     dispatching on the `.proto_key` to build the correct
@@ -75,6 +90,18 @@ def mk_maddr(
                 f'/{net_proto}/{host}/{maddr_proto}/{port}'
             )
 
+        # NOTE, interim `str`-only grammar (see the
+        # `_tipc_maddr_prefix` note above),
+        #
+        #   /tipc/<stype>/<instance>/<scope>
+        #
+        # mirroring how `uds` maps onto the spec-legal `/unix`.
+        case 'tipc':
+            _, stype, instance, scope = addr.unwrap()
+            return (
+                f'/{maddr_proto}/{stype}/{instance}/{scope}'
+            )
+
         case 'uds':
             filedir, filename = addr.unwrap()
             filepath = Path(filedir) / filename
@@ -100,6 +127,17 @@ def parse_maddr(
     # lazy imports to avoid circular deps
     from tractor.ipc._tcp import TCPAddress
     from tractor.ipc._uds import UDSAddress
+    from tractor.ipc._tipc import TIPCAddress
+
+    # XXX MUST come before `Multiaddr()` which rejects the
+    # not-yet-registered `/tipc` proto name outright.
+    if maddr_str.startswith(_tipc_maddr_prefix):
+        _, _, stype, instance, scope = maddr_str.split('/')
+        return TIPCAddress(
+            _stype=int(stype),
+            _instance=int(instance),
+            _scope=int(scope),
+        )
 
     maddr = Multiaddr(maddr_str)
     proto_names: list[str] = [