diff --git a/piker/data/tsp.py b/piker/data/tsp.py
index 3f293d83..9c327725 100644
--- a/piker/data/tsp.py
+++ b/piker/data/tsp.py
@@ -28,6 +28,7 @@ from math import (
     ceil,
     floor,
 )
+import time
 from typing import Literal
 
 import numpy as np
@@ -408,3 +409,51 @@ def dedupe(src_df: pl.DataFrame) -> tuple[
             deduped,
             was_deduped,
         )
+
+
+# NOTE: thanks to this SO answer for the below conversion routines
+# to go from numpy struct-arrays to polars dataframes and back:
+# https://stackoverflow.com/a/72054819
+def np2pl(array: np.ndarray) -> pl.DataFrame:
+    start = time.time()
+
+    # XXX: thanks to this SO answer for this conversion tip:
+    # https://stackoverflow.com/a/72054819
+    df = pl.DataFrame({
+        field_name: array[field_name]
+        for field_name in array.dtype.fields
+    })
+    delay: float = round(
+        time.time() - start,
+        ndigits=6,
+    )
+    log.info(
+        f'numpy -> polars conversion took {delay} secs\n'
+        f'polars df: {df}'
+    )
+    return df
+    # return pl.DataFrame({
+    #     field_name: array[field_name]
+    #     for field_name in array.dtype.fields
+    # })
+
+
+def pl2np(
+    df: pl.DataFrame,
+    dtype: np.dtype,
+
+) -> np.ndarray:
+
+    # Create numpy struct array of the correct size and dtype
+    # and loop through df columns to fill in array fields.
+    array = np.empty(
+        df.height,
+        dtype,
+    )
+    for field, col in zip(
+        dtype.fields,
+        df.columns,
+    ):
+        array[field] = df.get_column(col).to_numpy()
+
+    return array
diff --git a/piker/storage/cli.py b/piker/storage/cli.py
index 34d46046..54e7570e 100644
--- a/piker/storage/cli.py
+++ b/piker/storage/cli.py
@@ -260,22 +260,8 @@ def iter_dfs_from_shms(fqme: str) -> Generator[
         assert not opened
         ohlcv = shm.array
 
-        start = time.time()
-
-        # XXX: thanks to this SO answer for this conversion tip:
-        # https://stackoverflow.com/a/72054819
-        df = pl.DataFrame({
-            field_name: ohlcv[field_name]
-            for field_name in ohlcv.dtype.fields
-        })
-        delay: float = round(
-            time.time() - start,
-            ndigits=6,
-        )
-        log.info(
-            f'numpy -> polars conversion took {delay} secs\n'
-            f'polars df: {df}'
-        )
+        from .nativedb import np2pl
+        df: pl.DataFrame = np2pl(ohlcv)
 
         yield (
             shmfile,
@@ -316,7 +302,6 @@ def ldshm(
                         f'Something is wrong with time period for {shm}:\n{times}'
                     )
 
-
                 # over-write back to shm?
                 df: pl.DataFrame  # with dts
                 deduped: pl.DataFrame  # deduplicated dts
diff --git a/piker/storage/nativedb.py b/piker/storage/nativedb.py
index 0b15d4d7..04c4935b 100644
--- a/piker/storage/nativedb.py
+++ b/piker/storage/nativedb.py
@@ -65,8 +65,11 @@ from pendulum import (
 )
 
 from piker import config
-from piker.data import def_iohlcv_fields
-from piker.data import ShmArray
+from piker.data import (
+    def_iohlcv_fields,
+    ShmArray,
+    tsp,
+)
 from piker.log import get_logger
 from . import TimeseriesNotFound
 
@@ -74,37 +77,6 @@ from . import TimeseriesNotFound
 log = get_logger('storage.nativedb')
 
 
-# NOTE: thanks to this SO answer for the below conversion routines
-# to go from numpy struct-arrays to polars dataframes and back:
-# https://stackoverflow.com/a/72054819
-def np2pl(array: np.ndarray) -> pl.DataFrame:
-    return pl.DataFrame({
-        field_name: array[field_name]
-        for field_name in array.dtype.fields
-    })
-
-
-def pl2np(
-    df: pl.DataFrame,
-    dtype: np.dtype,
-
-) -> np.ndarray:
-
-    # Create numpy struct array of the correct size and dtype
-    # and loop through df columns to fill in array fields.
-    array = np.empty(
-        df.height,
-        dtype,
-    )
-    for field, col in zip(
-        dtype.fields,
-        df.columns,
-    ):
-        array[field] = df.get_column(col).to_numpy()
-
-    return array
-
-
 def detect_period(shm: ShmArray) -> float:
     '''
     Attempt to detect the series time step sampling period
@@ -290,7 +262,7 @@ class NativeStorageClient:
 
         # TODO: filter by end and limit inputs
         # times: pl.Series = df['time']
-        array: np.ndarray = pl2np(
+        array: np.ndarray = tsp.pl2np(
             df,
             dtype=np.dtype(def_iohlcv_fields),
         )
@@ -326,7 +298,7 @@ class NativeStorageClient:
             datadir=self._datadir,
         )
         if isinstance(ohlcv, np.ndarray):
-            df: pl.DataFrame = np2pl(ohlcv)
+            df: pl.DataFrame = tsp.np2pl(ohlcv)
         else:
             df = ohlcv