diff --git a/piker/fsp/_engine.py b/piker/fsp/_engine.py
index 66fb4961..e678ada0 100644
--- a/piker/fsp/_engine.py
+++ b/piker/fsp/_engine.py
@@ -37,6 +37,7 @@ from .. import data
 from ..data import attach_shm_array
 from ..data.feed import Feed
 from ..data._sharedmem import ShmArray
+from ..data._source import Symbol
 from ._api import (
     Fsp,
     _load_builtins,
@@ -76,7 +77,7 @@ async def filter_quotes_by_sym(
 async def fsp_compute(
 
     ctx: tractor.Context,
-    symbol: str,
+    symbol: Symbol,
     feed: Feed,
     quote_stream: trio.abc.ReceiveChannel,
 
@@ -95,13 +96,14 @@ async def fsp_compute(
         disabled=True
     )
 
+    fqsn = symbol.front_fqsn()
     out_stream = func(
 
         # TODO: do we even need this if we do the feed api right?
         # shouldn't a local stream do this before we get a handle
         # to the async iterable? it's that or we do some kinda
         # async itertools style?
-        filter_quotes_by_sym(symbol, quote_stream),
+        filter_quotes_by_sym(fqsn, quote_stream),
 
         # XXX: currently the ``ohlcv`` arg
         feed.shm,
@@ -241,8 +243,7 @@ async def cascade(
     ctx: tractor.Context,
 
     # data feed key
-    brokername: str,
-    symbol: str,
+    fqsn: str,
 
     src_shm_token: dict,
     dst_shm_token: tuple[str, np.dtype],
@@ -298,8 +299,7 @@ async def cascade(
 
     # open a data feed stream with requested broker
     async with data.feed.maybe_open_feed(
-        brokername,
-        [symbol],
+        [fqsn],
 
         # TODO throttle tick outputs from *this* daemon since
         # it'll emit tons of ticks due to the throttle only
@@ -308,6 +308,7 @@ async def cascade(
         # tick_throttle=60,
 
     ) as (feed, quote_stream):
+        symbol = feed.symbols[fqsn]
 
         profiler(f'{func}: feed up')