diff --git a/docs/README.rst b/docs/README.rst
index 630f5398..cea223ee 100644
--- a/docs/README.rst
+++ b/docs/README.rst
@@ -1,8 +1,5 @@
 |logo| ``tractor``: distributed structurred concurrency
 
-|gh_actions|
-|docs|
-
 ``tractor`` is a `structured concurrency`_ (SC), multi-processing_ runtime built on trio_.
 
 Fundamentally, ``tractor`` provides parallelism via
@@ -66,6 +63,13 @@ Features
   - (WIP) a ``TaskMngr``: one-cancels-one style nursery supervisor.
 
 
+Status of `main` / infra
+------------------------
+
+- |gh_actions|
+- |docs|
+
+
 Install
 -------
 ``tractor`` is still in a *alpha-near-beta-stage* for many
diff --git a/examples/advanced_faults/ipc_failure_during_stream.py b/examples/advanced_faults/ipc_failure_during_stream.py
index 950d5a6f..f3a709e0 100644
--- a/examples/advanced_faults/ipc_failure_during_stream.py
+++ b/examples/advanced_faults/ipc_failure_during_stream.py
@@ -120,6 +120,7 @@ async def main(
     break_parent_ipc_after: int|bool = False,
     break_child_ipc_after: int|bool = False,
     pre_close: bool = False,
+    tpt_proto: str = 'tcp',
 
 ) -> None:
 
@@ -131,6 +132,7 @@ async def main(
             # a hang since it never engages due to broken IPC
             debug_mode=debug_mode,
             loglevel=loglevel,
+            enable_transports=[tpt_proto],
 
         ) as an,
     ):
@@ -145,7 +147,8 @@ async def main(
             _testing.expect_ctxc(
                 yay=(
                     break_parent_ipc_after
-                    or break_child_ipc_after
+                    or
+                    break_child_ipc_after
                 ),
                 # TODO: we CAN'T remove this right?
                 # since we need the ctxc to bubble up from either
diff --git a/examples/debugging/root_cancelled_but_child_is_in_tty_lock.py b/examples/debugging/root_cancelled_but_child_is_in_tty_lock.py
index 16f92b81..72c6de4c 100644
--- a/examples/debugging/root_cancelled_but_child_is_in_tty_lock.py
+++ b/examples/debugging/root_cancelled_but_child_is_in_tty_lock.py
@@ -24,10 +24,9 @@ async def spawn_until(depth=0):
 
 
 async def main():
-    """The main ``tractor`` routine.
-
-    The process tree should look as approximately as follows when the debugger
-    first engages:
+    '''
+    The process tree should look as approximately as follows when the
+    debugger first engages:
 
     python examples/debugging/multi_nested_subactors_bp_forever.py
     ├─ python -m tractor._child --uid ('spawner1', '7eab8462 ...)
@@ -37,10 +36,11 @@ async def main():
     └─ python -m tractor._child --uid ('spawner0', '1d42012b ...)
        └─ python -m tractor._child --uid ('name_error', '6c2733b8 ...)
 
-    """
+    '''
     async with tractor.open_nursery(
         debug_mode=True,
-        loglevel='warning'
+        loglevel='devx',
+        enable_transports=['uds'],
     ) as n:
 
         # spawn both actors
diff --git a/examples/debugging/shield_hang_in_sub.py b/examples/debugging/shield_hang_in_sub.py
index 5387353f..bf045fe8 100644
--- a/examples/debugging/shield_hang_in_sub.py
+++ b/examples/debugging/shield_hang_in_sub.py
@@ -37,6 +37,7 @@ async def main(
             enable_stack_on_sig=True,
             # maybe_enable_greenback=False,
             loglevel='devx',
+            enable_transports=['uds'],
         ) as an,
     ):
         ptl: tractor.Portal  = await an.start_actor(
diff --git a/tests/conftest.py b/tests/conftest.py
index 674767ff..ca175a05 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,24 +1,27 @@
 """
-``tractor`` testing!!
+Top level of the testing suites!
+
 """
+from __future__ import annotations
 import sys
 import subprocess
 import os
-import random
 import signal
 import platform
 import time
 
 import pytest
-import tractor
 from tractor._testing import (
     examples_dir as examples_dir,
     tractor_test as tractor_test,
     expect_ctxc as expect_ctxc,
 )
 
-# TODO: include wtv plugin(s) we build in `._testing.pytest`?
-pytest_plugins = ['pytester']
+pytest_plugins: list[str] = [
+    'pytester',
+    'tractor._testing.pytest',
+]
+
 
 # Sending signal.SIGINT on subprocess fails on windows. Use CTRL_* alternatives
 if platform.system() == 'Windows':
@@ -30,7 +33,11 @@ else:
     _KILL_SIGNAL = signal.SIGKILL
     _INT_SIGNAL = signal.SIGINT
     _INT_RETURN_CODE = 1 if sys.version_info < (3, 8) else -signal.SIGINT.value
-    _PROC_SPAWN_WAIT = 0.6 if sys.version_info < (3, 7) else 0.4
+    _PROC_SPAWN_WAIT = (
+        0.6
+        if sys.version_info < (3, 7)
+        else 0.4
+    )
 
 
 no_windows = pytest.mark.skipif(
@@ -39,7 +46,12 @@ no_windows = pytest.mark.skipif(
 )
 
 
-def pytest_addoption(parser):
+def pytest_addoption(
+    parser: pytest.Parser,
+):
+    # ?TODO? should this be exposed from our `._testing.pytest`
+    # plugin or should we make it more explicit with `--tl` for
+    # tractor logging like we do in other client projects?
     parser.addoption(
         "--ll",
         action="store",
@@ -47,42 +59,10 @@ def pytest_addoption(parser):
         default='ERROR', help="logging level to set when testing"
     )
 
-    parser.addoption(
-        "--spawn-backend",
-        action="store",
-        dest='spawn_backend',
-        default='trio',
-        help="Processing spawning backend to use for test run",
-    )
-
-    parser.addoption(
-        "--tpdb", "--debug-mode",
-        action="store_true",
-        dest='tractor_debug_mode',
-        # default=False,
-        help=(
-            'Enable a flag that can be used by tests to to set the '
-            '`debug_mode: bool` for engaging the internal '
-            'multi-proc debugger sys.'
-        ),
-    )
-
-
-def pytest_configure(config):
-    backend = config.option.spawn_backend
-    tractor._spawn.try_set_start_method(backend)
-
-
-@pytest.fixture(scope='session')
-def debug_mode(request):
-    debug_mode: bool = request.config.option.tractor_debug_mode
-    # if debug_mode:
-    #     breakpoint()
-    return debug_mode
-
 
 @pytest.fixture(scope='session', autouse=True)
 def loglevel(request):
+    import tractor
     orig = tractor.log._default_loglevel
     level = tractor.log._default_loglevel = request.config.option.loglevel
     tractor.log.get_console_log(level)
@@ -90,106 +70,44 @@ def loglevel(request):
     tractor.log._default_loglevel = orig
 
 
-@pytest.fixture(scope='session')
-def spawn_backend(request) -> str:
-    return request.config.option.spawn_backend
-
-
-# @pytest.fixture(scope='function', autouse=True)
-# def debug_enabled(request) -> str:
-#     from tractor import _state
-#     if _state._runtime_vars['_debug_mode']:
-#         breakpoint()
-
 _ci_env: bool = os.environ.get('CI', False)
 
 
 @pytest.fixture(scope='session')
 def ci_env() -> bool:
     '''
-    Detect CI envoirment.
+    Detect CI environment.
 
     '''
     return _ci_env
 
 
-# TODO: also move this to `._testing` for now?
-# -[ ] possibly generalize and re-use for multi-tree spawning
-#    along with the new stuff for multi-addrs in distribute_dis
-#    branch?
-#
-# choose randomly at import time
-_reg_addr: tuple[str, int] = (
-    '127.0.0.1',
-    random.randint(1000, 9999),
-)
-
-
-@pytest.fixture(scope='session')
-def reg_addr() -> tuple[str, int]:
-
-    # globally override the runtime to the per-test-session-dynamic
-    # addr so that all tests never conflict with any other actor
-    # tree using the default.
-    from tractor import _root
-    _root._default_lo_addrs = [_reg_addr]
-
-    return _reg_addr
-
-
-def pytest_generate_tests(metafunc):
-    spawn_backend = metafunc.config.option.spawn_backend
-
-    if not spawn_backend:
-        # XXX some weird windows bug with `pytest`?
-        spawn_backend = 'trio'
-
-    # TODO: maybe just use the literal `._spawn.SpawnMethodKey`?
-    assert spawn_backend in (
-        'mp_spawn',
-        'mp_forkserver',
-        'trio',
-    )
-
-    # NOTE: used to be used to dyanmically parametrize tests for when
-    # you just passed --spawn-backend=`mp` on the cli, but now we expect
-    # that cli input to be manually specified, BUT, maybe we'll do
-    # something like this again in the future?
-    if 'start_method' in metafunc.fixturenames:
-        metafunc.parametrize("start_method", [spawn_backend], scope='module')
-
-
-# TODO: a way to let test scripts (like from `examples/`)
-# guarantee they won't registry addr collide!
-# @pytest.fixture
-# def open_test_runtime(
-#     reg_addr: tuple,
-# ) -> AsyncContextManager:
-#     return partial(
-#         tractor.open_nursery,
-#         registry_addrs=[reg_addr],
-#     )
-
-
-def sig_prog(proc, sig):
+def sig_prog(
+    proc: subprocess.Popen,
+    sig: int,
+    canc_timeout: float = 0.1,
+) -> int:
     "Kill the actor-process with ``sig``."
     proc.send_signal(sig)
-    time.sleep(0.1)
+    time.sleep(canc_timeout)
     if not proc.poll():
         # TODO: why sometimes does SIGINT not work on teardown?
         # seems to happen only when trace logging enabled?
         proc.send_signal(_KILL_SIGNAL)
-    ret = proc.wait()
+    ret: int = proc.wait()
     assert ret
 
 
 # TODO: factor into @cm and move to `._testing`?
 @pytest.fixture
 def daemon(
+    debug_mode: bool,
     loglevel: str,
     testdir,
     reg_addr: tuple[str, int],
-):
+    tpt_proto: str,
+
+) -> subprocess.Popen:
     '''
     Run a daemon root actor as a separate actor-process tree and
     "remote registrar" for discovery-protocol related tests.
@@ -200,28 +118,100 @@ def daemon(
         loglevel: str = 'info'
 
     code: str = (
-            "import tractor; "
-            "tractor.run_daemon([], registry_addrs={reg_addrs}, loglevel={ll})"
+        "import tractor; "
+        "tractor.run_daemon([], "
+        "registry_addrs={reg_addrs}, "
+        "debug_mode={debug_mode}, "
+        "loglevel={ll})"
     ).format(
         reg_addrs=str([reg_addr]),
         ll="'{}'".format(loglevel) if loglevel else None,
+        debug_mode=debug_mode,
     )
     cmd: list[str] = [
         sys.executable,
         '-c', code,
     ]
+    # breakpoint()
     kwargs = {}
     if platform.system() == 'Windows':
         # without this, tests hang on windows forever
         kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP
 
-    proc = testdir.popen(
+    proc: subprocess.Popen = testdir.popen(
         cmd,
-        stdout=subprocess.PIPE,
-        stderr=subprocess.PIPE,
         **kwargs,
     )
-    assert not proc.returncode
+
+    # UDS sockets are **really** fast to bind()/listen()/connect()
+    # so it's often required that we delay a bit more starting
+    # the first actor-tree..
+    if tpt_proto == 'uds':
+        global _PROC_SPAWN_WAIT
+        _PROC_SPAWN_WAIT = 0.6
+
     time.sleep(_PROC_SPAWN_WAIT)
+
+    assert not proc.returncode
     yield proc
     sig_prog(proc, _INT_SIGNAL)
+
+    # XXX! yeah.. just be reaaal careful with this bc sometimes it
+    # can lock up on the `_io.BufferedReader` and hang..
+    stderr: str = proc.stderr.read().decode()
+    if stderr:
+        print(
+            f'Daemon actor tree produced STDERR:\n'
+            f'{proc.args}\n'
+            f'\n'
+            f'{stderr}\n'
+        )
+    if proc.returncode != -2:
+        raise RuntimeError(
+            'Daemon actor tree failed !?\n'
+            f'{proc.args}\n'
+        )
+
+
+# @pytest.fixture(autouse=True)
+# def shared_last_failed(pytestconfig):
+#     val = pytestconfig.cache.get("example/value", None)
+#     breakpoint()
+#     if val is None:
+#         pytestconfig.cache.set("example/value", val)
+#     return val
+
+
+# TODO: a way to let test scripts (like from `examples/`)
+# guarantee they won't `registry_addrs` collide!
+# -[ ] maybe use some kinda standard `def main()` arg-spec that
+#     we can introspect from a fixture that is called from the test
+#     body?
+# -[ ] test and figure out typing for below prototype! Bp
+#
+# @pytest.fixture
+# def set_script_runtime_args(
+#     reg_addr: tuple,
+# ) -> Callable[[...], None]:
+
+#     def import_n_partial_in_args_n_triorun(
+#         script: Path,  # under examples?
+#         **runtime_args,
+#     ) -> Callable[[], Any]:  # a `partial`-ed equiv of `trio.run()`
+
+#         # NOTE, below is taken from
+#         # `.test_advanced_faults.test_ipc_channel_break_during_stream`
+#         mod: ModuleType = import_path(
+#             examples_dir() / 'advanced_faults'
+#             / 'ipc_failure_during_stream.py',
+#             root=examples_dir(),
+#             consider_namespace_packages=False,
+#         )
+#         return partial(
+#             trio.run,
+#             partial(
+#                 mod.main,
+#                 **runtime_args,
+#             )
+#         )
+#     return import_n_partial_in_args_n_triorun
diff --git a/tests/ipc/__init__.py b/tests/ipc/__init__.py
new file mode 100644
index 00000000..b8b1f156
--- /dev/null
+++ b/tests/ipc/__init__.py
@@ -0,0 +1,4 @@
+'''
+`tractor.ipc` subsystem(s)/unit testing suites.
+
+'''
diff --git a/tests/ipc/test_multi_tpt.py b/tests/ipc/test_multi_tpt.py
new file mode 100644
index 00000000..353385e1
--- /dev/null
+++ b/tests/ipc/test_multi_tpt.py
@@ -0,0 +1,95 @@
+'''
+Verify the `enable_transports` param drives various
+per-root/sub-actor IPC endpoint/server settings.
+
+'''
+from __future__ import annotations
+
+import pytest
+import trio
+import tractor
+from tractor import (
+    Actor,
+    Portal,
+    ipc,
+    msg,
+    _state,
+    _addr,
+)
+
+@tractor.context
+async def chk_tpts(
+    ctx: tractor.Context,
+    tpt_proto_key: str,
+):
+    rtvars = _state._runtime_vars
+    assert (
+        tpt_proto_key
+        in
+        rtvars['_enable_tpts']
+    )
+    actor: Actor = tractor.current_actor()
+    spec: msg.types.SpawnSpec = actor._spawn_spec
+    assert spec._runtime_vars == rtvars
+
+    # ensure individual IPC ep-addr types
+    serv: ipc._server.Server = actor.ipc_server
+    addr: ipc._types.Address
+    for addr in serv.addrs:
+        assert addr.proto_key == tpt_proto_key
+
+    # Actor delegate-props enforcement
+    assert (
+        actor.accept_addrs
+        ==
+        serv.accept_addrs
+    )
+
+    await ctx.started(serv.accept_addrs)
+
+
+# TODO, parametrize over mis-matched-proto-typed `registry_addrs`
+# since i seems to work in `piker` but not exactly sure if both tcp
+# & uds are being deployed then?
+#
+@pytest.mark.parametrize(
+    'tpt_proto_key',
+    ['tcp', 'uds'],
+    ids=lambda item: f'ipc_tpt={item!r}'
+)
+def test_root_passes_tpt_to_sub(
+    tpt_proto_key: str,
+    reg_addr: tuple,
+    debug_mode: bool,
+):
+    async def main():
+        async with tractor.open_nursery(
+            enable_transports=[tpt_proto_key],
+            registry_addrs=[reg_addr],
+            debug_mode=debug_mode,
+        ) as an:
+
+            assert (
+                tpt_proto_key
+                in
+                _state._runtime_vars['_enable_tpts']
+            )
+
+            ptl: Portal = await an.start_actor(
+                name='sub',
+                enable_modules=[__name__],
+            )
+            async with ptl.open_context(
+                chk_tpts,
+                tpt_proto_key=tpt_proto_key,
+            ) as (ctx, accept_addrs):
+
+                uw_addr: tuple
+                for uw_addr in accept_addrs:
+                    addr = _addr.wrap_address(uw_addr)
+                    assert addr.is_valid
+
+            # shudown sub-actor(s)
+            await an.cancel()
+
+    trio.run(main)
diff --git a/tests/ipc/test_server.py b/tests/ipc/test_server.py
new file mode 100644
index 00000000..1d63bd1b
--- /dev/null
+++ b/tests/ipc/test_server.py
@@ -0,0 +1,72 @@
+'''
+High-level `.ipc._server` unit tests.
+
+'''
+from __future__ import annotations
+
+import pytest
+import trio
+from tractor import (
+    devx,
+    ipc,
+    log,
+)
+from tractor._testing.addr import (
+    get_rando_addr,
+)
+# TODO, use/check-roundtripping with some of these wrapper types?
+#
+# from .._addr import Address
+# from ._chan import Channel
+# from ._transport import MsgTransport
+# from ._uds import UDSAddress
+# from ._tcp import TCPAddress
+
+
+@pytest.mark.parametrize(
+    '_tpt_proto',
+    ['uds', 'tcp']
+)
+def test_basic_ipc_server(
+    _tpt_proto: str,
+    debug_mode: bool,
+    loglevel: str,
+):
+
+    # so we see the socket-listener reporting on console
+    log.get_console_log("INFO")
+
+    rando_addr: tuple = get_rando_addr(
+        tpt_proto=_tpt_proto,
+    )
+    async def main():
+        async with ipc._server.open_ipc_server() as server:
+
+            assert (
+                server._parent_tn
+                and
+                server._parent_tn is server._stream_handler_tn
+            )
+            assert server._no_more_peers.is_set()
+
+            eps: list[ipc._server.Endpoint] = await server.listen_on(
+                accept_addrs=[rando_addr],
+                stream_handler_nursery=None,
+            )
+            assert (
+                len(eps) == 1
+                and
+                (ep := eps[0])._listener
+                and
+                not ep.peer_tpts
+            )
+
+            server._parent_tn.cancel_scope.cancel()
+
+        # !TODO! actually make a bg-task connection from a client
+        # using `ipc._chan._connect_chan()`
+
+    with devx.maybe_open_crash_handler(
+        pdb=debug_mode,
+    ):
+        trio.run(main)
diff --git a/tests/test_advanced_faults.py b/tests/test_advanced_faults.py
index de8a0e1c..061ae5aa 100644
--- a/tests/test_advanced_faults.py
+++ b/tests/test_advanced_faults.py
@@ -10,6 +10,9 @@ import pytest
 from _pytest.pathlib import import_path
 import trio
 import tractor
+from tractor import (
+    TransportClosed,
+)
 from tractor._testing import (
     examples_dir,
     break_ipc,
@@ -74,6 +77,7 @@ def test_ipc_channel_break_during_stream(
     spawn_backend: str,
     ipc_break: dict|None,
     pre_aclose_msgstream: bool,
+    tpt_proto: str,
 ):
     '''
     Ensure we can have an IPC channel break its connection during
@@ -91,7 +95,7 @@ def test_ipc_channel_break_during_stream(
         # non-`trio` spawners should never hit the hang condition that
         # requires the user to do ctl-c to cancel the actor tree.
         # expect_final_exc = trio.ClosedResourceError
-        expect_final_exc = tractor.TransportClosed
+        expect_final_exc = TransportClosed
 
     mod: ModuleType = import_path(
         examples_dir() / 'advanced_faults'
@@ -104,6 +108,8 @@ def test_ipc_channel_break_during_stream(
     # period" wherein the user eventually hits ctl-c to kill the
     # root-actor tree.
     expect_final_exc: BaseException = KeyboardInterrupt
+    expect_final_cause: BaseException|None = None
+
     if (
         # only expect EoC if trans is broken on the child side,
         ipc_break['break_child_ipc_after'] is not False
@@ -138,6 +144,9 @@ def test_ipc_channel_break_during_stream(
         # a user sending ctl-c by raising a KBI.
         if pre_aclose_msgstream:
             expect_final_exc = KeyboardInterrupt
+            if tpt_proto == 'uds':
+                expect_final_exc = TransportClosed
+                expect_final_cause = trio.BrokenResourceError
 
             # XXX OLD XXX
             # if child calls `MsgStream.aclose()` then expect EoC.
@@ -157,6 +166,10 @@ def test_ipc_channel_break_during_stream(
         if pre_aclose_msgstream:
             expect_final_exc = KeyboardInterrupt
 
+            if tpt_proto == 'uds':
+                expect_final_exc = TransportClosed
+                expect_final_cause = trio.BrokenResourceError
+
     # NOTE when the parent IPC side dies (even if the child does as well
     # but the child fails BEFORE the parent) we always expect the
     # IPC layer to raise a closed-resource, NEVER do we expect
@@ -169,8 +182,8 @@ def test_ipc_channel_break_during_stream(
         and
         ipc_break['break_child_ipc_after'] is False
     ):
-        # expect_final_exc = trio.ClosedResourceError
         expect_final_exc = tractor.TransportClosed
+        expect_final_cause = trio.ClosedResourceError
 
     # BOTH but, PARENT breaks FIRST
     elif (
@@ -181,8 +194,8 @@ def test_ipc_channel_break_during_stream(
             ipc_break['break_parent_ipc_after']
         )
     ):
-        # expect_final_exc = trio.ClosedResourceError
         expect_final_exc = tractor.TransportClosed
+        expect_final_cause = trio.ClosedResourceError
 
     with pytest.raises(
         expected_exception=(
@@ -198,6 +211,7 @@ def test_ipc_channel_break_during_stream(
                     start_method=spawn_backend,
                     loglevel=loglevel,
                     pre_close=pre_aclose_msgstream,
+                    tpt_proto=tpt_proto,
                     **ipc_break,
                 )
             )
@@ -220,10 +234,15 @@ def test_ipc_channel_break_during_stream(
                 )
             cause: Exception = tc.__cause__
             assert (
-                type(cause) is trio.ClosedResourceError
-                and
-                cause.args[0] == 'another task closed this fd'
+                # type(cause) is trio.ClosedResourceError
+                type(cause) is expect_final_cause
+
+                # TODO, should we expect a certain exc-message (per
+                # tpt) as well??
+                # and
+                # cause.args[0] == 'another task closed this fd'
             )
+
             raise
 
     # get raw instance from pytest wrapper
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index 18b2aa1b..65a76d08 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -7,7 +7,9 @@ import platform
 from functools import partial
 import itertools
 
+import psutil
 import pytest
+import subprocess
 import tractor
 from tractor._testing import tractor_test
 import trio
@@ -152,13 +154,23 @@ async def unpack_reg(actor_or_portal):
 async def spawn_and_check_registry(
     reg_addr: tuple,
     use_signal: bool,
+    debug_mode: bool = False,
     remote_arbiter: bool = False,
     with_streaming: bool = False,
+    maybe_daemon: tuple[
+        subprocess.Popen,
+        psutil.Process,
+    ]|None = None,
 
 ) -> None:
 
+    if maybe_daemon:
+        popen, proc = maybe_daemon
+        # breakpoint()
+
     async with tractor.open_root_actor(
         registry_addrs=[reg_addr],
+        debug_mode=debug_mode,
     ):
         async with tractor.get_registry(reg_addr) as portal:
             # runtime needs to be up to call this
@@ -176,11 +188,11 @@ async def spawn_and_check_registry(
                 extra = 2  # local root actor + remote arbiter
 
             # ensure current actor is registered
-            registry = await get_reg()
+            registry: dict = await get_reg()
             assert actor.uid in registry
 
             try:
-                async with tractor.open_nursery() as n:
+                async with tractor.open_nursery() as an:
                     async with trio.open_nursery(
                         strict_exception_groups=False,
                     ) as trion:
@@ -189,17 +201,17 @@ async def spawn_and_check_registry(
                         for i in range(3):
                             name = f'a{i}'
                             if with_streaming:
-                                portals[name] = await n.start_actor(
+                                portals[name] = await an.start_actor(
                                     name=name, enable_modules=[__name__])
 
                             else:  # no streaming
-                                portals[name] = await n.run_in_actor(
+                                portals[name] = await an.run_in_actor(
                                     trio.sleep_forever, name=name)
 
                         # wait on last actor to come up
                         async with tractor.wait_for_actor(name):
                             registry = await get_reg()
-                            for uid in n._children:
+                            for uid in an._children:
                                 assert uid in registry
 
                         assert len(portals) + extra == len(registry)
@@ -232,6 +244,7 @@ async def spawn_and_check_registry(
 @pytest.mark.parametrize('use_signal', [False, True])
 @pytest.mark.parametrize('with_streaming', [False, True])
 def test_subactors_unregister_on_cancel(
+    debug_mode: bool,
     start_method,
     use_signal,
     reg_addr,
@@ -248,6 +261,7 @@ def test_subactors_unregister_on_cancel(
                 spawn_and_check_registry,
                 reg_addr,
                 use_signal,
+                debug_mode=debug_mode,
                 remote_arbiter=False,
                 with_streaming=with_streaming,
             ),
@@ -257,7 +271,8 @@ def test_subactors_unregister_on_cancel(
 @pytest.mark.parametrize('use_signal', [False, True])
 @pytest.mark.parametrize('with_streaming', [False, True])
 def test_subactors_unregister_on_cancel_remote_daemon(
-    daemon,
+    daemon: subprocess.Popen,
+    debug_mode: bool,
     start_method,
     use_signal,
     reg_addr,
@@ -273,8 +288,13 @@ def test_subactors_unregister_on_cancel_remote_daemon(
                 spawn_and_check_registry,
                 reg_addr,
                 use_signal,
+                debug_mode=debug_mode,
                 remote_arbiter=True,
                 with_streaming=with_streaming,
+                maybe_daemon=(
+                    daemon,
+                    psutil.Process(daemon.pid)
+                ),
             ),
         )
 
@@ -373,7 +393,7 @@ def test_close_channel_explicit(
 
 @pytest.mark.parametrize('use_signal', [False, True])
 def test_close_channel_explicit_remote_arbiter(
-    daemon,
+    daemon: subprocess.Popen,
     start_method,
     use_signal,
     reg_addr,
diff --git a/tests/test_resource_cache.py b/tests/test_resource_cache.py
index d3859814..bdcdd6c9 100644
--- a/tests/test_resource_cache.py
+++ b/tests/test_resource_cache.py
@@ -100,16 +100,29 @@ async def streamer(
 @acm
 async def open_stream() -> Awaitable[tractor.MsgStream]:
 
-    async with tractor.open_nursery() as tn:
-        portal = await tn.start_actor('streamer', enable_modules=[__name__])
-        async with (
-            portal.open_context(streamer) as (ctx, first),
-            ctx.open_stream() as stream,
-        ):
-            yield stream
+    try:
+        async with tractor.open_nursery() as an:
+            portal = await an.start_actor(
+                'streamer',
+                enable_modules=[__name__],
+            )
+            async with (
+                portal.open_context(streamer) as (ctx, first),
+                ctx.open_stream() as stream,
+            ):
+                yield stream
 
-        await portal.cancel_actor()
-    print('CANCELLED STREAMER')
+            print('Cancelling streamer')
+            await portal.cancel_actor()
+            print('Cancelled streamer')
+
+    except Exception as err:
+        print(
+            f'`open_stream()` errored?\n'
+            f'{err!r}\n'
+        )
+        await tractor.pause(shield=True)
+        raise err
 
 
 @acm
@@ -132,19 +145,28 @@ async def maybe_open_stream(taskname: str):
             yield stream
 
 
-def test_open_local_sub_to_stream():
+def test_open_local_sub_to_stream(
+    debug_mode: bool,
+):
     '''
     Verify a single inter-actor stream can can be fanned-out shared to
-    N local tasks using ``trionics.maybe_open_context():``.
+    N local tasks using `trionics.maybe_open_context()`.
 
     '''
-    timeout: float = 3.6 if platform.system() != "Windows" else 10
+    timeout: float = 3.6
+    if platform.system() == "Windows":
+        timeout: float = 10
+
+    if debug_mode:
+        timeout = 999
 
     async def main():
 
         full = list(range(1000))
 
         async def get_sub_and_pull(taskname: str):
+
+            stream: tractor.MsgStream
             async with (
                 maybe_open_stream(taskname) as stream,
             ):
@@ -165,17 +187,27 @@ def test_open_local_sub_to_stream():
                 assert set(seq).issubset(set(full))
             print(f'{taskname} finished')
 
-        with trio.fail_after(timeout):
+        with trio.fail_after(timeout) as cs:
             # TODO: turns out this isn't multi-task entrant XD
             # We probably need an indepotent entry semantic?
-            async with tractor.open_root_actor():
+            async with tractor.open_root_actor(
+                debug_mode=debug_mode,
+            ):
                 async with (
-                    trio.open_nursery() as nurse,
+                    trio.open_nursery() as tn,
                 ):
                     for i in range(10):
-                        nurse.start_soon(get_sub_and_pull, f'task_{i}')
+                        tn.start_soon(
+                            get_sub_and_pull,
+                            f'task_{i}',
+                        )
                         await trio.sleep(0.001)
 
                 print('all consumer tasks finished')
 
+        if cs.cancelled_caught:
+            pytest.fail(
+                'Should NOT time out in `open_root_actor()` ?'
+            )
+
     trio.run(main)
diff --git a/tests/test_trioisms.py b/tests/test_trioisms.py
index 9f1ccec9..3343d788 100644
--- a/tests/test_trioisms.py
+++ b/tests/test_trioisms.py
@@ -180,7 +180,8 @@ def test_acm_embedded_nursery_propagates_enter_err(
         with tractor.devx.maybe_open_crash_handler(
             pdb=debug_mode,
         ) as bxerr:
-            assert not bxerr.value
+            if bxerr:
+                assert not bxerr.value
 
             async with (
                 wraps_tn_that_always_cancels() as tn,
diff --git a/tractor/_testing/addr.py b/tractor/_testing/addr.py
new file mode 100644
index 00000000..1b066336
--- /dev/null
+++ b/tractor/_testing/addr.py
@@ -0,0 +1,70 @@
+# 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/>.
+
+'''
+Random IPC addr generation for isolating
+the discovery space between test sessions.
+
+Might be eventually useful to expose as a util set from
+our `tractor.discovery` subsys?
+
+'''
+import random
+from typing import (
+    Type,
+)
+from tractor import (
+    _addr,
+)
+
+
+def get_rando_addr(
+    tpt_proto: str,
+    *,
+
+    # choose random port at import time
+    _rando_port: str = random.randint(1000, 9999)
+
+) -> tuple[str, str|int]:
+    '''
+    Used to globally override the runtime to the
+    per-test-session-dynamic addr so that all tests never conflict
+    with any other actor tree using the default.
+
+    '''
+    addr_type: Type[_addr.Addres] = _addr._address_types[tpt_proto]
+    def_reg_addr: tuple[str, int] = _addr._default_lo_addrs[tpt_proto]
+
+    # this is the "unwrapped" form expected to be passed to
+    # `.open_root_actor()` by test body.
+    testrun_reg_addr: tuple[str, int|str]
+    match tpt_proto:
+        case 'tcp':
+            testrun_reg_addr = (
+                addr_type.def_bindspace,
+                _rando_port,
+            )
+
+        # NOTE, file-name uniqueness (no-collisions) will be based on
+        # the runtime-directory and root (pytest-proc's) pid.
+        case 'uds':
+            testrun_reg_addr = addr_type.get_random().unwrap()
+
+    # XXX, as sanity it should never the same as the default for the
+    # host-singleton registry actor.
+    assert def_reg_addr != testrun_reg_addr
+
+    return testrun_reg_addr
diff --git a/tractor/_testing/pytest.py b/tractor/_testing/pytest.py
index 93eeaf72..1a2f63ab 100644
--- a/tractor/_testing/pytest.py
+++ b/tractor/_testing/pytest.py
@@ -26,29 +26,46 @@ from functools import (
 import inspect
 import platform
 
+import pytest
 import tractor
 import trio
 
 
 def tractor_test(fn):
     '''
-    Decorator for async test funcs to present them as "native"
-    looking sync funcs runnable by `pytest` using `trio.run()`.
+    Decorator for async test fns to decorator-wrap them as "native"
+    looking sync funcs runnable by `pytest` and auto invoked with
+    `trio.run()` (much like the `pytest-trio` plugin's approach).
 
-    Use:
+    Further the test fn body will be invoked AFTER booting the actor
+    runtime, i.e. from inside a `tractor.open_root_actor()` block AND
+    with various runtime and tooling parameters implicitly passed as
+    requested by by the test session's config; see immediately below.
 
-    @tractor_test
-    async def test_whatever():
-        await ...
+    Basic deco use:
+    ---------------
 
-    If fixtures:
+      @tractor_test
+      async def test_whatever():
+          await ...
 
-        - ``reg_addr`` (a socket addr tuple where arbiter is listening)
-        - ``loglevel`` (logging level passed to tractor internals)
-        - ``start_method`` (subprocess spawning backend)
 
-    are defined in the `pytest` fixture space they will be automatically
-    injected to tests declaring these funcargs.
+    Runtime config via special fixtures:
+    ------------------------------------
+    If any of the following fixture are requested by the wrapped test
+    fn (via normal func-args declaration),
+
+    - `reg_addr` (a socket addr tuple where arbiter is listening)
+    - `loglevel` (logging level passed to tractor internals)
+    - `start_method` (subprocess spawning backend)
+
+    (TODO support)
+    - `tpt_proto` (IPC transport protocol key)
+
+    they will be automatically injected to each test as normally
+    expected as well as passed to the initial
+    `tractor.open_root_actor()` funcargs.
+
     '''
     @wraps(fn)
     def wrapper(
@@ -111,3 +128,164 @@ def tractor_test(fn):
         return trio.run(main)
 
     return wrapper
+
+
+def pytest_addoption(
+    parser: pytest.Parser,
+):
+    # parser.addoption(
+    #     "--ll",
+    #     action="store",
+    #     dest='loglevel',
+    #     default='ERROR', help="logging level to set when testing"
+    # )
+
+    parser.addoption(
+        "--spawn-backend",
+        action="store",
+        dest='spawn_backend',
+        default='trio',
+        help="Processing spawning backend to use for test run",
+    )
+
+    parser.addoption(
+        "--tpdb",
+        "--debug-mode",
+        action="store_true",
+        dest='tractor_debug_mode',
+        # default=False,
+        help=(
+            'Enable a flag that can be used by tests to to set the '
+            '`debug_mode: bool` for engaging the internal '
+            'multi-proc debugger sys.'
+        ),
+    )
+
+    # provide which IPC transport protocols opting-in test suites
+    # should accumulatively run against.
+    parser.addoption(
+        "--tpt-proto",
+        nargs='+',  # accumulate-multiple-args
+        action="store",
+        dest='tpt_protos',
+        default=['tcp'],
+        help="Transport protocol to use under the `tractor.ipc.Channel`",
+    )
+
+
+def pytest_configure(config):
+    backend = config.option.spawn_backend
+    tractor._spawn.try_set_start_method(backend)
+
+
+@pytest.fixture(scope='session')
+def debug_mode(request) -> bool:
+    '''
+    Flag state for whether `--tpdb` (for `tractor`-py-debugger)
+    was passed to the test run.
+
+    Normally tests should pass this directly to `.open_root_actor()`
+    to allow the user to opt into suite-wide crash handling.
+
+    '''
+    debug_mode: bool = request.config.option.tractor_debug_mode
+    return debug_mode
+
+
+@pytest.fixture(scope='session')
+def spawn_backend(request) -> str:
+    return request.config.option.spawn_backend
+
+
+@pytest.fixture(scope='session')
+def tpt_protos(request) -> list[str]:
+
+    # allow quoting on CLI
+    proto_keys: list[str] = [
+        proto_key.replace('"', '').replace("'", "")
+        for proto_key in request.config.option.tpt_protos
+    ]
+
+    # ?TODO, eventually support multiple protos per test-sesh?
+    if len(proto_keys) > 1:
+        pytest.fail(
+            'We only support one `--tpt-proto <key>` atm!\n'
+        )
+
+    # XXX ensure we support the protocol by name via lookup!
+    for proto_key in proto_keys:
+        addr_type = tractor._addr._address_types[proto_key]
+        assert addr_type.proto_key == proto_key
+
+    yield proto_keys
+
+
+@pytest.fixture(
+    scope='session',
+    autouse=True,
+)
+def tpt_proto(
+    tpt_protos: list[str],
+) -> str:
+    proto_key: str = tpt_protos[0]
+
+    from tractor import _state
+    if _state._def_tpt_proto != proto_key:
+        _state._def_tpt_proto = proto_key
+
+    yield proto_key
+
+
+@pytest.fixture(scope='session')
+def reg_addr(
+    tpt_proto: str,
+) -> tuple[str, int|str]:
+    '''
+    Deliver a test-sesh unique registry address such
+    that each run's (tests which use this fixture) will
+    have no conflicts/cross-talk when running simultaneously
+    nor will interfere with other live `tractor` apps active
+    on the same network-host (namespace).
+
+    '''
+    from tractor._testing.addr import get_rando_addr
+    return get_rando_addr(
+        tpt_proto=tpt_proto,
+    )
+
+
+def pytest_generate_tests(
+    metafunc: pytest.Metafunc,
+):
+    spawn_backend: str = metafunc.config.option.spawn_backend
+
+    if not spawn_backend:
+        # XXX some weird windows bug with `pytest`?
+        spawn_backend = 'trio'
+
+    # TODO: maybe just use the literal `._spawn.SpawnMethodKey`?
+    assert spawn_backend in (
+        'mp_spawn',
+        'mp_forkserver',
+        'trio',
+    )
+
+    # NOTE: used-to-be-used-to dyanmically parametrize tests for when
+    # you just passed --spawn-backend=`mp` on the cli, but now we expect
+    # that cli input to be manually specified, BUT, maybe we'll do
+    # something like this again in the future?
+    if 'start_method' in metafunc.fixturenames:
+        metafunc.parametrize(
+            "start_method",
+            [spawn_backend],
+            scope='module',
+        )
+
+    # TODO, parametrize any `tpt_proto: str` declaring tests!
+    # proto_tpts: list[str] = metafunc.config.option.proto_tpts
+    # if 'tpt_proto' in metafunc.fixturenames:
+    #     metafunc.parametrize(
+    #         'tpt_proto',
+    #         proto_tpts,  # TODO, double check this list usage!
+    #         scope='module',
+    #     )
diff --git a/tractor/ipc/_server.py b/tractor/ipc/_server.py
index e06e747c..cec0e56f 100644
--- a/tractor/ipc/_server.py
+++ b/tractor/ipc/_server.py
@@ -289,7 +289,7 @@ async def maybe_wait_on_canced_subs(
 #
 # -[x] maybe change to mod-func and rename for implied
 #    multi-transport semantics?
-# -[ ] register each stream/tpt/chan with the owning `IPCEndpoint`
+# -[ ] register each stream/tpt/chan with the owning `Endpoint`
 #     so that we can query per tpt all peer contact infos?
 #  |_[ ] possibly provide a global viewing via a
 #        `collections.ChainMap`?
@@ -309,7 +309,7 @@ async def handle_stream_from_peer(
     any `IPCServer.listen_on()` passed `stream_handler_tn: Nursery`
     such that it is invoked as,
 
-      IPCEndpoint.stream_handler_tn.start_soon(
+      Endpoint.stream_handler_tn.start_soon(
           handle_stream,
           stream,
       )
@@ -577,7 +577,7 @@ async def handle_stream_from_peer(
     # finally block closure
 
 
-class IPCEndpoint(Struct):
+class Endpoint(Struct):
     '''
     An instance of an IPC "bound" address where the lifetime of the
     "ability to accept connections" (from clients) and then handle
@@ -636,7 +636,7 @@ class IPCEndpoint(Struct):
         )
 
 
-class IPCServer(Struct):
+class Server(Struct):
     _parent_tn: Nursery
     _stream_handler_tn: Nursery
     # level-triggered sig for whether "no peers are currently
@@ -644,7 +644,7 @@ class IPCServer(Struct):
     # initialized with `.is_set() == True`.
     _no_more_peers: trio.Event
 
-    _endpoints: list[IPCEndpoint] = []
+    _endpoints: list[Endpoint] = []
 
     # connection tracking & mgmt
     _peers: defaultdict[
@@ -659,10 +659,10 @@ class IPCServer(Struct):
     # syncs for setup/teardown sequences
     _shutdown: trio.Event|None = None
 
-    # TODO, maybe just make `._endpoints: list[IPCEndpoint]` and
+    # TODO, maybe just make `._endpoints: list[Endpoint]` and
     # provide dict-views onto it?
     # @property
-    # def addrs2eps(self) -> dict[Address, IPCEndpoint]:
+    # def addrs2eps(self) -> dict[Address, Endpoint]:
     #     ...
 
     @property
@@ -708,7 +708,7 @@ class IPCServer(Struct):
             await self._shutdown.wait()
         else:
             tpt_protos: list[str] = []
-            ep: IPCEndpoint
+            ep: Endpoint
             for ep in self._endpoints:
                 tpt_protos.append(ep.addr.proto_key)
 
@@ -790,7 +790,7 @@ class IPCServer(Struct):
 
     def epsdict(self) -> dict[
         Address,
-        IPCEndpoint,
+        Endpoint,
     ]:
         return {
             ep.addr: ep
@@ -804,7 +804,7 @@ class IPCServer(Struct):
         return ev.is_set()
 
     def pformat(self) -> str:
-        eps: list[IPCEndpoint] = self._endpoints
+        eps: list[Endpoint] = self._endpoints
 
         state_repr: str = (
             f'{len(eps)!r} IPC-endpoints active'
@@ -835,13 +835,13 @@ class IPCServer(Struct):
 
     # TODO? maybe allow shutting down a `.listen_on()`s worth of
     # listeners by cancelling the corresponding
-    # `IPCEndpoint._listen_tn` only ?
+    # `Endpoint._listen_tn` only ?
     # -[ ] in theory you could use this to
     #     "boot-and-wait-for-reconnect" of all current and connecting
     #     peers?
     #  |_ would require that the stream-handler is intercepted so we
     #     can intercept every `MsgTransport` (stream) and track per
-    #     `IPCEndpoint` likely?
+    #     `Endpoint` likely?
     #
     # async def unlisten(
     #     self,
@@ -854,7 +854,7 @@ class IPCServer(Struct):
         *,
         accept_addrs: list[tuple[str, int|str]]|None = None,
         stream_handler_nursery: Nursery|None = None,
-    ) -> list[IPCEndpoint]:
+    ) -> list[Endpoint]:
         '''
         Start `SocketListeners` (i.e. bind and call `socket.listen()`)
         for all IPC-transport-protocol specific `Address`-types
@@ -888,7 +888,7 @@ class IPCServer(Struct):
             f'Binding to endpoints for,\n'
             f'{accept_addrs}\n'
         )
-        eps: list[IPCEndpoint] = await self._parent_tn.start(
+        eps: list[Endpoint] = await self._parent_tn.start(
             partial(
                 _serve_ipc_eps,
                 server=self,
@@ -904,7 +904,7 @@ class IPCServer(Struct):
         self._endpoints.extend(eps)
         # XXX, just a little bit of sanity
         group_tn: Nursery|None = None
-        ep: IPCEndpoint
+        ep: Endpoint
         for ep in eps:
             if ep.addr not in self.addrs:
                 breakpoint()
@@ -917,6 +917,10 @@ class IPCServer(Struct):
         return eps
 
 
+# alias until we decide on final naming
+IPCServer = Server
+
+
 async def _serve_ipc_eps(
     *,
     server: IPCServer,
@@ -941,12 +945,12 @@ async def _serve_ipc_eps(
         listen_tn: Nursery
         async with trio.open_nursery() as listen_tn:
 
-            eps: list[IPCEndpoint] = []
+            eps: list[Endpoint] = []
             # XXX NOTE, required to call `serve_listeners()` below.
             # ?TODO, maybe just pass `list(eps.values()` tho?
             listeners: list[trio.abc.Listener] = []
             for addr in listen_addrs:
-                ep = IPCEndpoint(
+                ep = Endpoint(
                     addr=addr,
                     listen_tn=listen_tn,
                     stream_handler_tn=stream_handler_tn,
@@ -1010,7 +1014,7 @@ async def _serve_ipc_eps(
     finally:
         if eps:
             addr: Address
-            ep: IPCEndpoint
+            ep: Endpoint
             for addr, ep in server.epsdict().items():
                 ep.close_listener()
                 server._endpoints.remove(ep)