diff --git a/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.md b/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.md
new file mode 100644
index 00000000..d87a7c6a
--- /dev/null
+++ b/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.md
@@ -0,0 +1,70 @@
+---
+model: openai/gpt-5.6-sol
+service: opencode
+session: dependency-neutral-discovery-types
+timestamp: 2026-09-03T20:15:30Z
+git_ref: d097090f
+scope: code
+substantive: true
+raw_file: 20260903T201530Z_d097090f_discovery_types.raw.md
+---
+
+## Prompt
+
+The maintainer rejected annotation-only model names rebound to `Any`,
+questioned the self-referential `get_type_hints()` regression, selected a
+dependency-neutral `tractor.discovery.types` module as the preferred
+direction, and then requested implementation of that first design layer.
+
+The maintainer separately asked how to handle the disliked staged
+`tractor/net/_bootstrap.py` implementation. That file was excluded from
+this implementation boundary and retained as review evidence.
+
+## Response summary
+
+Added a dependency-neutral module for canonical primitive address
+descriptors and separate structural contracts for concrete transport
+addresses and tunnel-capable address declarations. Migrated discovery,
+IPC, root, runtime, and tunnel annotations to import those real types,
+removing every runtime model-name assignment to `Any`.
+
+Kept parser table aliases beside `parse_endpoints()` instead of turning
+the new module into a general alias registry. Kept transport-specific
+factories on TCP and UDS classes because their accepted descriptor and
+bindspace types differ. Replaced the old `get_type_hints()` assertions
+with cold-import and canonical-identity coverage.
+
+## Files changed
+
+- `tractor/discovery/types.py` - dependency-neutral descriptors and
+  address protocols.
+- `tractor/discovery/_addr.py` - imports and re-exports canonical types;
+  retains concrete factory registry.
+- `tractor/discovery/_multiaddr.py` - uses the structural declaration
+  type and runtime-safe parsed table alias.
+- `tractor/ipc/_tcp.py` - imports the real TCP descriptor alias.
+- `tractor/ipc/_uds.py` - imports the real Unix descriptor alias.
+- `tractor/ipc/_transport.py` - imports the concrete-address protocol
+  without cycling through `_addr`.
+- `tractor/ipc/_chan.py` - accepts structural address declarations
+  without a `TunnelledAddress = Any` fallback.
+- `tractor/ipc/_server.py` - retains declaration metadata structurally
+  and routes reconstruction through the concrete address registry.
+- `tractor/net/_tunnel.py` - imports real dependency-neutral address
+  types while retaining dynamic `Any` only for external netlink data.
+- `tractor/_root.py` - removes the `Bindspace = Any` fallback and uses
+  concrete address-factory dispatch.
+- `tractor/runtime/_runtime.py` - infers concrete registry address types
+  for random listener allocation.
+- `tests/test_lazy_imports.py` - replaces workaround introspection with
+  dependency and canonical-identity checks.
+
+## Human edits
+
+The maintainer identified the `Any` aliases and their introspection test
+as an unjustified circular contract, directed investigation of the real
+cycle/import-performance cause, selected `tractor.discovery.types`, and
+approved beginning implementation. The maintainer also required that the
+current bootstrap implementation not be treated as acceptable design and
+provided direct review annotations which remain preserved in the
+worktree.
diff --git a/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.raw.md b/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.raw.md
new file mode 100644
index 00000000..a0d641d7
--- /dev/null
+++ b/ai/prompt-io/opencode/20260903T201530Z_d097090f_discovery_types.raw.md
@@ -0,0 +1,34 @@
+---
+model: openai/gpt-5.6-sol
+service: opencode
+timestamp: 2026-09-03T20:15:30Z
+git_ref: d097090f
+diff_cmd: git diff HEAD~1..HEAD
+---
+
+Implemented a dependency-neutral discovery typing layer after reviewing
+the address, transport, tunnel, and lazy-import dependency graph.
+
+> `git diff HEAD~1..HEAD -- tractor/discovery/types.py tractor/discovery/_addr.py tractor/discovery/_multiaddr.py tractor/ipc/_tcp.py tractor/ipc/_uds.py tractor/ipc/_transport.py tractor/ipc/_chan.py tractor/ipc/_server.py tractor/net/_tunnel.py tractor/_root.py tractor/runtime/_runtime.py tests/test_lazy_imports.py`
+
+The generated changes move primitive address descriptors and structural
+address protocols into `tractor.discovery.types`. Concrete transport
+factories remain outside the shared protocol because TCP and UDS accept
+different descriptor and bindspace inputs. Runtime names are no longer
+rebound to `Any` merely to satisfy `typing.get_type_hints()`.
+
+The old annotation-introspection regression was replaced with coverage
+that checks dependency-neutral cold imports and canonical type identity
+across discovery, IPC, and tunnel modules.
+
+Verification completed with the worktree-local Python 3.13 environment:
+
+- focused address/lazy/tunnel coverage: 69 passed;
+- discovery, IPC, and local coverage: 77 passed, 2 xpassed;
+- root/runtime coverage: 6 passed with 24 multiprocessing fork
+  deprecation warnings.
+
+Ruff was unavailable in the existing `py313` environment. Scoped
+`git diff --check` passed. The global whitespace check reports only a
+pre-existing maintainer annotation in `tractor/net/_bootstrap.py`, which
+was deliberately left untouched.
diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index b2b61f35..02361544 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -7,21 +7,6 @@ import os
 from statistics import median
 import subprocess
 import sys
-from typing import (
-    Any,
-    get_type_hints,
-)
-
-import tractor
-from tractor.discovery import (
-    _addr,
-    _multiaddr,
-)
-from tractor.ipc import (
-    _tcp,
-    _uds,
-)
-
 
 def run_cold_import(code: str) -> dict[str, object]:
     result = subprocess.run(
@@ -260,28 +245,56 @@ def test_net_root_export_and_old_discovery_surface():
     }
 
 
-def test_lazy_annotation_names_resolve():
+def test_discovery_types_are_dependency_neutral():
     '''
-    Resolve annotations without importing optional dependencies.
+    Keep canonical address types independent of runtime implementations.
 
-    Moving annotation-only third-party names under `TYPE_CHECKING`
-    left their runtime globals undefined, causing
-    `typing.get_type_hints()` to raise `NameError`. Resolve every
-    affected API and prove the lazy aliases retain import-free runtime
-    introspection.
+    Annotation-only imports previously rebound unavailable model names
+    to `Any` so `get_type_hints()` could resolve them. That test only
+    verified its own workaround and hid the `_addr`/transport import
+    cycle. Import the canonical declarations in a cold interpreter and
+    prove they do not pull in optional networking modules. Then prove
+    each implementation imports the same real declarations instead of
+    substituting `Any` under the model names.
 
     '''
-    assert get_type_hints(_multiaddr.mk_maddr)['return'] is Any
-    assert get_type_hints(_tcp.MsgpackTCPStream.maddr.fget)[
-        'return'
-    ] is Any
-    assert get_type_hints(_uds.MsgpackUDSStream.maddr.fget)[
-        'return'
-    ] == Any|str
-    assert get_type_hints(_addr.Address.get_random)[
-        'current_actor'
-    ] is Any
-    assert get_type_hints(tractor.open_root_actor)[
-        'bindspace'
-    ] == Any|None
-    assert _addr.__annotations__['_address_types'].startswith('dict')
+    cold = run_cold_import(
+        'import json, sys; '
+        'from tractor.discovery import types; '
+        'blocked = ('
+        '"multiaddr", "multibase", "pyroute2", '
+        '"tractor.discovery._multiaddr", "tractor.net", '
+        '"tractor.net._bindspace", "tractor.net._tunnel"); '
+        'print(json.dumps({'
+        '"address_module": types.Address.__module__, '
+        '"blocked": [name for name in blocked '
+        'if name in sys.modules]}))'
+    )
+    assert cold == {
+        'address_module': 'tractor.discovery.types',
+        'blocked': [],
+    }
+
+    from tractor.discovery import (
+        _addr,
+        _multiaddr,
+        types,
+    )
+    from tractor.ipc import (
+        _chan,
+        _server,
+        _tcp,
+        _transport,
+        _uds,
+    )
+    from tractor.net import _tunnel
+
+    assert _addr.Address is types.Address
+    assert _addr.UnwrappedAddress is types.UnwrappedAddress
+    assert _multiaddr.AddressDeclaration is types.AddressDeclaration
+    assert _tcp.TaggedTCPAddress is types.TaggedTCPAddress
+    assert _uds.TaggedUnixAddress is types.TaggedUnixAddress
+    assert _transport.Address is types.Address
+    assert _chan.AddressDeclaration is types.AddressDeclaration
+    assert _server.AddressDeclaration is types.AddressDeclaration
+    assert _tunnel.AddressDeclaration is types.AddressDeclaration
diff --git a/tractor/_root.py b/tractor/_root.py
index 13c9132a..5c48f42e 100644
--- a/tractor/_root.py
+++ b/tractor/_root.py
@@ -53,12 +53,15 @@ from .runtime import _state
 from . import log
 from .discovery._api import _probe_registry_addrs
 from .discovery._addr import (
-    Address,
-    UnwrappedAddress,
     default_lo_addrs,
+    get_address_cls,
     mk_uuid,
     wrap_address,
 )
+from .discovery.types import (
+    Address,
+    UnwrappedAddress,
+)
 from .trionics import (
     is_multi_cancelled,
     collapse_eg,
@@ -69,8 +72,6 @@ from ._exceptions import (
 
 if TYPE_CHECKING:
     from .net._bindspace import Bindspace
-else:
-    Bindspace = Any
 
 
 logger = log.get_logger('tractor')
@@ -187,7 +188,7 @@ async def open_root_actor(
     bindspace: Bindspace|None = None,
 
     tpt_bind_addrs: list[
-        Address  # `Address.get_random()` case
+        Address  # concrete transport address case
         |UnwrappedAddress  # registrar case `= uw_reg_addrs`
     ]|None = None,
 
@@ -561,6 +562,9 @@ async def open_root_actor(
 
                 for addr in ponged_addrs:
                     bindable_addr: Address = strip_tunnels(addr)
+                    address_type = get_address_cls(
+                        bindable_addr.proto_key
+                    )
                     tpt_bind_addrs.append(
                         # XXX, these are `Address` NOT `UnwrappedAddress`.
                         #
@@ -568,7 +572,7 @@ async def open_root_actor(
                         # protos we allocate port=0 such that the system
                         # allocates a random value at bind time; this
                         # happens in the `.ipc.*` stack's backend.
-                        bindable_addr.get_random(
+                        address_type.get_random(
                             bindspace=bindable_addr.bindspace,
                         )
                     )
diff --git a/tractor/discovery/_addr.py b/tractor/discovery/_addr.py
index ed080690..a7ea862f 100644
--- a/tractor/discovery/_addr.py
+++ b/tractor/discovery/_addr.py
@@ -15,19 +15,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 from __future__ import annotations
 from uuid import uuid4
-from typing import (
-    Any,
-    Protocol,
-    ClassVar,
-    Literal,
-    Type,
-    TypeAlias,
-    TYPE_CHECKING,
-)
-
-from trio import (
-    SocketListener,
-)
+from typing import TypeAlias
 
 from ..log import get_logger
 from ..runtime._state import (
@@ -38,70 +26,19 @@ from ..ipc._uds import (
     UDSAddress,
     HAS_UDS,
 )
-
-if TYPE_CHECKING:
-    # ONLY type-annots, the eager import costs ~4.5ms
-    # of `import tractor` wall-time (gh #470).
-    from tractor.net._tunnel import (
-        TunnelledAddress,
-    )
-    from ..runtime._runtime import Actor
-else:
-    Actor = Any
-    TunnelledAddress = Any
+from .types import (
+    Address as Address,
+    AddressDeclaration,
+    LegacyUnwrappedAddress,
+    TaggedAddress,
+    TaggedUDSAlias,
+    UnwrappedAddress,
+)
 
 log = get_logger()
 
-# TODO, maybe breakout the netns key to a struct?
-# class NetNs(Struct)[str, int]:
-#     ...
+_AddressType: TypeAlias = type[TCPAddress]|type[UDSAddress]
 
-# TODO, can't we just use a type alias
-# for this? namely just some `tuple[str, int, str, str]`?
-#
-# -[ ] would also just be simpler to keep this as SockAddr[tuple]
-#     or something, implying it's just a simple pair of values which can
-#     presumably be mapped to all transports?
-# -[ ] `pydoc socket.socket.getsockname()` delivers a 4-tuple for
-#     ipv6 `(hostaddr, port, flowinfo, scope_id)`.. so how should we
-#     handle that?
-# -[ ] as a further alternative to this wrap()/unwrap() approach we
-#     could just implement `enc/dec_hook()`s for the `Address`-types
-#     and just deal with our internal objs directly and always and
-#     leave it to the codec layer to figure out marshalling?
-#    |_ would mean only one spot to do the `.unwrap()` (which we may
-#       end up needing to call from the hook()s anyway?)
-# -[x] rename to `UnwrappedAddress[Descriptor]` ??
-#    seems like the right name as per,
-#    https://www.geeksforgeeks.org/introduction-to-address-descriptor/
-#
-TaggedTCPAddress: TypeAlias = tuple[
-    Literal['tcp'],
-    str,
-    int,
-]
-TaggedUnixAddress: TypeAlias = tuple[
-    Literal['unix'],
-    str,
-]
-TaggedUDSAlias: TypeAlias = tuple[
-    Literal['uds'],
-    str,
-]
-TaggedAddress: TypeAlias = (
-    TaggedTCPAddress
-    |TaggedUnixAddress
-)
-
-# Input-only compatibility forms retained for older callers and
-# serialized payloads.
-LegacyTCPAddress: TypeAlias = tuple[str, int]
-LegacyUDSAddress: TypeAlias = tuple[str, str]
-LegacyUnwrappedAddress: TypeAlias = (
-    LegacyTCPAddress
-    |LegacyUDSAddress
-)
-UnwrappedAddress = TaggedAddress
 # ?TODO? should we also include another 2 fields from our `Aid` msg
 # such that we include the runtime `Actor.uid` of `.name` and `.uuid`?
 # - would ensure uniqueness across entire net?
@@ -109,106 +46,14 @@ UnwrappedAddress = TaggedAddress
 #   name"
 
 
-# TODO, maybe rename to `SocketAddress`?
-class Address(Protocol):
-    proto_key: ClassVar[str]
-    unwrapped_type: ClassVar[type]
-
-    # TODO, i feel like an `.is_bound()` is a better thing to
-    # support?
-    # Lke, what use does this have besides a noop and if it's not
-    # valid why aren't we erroring on creation/use?
-    @property
-    def is_valid(self) -> bool:
-        ...
-
-    # TODO, maybe `.netns` is a better name?
-    @property
-    def namespace(self) -> tuple[str, str|int]|None:
-        '''
-        The if-available, OS-specific "network namespace" key.
-
-        '''
-        ...
-
-    @property
-    def bindspace(self) -> str:
-        '''
-        Deliver the socket address' "bindable space" from
-        a `socket.socket.bind()` and thus from the perspective of
-        specific transport protocol domain.
-
-        I.e. for most (layer-4) network-socket protocols this is
-        normally the ipv4/6 address, for UDS this is normally
-        a filesystem (sub-directory).
-
-        For (distributed) network protocols this is normally the routing
-        layer's domain/(ip-)address, though it might also include a "network namespace"
-        key different then the default.
-
-        For local-host-only transports this is either an explicit
-        namespace (with types defined by the OS: netns, Cgroup, IPC,
-        pid, etc. on linux) or failing that the sub-directory in the
-        filesys in which socket/shm files are located *under*.
-
-        '''
-        ...
-
-    @classmethod
-    def from_addr(cls, addr: UnwrappedAddress) -> Address:
-        ...
-
-    def unwrap(self) -> UnwrappedAddress:
-        '''
-        Deliver the underying minimum field set in
-        a primitive python data type-structure.
-        '''
-        ...
-
-    @classmethod
-    def get_random(
-        cls,
-        current_actor: Actor,
-        bindspace: str|None = None,
-    ) -> Address:
-        ...
-
-    # TODO, this should be something like a `.get_def_registar_addr()`
-    # or similar since,
-    # - it should be a **host singleton** (not root/tree singleton)
-    # - we **only need this value** when one isn't provided to the
-    #   runtime at boot and we want to implicitly provide a host-wide
-    #   registrar.
-    # - each rooted-actor-tree should likely have its own
-    #   micro-registry (likely the root being it), also see
-    @classmethod
-    def get_root(cls) -> Address:
-        ...
-
-    def __repr__(self) -> str:
-        ...
-
-    def __eq__(self, other) -> bool:
-        ...
-
-    async def open_listener(
-        self,
-        **kwargs,
-    ) -> SocketListener:
-        ...
-
-    async def close_listener(self):
-        ...
-
-
 # the address types available on this host: TCP always, UDS only
 # where usable (`HAS_UDS`). Both registries derive from this single
 # list via each type's `proto_key`.
-_address_protos: list[Type[Address]] = [TCPAddress]
+_address_protos: list[_AddressType] = [TCPAddress]
 if HAS_UDS:
     _address_protos.append(UDSAddress)
 
-_address_types: dict[str, Type[Address]] = {
+_address_types: dict[str, _AddressType] = {
     cls.proto_key: cls
     for cls in _address_protos
 }
@@ -216,13 +61,22 @@ _address_types: dict[str, Type[Address]] = {
 
 # TODO! really these are discovery sys default addrs ONLY useful for
 # when none is provided to a root actor on first boot.
+#
+# TODO, this should be something like a `.get_def_registar_addr()`
+# or similar since,
+# - it should be a **host singleton** (not root/tree singleton)
+# - we **only need this value** when one isn't provided to the
+#   runtime at boot and we want to implicitly provide a host-wide
+#   registrar.
+# - each rooted-actor-tree should likely have its own
+#   micro-registry (likely the root being it), also see
 _default_lo_addrs: dict[str, UnwrappedAddress] = {
     cls.proto_key: cls.get_root().unwrap()
     for cls in _address_protos
 }
 
 
-def get_address_cls(name: str) -> Type[Address]:
+def get_address_cls(name: str) -> _AddressType:
     try:
         return _address_types[name]
     except KeyError:
@@ -233,7 +87,7 @@ def get_address_cls(name: str) -> Type[Address]:
         )
 
 
-def is_wrapped_addr(addr: any) -> bool:
+def is_wrapped_addr(addr: object) -> bool:
     # XXX NOTE, a `TunnelledAddress` is genuinely "wrapped" but is
     # deliberately NOT in `_address_types`: it has no
     # `MsgTransport` of its own (a tunnel is transparent to
@@ -264,10 +118,9 @@ def wrap_address(
         |LegacyUnwrappedAddress
         |list[str|int]
         |str
-        |Address
-        |TunnelledAddress
+        |AddressDeclaration
     ),
-) -> Address|TunnelledAddress:
+) -> AddressDeclaration:
     '''
     Wrap an `UnwrappedAddress` as an `Address`-type based
     on matching builtin python data-structures which we adhoc
@@ -284,7 +137,7 @@ def wrap_address(
     if is_wrapped_addr(addr):
         return addr
 
-    cls: Type|None = None
+    cls: _AddressType|None = None
     # if 'sock' in addr[0]:
     #     import pdbp; pdbp.set_trace()
     match addr:
@@ -328,7 +181,7 @@ def wrap_address(
             |
             [None, None]
         ):
-            cls: Type[Address] = get_address_cls(_def_tpt_proto)
+            cls = get_address_cls(_def_tpt_proto)
             addr: UnwrappedAddress = cls.get_root().unwrap()
 
         # multiaddr-format string, e.g.
@@ -354,7 +207,7 @@ def wrap_address(
 
 def default_lo_addrs(
     transports: list[str],
-) -> list[Type[Address]]:
+) -> list[UnwrappedAddress]:
     '''
     Return the default, host-singleton, registry address
     for an input transport key set.
diff --git a/tractor/discovery/_multiaddr.py b/tractor/discovery/_multiaddr.py
index 2fd7899d..b10a97a3 100644
--- a/tractor/discovery/_multiaddr.py
+++ b/tractor/discovery/_multiaddr.py
@@ -27,24 +27,15 @@ Multiaddress support using the upstream `py-multiaddr` lib
 from __future__ import annotations
 import ipaddress
 from pathlib import Path
-from typing import (
-    Any,
-    TYPE_CHECKING,
-)
+from typing import TYPE_CHECKING
+
+from .types import AddressDeclaration
 
 if TYPE_CHECKING:
     # NOTE, `multiaddr` is lazy-imported at first use
     # (in the fns below) to keep it off the eager
     # `import tractor` path (gh #470).
     from multiaddr import Multiaddr
-    from tractor.discovery._addr import Address
-    from tractor.net._tunnel import (
-        TunnelledAddress,
-    )
-else:
-    Multiaddr = Any
-    Address = Any
-    TunnelledAddress = Any
 
 # map from tractor-internal `proto_key` identifiers
 # to the standard multiaddr protocol name strings.
@@ -61,7 +52,7 @@ _maddr_to_tpt_proto: dict[str, str] = {
 
 
 def mk_maddr(
-    addr: 'Address|TunnelledAddress',
+    addr: AddressDeclaration,
 ) -> Multiaddr:
     '''
     Construct a `Multiaddr` from a tractor `Address` instance,
@@ -111,7 +102,7 @@ def mk_maddr(
 
 def parse_maddr(
     maddr_str: str,
-) -> 'Address|TunnelledAddress':
+) -> AddressDeclaration:
     '''
     Parse a multiaddr string into a tractor `Address`.
 
@@ -173,15 +164,15 @@ def parse_maddr(
 # or raw unwrapped-address tuples (as accepted by
 # `wrap_address()`).
 EndpointsTable = dict[
-    str,                    # actor/service name
-    list[str|tuple],        # maddr strs or UnwrappedAddress
+    str,  # actor/service name
+    list[str|tuple|AddressDeclaration],
 ]
 
 # output table: actor/service name -> list of wrapped address
 # declarations ready for bindspace handling.
 ParsedEndpoints = dict[
-    str,                    # actor/service name
-    list['Address|TunnelledAddress'],
+    str,  # actor/service name
+    list[AddressDeclaration],
 ]
 
 
diff --git a/tractor/discovery/types.py b/tractor/discovery/types.py
new file mode 100644
index 00000000..571f8e58
--- /dev/null
+++ b/tractor/discovery/types.py
@@ -0,0 +1,176 @@
+# tractor: structured concurrent "actors".
+# Copyright 2018-eternity Tyler Goodlet.
+
+# This program is free software: you can redistribute it and/or
+# modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public
+# License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+
+'''
+Dependency-neutral address typing declarations.
+
+Keep this module independent of concrete IPC transports, actor
+runtime models, network resources, tunnels, and optional
+dependencies.
+
+'''
+from __future__ import annotations
+
+from pathlib import Path
+from typing import (
+    ClassVar,
+    Literal,
+    Protocol,
+    TypeAlias,
+)
+
+
+# TODO, maybe breakout the netns key to a struct?
+# class NetNs(Struct)[str, int]:
+#     ...
+
+# TODO, can't we just use a type alias
+# for this? namely just some `tuple[str, int, str, str]`?
+#
+# -[ ] would also just be simpler to keep this as
+#     SockAddr[tuple] or something, implying it's just a simple pair
+#     of values which can presumably be mapped to all transports?
+# -[ ] `pydoc socket.socket.getsockname()` delivers a 4-tuple for
+#     ipv6 `(hostaddr, port, flowinfo, scope_id)`.. so how should we
+#     handle that?
+# -[ ] as a further alternative to this wrap()/unwrap() approach we
+#     could just implement `enc/dec_hook()`s for the `Address`-types
+#     and just deal with our internal objs directly and always and
+#     leave it to the codec layer to figure out marshalling?
+#    |_ would mean only one spot to do the `.unwrap()` (which we may
+#       end up needing to call from the hook()s anyway?)
+# -[x] rename to `UnwrappedAddress[Descriptor]` ??
+#    seems like the right name as per the GeeksForGeeks article,
+#    "Introduction to Address Descriptor".
+#
+TaggedTCPAddress: TypeAlias = tuple[
+    Literal['tcp'],
+    str,
+    int,
+]
+TaggedUnixAddress: TypeAlias = tuple[
+    Literal['unix'],
+    str,
+]
+TaggedUDSAlias: TypeAlias = tuple[
+    Literal['uds'],
+    str,
+]
+TaggedAddress: TypeAlias = (
+    TaggedTCPAddress
+    |TaggedUnixAddress
+)
+
+# Input-only compatibility forms retained for older callers and
+# serialized payloads.
+LegacyTCPAddress: TypeAlias = tuple[str, int]
+LegacyUDSAddress: TypeAlias = tuple[str, str]
+LegacyUnwrappedAddress: TypeAlias = (
+    LegacyTCPAddress
+    |LegacyUDSAddress
+)
+UnwrappedAddress = TaggedAddress
+
+
+class AddressDeclaration(Protocol):
+    '''
+    Common instance shape of plain and tunnelled addresses.
+
+    This protocol deliberately excludes transport registration and
+    listener operations. A tunnel declaration delegates these address
+    properties to its innermost concrete transport address.
+
+    '''
+    @property
+    def proto_key(self) -> str:
+        ...
+
+    @property
+    def is_valid(self) -> bool:
+        ...
+
+    @property
+    def namespace(self) -> tuple[str, str|int]|None:
+        ...
+
+    @property
+    def bindspace(self) -> str|Path:
+        ...
+
+    def unwrap(self) -> UnwrappedAddress:
+        ...
+
+
+# TODO, maybe rename to `SocketAddress`?
+class Address(Protocol):
+    '''
+    Concrete address contract used by IPC transport backends.
+
+    Unlike `AddressDeclaration`, transport registries require
+    class-level protocol metadata. Transport-specific factories stay
+    on their concrete address classes because their descriptor and
+    bindspace inputs differ.
+
+    '''
+    proto_key: ClassVar[str]
+    unwrapped_type: ClassVar[type]
+
+    # TODO, i feel like an `.is_bound()` is a better thing to
+    # support?
+    # Lke, what use does this have besides a noop and if it's not
+    # valid why aren't we erroring on creation/use?
+    @property
+    def is_valid(self) -> bool:
+        ...
+
+    # TODO, maybe `.netns` is a better name?
+    @property
+    def namespace(self) -> tuple[str, str|int]|None:
+        '''
+        The if-available, OS-specific "network namespace" key.
+
+        '''
+        ...
+
+    @property
+    def bindspace(self) -> str|Path:
+        '''
+        Deliver the address' transport-specific bindable space.
+
+        '''
+        ...
+
+    def unwrap(self) -> UnwrappedAddress:
+        '''
+        Deliver the underlying primitive address descriptor.
+
+        '''
+        ...
+
+__all__ = (
+    'Address',
+    'AddressDeclaration',
+    'LegacyTCPAddress',
+    'LegacyUDSAddress',
+    'LegacyUnwrappedAddress',
+    'TaggedAddress',
+    'TaggedTCPAddress',
+    'TaggedUDSAlias',
+    'TaggedUnixAddress',
+    'UnwrappedAddress',
+)
diff --git a/tractor/ipc/_chan.py b/tractor/ipc/_chan.py
index 13aa0244..750ff1c6 100644
--- a/tractor/ipc/_chan.py
+++ b/tractor/ipc/_chan.py
@@ -43,7 +43,10 @@ from ._types import (
 from tractor.discovery._addr import (
     is_wrapped_addr,
     wrap_address,
+)
+from tractor.discovery.types import (
     Address,
+    AddressDeclaration,
     UnwrappedAddress,
 )
 from tractor.log import get_logger
@@ -59,9 +62,6 @@ from tractor.msg import (
 
 if TYPE_CHECKING:
     from ._transport import MsgTransport
-    from tractor.net._tunnel import TunnelledAddress
-else:
-    TunnelledAddress = Any
 
 
 log = get_logger()
@@ -185,7 +185,7 @@ class Channel:
     @classmethod
     async def from_addr(
         cls,
-        addr: UnwrappedAddress|Address|TunnelledAddress,
+        addr: UnwrappedAddress|AddressDeclaration,
         **kwargs
     ) -> Channel:
 
@@ -557,7 +557,7 @@ class Channel:
 
 @acm
 async def _connect_chan(
-    addr: UnwrappedAddress|Address|TunnelledAddress,
+    addr: UnwrappedAddress|AddressDeclaration,
     close_timeout: float|None = None,
 ) -> typing.AsyncGenerator[Channel, None]:
     '''
diff --git a/tractor/ipc/_server.py b/tractor/ipc/_server.py
index 84f5ebc1..dd3d8b69 100644
--- a/tractor/ipc/_server.py
+++ b/tractor/ipc/_server.py
@@ -59,8 +59,10 @@ from ..msg import (
 from ..trionics import maybe_open_nursery
 from ..runtime import _state
 from .. import log
-from ..discovery._addr import (
+from ..discovery._addr import get_address_cls
+from ..discovery.types import (
     Address,
+    AddressDeclaration,
     UnwrappedAddress,
 )
 from ._chan import Channel
@@ -68,7 +70,6 @@ from ._transport import MsgTransport
 
 
 if TYPE_CHECKING:
-    from ..net._tunnel import TunnelledAddress
     from ..runtime._runtime import Actor
     from ..runtime._supervise import ActorNursery
 
@@ -631,7 +632,7 @@ class Endpoint(Struct):
 
     '''
     addr: Address
-    declared_addr: Address|TunnelledAddress
+    declared_addr: AddressDeclaration
     listen_tn: Nursery
     stream_handler_tn: Nursery|None = None
 
@@ -689,7 +690,8 @@ class Endpoint(Struct):
             !=
             self.addr.unwrap()
         ):
-            self.addr=self.addr.from_addr(unwrapped)
+            address_type = get_address_cls(self.addr.proto_key)
+            self.addr = address_type.from_addr(unwrapped)
 
         self._listener = lstnr
         return lstnr
@@ -991,7 +993,7 @@ class Server(Struct):
         self,
         *,
         accept_addrs: list[
-            UnwrappedAddress|Address|TunnelledAddress
+            UnwrappedAddress|AddressDeclaration
         ]|None = None,
         stream_handler_nursery: Nursery|None = None,
     ) -> list[Endpoint]:
@@ -1075,7 +1077,7 @@ async def _serve_ipc_eps(
     *,
     server: IPCServer,
     stream_handler_tn: Nursery,
-    listen_addrs: list[Address|TunnelledAddress],
+    listen_addrs: list[AddressDeclaration],
 
     task_status: TaskStatus[
         Nursery,
diff --git a/tractor/ipc/_tcp.py b/tractor/ipc/_tcp.py
index 40cb8e81..fe3e525e 100644
--- a/tractor/ipc/_tcp.py
+++ b/tractor/ipc/_tcp.py
@@ -20,7 +20,6 @@ TCP implementation of tractor.ipc._transport.MsgTransport protocol
 from __future__ import annotations
 import ipaddress
 from typing import (
-    Any,
     ClassVar,
     TYPE_CHECKING,
 )
@@ -41,15 +40,12 @@ from tractor.ipc._transport import (
     MsgTransport,
     MsgpackTransport,
 )
+from tractor.discovery.types import TaggedTCPAddress
 
 if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
-    from tractor.discovery._addr import TaggedTCPAddress
-else:
-    Multiaddr = Any
-    TaggedTCPAddress = Any
 
 
 log = get_logger()
diff --git a/tractor/ipc/_transport.py b/tractor/ipc/_transport.py
index 018b70c4..5afdde27 100644
--- a/tractor/ipc/_transport.py
+++ b/tractor/ipc/_transport.py
@@ -55,9 +55,7 @@ from tractor.msg import (
     types as msgtypes,
     pretty_struct,
 )
-
-if TYPE_CHECKING:
-    from tractor.discovery._addr import Address
+from tractor.discovery.types import Address
 
 log = get_logger()
 
diff --git a/tractor/ipc/_uds.py b/tractor/ipc/_uds.py
index cfba9519..387733d0 100644
--- a/tractor/ipc/_uds.py
+++ b/tractor/ipc/_uds.py
@@ -43,7 +43,6 @@ except ImportError:
     AF_UNIX = None
 import struct
 from typing import (
-    Any,
     Type,
     TYPE_CHECKING,
     ClassVar,
@@ -71,17 +70,13 @@ from tractor.runtime._state import (
     current_actor,
     is_root_process,
 )
+from tractor.discovery.types import TaggedUnixAddress
 
 if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
-    from tractor.discovery._addr import TaggedUnixAddress
     from tractor.runtime._runtime import Actor
-else:
-    Multiaddr = Any
-    Actor = Any
-    TaggedUnixAddress = Any
 
 
 # Platform-specific credential passing constants
diff --git a/tractor/net/_tunnel.py b/tractor/net/_tunnel.py
index 34dfe79a..c76e64eb 100644
--- a/tractor/net/_tunnel.py
+++ b/tractor/net/_tunnel.py
@@ -93,6 +93,11 @@ import multibase
 import trio
 
 from ..msg._local import ProcessLocal
+from ..discovery.types import (
+    Address,
+    AddressDeclaration,
+    UnwrappedAddress,
+)
 from ._bindspace import (
     Bindspace,
     BindspaceRef,
@@ -103,16 +108,6 @@ from ._bindspace import (
 if TYPE_CHECKING:
     from multiaddr import Multiaddr
 
-    from ..discovery._addr import (
-        Address,
-        UnwrappedAddress,
-    )
-else:
-    Address = Any
-    Multiaddr = Any
-    UnwrappedAddress = Any
-
-
 class WGTunnelSpec(
     msgspec.Struct,
     frozen=True,
@@ -879,7 +874,7 @@ class TunnelledAddress(
     `strip_tunnels()`.
 
     '''
-    overlay: Address|TunnelledAddress
+    overlay: AddressDeclaration
     tunnel: TunnelSpec
     bindspace_ref: BindspaceRef|None = None
 
@@ -1057,7 +1052,7 @@ def parse_wg_maddr(
     match overlay_names:
         case [('ip4' | 'ip6'), 'tcp']:
             from ..discovery._multiaddr import parse_maddr
-            overlay: Address|TunnelledAddress = parse_maddr(
+            overlay: AddressDeclaration = parse_maddr(
                 str(overlay_ma)
             )
 
@@ -1172,7 +1167,7 @@ def mk_wg_maddr(
 
 
 def strip_tunnels(
-    addr: Address|TunnelledAddress,
+    addr: AddressDeclaration,
 ) -> Address:
     '''
     Deliver the bindable `Address`, peeling any tunnel
@@ -1191,7 +1186,7 @@ def strip_tunnels(
 
 
 def tunnels_of(
-    addr: Address|TunnelledAddress,
+    addr: AddressDeclaration,
 ) -> tuple[TunnelSpec, ...]:
     '''
     Deliver every tunnel spec wrapping `addr`, outermost first.
diff --git a/tractor/runtime/_runtime.py b/tractor/runtime/_runtime.py
index 27e861f8..dcc187a3 100644
--- a/tractor/runtime/_runtime.py
+++ b/tractor/runtime/_runtime.py
@@ -60,7 +60,6 @@ import sys
 from typing import (
     Any,
     Callable,
-    Type,
     TYPE_CHECKING,
 )
 import uuid
@@ -1684,10 +1683,10 @@ async def async_main(
                     [_state._def_tpt_proto]
                 )
                 for transport_key in enable_transports:
-                    transport_cls: Type[Address] = get_address_cls(
+                    address_type = get_address_cls(
                         transport_key
                     )
-                    addr: Address = transport_cls.get_random()
+                    addr: Address = address_type.get_random()
                     accept_addrs.append(addr.unwrap())
 
         # XXX, either passed in by caller or delivered