diff --git a/piker/brokers/data.py b/piker/brokers/data.py
index 48b20d80..f0a8d367 100644
--- a/piker/brokers/data.py
+++ b/piker/brokers/data.py
@@ -38,6 +38,7 @@ import contextlib
 
 import trio
 import tractor
+from tractor.experimental import msgpub
 from async_generator import asynccontextmanager
 
 from ..log import get_logger, get_console_log
@@ -98,7 +99,7 @@ class BrokerFeed:
     )
 
 
-@tractor.msg.pub(tasks=['stock', 'option'])
+@msgpub(tasks=['stock', 'option'])
 async def stream_poll_requests(
     get_topics: Callable,
     get_quotes: Coroutine,
@@ -293,7 +294,7 @@ async def start_quote_stream(
 
         await stream_poll_requests(
 
-            # ``msg.pub`` required kwargs
+            # ``trionics.msgpub`` required kwargs
             task_name=feed_type,
             ctx=ctx,
             topics=symbols,
diff --git a/piker/brokers/ib.py b/piker/brokers/ib.py
index b378f5f2..4dcf7b14 100644
--- a/piker/brokers/ib.py
+++ b/piker/brokers/ib.py
@@ -1032,7 +1032,11 @@ async def get_client(
 # https://interactivebrokers.github.io/tws-api/tick_types.html
 tick_types = {
     77: 'trade',
-    48: 'utrade',
+
+    # a "utrade" aka an off exchange "unreportable" (dark) vlm:
+    # https://interactivebrokers.github.io/tws-api/tick_types.html#rt_volume
+    48: 'dark_trade',
+
     0: 'bsize',
     1: 'bid',
     2: 'ask',
@@ -1046,13 +1050,17 @@ tick_types = {
 def normalize(
     ticker: Ticker,
     calc_price: bool = False
+
 ) -> dict:
     # convert named tuples to dicts so we send usable keys
     new_ticks = []
     for tick in ticker.ticks:
         if tick and not isinstance(tick, dict):
             td = tick._asdict()
-            td['type'] = tick_types.get(td['tickType'], 'n/a')
+            td['type'] = tick_types.get(
+                td['tickType'],
+                'n/a',
+            )
 
             new_ticks.append(td)
 
diff --git a/piker/brokers/kraken.py b/piker/brokers/kraken.py
index 3278e40b..24d2dab3 100644
--- a/piker/brokers/kraken.py
+++ b/piker/brokers/kraken.py
@@ -553,8 +553,6 @@ async def stream_quotes(
                     quote = ohlc
                     topic = quote['symbol'].lower()
 
-                # XXX: format required by ``tractor.msg.pub``
-                # requires a ``Dict[topic: str, quote: dict]``
                 await send_chan.send({topic: quote})
 
 
diff --git a/piker/data/_normalize.py b/piker/data/_normalize.py
index 3474879e..56d64b75 100644
--- a/piker/data/_normalize.py
+++ b/piker/data/_normalize.py
@@ -25,14 +25,18 @@ import numpy as np
 
 def iterticks(
     quote: dict,
-    types: Tuple[str] = ('trade', 'utrade'),
+    types: Tuple[str] = ('trade', 'dark_trade'),
+
 ) -> AsyncIterator:
-    """Iterate through ticks delivered per quote cycle.
-    """
+    '''
+    Iterate through ticks delivered per quote cycle.
+
+    '''
     # print(f"{quote}\n\n")
     ticks = quote.get('ticks', ())
     if ticks:
         for tick in ticks:
             # print(f"{quote['symbol']}: {tick}")
-            if tick.get('type') in types:
+            ttype = tick.get('type')
+            if ttype in types:
                 yield tick
diff --git a/piker/data/_sampling.py b/piker/data/_sampling.py
index 5e702e08..b29b0f7d 100644
--- a/piker/data/_sampling.py
+++ b/piker/data/_sampling.py
@@ -176,12 +176,11 @@ async def sample_and_broadcast(
         # TODO: ``numba`` this!
         for sym, quote in quotes.items():
 
-            # TODO: in theory you can send the IPC msg *before*
-            # writing to the sharedmem array to decrease latency,
-            # however, that will require `tractor.msg.pub` support
-            # here or at least some way to prevent task switching
-            # at the yield such that the array write isn't delayed
-            # while another consumer is serviced..
+            # TODO: in theory you can send the IPC msg *before* writing
+            # to the sharedmem array to decrease latency, however, that
+            # will require at least some way to prevent task switching
+            # at the yield such that the array write isn't delayed while
+            # another consumer is serviced..
 
             # start writing the shm buffer with appropriate
             # trade data
diff --git a/piker/fsp/_api.py b/piker/fsp/_api.py
new file mode 100644
index 00000000..f2c7cdc8
--- /dev/null
+++ b/piker/fsp/_api.py
@@ -0,0 +1,163 @@
+# piker: trading gear for hackers
+# Copyright (C) Tyler Goodlet (in stewardship of pikers)
+
+# 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/>.
+
+'''
+FSP (financial signal processing) apis.
+
+'''
+
+# TODO: things to figure the heck out:
+# - how to handle non-plottable values (pyqtgraph has facility for this
+#   now in `arrayToQPath()`)
+# - composition of fsps / implicit chaining syntax (we need an issue)
+
+from __future__ import annotations
+from functools import partial
+from typing import (
+    Any,
+    Callable,
+    Awaitable,
+    Optional,
+)
+
+import numpy as np
+import tractor
+from tractor.msg import NamespacePath
+
+from ..data._sharedmem import (
+    ShmArray,
+    maybe_open_shm_array,
+)
+from ..log import get_logger
+
+log = get_logger(__name__)
+
+# global fsp registry filled out by @fsp decorator below
+_fsp_registry = {}
+
+
+def _load_builtins() -> dict[tuple, Callable]:
+
+    # import to implicity trigger registration via ``@fsp``
+    from . import _momo  # noqa
+    from . import _volume  # noqa
+
+    return _fsp_registry
+
+
+class Fsp:
+    '''
+    "Financial signal processor" decorator wrapped async function.
+
+    '''
+
+    # TODO: checkout the advanced features from ``wrapt``:
+    # - dynamic enable toggling,
+    # https://wrapt.readthedocs.io/en/latest/decorators.html#dynamically-disabling-decorators
+    # - custom object proxies, might be useful for implementing n-compose
+    # https://wrapt.readthedocs.io/en/latest/wrappers.html#custom-object-proxies
+    # - custom function wrappers,
+    # https://wrapt.readthedocs.io/en/latest/wrappers.html#custom-function-wrappers
+
+    def __init__(
+        self,
+        func: Callable[..., Awaitable],
+        *,
+        outputs: tuple[str] = (),
+        display_name: Optional[str] = None,
+        **config,
+
+    ) -> None:
+
+        # TODO (maybe):
+        # - type introspection?
+        # - should we make this a wrapt object proxy?
+        self.func = func
+        self.__name__ = func.__name__  # XXX: must have func-object name
+
+        self.ns_path: tuple[str, str] = NamespacePath.from_ref(func)
+        self.outputs = outputs
+        self.config: dict[str, Any] = config
+
+        # register with declared set.
+        _fsp_registry[self.ns_path] = func
+
+    @property
+    def name(self) -> str:
+        return self.__name__
+
+    def __call__(
+        self,
+
+        # TODO: when we settle on py3.10 we should probably use the new
+        # type annots from pep 612:
+        # https://www.python.org/dev/peps/pep-0612/
+        # instance,
+        *args,
+        **kwargs
+    ):
+        return self.func(*args, **kwargs)
+
+
+def fsp(
+    wrapped=None,
+    *,
+    outputs: tuple[str] = (),
+    display_name: Optional[str] = None,
+    **config,
+
+) -> Fsp:
+
+    if wrapped is None:
+        return partial(
+            Fsp,
+            outputs=outputs,
+            display_name=display_name,
+            **config,
+        )
+
+    return Fsp(wrapped, outputs=(wrapped.__name__,))
+
+
+def maybe_mk_fsp_shm(
+    sym: str,
+    target: fsp,
+    readonly: bool = True,
+
+) -> (ShmArray, bool):
+    '''
+    Allocate a single row shm array for an symbol-fsp pair if none
+    exists, otherwise load the shm already existing for that token.
+
+    '''
+    uid = tractor.current_actor().uid
+
+    # TODO: load output types from `Fsp`
+    # - should `index` be a required internal field?
+    fsp_dtype = np.dtype(
+        [('index', int)] +
+        [(field_name, float) for field_name in target.outputs]
+    )
+
+    key = f'{sym}.fsp.{target.name}.{".".join(uid)}'
+
+    shm, opened = maybe_open_shm_array(
+        key,
+        # TODO: create entry for each time frame
+        dtype=fsp_dtype,
+        readonly=True,
+    )
+    return shm, opened
diff --git a/piker/fsp/_engine.py b/piker/fsp/_engine.py
index aafaf76c..afd986e0 100644
--- a/piker/fsp/_engine.py
+++ b/piker/fsp/_engine.py
@@ -1,5 +1,5 @@
 # piker: trading gear for hackers
-# Copyright (C) Tyler Goodlet (in stewardship of piker0)
+# Copyright (C) Tyler Goodlet (in stewardship of pikers)
 
 # 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
@@ -27,29 +27,18 @@ import pyqtgraph as pg
 import trio
 from trio_typing import TaskStatus
 import tractor
+from tractor.msg import NamespacePath
 
 from ..log import get_logger, get_console_log
 from .. import data
 from ..data import attach_shm_array
 from ..data.feed import Feed
 from ..data._sharedmem import ShmArray
-from ._momo import _rsi, _wma
-from ._volume import _tina_vwap, dolla_vlm
+from ._api import Fsp
+from ._api import _load_builtins
 
 log = get_logger(__name__)
 
-_fsp_builtins = {
-    'rsi': _rsi,
-    'wma': _wma,
-    'vwap': _tina_vwap,
-    'dolla_vlm': dolla_vlm,
-}
-
-# TODO: things to figure the heck out:
-# - how to handle non-plottable values (pyqtgraph has facility for this
-#   now in `arrayToQPath()`)
-# - composition of fsps / implicit chaining syntax (we need an issue)
-
 
 @dataclass
 class TaskTracker:
@@ -88,7 +77,6 @@ async def fsp_compute(
     src: ShmArray,
     dst: ShmArray,
 
-    func_name: str,
     func: Callable,
 
     attach_stream: bool = False,
@@ -115,15 +103,27 @@ async def fsp_compute(
     # and get historical output
     history_output = await out_stream.__anext__()
 
+    func_name = func.__name__
     profiler(f'{func_name} generated history')
 
-    # build a struct array which includes an 'index' field to push
-    # as history
-    history = np.array(
-        np.arange(len(history_output)),
+    # build struct array with an 'index' field to push as history
+    history = np.zeros(
+        len(history_output),
         dtype=dst.array.dtype
     )
-    history[func_name] = history_output
+
+    # TODO: push using a[['f0', 'f1', .., 'fn']] = .. syntax no?
+    # if the output array is multi-field then push
+    # each respective field.
+    fields = getattr(history.dtype, 'fields', None)
+    if fields:
+        for key in fields.keys():
+            if key in history.dtype.fields:
+                history[func_name] = history_output
+
+    # single-key output stream
+    else:
+        history[func_name] = history_output
 
     # TODO: XXX:
     # THERE'S A BIG BUG HERE WITH THE `index` field since we're
@@ -164,8 +164,9 @@ async def fsp_compute(
                 async for processed in out_stream:
 
                     log.debug(f"{func_name}: {processed}")
+                    key, output = processed
                     index = src.index
-                    dst.array[-1][func_name] = processed
+                    dst.array[-1][key] = output
 
                     # NOTE: for now we aren't streaming this to the consumer
                     # stream latest array index entry which basically just acts
@@ -194,7 +195,7 @@ async def cascade(
     src_shm_token: dict,
     dst_shm_token: tuple[str, np.dtype],
 
-    func_name: str,
+    ns_path: NamespacePath,
 
     zero_on_step: bool = False,
     loglevel: Optional[str] = None,
@@ -213,10 +214,18 @@ async def cascade(
     src = attach_shm_array(token=src_shm_token)
     dst = attach_shm_array(readonly=False, token=dst_shm_token)
 
-    func: Callable = _fsp_builtins.get(func_name)
+    reg = _load_builtins()
+    lines = '\n'.join([f'{key.rpartition(":")[2]} => {key}' for key in reg])
+    log.info(
+        f'Registered FSP set:\n{lines}'
+    )
+    func: Fsp = reg.get(
+        NamespacePath(ns_path)
+    )
+
     if not func:
         # TODO: assume it's a func target path
-        raise ValueError('Unknown fsp target: {func_name}')
+        raise ValueError(f'Unknown fsp target: {ns_path}')
 
     # open a data feed stream with requested broker
     async with data.feed.maybe_open_feed(
@@ -231,11 +240,12 @@ async def cascade(
 
     ) as (feed, quote_stream):
 
-        profiler(f'{func_name}: feed up')
+        profiler(f'{func}: feed up')
 
         assert src.token == feed.shm.token
         # last_len = new_len = len(src.array)
 
+        func_name = func.__name__
         async with (
             trio.open_nursery() as n,
         ):
@@ -252,7 +262,7 @@ async def cascade(
                 src=src,
                 dst=dst,
 
-                func_name=func_name,
+                # func_name=func_name,
                 func=func
             )
 
diff --git a/piker/fsp/_momo.py b/piker/fsp/_momo.py
index 2ee55e00..29e94f98 100644
--- a/piker/fsp/_momo.py
+++ b/piker/fsp/_momo.py
@@ -23,6 +23,7 @@ from typing import AsyncIterator, Optional
 import numpy as np
 from numba import jit, float64, optional, int64
 
+from ._api import fsp
 from ..data._normalize import iterticks
 from ..data._sharedmem import ShmArray
 
@@ -106,7 +107,7 @@ def ema(
 #     nopython=True,
 #     nogil=True
 # )
-def rsi(
+def _rsi(
 
     # TODO: use https://github.com/ramonhagenaars/nptyping
     signal: 'np.ndarray[float64]',
@@ -146,7 +147,7 @@ def rsi(
     return rsi, up_ema[-1], down_ema[-1]
 
 
-def wma(
+def _wma(
 
     signal: np.ndarray,
     length: int,
@@ -169,10 +170,8 @@ def wma(
     return np.convolve(signal, weights, 'valid')
 
 
-# @piker.fsp.emit(
-#     timeframes=['1s', '5s', '15s', '1m', '5m', '1H'],
-# )
-async def _rsi(
+@fsp
+async def rsi(
 
     source: 'QuoteStream[Dict[str, Any]]',  # noqa
     ohlcv: ShmArray,
@@ -188,11 +187,11 @@ async def _rsi(
     sig = ohlcv.array['close']
 
     # wilder says to seed the RSI EMAs with the SMA for the "period"
-    seed = wma(ohlcv.last(period)['close'], period)[0]
+    seed = _wma(ohlcv.last(period)['close'], period)[0]
 
     # TODO: the emas here should be seeded with a period SMA as per
     # wilder's original formula..
-    rsi_h, last_up_ema_close, last_down_ema_close = rsi(
+    rsi_h, last_up_ema_close, last_down_ema_close = _rsi(
         sig, period, seed, seed)
     up_ema_last = last_up_ema_close
     down_ema_last = last_down_ema_close
@@ -218,7 +217,7 @@ async def _rsi(
                 last_down_ema_close = down_ema_last
                 index = ohlcv.index
 
-            rsi_out, up_ema_last, down_ema_last = rsi(
+            rsi_out, up_ema_last, down_ema_last = _rsi(
                 sig,
                 period=period,
                 up_ema_last=last_up_ema_close,
@@ -227,7 +226,8 @@ async def _rsi(
             yield rsi_out[-1:]
 
 
-async def _wma(
+@fsp
+async def wma(
 
     source,  #: AsyncStream[np.ndarray],
     length: int,
@@ -243,10 +243,10 @@ async def _wma(
 
     '''
     # deliver historical output as "first yield"
-    yield wma(ohlcv.array['close'], length)
+    yield _wma(ohlcv.array['close'], length)
 
     # begin real-time section
 
     async for quote in source:
         for tick in iterticks(quote, type='trade'):
-            yield wma(ohlcv.last(length))
+            yield _wma(ohlcv.last(length))
diff --git a/piker/fsp/_volume.py b/piker/fsp/_volume.py
index e662343f..7cf7d7b4 100644
--- a/piker/fsp/_volume.py
+++ b/piker/fsp/_volume.py
@@ -1,5 +1,5 @@
 # piker: trading gear for hackers
-# Copyright (C) 2018-present  Tyler Goodlet (in stewardship of piker0)
+# Copyright (C) Tyler Goodlet (in stewardship of pikers)
 
 # 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
@@ -19,6 +19,7 @@ from typing import AsyncIterator, Optional, Union
 import numpy as np
 from tractor.trionics._broadcast import AsyncReceiver
 
+from ._api import fsp
 from ..data._normalize import iterticks
 from ..data._sharedmem import ShmArray
 
@@ -50,7 +51,8 @@ def wap(
     )
 
 
-async def _tina_vwap(
+@fsp
+async def tina_vwap(
 
     source: AsyncReceiver[dict],
     ohlcv: ShmArray,  # OHLC sampled history
@@ -62,7 +64,8 @@ async def _tina_vwap(
     AsyncIterator[np.ndarray],
     float
 ]:
-    '''Streaming volume weighted moving average.
+    '''
+    Streaming volume weighted moving average.
 
     Calling this "tina" for now since we're using HLC3 instead of tick.
 
@@ -100,26 +103,25 @@ async def _tina_vwap(
             w_tot += price * size
 
             # yield ((((o + h + l) / 3) * v) weights_tot) / v_tot
-            yield w_tot / v_tot
+            yield 'tina_vwap', w_tot / v_tot
 
 
-# @fsp.config(
-#     name='dolla_vlm',
-#     ohlc=False,
-#     style='step',
-# )
+@fsp(
+    outputs=('dolla_vlm', 'dark_vlm'),
+    ohlc=False,
+    curve_style='step',
+)
 async def dolla_vlm(
     source: AsyncReceiver[dict],
     ohlcv: ShmArray,  # OHLC sampled history
 
-) -> Union[
-    AsyncIterator[np.ndarray],
-    float
+) -> AsyncIterator[
+    tuple[str, Union[np.ndarray, float]],
 ]:
     '''
     "Dollar Volume", aka the volume in asset-currency-units (usually
     a fiat) computed from some price function for the sample step
-    *times* the asset unit volume.
+    *multiplied* (*) by the asset unit volume.
 
     Useful for comparing cross asset "money flow" in #s that are
     asset-currency-independent.
@@ -129,11 +131,12 @@ async def dolla_vlm(
     chl3 = (a['close'] + a['high'] + a['low']) / 3
     v = a['volume']
 
-    # history
+    # on first iteration yield history
     yield chl3 * v
 
     i = ohlcv.index
-    lvlm = 0
+    output = vlm = 0
+    dvlm = 0
 
     async for quote in source:
         for tick in iterticks(quote):
@@ -145,14 +148,30 @@ async def dolla_vlm(
             li = ohlcv.index
             if li > i:
                 i = li
-                lvlm = 0
+                vlm = 0
+                dvlm = 0
 
-            c, h, l, v = ohlcv.last()[
-                ['close', 'high', 'low', 'volume']
-            ][0]
+            # TODO: for marginned instruments (futes, etfs?) we need to
+            # show the margin $vlm by multiplying by whatever multiplier
+            # is reported in the sym info.
 
-            lvlm += price * size
-            tina_lvlm = c+h+l/3 * v
+            ttype = tick.get('type')
+            if ttype == 'dark_trade':
+                print(f'dark_trade: {tick}')
+                key = 'dark_vlm'
+                dvlm += price * size
+                output = dvlm
+
+            else:
+                key = 'dolla_vlm'
+                vlm += price * size
+                output = vlm
+
+            # TODO: plot both to compare?
+            # c, h, l, v = ohlcv.last()[
+            #     ['close', 'high', 'low', 'volume']
+            # ][0]
+            # tina_lvlm = c+h+l/3 * v
             # print(f' tinal vlm: {tina_lvlm}')
 
-            yield lvlm
+            yield key, output
diff --git a/piker/ui/_fsp.py b/piker/ui/_fsp.py
index 22196f23..937b7e1e 100644
--- a/piker/ui/_fsp.py
+++ b/piker/ui/_fsp.py
@@ -28,7 +28,6 @@ from typing import Optional, AsyncGenerator, Any
 import numpy as np
 from pydantic import create_model
 import tractor
-# from tractor.trionics import gather_contexts
 import pyqtgraph as pg
 import trio
 from trio_typing import TaskStatus
@@ -38,57 +37,25 @@ from .._cacheables import maybe_open_context
 from ..calc import humanize
 from ..data._sharedmem import (
     ShmArray,
-    maybe_open_shm_array,
     try_read,
 )
 from ._chart import (
     ChartPlotWidget,
     LinkedSplits,
 )
-from .. import fsp
 from ._forms import (
     FieldsForm,
     mk_form,
     open_form_input_handling,
 )
+from ..fsp._api import maybe_mk_fsp_shm, Fsp
+from ..fsp import cascade
+from ..fsp._volume import tina_vwap, dolla_vlm
 from ..log import get_logger
 
 log = get_logger(__name__)
 
 
-def maybe_mk_fsp_shm(
-    sym: str,
-    field_name: str,
-    display_name: Optional[str] = None,
-    readonly: bool = True,
-
-) -> (ShmArray, bool):
-    '''
-    Allocate a single row shm array for an symbol-fsp pair if none
-    exists, otherwise load the shm already existing for that token.
-
-    '''
-    uid = tractor.current_actor().uid
-    if not display_name:
-        display_name = field_name
-
-    # TODO: load function here and introspect
-    # return stream type(s)
-
-    # TODO: should `index` be a required internal field?
-    fsp_dtype = np.dtype([('index', int), (field_name, float)])
-
-    key = f'{sym}.fsp.{display_name}.{".".join(uid)}'
-
-    shm, opened = maybe_open_shm_array(
-        key,
-        # TODO: create entry for each time frame
-        dtype=fsp_dtype,
-        readonly=True,
-    )
-    return shm, opened
-
-
 def has_vlm(ohlcv: ShmArray) -> bool:
     # make sure that the instrument supports volume history
     # (sometimes this is not the case for some commodities and
@@ -148,11 +115,11 @@ async def open_fsp_sidepane(
     assert len(conf) == 1  # for now
 
     # add (single) selection widget
-    for display_name, config in conf.items():
-        schema[display_name] = {
+    for name, config in conf.items():
+        schema[name] = {
                 'label': '**fsp**:',
                 'type': 'select',
-                'default_value': [display_name],
+                'default_value': [name],
             }
 
         # add parameters for selection "options"
@@ -180,7 +147,7 @@ async def open_fsp_sidepane(
     # https://pydantic-docs.helpmanual.io/usage/models/#dynamic-model-creation
     FspConfig = create_model(
         'FspConfig',
-        name=display_name,
+        name=name,
         **params,
     )
     sidepane.model = FspConfig()
@@ -228,8 +195,7 @@ async def run_fsp_ui(
     linkedsplits: LinkedSplits,
     shm: ShmArray,
     started: trio.Event,
-    func_name: str,
-    display_name: str,
+    target: Fsp,
     conf: dict[str, dict],
     loglevel: str,
     # profiler: pg.debug.Profiler,
@@ -244,17 +210,18 @@ async def run_fsp_ui(
     config.
 
     '''
-    # profiler(f'started UI task for fsp: {func_name}')
+    name = target.name
+    # profiler(f'started UI task for fsp: {name}')
 
     async with (
         # side UI for parameters/controls
         open_fsp_sidepane(
             linkedsplits,
-            {display_name: conf},
+            {name: conf},
         ) as sidepane,
     ):
         await started.wait()
-        # profiler(f'fsp:{func_name} attached to fsp ctx-stream')
+        # profiler(f'fsp:{name} attached to fsp ctx-stream')
 
         overlay_with = conf.get('overlay', False)
         if overlay_with:
@@ -264,24 +231,24 @@ async def run_fsp_ui(
                 chart = linkedsplits.subplots[overlay_with]
 
             chart.draw_curve(
-                name=display_name,
+                name=name,
                 data=shm.array,
                 overlay=True,
                 color='default_light',
-                array_key=func_name,
+                array_key=name,
                 separate_axes=conf.get('separate_axes', False),
                 **conf.get('chart_kwargs', {})
             )
             # specially store ref to shm for lookup in display loop
-            chart._overlays[display_name] = shm
+            chart._overlays[name] = shm
 
         else:
             # create a new sub-chart widget for this fsp
             chart = linkedsplits.add_plot(
-                name=display_name,
+                name=name,
                 array=shm.array,
 
-                array_key=func_name,
+                array_key=name,
                 sidepane=sidepane,
 
                 # curve by default
@@ -299,15 +266,15 @@ async def run_fsp_ui(
             # should **not** be the same sub-chart widget
             assert chart.name != linkedsplits.chart.name
 
-        array_key = func_name
+        array_key = name
 
-        # profiler(f'fsp:{func_name} chart created')
+        # profiler(f'fsp:{name} chart created')
 
         # first UI update, usually from shm pushed history
         update_fsp_chart(
             chart,
             shm,
-            display_name,
+            name,
             array_key=array_key,
         )
 
@@ -320,7 +287,7 @@ async def run_fsp_ui(
         # logic inside ``.paint()`` for ``self.opts['fillLevel']`` which
         # might be the best solution?
 
-        # graphics = chart.update_from_array(chart.name, array[func_name])
+        # graphics = chart.update_from_array(chart.name, array[name])
         # graphics.curve.setBrush(50, 50, 200, 100)
         # graphics.curve.setFillLevel(50)
 
@@ -410,7 +377,7 @@ class FspAdmin:
         started: trio.Event,
         dst_shm: ShmArray,
         conf: dict,
-        func_name: str,
+        target: Fsp,
         loglevel: str,
 
     ) -> None:
@@ -420,11 +387,12 @@ class FspAdmin:
 
         '''
         brokername, sym = self.linked.symbol.front_feed()
+        ns_path = str(target.ns_path)
         async with (
             portal.open_context(
 
                 # chaining entrypoint
-                fsp.cascade,
+                cascade,
 
                 # data feed key
                 brokername=brokername,
@@ -435,7 +403,7 @@ class FspAdmin:
                 dst_shm_token=dst_shm.token,
 
                 # target
-                func_name=func_name,
+                ns_path=ns_path,
 
                 loglevel=loglevel,
                 zero_on_step=conf.get('zero_on_step', False),
@@ -444,8 +412,13 @@ class FspAdmin:
             ctx.open_stream() as stream,
         ):
             # register output data
-            self._registry[(brokername, sym, func_name)] = (
-                stream, dst_shm, complete)
+            self._registry[
+                (brokername, sym, ns_path)
+            ] = (
+                stream,
+                dst_shm,
+                complete
+            )
 
             started.set()
 
@@ -455,39 +428,38 @@ class FspAdmin:
     async def start_engine_task(
         self,
 
-        display_name: str,
+        target: Fsp,
         conf: dict[str, dict[str, Any]],
 
         worker_name: Optional[str] = None,
-        loglevel: str = 'error',
+        loglevel: str = 'info',
 
     ) -> (ShmArray, trio.Event):
 
-        # unpack FSP details from config dict
-        func_name = conf['func_name']
+        fqsn = self.linked.symbol.front_feed()
 
         # allocate an output shm array
         dst_shm, opened = maybe_mk_fsp_shm(
-            self.linked.symbol.front_feed(),
-            field_name=func_name,
-            display_name=display_name,
+            fqsn,
+            target=target,
             readonly=True,
         )
-        if not opened:
-            raise RuntimeError(f'Already started FSP {func_name}')
+        # if not opened:
+        #     raise RuntimeError(
+        #         f'Already started FSP `{fqsn}:{func_name}`'
+        #     )
 
         portal = self.cluster.get(worker_name) or self.rr_next_portal()
         complete = trio.Event()
         started = trio.Event()
         self.tn.start_soon(
             self.open_chain,
-
             portal,
             complete,
             started,
             dst_shm,
             conf,
-            func_name,
+            target,
             loglevel,
         )
 
@@ -495,16 +467,16 @@ class FspAdmin:
 
     async def open_fsp_chart(
         self,
-        display_name: str,
+
+        target: Fsp,
+
         conf: dict,  # yeah probably dumb..
         loglevel: str = 'error',
 
     ) -> (trio.Event, ChartPlotWidget):
 
-        func_name = conf['func_name']
-
         shm, started = await self.start_engine_task(
-            display_name,
+            target,
             conf,
             loglevel,
         )
@@ -517,8 +489,7 @@ class FspAdmin:
                 self.linked,
                 shm,
                 started,
-                func_name,
-                display_name,
+                target,
 
                 conf=conf,
                 loglevel=loglevel,
@@ -621,14 +592,22 @@ async def open_vlm_displays(
         )
 
         # force 0 to always be in view
-        def maxmin(name) -> tuple[float, float]:
-            mxmn = chart.maxmin(name=name)
-            if mxmn:
-                return 0, mxmn[1]
+        def maxmin(
+            names: list[str],
 
-            return 0, 0
+        ) -> tuple[float, float]:
+            mx = 0
+            for name in names:
+                mxmn = chart.maxmin(name=name)
+                if mxmn:
+                    mx = max(mxmn[1], mx)
 
-        chart.view._maxmin = partial(maxmin, name='volume')
+            # if mx:
+            #     return 0, mxmn[1]
+
+            return 0, mx
+
+        chart.view._maxmin = partial(maxmin, names=['volume'])
 
         # TODO: fix the x-axis label issue where if you put
         # the axis on the left it's totally not lined up...
@@ -671,8 +650,8 @@ async def open_vlm_displays(
 
             # spawn and overlay $ vlm on the same subchart
             shm, started = await admin.start_engine_task(
-                'dolla_vlm',
-                # linked.symbol.front_feed(),  # data-feed symbol key
+                dolla_vlm,
+
                 {  # fsp engine conf
                     'func_name': 'dolla_vlm',
                     'zero_on_step': True,
@@ -704,18 +683,17 @@ async def open_vlm_displays(
             )
 
             # add custom auto range handler
-            pi.vb._maxmin = partial(maxmin, name='dolla_vlm')
+            pi.vb._maxmin = partial(
+                maxmin,
+                # keep both regular and dark vlm in view
+                names=['dolla_vlm', 'dark_vlm'],
+            )
 
             curve, _ = chart.draw_curve(
-
                 name='dolla_vlm',
                 data=shm.array,
-
                 array_key='dolla_vlm',
                 overlay=pi,
-                # color='bracket',
-                # TODO: this color or dark volume
-                # color='charcoal',
                 step_mode=True,
                 # **conf.get('chart_kwargs', {})
             )
@@ -732,6 +710,17 @@ async def open_vlm_displays(
             # ``.draw_curve()``.
             chart._overlays['dolla_vlm'] = shm
 
+            curve, _ = chart.draw_curve(
+
+                name='dark_vlm',
+                data=shm.array,
+                array_key='dark_vlm',
+                overlay=pi,
+                color='charcoal',  # darker theme hue
+                step_mode=True,
+                # **conf.get('chart_kwargs', {})
+            )
+            chart._overlays['dark_vlm'] = shm
             # XXX: old dict-style config before it was moved into the
             # helper task
             #     'dolla_vlm': {
@@ -759,15 +748,14 @@ async def open_vlm_displays(
                     axis.size_to_values()
 
         # built-in vlm fsps
-        for display_name, conf in {
-            'vwap': {
-                'func_name': 'vwap',
+        for target, conf in {
+            tina_vwap: {
                 'overlay': 'ohlc',  # overlays with OHLCV (main) chart
                 'anchor': 'session',
             },
         }.items():
             started = await admin.open_fsp_chart(
-                display_name,
+                target,
                 conf,
             )
 
@@ -815,27 +803,26 @@ async def start_fsp_displays(
         disabled=False
     )
 
-    # async with gather_contexts((
     async with (
 
         # NOTE: this admin internally opens an actor cluster
         open_fsp_admin(linked, ohlcv) as admin,
     ):
         statuses = []
-        for display_name, conf in fsp_conf.items():
+        for target, conf in fsp_conf.items():
             started = await admin.open_fsp_chart(
-                display_name,
+                target,
                 conf,
             )
             done = linked.window().status_bar.open_status(
-                f'loading fsp, {display_name}..',
+                f'loading fsp, {target}..',
                 group_key=group_status_key,
             )
             statuses.append((started, done))
 
         for fsp_loaded, status_cb in statuses:
             await fsp_loaded.wait()
-            profiler(f'attached to fsp portal: {display_name}')
+            profiler(f'attached to fsp portal: {target}')
             status_cb()
 
     # blocks on nursery until all fsp actors complete
diff --git a/requirements.txt b/requirements.txt
index ca910e01..680360b0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 # we require a pinned dev branch to get some edge features that
 # are often untested in tractor's CI and/or being tested by us
 # first before committing as core features in tractor's base.
--e git+git://github.com/goodboy/tractor.git@piker_pin#egg=tractor
+-e git+git://github.com/goodboy/tractor.git@master#egg=tractor
 
 # `pyqtgraph` peeps keep breaking, fixing, improving so might as well
 # pin this to a dev branch that we have more control over especially