From f88dc2dcafcde75601d30d124c8f661b5622314b Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sat, 18 Apr 2026 14:07:00 -0600
Subject: [PATCH 01/20] First draft

---
 src/spikeinterface/core/baserecording.py      |   4 +-
 .../core/baserecordingsnippets.py             | 121 ++++++------------
 src/spikeinterface/core/basesnippets.py       |   2 +-
 .../core/channelsaggregationrecording.py      |  15 ++-
 src/spikeinterface/core/channelslice.py       |  64 +++++++--
 src/spikeinterface/core/zarrextractors.py     |   2 +-
 .../extractors/neoextractors/biocam.py        |   6 +-
 .../extractors/tests/test_iblextractors.py    |   1 -
 .../tests/test_interpolate_bad_channels.py    |  20 ++-
 .../preprocessing/zero_channel_pad.py         |   2 +-
 .../motion/motion_interpolation.py            |  16 ++-
 11 files changed, 137 insertions(+), 116 deletions(-)

diff --git a/src/spikeinterface/core/baserecording.py b/src/spikeinterface/core/baserecording.py
index f23b524271..2c47693c32 100644
--- a/src/spikeinterface/core/baserecording.py
+++ b/src/spikeinterface/core/baserecording.py
@@ -637,7 +637,7 @@ def _save(self, format="binary", verbose: bool = False, **save_kwargs):
         else:
             raise ValueError(f"format {format} not supported")
 
-        if self.get_property("contact_vector") is not None:
+        if self.has_probe():
             probegroup = self.get_probegroup()
             cached.set_probegroup(probegroup)
 
@@ -665,7 +665,7 @@ def _extra_metadata_from_folder(self, folder):
 
     def _extra_metadata_to_folder(self, folder):
         # save probe
-        if self.get_property("contact_vector") is not None:
+        if self.has_probe():
             probegroup = self.get_probegroup()
             write_probeinterface(folder / "probe.json", probegroup)
 
diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 58e91ec35c..0b99dfe435 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -19,6 +19,7 @@ def __init__(self, sampling_frequency: float, channel_ids: list[str, int], dtype
         BaseExtractor.__init__(self, channel_ids)
         self._sampling_frequency = float(sampling_frequency)
         self._dtype = np.dtype(dtype)
+        self._probegroup = None
 
     @property
     def channel_ids(self):
@@ -51,7 +52,7 @@ def has_scaleable_traces(self) -> bool:
             return True
 
     def has_probe(self) -> bool:
-        return "contact_vector" in self.get_property_keys()
+        return self._probegroup is not None
 
     def has_channel_location(self) -> bool:
         return self.has_probe() or "location" in self.get_property_keys()
@@ -145,24 +146,18 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
             probe.device_channel_indices is not None for probe in probegroup.probes
         ), "Probe must have device_channel_indices"
 
-        # this is a vector with complex fileds (dataframe like) that handle all contact attr
-        probe_as_numpy_array = probegroup.to_numpy(complete=True)
-
-        # keep only connected contact ( != -1)
-        keep = probe_as_numpy_array["device_channel_indices"] >= 0
-        if np.any(~keep):
+        # identify connected contacts; device_channel_indices values are preserved as provenance
+        global_device_channel_indices = probegroup.get_global_device_channel_indices()["device_channel_indices"]
+        connected_mask = global_device_channel_indices >= 0
+        if np.any(~connected_mask):
             warn("The given probes have unconnected contacts: they are removed")
 
-        probe_as_numpy_array = probe_as_numpy_array[keep]
-
-        device_channel_indices = probe_as_numpy_array["device_channel_indices"]
-        order = np.argsort(device_channel_indices)
-        device_channel_indices = device_channel_indices[order]
+        device_channel_indices = np.sort(global_device_channel_indices[connected_mask])
 
-        # check TODO: Where did this came from?
+        # validate indices fit the recording
         number_of_device_channel_indices = np.max(list(device_channel_indices) + [0])
         if number_of_device_channel_indices >= self.get_num_channels():
-            error_msg = (
+            raise ValueError(
                 f"The given Probe either has 'device_channel_indices' that does not match channel count \n"
                 f"{len(device_channel_indices)} vs {self.get_num_channels()} \n"
                 f"or it's max index {number_of_device_channel_indices} is the same as the number of channels {self.get_num_channels()} \n"
@@ -170,11 +165,13 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
                 f"device_channel_indices are the following: {device_channel_indices} \n"
                 f"recording channels are the following: {self.get_channel_ids()} \n"
             )
-            raise ValueError(error_msg)
 
         new_channel_ids = self.get_channel_ids()[device_channel_indices]
-        probe_as_numpy_array = probe_as_numpy_array[order]
-        probe_as_numpy_array["device_channel_indices"] = np.arange(probe_as_numpy_array.size, dtype="int64")
+
+        # drop only the unconnected contacts from the stored probegroup; preserve device_channel_indices values
+        probegroup = probegroup.get_slice(connected_mask)
+        probegroup._build_contact_vector()
+        contact_vector = probegroup.contact_vector
 
         # create recording : channel slice or clone or self
         if in_place:
@@ -187,25 +184,18 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
             else:
                 sub_recording = self.select_channels(new_channel_ids)
 
-        # create a vector that handle all contacts in property
-        sub_recording.set_property("contact_vector", probe_as_numpy_array, ids=None)
+        sub_recording._probegroup = probegroup
 
-        # planar_contour is saved in annotations
-        for probe_index, probe in enumerate(probegroup.probes):
-            contour = probe.probe_planar_contour
-            if contour is not None:
-                sub_recording.set_annotation(f"probe_{probe_index}_planar_contour", contour, overwrite=True)
-
-        # duplicate positions to "locations" property
+        # duplicate positions to "location" property so SpikeInterface-level readers keep working
         ndim = probegroup.ndim
-        locations = np.zeros((probe_as_numpy_array.size, ndim), dtype="float64")
+        locations = np.zeros((contact_vector.size, ndim), dtype="float64")
         for i, dim in enumerate(["x", "y", "z"][:ndim]):
-            locations[:, i] = probe_as_numpy_array[dim]
+            locations[:, i] = contact_vector[dim]
         sub_recording.set_property("location", locations, ids=None)
 
-        # handle groups
-        has_shank_id = "shank_ids" in probe_as_numpy_array.dtype.fields
-        has_contact_side = "contact_sides" in probe_as_numpy_array.dtype.fields
+        # derive groups from contact_vector
+        has_shank_id = "shank_ids" in contact_vector.dtype.fields
+        has_contact_side = "contact_sides" in contact_vector.dtype.fields
         if group_mode == "auto":
             group_keys = ["probe_index"]
             if has_shank_id:
@@ -223,21 +213,15 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
                 group_keys = ["probe_index", "shank_ids", "contact_sides"]
             else:
                 group_keys = ["probe_index", "contact_sides"]
-        groups = np.zeros(probe_as_numpy_array.size, dtype="int64")
-        unique_keys = np.unique(probe_as_numpy_array[group_keys])
+        groups = np.zeros(contact_vector.size, dtype="int64")
+        unique_keys = np.unique(contact_vector[group_keys])
         for group, a in enumerate(unique_keys):
-            mask = np.ones(probe_as_numpy_array.size, dtype=bool)
+            mask = np.ones(contact_vector.size, dtype=bool)
             for k in group_keys:
-                mask &= probe_as_numpy_array[k] == a[k]
+                mask &= contact_vector[k] == a[k]
             groups[mask] = group
         sub_recording.set_property("group", groups, ids=None)
 
-        # add probe annotations to recording
-        probes_info = []
-        for probe in probegroup.probes:
-            probes_info.append(probe.annotations)
-        sub_recording.annotate(probes_info=probes_info)
-
         return sub_recording
 
     def get_probe(self):
@@ -250,30 +234,9 @@ def get_probes(self):
         return probegroup.probes
 
     def get_probegroup(self):
-        arr = self.get_property("contact_vector")
-        if arr is None:
-            positions = self.get_property("location")
-            if positions is None:
-                raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
-            else:
-                warn("There is no Probe attached to this recording. Creating a dummy one with contact positions")
-                probe = self.create_dummy_probe_from_locations(positions)
-                #  probe.create_auto_shape()
-                probegroup = ProbeGroup()
-                probegroup.add_probe(probe)
-        else:
-            probegroup = ProbeGroup.from_numpy(arr)
-
-            if "probes_info" in self.get_annotation_keys():
-                probes_info = self.get_annotation("probes_info")
-                for probe, probe_info in zip(probegroup.probes, probes_info):
-                    probe.annotations = probe_info
-
-            for probe_index, probe in enumerate(probegroup.probes):
-                contour = self.get_annotation(f"probe_{probe_index}_planar_contour")
-                if contour is not None:
-                    probe.set_planar_contour(contour)
-        return probegroup
+        if self._probegroup is None:
+            raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
+        return self._probegroup
 
     def _extra_metadata_from_folder(self, folder):
         # load probe
@@ -284,7 +247,7 @@ def _extra_metadata_from_folder(self, folder):
 
     def _extra_metadata_to_folder(self, folder):
         # save probe
-        if self.get_property("contact_vector") is not None:
+        if self.has_probe():
             probegroup = self.get_probegroup()
             write_probeinterface(folder / "probe.json", probegroup)
 
@@ -341,7 +304,7 @@ def set_dummy_probe_from_locations(self, locations, shape="circle", shape_params
         self.set_probe(probe, in_place=True)
 
     def set_channel_locations(self, locations, channel_ids=None):
-        if self.get_property("contact_vector") is not None:
+        if self.has_probe():
             raise ValueError("set_channel_locations(..) destroys the probe description, prefer _set_probes(..)")
         self.set_property("location", locations, ids=channel_ids)
 
@@ -349,21 +312,15 @@ def get_channel_locations(self, channel_ids=None, axes: str = "xy") -> np.ndarra
         if channel_ids is None:
             channel_ids = self.get_channel_ids()
         channel_indices = self.ids_to_indices(channel_ids)
-        contact_vector = self.get_property("contact_vector")
-        if contact_vector is not None:
-            # here we bypass the probe reconstruction so this works both for probe and probegroup
-            ndim = len(axes)
-            all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
-            for i, dim in enumerate(axes):
-                all_positions[:, i] = contact_vector[dim]
-            positions = all_positions[channel_indices]
-            return positions
-        else:
-            locations = self.get_property("location")
-            if locations is None:
-                raise Exception("There are no channel locations")
-            locations = np.asarray(locations)[channel_indices]
-            return select_axes(locations, axes)
+        if not self.has_probe():
+            raise ValueError("get_channel_locations(..) needs a probe to be attached to the recording")
+        self._probegroup._build_contact_vector()
+        contact_vector = self._probegroup.contact_vector
+        ndim = len(axes)
+        all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
+        for i, dim in enumerate(axes):
+            all_positions[:, i] = contact_vector[dim]
+        return all_positions[channel_indices]
 
     def has_3d_locations(self) -> bool:
         return self.get_property("location").shape[1] == 3
diff --git a/src/spikeinterface/core/basesnippets.py b/src/spikeinterface/core/basesnippets.py
index b56a093ccc..fa47365200 100644
--- a/src/spikeinterface/core/basesnippets.py
+++ b/src/spikeinterface/core/basesnippets.py
@@ -259,7 +259,7 @@ def _save(self, format="npy", **save_kwargs):
         else:
             raise ValueError(f"format {format} not supported")
 
-        if self.get_property("contact_vector") is not None:
+        if self.has_probe():
             probegroup = self.get_probegroup()
             cached.set_probegroup(probegroup)
 
diff --git a/src/spikeinterface/core/channelsaggregationrecording.py b/src/spikeinterface/core/channelsaggregationrecording.py
index 697aab875e..59501d0ba1 100644
--- a/src/spikeinterface/core/channelsaggregationrecording.py
+++ b/src/spikeinterface/core/channelsaggregationrecording.py
@@ -2,6 +2,8 @@
 
 import numpy as np
 
+from probeinterface import ProbeGroup
+
 from .baserecording import BaseRecording, BaseRecordingSegment
 
 
@@ -90,11 +92,18 @@ def __init__(self, recording_list_or_dict=None, renamed_channel_ids=None, record
                             break
 
         for prop_name, prop_values in property_dict.items():
-            if prop_name == "contact_vector":
-                # remap device channel indices correctly
-                prop_values["device_channel_indices"] = np.arange(self.get_num_channels())
             self.set_property(key=prop_name, values=prop_values)
 
+        # aggregate probegroups across the inputs and reset wiring to the new channel order
+        if all(rec.has_probe() for rec in recording_list):
+            aggregated_probegroup = ProbeGroup()
+            for rec in recording_list:
+                for probe in rec.get_probegroup().probes:
+                    aggregated_probegroup.add_probe(probe.copy())
+            aggregated_probegroup.set_global_device_channel_indices(np.arange(self.get_num_channels(), dtype="int64"))
+            aggregated_probegroup._build_contact_vector()
+            self._probegroup = aggregated_probegroup
+
         # if locations are present, check that they are all different!
         if "location" in self.get_property_keys():
             location_tuple = [tuple(loc) for loc in self.get_property("location")]
diff --git a/src/spikeinterface/core/channelslice.py b/src/spikeinterface/core/channelslice.py
index de693d5c26..82e842dabc 100644
--- a/src/spikeinterface/core/channelslice.py
+++ b/src/spikeinterface/core/channelslice.py
@@ -61,11 +61,33 @@ def __init__(self, parent_recording, channel_ids=None, renamed_channel_ids=None)
         parent_recording.copy_metadata(self, only_main=False, ids=self._channel_ids)
         self._parent = parent_recording
 
-        # change the wiring of the probe
-        contact_vector = self.get_property("contact_vector")
-        if contact_vector is not None:
-            contact_vector["device_channel_indices"] = np.arange(len(channel_ids), dtype="int64")
-            self.set_property("contact_vector", contact_vector)
+        # filter the probegroup to contacts wired to the retained channels
+        if parent_recording.has_probe():
+            parent_probegroup = parent_recording.get_probegroup()
+            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
+            child_dci_values = parent_dci_sorted[self._parent_channel_indices]
+            are_channels_reordered: bool = not np.all(np.diff(child_dci_values) >= 0)
+            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
+            keep_mask = np.isin(probe_dci, child_dci_values)
+            sliced_probegroup = parent_probegroup.get_slice(keep_mask)
+
+            if not are_channels_reordered:
+                # simple case: the child's channels are already in ascending device_channel_indices order
+                # so _build_contact_vector on the filtered probegroup will produce rows in the child's
+                # channel order. Nothing else to do.
+                pass
+            else:
+                # reorder case: the user picked channels in an order that does not match sort-by-dci.
+                # We have to rewrite device_channel_indices on the child's copy so that the sort done
+                # by _build_contact_vector aligns with the child's channel order.
+                new_dci_by_old = {int(d): new for new, d in enumerate(child_dci_values.tolist())}
+                sliced_dci = sliced_probegroup.get_global_device_channel_indices()["device_channel_indices"]
+                sliced_probegroup.set_global_device_channel_indices(
+                    np.array([new_dci_by_old[int(d)] for d in sliced_dci], dtype="int64")
+                )
+
+            sliced_probegroup._build_contact_vector()
+            self._probegroup = sliced_probegroup
 
         # update dump dict
         self._kwargs = {
@@ -151,11 +173,33 @@ def __init__(self, parent_snippets, channel_ids=None, renamed_channel_ids=None):
         # copy annotation and properties
         parent_snippets.copy_metadata(self, only_main=False, ids=self._channel_ids)
 
-        # change the wiring of the probe
-        contact_vector = self.get_property("contact_vector")
-        if contact_vector is not None:
-            contact_vector["device_channel_indices"] = np.arange(len(channel_ids), dtype="int64")
-            self.set_property("contact_vector", contact_vector)
+        # filter the probegroup to contacts wired to the retained channels
+        if parent_snippets.has_probe():
+            parent_probegroup = parent_snippets.get_probegroup()
+            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
+            child_dci_values = parent_dci_sorted[self._parent_channel_indices]
+            are_channels_reordered: bool = not np.all(np.diff(child_dci_values) >= 0)
+            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
+            keep_mask = np.isin(probe_dci, child_dci_values)
+            sliced_probegroup = parent_probegroup.get_slice(keep_mask)
+
+            if not are_channels_reordered:
+                # simple case: the child's channels are already in ascending device_channel_indices order
+                # so _build_contact_vector on the filtered probegroup will produce rows in the child's
+                # channel order. Nothing else to do.
+                pass
+            else:
+                # reorder case: the user picked channels in an order that does not match sort-by-dci.
+                # We have to rewrite device_channel_indices on the child's copy so that the sort done
+                # by _build_contact_vector aligns with the child's channel order.
+                new_dci_by_old = {int(d): new for new, d in enumerate(child_dci_values.tolist())}
+                sliced_dci = sliced_probegroup.get_global_device_channel_indices()["device_channel_indices"]
+                sliced_probegroup.set_global_device_channel_indices(
+                    np.array([new_dci_by_old[int(d)] for d in sliced_dci], dtype="int64")
+                )
+
+            sliced_probegroup._build_contact_vector()
+            self._probegroup = sliced_probegroup
 
         # update dump dict
         self._kwargs = {
diff --git a/src/spikeinterface/core/zarrextractors.py b/src/spikeinterface/core/zarrextractors.py
index 1ef5d76e5a..941a99b877 100644
--- a/src/spikeinterface/core/zarrextractors.py
+++ b/src/spikeinterface/core/zarrextractors.py
@@ -503,7 +503,7 @@ def add_recording_to_zarr_group(
     )
 
     # save probe
-    if recording.get_property("contact_vector") is not None:
+    if recording.has_probe():
         probegroup = recording.get_probegroup()
         zarr_group.attrs["probe"] = check_json(probegroup.to_dict(array_as_list=True))
 
diff --git a/src/spikeinterface/extractors/neoextractors/biocam.py b/src/spikeinterface/extractors/neoextractors/biocam.py
index 8d1fac0c72..c2ceb66523 100644
--- a/src/spikeinterface/extractors/neoextractors/biocam.py
+++ b/src/spikeinterface/extractors/neoextractors/biocam.py
@@ -1,5 +1,6 @@
 from pathlib import Path
 
+import numpy as np
 import probeinterface
 
 from spikeinterface.core.core_tools import define_function_from_class
@@ -71,8 +72,9 @@ def __init__(
             probe_kwargs["electrode_width"] = electrode_width
         probe = probeinterface.read_3brain(file_path, **probe_kwargs)
         self.set_probe(probe, in_place=True)
-        self.set_property("row", self.get_property("contact_vector")["row"])
-        self.set_property("col", self.get_property("contact_vector")["col"])
+        probe = self.get_probegroup().probes[0]
+        self.set_property("row", np.asarray(probe.contact_annotations["row"]))
+        self.set_property("col", np.asarray(probe.contact_annotations["col"]))
 
         self._kwargs.update(
             {
diff --git a/src/spikeinterface/extractors/tests/test_iblextractors.py b/src/spikeinterface/extractors/tests/test_iblextractors.py
index 5306de2441..ff21c7a3c7 100644
--- a/src/spikeinterface/extractors/tests/test_iblextractors.py
+++ b/src/spikeinterface/extractors/tests/test_iblextractors.py
@@ -84,7 +84,6 @@ def test_property_keys(self):
         expected_property_keys = [
             "gain_to_uV",
             "offset_to_uV",
-            "contact_vector",
             "location",
             "group",
             "shank",
diff --git a/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py b/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
index a571894374..6b40548bc4 100644
--- a/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
+++ b/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
@@ -126,8 +126,10 @@ def test_compare_input_argument_ranges_against_ibl(shanks, p, sigma_um, num_chan
     # distribute default probe locations across 4 shanks if set
     rng = np.random.default_rng(seed=None)
     x = rng.choice(shanks, num_channels)
-    for idx, __ in enumerate(recording._properties["contact_vector"]):
-        recording._properties["contact_vector"][idx][1] = x[idx]
+    probe = recording.get_probegroup().probes[0]
+    probe._contact_positions[:, 0] = x
+    recording._probegroup._build_contact_vector()
+    recording.set_property("location", recording.get_channel_locations())
 
     # generate random bad channel locations
     bad_channel_indexes = rng.choice(num_channels, rng.integers(1, int(num_channels / 5)), replace=False)
@@ -170,9 +172,12 @@ def test_output_values():
         [5, 5, 5, 7, 3],
     ]  # all others equal distance away.
     # Overwrite the probe information with the new locations
+    probe = recording.get_probegroup().probes[0]
     for idx, (x, y) in enumerate(zip(*new_probe_locs)):
-        recording._properties["contact_vector"][idx][1] = x
-        recording._properties["contact_vector"][idx][2] = y
+        probe._contact_positions[idx, 0] = x
+        probe._contact_positions[idx, 1] = y
+    recording._probegroup._build_contact_vector()
+    recording.set_property("location", recording.get_channel_locations())
 
     # Run interpolation in SI and check the interpolated channel
     # 0 is a linear combination of other channels
@@ -186,8 +191,11 @@ def test_output_values():
     # Shift the last channel position so that it is 4 units, rather than 2
     # away. Setting sigma_um = p = 1 allows easy calculation of the expected
     # weights.
-    recording._properties["contact_vector"][-1][1] = 5
-    recording._properties["contact_vector"][-1][2] = 9
+    probe = recording.get_probegroup().probes[0]
+    probe._contact_positions[-1, 0] = 5
+    probe._contact_positions[-1, 1] = 9
+    recording._probegroup._build_contact_vector()
+    recording.set_property("location", recording.get_channel_locations())
     expected_weights = np.r_[np.tile(np.exp(-2), 3), np.exp(-4)]
     expected_weights /= np.sum(expected_weights)
 
diff --git a/src/spikeinterface/preprocessing/zero_channel_pad.py b/src/spikeinterface/preprocessing/zero_channel_pad.py
index 45d4809cd8..a84d3bbf64 100644
--- a/src/spikeinterface/preprocessing/zero_channel_pad.py
+++ b/src/spikeinterface/preprocessing/zero_channel_pad.py
@@ -157,7 +157,7 @@ def __init__(self, recording: BaseRecording, num_channels: int, channel_mapping:
                 "The new mapping cannot exceed total number of channels " "in the zero-chanenl-padded recording."
             )
         else:
-            if "locations" in recording.get_property_keys() or "contact_vector" in recording.get_property_keys():
+            if recording.has_probe() or "location" in recording.get_property_keys():
                 self.channel_mapping = np.argsort(recording.get_channel_locations()[:, 1])
             else:
                 self.channel_mapping = np.arange(recording.get_num_channels())
diff --git a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
index 7c4c4b166e..027f2bbb66 100644
--- a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
+++ b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
@@ -403,13 +403,15 @@ def __init__(
         dtype_ = fix_dtype(recording, dtype)
         BasePreprocessor.__init__(self, recording, channel_ids=channel_ids, dtype=dtype_)
 
-        if border_mode == "remove_channels":
-            # change the wiring of the probe
-            # TODO this is also done in ChannelSliceRecording, this should be done in a common place
-            contact_vector = self.get_property("contact_vector")
-            if contact_vector is not None:
-                contact_vector["device_channel_indices"] = np.arange(len(channel_ids), dtype="int64")
-                self.set_property("contact_vector", contact_vector)
+        if border_mode == "remove_channels" and recording.has_probe():
+            # filter the probegroup to contacts wired to the retained channels; order is preserved (channel_inds is ascending)
+            parent_probegroup = recording.get_probegroup()
+            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
+            child_dci_values = parent_dci_sorted[channel_inds]
+            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
+            sliced_probegroup = parent_probegroup.get_slice(np.isin(probe_dci, child_dci_values))
+            sliced_probegroup._build_contact_vector()
+            self._probegroup = sliced_probegroup
 
         # handle manual interpolation_time_bin_centers_s
         # the case where interpolation_time_bin_size_s is set is handled per-segment below

From cd52ef333496f638e0fd7115c50625bec4ef403c Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sat, 18 Apr 2026 14:10:47 -0600
Subject: [PATCH 02/20] second iteration

---
 .../core/baserecordingsnippets.py             | 13 +++--
 src/spikeinterface/core/channelslice.py       | 52 +++----------------
 .../motion/motion_interpolation.py            |  8 ++-
 3 files changed, 18 insertions(+), 55 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 0b99dfe435..b8de26df3d 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -146,13 +146,17 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
             probe.device_channel_indices is not None for probe in probegroup.probes
         ), "Probe must have device_channel_indices"
 
-        # identify connected contacts; device_channel_indices values are preserved as provenance
+        # identify connected contacts and their channel-order
         global_device_channel_indices = probegroup.get_global_device_channel_indices()["device_channel_indices"]
         connected_mask = global_device_channel_indices >= 0
         if np.any(~connected_mask):
             warn("The given probes have unconnected contacts: they are removed")
 
-        device_channel_indices = np.sort(global_device_channel_indices[connected_mask])
+        connected_contact_indices = np.where(connected_mask)[0]
+        connected_channel_values = global_device_channel_indices[connected_mask]
+        order = np.argsort(connected_channel_values)
+        sorted_contact_indices = connected_contact_indices[order]
+        device_channel_indices = connected_channel_values[order]
 
         # validate indices fit the recording
         number_of_device_channel_indices = np.max(list(device_channel_indices) + [0])
@@ -168,8 +172,9 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
 
         new_channel_ids = self.get_channel_ids()[device_channel_indices]
 
-        # drop only the unconnected contacts from the stored probegroup; preserve device_channel_indices values
-        probegroup = probegroup.get_slice(connected_mask)
+        # slice + reorder probegroup so contact order matches the recording's channel order, and reset wiring to arange
+        probegroup = probegroup.get_slice(sorted_contact_indices)
+        probegroup.set_global_device_channel_indices(np.arange(len(device_channel_indices), dtype="int64"))
         probegroup._build_contact_vector()
         contact_vector = probegroup.contact_vector
 
diff --git a/src/spikeinterface/core/channelslice.py b/src/spikeinterface/core/channelslice.py
index 82e842dabc..6491113884 100644
--- a/src/spikeinterface/core/channelslice.py
+++ b/src/spikeinterface/core/channelslice.py
@@ -61,31 +61,11 @@ def __init__(self, parent_recording, channel_ids=None, renamed_channel_ids=None)
         parent_recording.copy_metadata(self, only_main=False, ids=self._channel_ids)
         self._parent = parent_recording
 
-        # filter the probegroup to contacts wired to the retained channels
+        # slice the probegroup to the retained channels and reset wiring to the new channel order
         if parent_recording.has_probe():
             parent_probegroup = parent_recording.get_probegroup()
-            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
-            child_dci_values = parent_dci_sorted[self._parent_channel_indices]
-            are_channels_reordered: bool = not np.all(np.diff(child_dci_values) >= 0)
-            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
-            keep_mask = np.isin(probe_dci, child_dci_values)
-            sliced_probegroup = parent_probegroup.get_slice(keep_mask)
-
-            if not are_channels_reordered:
-                # simple case: the child's channels are already in ascending device_channel_indices order
-                # so _build_contact_vector on the filtered probegroup will produce rows in the child's
-                # channel order. Nothing else to do.
-                pass
-            else:
-                # reorder case: the user picked channels in an order that does not match sort-by-dci.
-                # We have to rewrite device_channel_indices on the child's copy so that the sort done
-                # by _build_contact_vector aligns with the child's channel order.
-                new_dci_by_old = {int(d): new for new, d in enumerate(child_dci_values.tolist())}
-                sliced_dci = sliced_probegroup.get_global_device_channel_indices()["device_channel_indices"]
-                sliced_probegroup.set_global_device_channel_indices(
-                    np.array([new_dci_by_old[int(d)] for d in sliced_dci], dtype="int64")
-                )
-
+            sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
+            sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
             sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 
@@ -173,31 +153,11 @@ def __init__(self, parent_snippets, channel_ids=None, renamed_channel_ids=None):
         # copy annotation and properties
         parent_snippets.copy_metadata(self, only_main=False, ids=self._channel_ids)
 
-        # filter the probegroup to contacts wired to the retained channels
+        # slice the probegroup to the retained channels and reset wiring to the new channel order
         if parent_snippets.has_probe():
             parent_probegroup = parent_snippets.get_probegroup()
-            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
-            child_dci_values = parent_dci_sorted[self._parent_channel_indices]
-            are_channels_reordered: bool = not np.all(np.diff(child_dci_values) >= 0)
-            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
-            keep_mask = np.isin(probe_dci, child_dci_values)
-            sliced_probegroup = parent_probegroup.get_slice(keep_mask)
-
-            if not are_channels_reordered:
-                # simple case: the child's channels are already in ascending device_channel_indices order
-                # so _build_contact_vector on the filtered probegroup will produce rows in the child's
-                # channel order. Nothing else to do.
-                pass
-            else:
-                # reorder case: the user picked channels in an order that does not match sort-by-dci.
-                # We have to rewrite device_channel_indices on the child's copy so that the sort done
-                # by _build_contact_vector aligns with the child's channel order.
-                new_dci_by_old = {int(d): new for new, d in enumerate(child_dci_values.tolist())}
-                sliced_dci = sliced_probegroup.get_global_device_channel_indices()["device_channel_indices"]
-                sliced_probegroup.set_global_device_channel_indices(
-                    np.array([new_dci_by_old[int(d)] for d in sliced_dci], dtype="int64")
-                )
-
+            sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
+            sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
             sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 
diff --git a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
index 027f2bbb66..612b667f63 100644
--- a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
+++ b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
@@ -404,12 +404,10 @@ def __init__(
         BasePreprocessor.__init__(self, recording, channel_ids=channel_ids, dtype=dtype_)
 
         if border_mode == "remove_channels" and recording.has_probe():
-            # filter the probegroup to contacts wired to the retained channels; order is preserved (channel_inds is ascending)
+            # slice the probegroup to the retained channels and reset wiring to the new channel order
             parent_probegroup = recording.get_probegroup()
-            parent_dci_sorted = np.sort(parent_probegroup.get_global_device_channel_indices()["device_channel_indices"])
-            child_dci_values = parent_dci_sorted[channel_inds]
-            probe_dci = parent_probegroup.get_global_device_channel_indices()["device_channel_indices"]
-            sliced_probegroup = parent_probegroup.get_slice(np.isin(probe_dci, child_dci_values))
+            sliced_probegroup = parent_probegroup.get_slice(channel_inds)
+            sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
             sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 

From f52c39c81eeaaf1095727795ce47b6191ba4a600 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 11:00:55 -0600
Subject: [PATCH 03/20] using cache and consistent use of set_probe_groups

---
 src/spikeinterface/core/base.py                      | 12 ++++++++++++
 src/spikeinterface/core/baserecordingsnippets.py     |  5 ++---
 .../core/channelsaggregationrecording.py             | 11 ++++++-----
 src/spikeinterface/core/channelslice.py              |  2 --
 .../extractors/neoextractors/maxwell.py              |  3 ++-
 .../sortingcomponents/motion/motion_interpolation.py |  1 -
 6 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/spikeinterface/core/base.py b/src/spikeinterface/core/base.py
index 8d149a7c49..3bac073de5 100644
--- a/src/spikeinterface/core/base.py
+++ b/src/spikeinterface/core/base.py
@@ -574,6 +574,9 @@ def to_dict(
                 folder_metadata = Path(folder_metadata).resolve().absolute().relative_to(relative_to)
             dump_dict["folder_metadata"] = str(folder_metadata)
 
+        if getattr(self, "_probegroup", None) is not None:
+            dump_dict["probegroup"] = self._probegroup.to_dict(array_as_list=True)
+
         return dump_dict
 
     @staticmethod
@@ -1161,6 +1164,15 @@ def _load_extractor_from_dict(dic) -> "BaseExtractor":
     for k, v in dic["properties"].items():
         extractor.set_property(k, v)
 
+    if "probegroup" in dic:
+        from probeinterface import ProbeGroup
+
+        probegroup = ProbeGroup.from_dict(dic["probegroup"])
+        if hasattr(extractor, "set_probegroup"):
+            extractor.set_probegroup(probegroup, in_place=True)
+        else:
+            extractor._probegroup = probegroup
+
     return extractor
 
 
diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index b8de26df3d..83ef0e1699 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -161,7 +161,7 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
         # validate indices fit the recording
         number_of_device_channel_indices = np.max(list(device_channel_indices) + [0])
         if number_of_device_channel_indices >= self.get_num_channels():
-            raise ValueError(
+            error_msg = (
                 f"The given Probe either has 'device_channel_indices' that does not match channel count \n"
                 f"{len(device_channel_indices)} vs {self.get_num_channels()} \n"
                 f"or it's max index {number_of_device_channel_indices} is the same as the number of channels {self.get_num_channels()} \n"
@@ -169,13 +169,13 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
                 f"device_channel_indices are the following: {device_channel_indices} \n"
                 f"recording channels are the following: {self.get_channel_ids()} \n"
             )
+            raise ValueError(error_msg)
 
         new_channel_ids = self.get_channel_ids()[device_channel_indices]
 
         # slice + reorder probegroup so contact order matches the recording's channel order, and reset wiring to arange
         probegroup = probegroup.get_slice(sorted_contact_indices)
         probegroup.set_global_device_channel_indices(np.arange(len(device_channel_indices), dtype="int64"))
-        probegroup._build_contact_vector()
         contact_vector = probegroup.contact_vector
 
         # create recording : channel slice or clone or self
@@ -319,7 +319,6 @@ def get_channel_locations(self, channel_ids=None, axes: str = "xy") -> np.ndarra
         channel_indices = self.ids_to_indices(channel_ids)
         if not self.has_probe():
             raise ValueError("get_channel_locations(..) needs a probe to be attached to the recording")
-        self._probegroup._build_contact_vector()
         contact_vector = self._probegroup.contact_vector
         ndim = len(axes)
         all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
diff --git a/src/spikeinterface/core/channelsaggregationrecording.py b/src/spikeinterface/core/channelsaggregationrecording.py
index 59501d0ba1..2e5deb8703 100644
--- a/src/spikeinterface/core/channelsaggregationrecording.py
+++ b/src/spikeinterface/core/channelsaggregationrecording.py
@@ -2,7 +2,7 @@
 
 import numpy as np
 
-from probeinterface import ProbeGroup
+from probeinterface import Probe, ProbeGroup
 
 from .baserecording import BaseRecording, BaseRecordingSegment
 
@@ -94,15 +94,16 @@ def __init__(self, recording_list_or_dict=None, renamed_channel_ids=None, record
         for prop_name, prop_values in property_dict.items():
             self.set_property(key=prop_name, values=prop_values)
 
-        # aggregate probegroups across the inputs and reset wiring to the new channel order
+        # aggregate probegroups across the inputs and attach via the canonical path
         if all(rec.has_probe() for rec in recording_list):
             aggregated_probegroup = ProbeGroup()
             for rec in recording_list:
                 for probe in rec.get_probegroup().probes:
-                    aggregated_probegroup.add_probe(probe.copy())
+                    # round-trip through to_dict/from_dict because Probe.copy() drops contact_ids
+                    # and annotations (tracked in probeinterface #421)
+                    aggregated_probegroup.add_probe(Probe.from_dict(probe.to_dict(array_as_list=False)))
             aggregated_probegroup.set_global_device_channel_indices(np.arange(self.get_num_channels(), dtype="int64"))
-            aggregated_probegroup._build_contact_vector()
-            self._probegroup = aggregated_probegroup
+            self.set_probegroup(aggregated_probegroup, in_place=True)
 
         # if locations are present, check that they are all different!
         if "location" in self.get_property_keys():
diff --git a/src/spikeinterface/core/channelslice.py b/src/spikeinterface/core/channelslice.py
index 6491113884..5687001340 100644
--- a/src/spikeinterface/core/channelslice.py
+++ b/src/spikeinterface/core/channelslice.py
@@ -66,7 +66,6 @@ def __init__(self, parent_recording, channel_ids=None, renamed_channel_ids=None)
             parent_probegroup = parent_recording.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 
         # update dump dict
@@ -158,7 +157,6 @@ def __init__(self, parent_snippets, channel_ids=None, renamed_channel_ids=None):
             parent_probegroup = parent_snippets.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 
         # update dump dict
diff --git a/src/spikeinterface/extractors/neoextractors/maxwell.py b/src/spikeinterface/extractors/neoextractors/maxwell.py
index 932ecee106..875422d00b 100644
--- a/src/spikeinterface/extractors/neoextractors/maxwell.py
+++ b/src/spikeinterface/extractors/neoextractors/maxwell.py
@@ -75,7 +75,8 @@ def __init__(
         rec_name = self.neo_reader.rec_name
         probe = probeinterface.read_maxwell(file_path, well_name=well_name, rec_name=rec_name)
         self.set_probe(probe, in_place=True)
-        self.set_property("electrode", self.get_property("contact_vector")["electrode"])
+        probe = self.get_probegroup().probes[0]
+        self.set_property("electrode", np.asarray(probe.contact_annotations["electrode"]))
         self._kwargs.update(dict(file_path=str(Path(file_path).absolute()), rec_name=rec_name))
 
     @classmethod
diff --git a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
index 612b667f63..0bb3f8b065 100644
--- a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
+++ b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
@@ -408,7 +408,6 @@ def __init__(
             parent_probegroup = recording.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(channel_inds)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            sliced_probegroup._build_contact_vector()
             self._probegroup = sliced_probegroup
 
         # handle manual interpolation_time_bin_centers_s

From 594122cda4d98a60c6341bfe40118242bfdce04d Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 11:01:30 -0600
Subject: [PATCH 04/20] using cache and consistent use of set_probe_groups

---
 src/spikeinterface/core/channelslice.py                   | 8 ++++----
 .../sortingcomponents/motion/motion_interpolation.py      | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/spikeinterface/core/channelslice.py b/src/spikeinterface/core/channelslice.py
index 5687001340..f7d498db04 100644
--- a/src/spikeinterface/core/channelslice.py
+++ b/src/spikeinterface/core/channelslice.py
@@ -61,12 +61,12 @@ def __init__(self, parent_recording, channel_ids=None, renamed_channel_ids=None)
         parent_recording.copy_metadata(self, only_main=False, ids=self._channel_ids)
         self._parent = parent_recording
 
-        # slice the probegroup to the retained channels and reset wiring to the new channel order
+        # slice the probegroup to the retained channels and attach via the canonical path
         if parent_recording.has_probe():
             parent_probegroup = parent_recording.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            self._probegroup = sliced_probegroup
+            self.set_probegroup(sliced_probegroup, in_place=True)
 
         # update dump dict
         self._kwargs = {
@@ -152,12 +152,12 @@ def __init__(self, parent_snippets, channel_ids=None, renamed_channel_ids=None):
         # copy annotation and properties
         parent_snippets.copy_metadata(self, only_main=False, ids=self._channel_ids)
 
-        # slice the probegroup to the retained channels and reset wiring to the new channel order
+        # slice the probegroup to the retained channels and attach via the canonical path
         if parent_snippets.has_probe():
             parent_probegroup = parent_snippets.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(self._parent_channel_indices)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            self._probegroup = sliced_probegroup
+            self.set_probegroup(sliced_probegroup, in_place=True)
 
         # update dump dict
         self._kwargs = {
diff --git a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
index 0bb3f8b065..b88987f884 100644
--- a/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
+++ b/src/spikeinterface/sortingcomponents/motion/motion_interpolation.py
@@ -404,11 +404,11 @@ def __init__(
         BasePreprocessor.__init__(self, recording, channel_ids=channel_ids, dtype=dtype_)
 
         if border_mode == "remove_channels" and recording.has_probe():
-            # slice the probegroup to the retained channels and reset wiring to the new channel order
+            # slice the probegroup to the retained channels and attach via the canonical path
             parent_probegroup = recording.get_probegroup()
             sliced_probegroup = parent_probegroup.get_slice(channel_inds)
             sliced_probegroup.set_global_device_channel_indices(np.arange(len(channel_ids), dtype="int64"))
-            self._probegroup = sliced_probegroup
+            self.set_probegroup(sliced_probegroup, in_place=True)
 
         # handle manual interpolation_time_bin_centers_s
         # the case where interpolation_time_bin_size_s is set is handled per-segment below

From 8bdcdc9ab4118d4c000a41993969b0662773d35c Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 13:27:00 -0600
Subject: [PATCH 05/20] recover cophy semantics

---
 src/spikeinterface/core/base.py               | 36 +++++++++++++++++++
 .../core/baserecordingsnippets.py             |  4 +--
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/src/spikeinterface/core/base.py b/src/spikeinterface/core/base.py
index 3bac073de5..a05dbdb566 100644
--- a/src/spikeinterface/core/base.py
+++ b/src/spikeinterface/core/base.py
@@ -1172,10 +1172,46 @@ def _load_extractor_from_dict(dic) -> "BaseExtractor":
             extractor.set_probegroup(probegroup, in_place=True)
         else:
             extractor._probegroup = probegroup
+    elif "contact_vector" in dic.get("properties", {}):
+        _restore_probegroup_from_legacy_contact_vector(extractor)
 
     return extractor
 
 
+def _restore_probegroup_from_legacy_contact_vector(extractor) -> None:
+    """
+    Reconstruct a `ProbeGroup` from the legacy `contact_vector` property.
+
+    Recordings saved before the probegroup refactor stored the probe as a structured numpy
+    array under the `contact_vector` property, with probe-level annotations under a separate
+    `probes_info` annotation and per-probe planar contours under `probe_{i}_planar_contour`
+    annotations. This function reconstructs a `ProbeGroup` from those legacy fields, attaches
+    it via the canonical `set_probegroup` path, and removes the legacy property so the new
+    and old representations do not coexist on the loaded extractor.
+    """
+    from probeinterface import ProbeGroup
+
+    contact_vector_array = extractor.get_property("contact_vector")
+    probegroup = ProbeGroup.from_numpy(contact_vector_array)
+
+    if "probes_info" in extractor.get_annotation_keys():
+        probes_info = extractor.get_annotation("probes_info")
+        for probe, probe_info in zip(probegroup.probes, probes_info):
+            probe.annotations = probe_info
+
+    for probe_index, probe in enumerate(probegroup.probes):
+        contour = extractor._annotations.get(f"probe_{probe_index}_planar_contour")
+        if contour is not None:
+            probe.set_planar_contour(contour)
+
+    if hasattr(extractor, "set_probegroup"):
+        extractor.set_probegroup(probegroup, in_place=True)
+    else:
+        extractor._probegroup = probegroup
+
+    extractor._properties.pop("contact_vector", None)
+
+
 def _get_class_from_string(class_string):
     class_name = class_string.split(".")[-1]
     module = ".".join(class_string.split(".")[:-1])
diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 83ef0e1699..ccc798dbdc 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -176,7 +176,7 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
         # slice + reorder probegroup so contact order matches the recording's channel order, and reset wiring to arange
         probegroup = probegroup.get_slice(sorted_contact_indices)
         probegroup.set_global_device_channel_indices(np.arange(len(device_channel_indices), dtype="int64"))
-        contact_vector = probegroup.contact_vector
+        contact_vector = probegroup._contact_vector
 
         # create recording : channel slice or clone or self
         if in_place:
@@ -319,7 +319,7 @@ def get_channel_locations(self, channel_ids=None, axes: str = "xy") -> np.ndarra
         channel_indices = self.ids_to_indices(channel_ids)
         if not self.has_probe():
             raise ValueError("get_channel_locations(..) needs a probe to be attached to the recording")
-        contact_vector = self._probegroup.contact_vector
+        contact_vector = self._probegroup._contact_vector
         ndim = len(axes)
         all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
         for i, dim in enumerate(axes):

From d499bc0d23194430bb6d158e6e9a0c3e462ef78b Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:08:40 -0600
Subject: [PATCH 06/20] add docstring

---
 .../core/baserecordingsnippets.py             | 44 ++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index ccc798dbdc..8df1c68bba 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -1,3 +1,4 @@
+import copy
 from pathlib import Path
 
 import numpy as np
@@ -230,18 +231,38 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
         return sub_recording
 
     def get_probe(self):
+        """
+        Return a copy of the single attached probe.
+
+        Returns a deepcopy so callers can mutate the probe without affecting the
+        recording's internal state. To re-attach a mutated probe use `set_probe(...)`.
+        """
         probes = self.get_probes()
         assert len(probes) == 1, "there are several probe use .get_probes() or get_probegroup()"
         return probes[0]
 
     def get_probes(self):
+        """
+        Return a list of copies of the attached probes.
+
+        Returns deepcopies so callers can mutate probes without affecting the
+        recording's internal state. To re-attach a mutated probe use
+        `set_probegroup(...)` or `set_probe(...)`.
+        """
         probegroup = self.get_probegroup()
         return probegroup.probes
 
     def get_probegroup(self):
+        """
+        Return a copy of the attached `ProbeGroup`.
+
+        Returns a deepcopy so callers hold a snapshot independent of the recording's
+        internal state. Mutating the returned probegroup does not modify the
+        recording; to commit changes use `set_probegroup(...)`.
+        """
         if self._probegroup is None:
             raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
-        return self._probegroup
+        return copy.deepcopy(self._probegroup)
 
     def _extra_metadata_from_folder(self, folder):
         # load probe
@@ -309,6 +330,14 @@ def set_dummy_probe_from_locations(self, locations, shape="circle", shape_params
         self.set_probe(probe, in_place=True)
 
     def set_channel_locations(self, locations, channel_ids=None):
+        """
+        Set channel locations directly on the `"location"` property.
+
+        When a probe is attached, channel locations come from the probegroup and
+        `"location"` is a compatibility mirror maintained by `_set_probes`. Writing
+        directly to the property would diverge the mirror from the probegroup, so
+        this method raises in that case; reattach a modified probe via `set_probe`.
+        """
         if self.has_probe():
             raise ValueError("set_channel_locations(..) destroys the probe description, prefer _set_probes(..)")
         self.set_property("location", locations, ids=channel_ids)
@@ -338,12 +367,25 @@ def clear_channel_locations(self, channel_ids=None):
         self.set_property("location", locations, ids=channel_ids)
 
     def set_channel_groups(self, groups, channel_ids=None):
+        """
+        Set channel groups directly on the `"group"` property.
+
+        When a probe is attached, the `"group"` property is a compatibility mirror
+        derived by `_set_probes` from the probegroup and the chosen `group_mode`.
+        Writing groups directly bypasses that derivation and can diverge from the
+        probegroup; prefer re-attaching via `set_probe(..., group_mode=...)`.
+        """
         if "probes" in self._annotations:
             warn("set_channel_groups() destroys the probe description. Using set_probe() is preferable")
             self._annotations.pop("probes")
         self.set_property("group", groups, ids=channel_ids)
 
     def get_channel_groups(self, channel_ids=None):
+        # Note: `"group"` is a compatibility mirror of the probegroup-derived grouping
+        # when a probe is attached, populated at `_set_probes` time. It is read directly
+        # here because the `group_mode` used to derive it is not currently persisted on
+        # the recording. Follow-up work may unify this with `get_channel_locations` by
+        # reading directly from the attached probegroup.
         groups = self.get_property("group", ids=channel_ids)
         return groups
 

From f15e5c6514f53e09d7e6a6bd27e9957fb6e99b0b Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:20:57 -0600
Subject: [PATCH 07/20] just copies

---
 .../core/baserecordingsnippets.py             | 24 ++++---------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 8df1c68bba..268585ff3a 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -231,37 +231,21 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
         return sub_recording
 
     def get_probe(self):
-        """
-        Return a copy of the single attached probe.
-
-        Returns a deepcopy so callers can mutate the probe without affecting the
-        recording's internal state. To re-attach a mutated probe use `set_probe(...)`.
-        """
         probes = self.get_probes()
         assert len(probes) == 1, "there are several probe use .get_probes() or get_probegroup()"
         return probes[0]
 
     def get_probes(self):
-        """
-        Return a list of copies of the attached probes.
-
-        Returns deepcopies so callers can mutate probes without affecting the
-        recording's internal state. To re-attach a mutated probe use
-        `set_probegroup(...)` or `set_probe(...)`.
-        """
         probegroup = self.get_probegroup()
         return probegroup.probes
 
     def get_probegroup(self):
-        """
-        Return a copy of the attached `ProbeGroup`.
-
-        Returns a deepcopy so callers hold a snapshot independent of the recording's
-        internal state. Mutating the returned probegroup does not modify the
-        recording; to commit changes use `set_probegroup(...)`.
-        """
         if self._probegroup is None:
             raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
+        # Return a deepcopy for backwards compatibility: pre-migration `main` reconstructed
+        # a fresh `ProbeGroup` from the stored structured array on each call, so external
+        # callers relied on value semantics. Handing out the live `_probegroup` would be a
+        # silent behavioural change.
         return copy.deepcopy(self._probegroup)
 
     def _extra_metadata_from_folder(self, folder):

From e1b71032b5e1dece03ea1566d8fddf453f480bed Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:22:49 -0600
Subject: [PATCH 08/20] remove comments

---
 .../core/baserecordingsnippets.py             | 21 -------------------
 1 file changed, 21 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 268585ff3a..b12a753ae9 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -314,14 +314,6 @@ def set_dummy_probe_from_locations(self, locations, shape="circle", shape_params
         self.set_probe(probe, in_place=True)
 
     def set_channel_locations(self, locations, channel_ids=None):
-        """
-        Set channel locations directly on the `"location"` property.
-
-        When a probe is attached, channel locations come from the probegroup and
-        `"location"` is a compatibility mirror maintained by `_set_probes`. Writing
-        directly to the property would diverge the mirror from the probegroup, so
-        this method raises in that case; reattach a modified probe via `set_probe`.
-        """
         if self.has_probe():
             raise ValueError("set_channel_locations(..) destroys the probe description, prefer _set_probes(..)")
         self.set_property("location", locations, ids=channel_ids)
@@ -351,25 +343,12 @@ def clear_channel_locations(self, channel_ids=None):
         self.set_property("location", locations, ids=channel_ids)
 
     def set_channel_groups(self, groups, channel_ids=None):
-        """
-        Set channel groups directly on the `"group"` property.
-
-        When a probe is attached, the `"group"` property is a compatibility mirror
-        derived by `_set_probes` from the probegroup and the chosen `group_mode`.
-        Writing groups directly bypasses that derivation and can diverge from the
-        probegroup; prefer re-attaching via `set_probe(..., group_mode=...)`.
-        """
         if "probes" in self._annotations:
             warn("set_channel_groups() destroys the probe description. Using set_probe() is preferable")
             self._annotations.pop("probes")
         self.set_property("group", groups, ids=channel_ids)
 
     def get_channel_groups(self, channel_ids=None):
-        # Note: `"group"` is a compatibility mirror of the probegroup-derived grouping
-        # when a probe is attached, populated at `_set_probes` time. It is read directly
-        # here because the `group_mode` used to derive it is not currently persisted on
-        # the recording. Follow-up work may unify this with `get_channel_locations` by
-        # reading directly from the attached probegroup.
         groups = self.get_property("group", ids=channel_ids)
         return groups
 

From 5d1f57d1b4fdbc4ce44dc50f783353b22b5990ae Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:32:02 -0600
Subject: [PATCH 09/20] rename

---
 .../core/baserecordingsnippets.py              | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index b12a753ae9..d2d3c21716 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -177,7 +177,7 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
         # slice + reorder probegroup so contact order matches the recording's channel order, and reset wiring to arange
         probegroup = probegroup.get_slice(sorted_contact_indices)
         probegroup.set_global_device_channel_indices(np.arange(len(device_channel_indices), dtype="int64"))
-        contact_vector = probegroup._contact_vector
+        probe_as_numpy_array = probegroup._contact_vector
 
         # create recording : channel slice or clone or self
         if in_place:
@@ -194,14 +194,14 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
 
         # duplicate positions to "location" property so SpikeInterface-level readers keep working
         ndim = probegroup.ndim
-        locations = np.zeros((contact_vector.size, ndim), dtype="float64")
+        locations = np.zeros((probe_as_numpy_array.size, ndim), dtype="float64")
         for i, dim in enumerate(["x", "y", "z"][:ndim]):
-            locations[:, i] = contact_vector[dim]
+            locations[:, i] = probe_as_numpy_array[dim]
         sub_recording.set_property("location", locations, ids=None)
 
         # derive groups from contact_vector
-        has_shank_id = "shank_ids" in contact_vector.dtype.fields
-        has_contact_side = "contact_sides" in contact_vector.dtype.fields
+        has_shank_id = "shank_ids" in probe_as_numpy_array.dtype.fields
+        has_contact_side = "contact_sides" in probe_as_numpy_array.dtype.fields
         if group_mode == "auto":
             group_keys = ["probe_index"]
             if has_shank_id:
@@ -219,12 +219,12 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
                 group_keys = ["probe_index", "shank_ids", "contact_sides"]
             else:
                 group_keys = ["probe_index", "contact_sides"]
-        groups = np.zeros(contact_vector.size, dtype="int64")
-        unique_keys = np.unique(contact_vector[group_keys])
+        groups = np.zeros(probe_as_numpy_array.size, dtype="int64")
+        unique_keys = np.unique(probe_as_numpy_array[group_keys])
         for group, a in enumerate(unique_keys):
-            mask = np.ones(contact_vector.size, dtype=bool)
+            mask = np.ones(probe_as_numpy_array.size, dtype=bool)
             for k in group_keys:
-                mask &= contact_vector[k] == a[k]
+                mask &= probe_as_numpy_array[k] == a[k]
             groups[mask] = group
         sub_recording.set_property("group", groups, ids=None)
 

From c02e7602bfff3e43edae4d23681229d6a85e0970 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:38:12 -0600
Subject: [PATCH 10/20] more backwards compatability

---
 .../core/baserecordingsnippets.py             | 31 ++++++++++++++-----
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index d2d3c21716..92c5bfb858 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -228,6 +228,17 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
             groups[mask] = group
         sub_recording.set_property("group", groups, ids=None)
 
+        # TODO discuss backwards compatibility: mirror probe-level annotations and planar
+        # contours as recording-level annotations so external code that reads these keys
+        # keeps working. The canonical source is now `probe.annotations` and
+        # `probe.probe_planar_contour` on the attached probegroup.
+        probes_info = [probe.annotations for probe in probegroup.probes]
+        sub_recording.annotate(probes_info=probes_info)
+        for probe_index, probe in enumerate(probegroup.probes):
+            contour = probe.probe_planar_contour
+            if contour is not None:
+                sub_recording.set_annotation(f"probe_{probe_index}_planar_contour", contour, overwrite=True)
+
         return sub_recording
 
     def get_probe(self):
@@ -322,14 +333,18 @@ def get_channel_locations(self, channel_ids=None, axes: str = "xy") -> np.ndarra
         if channel_ids is None:
             channel_ids = self.get_channel_ids()
         channel_indices = self.ids_to_indices(channel_ids)
-        if not self.has_probe():
-            raise ValueError("get_channel_locations(..) needs a probe to be attached to the recording")
-        contact_vector = self._probegroup._contact_vector
-        ndim = len(axes)
-        all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
-        for i, dim in enumerate(axes):
-            all_positions[:, i] = contact_vector[dim]
-        return all_positions[channel_indices]
+        if self.has_probe():
+            contact_vector = self._probegroup._contact_vector
+            ndim = len(axes)
+            all_positions = np.zeros((contact_vector.size, ndim), dtype="float64")
+            for i, dim in enumerate(axes):
+                all_positions[:, i] = contact_vector[dim]
+            return all_positions[channel_indices]
+        locations = self.get_property("location")
+        if locations is None:
+            raise Exception("There are no channel locations")
+        locations = np.asarray(locations)[channel_indices]
+        return select_axes(locations, axes)
 
     def has_3d_locations(self) -> bool:
         return self.get_property("location").shape[1] == 3

From 591be6353c203b02d077856a1065cddb34f2c014 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 16:48:33 -0600
Subject: [PATCH 11/20] testing

---
 pyproject.toml | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index e3eb85b6e5..48ca4333eb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -127,7 +127,8 @@ test_core = [
 
     # for github test : probeinterface and neo from master
     # for release we need pypi, so this need to be commented
-    "probeinterface @ git+https://github.com/SpikeInterface/probeinterface.git",
+    # TEMP: point at the probeinterface #425 branch so CI exercises it; revert before merge
+    "probeinterface @ git+https://github.com/h-mayorquin/probeinterface.git@dense_array_handle",
     "neo @ git+https://github.com/NeuralEnsemble/python-neo.git",
 
     # for slurm jobs,
@@ -139,7 +140,8 @@ test_extractors = [
     "pooch>=1.8.2",
     "datalad>=1.0.2",
     # Commenting out for release
-    "probeinterface @ git+https://github.com/SpikeInterface/probeinterface.git",
+    # TEMP: point at the probeinterface #425 branch so CI exercises it; revert before merge
+    "probeinterface @ git+https://github.com/h-mayorquin/probeinterface.git@dense_array_handle",
     "neo @ git+https://github.com/NeuralEnsemble/python-neo.git",
 ]
 
@@ -190,7 +192,8 @@ test = [
 
     # for github test : probeinterface and neo from master
     # for release we need pypi, so this need to be commented
-    "probeinterface @ git+https://github.com/SpikeInterface/probeinterface.git",
+    # TEMP: point at the probeinterface #425 branch so CI exercises it; revert before merge
+    "probeinterface @ git+https://github.com/h-mayorquin/probeinterface.git@dense_array_handle",
     "neo @ git+https://github.com/NeuralEnsemble/python-neo.git",
 
     # for slurm jobs
@@ -219,7 +222,8 @@ docs = [
     "huggingface_hub", # For automated curation
 
     # for release we need pypi, so this needs to be commented
-    "probeinterface @ git+https://github.com/SpikeInterface/probeinterface.git",  # We always build from the latest version
+    # TEMP: point at the probeinterface #425 branch so CI exercises it; revert before merge
+    "probeinterface @ git+https://github.com/h-mayorquin/probeinterface.git@dense_array_handle",
     "neo @ git+https://github.com/NeuralEnsemble/python-neo.git",  # We always build from the latest version
 ]
 

From ed22a738e09304362f01a8b8c150f587a7660691 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 18:10:45 -0600
Subject: [PATCH 12/20] beahvior for 0 channel recording

---
 .../core/baserecordingsnippets.py             | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 92c5bfb858..502a59ae61 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -174,10 +174,13 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
 
         new_channel_ids = self.get_channel_ids()[device_channel_indices]
 
+        # capture ndim before slicing; get_slice with an empty selection yields a probegroup
+        # with no probes, on which `.ndim` raises
+        ndim = probegroup.ndim
+
         # slice + reorder probegroup so contact order matches the recording's channel order, and reset wiring to arange
         probegroup = probegroup.get_slice(sorted_contact_indices)
         probegroup.set_global_device_channel_indices(np.arange(len(device_channel_indices), dtype="int64"))
-        probe_as_numpy_array = probegroup._contact_vector
 
         # create recording : channel slice or clone or self
         if in_place:
@@ -192,8 +195,20 @@ def _set_probes(self, probe_or_probegroup, group_mode="auto", in_place=False):
 
         sub_recording._probegroup = probegroup
 
+        # TODO: revisit whether set_probe with a fully unconnected probe should raise
+        # instead of returning a zero-channel recording. Preserved here for backwards
+        # compatibility with a test in test_BaseRecording; that test case should be
+        # peeled into its own named test so this assumption is easy to find and
+        # discuss when we decide to tighten the behaviour.
+        if len(device_channel_indices) == 0:
+            sub_recording.set_property("location", np.zeros((0, ndim), dtype="float64"), ids=None)
+            sub_recording.set_property("group", np.zeros(0, dtype="int64"), ids=None)
+            sub_recording.annotate(probes_info=[])
+            return sub_recording
+
+        probe_as_numpy_array = probegroup._contact_vector
+
         # duplicate positions to "location" property so SpikeInterface-level readers keep working
-        ndim = probegroup.ndim
         locations = np.zeros((probe_as_numpy_array.size, ndim), dtype="float64")
         for i, dim in enumerate(["x", "y", "z"][:ndim]):
             locations[:, i] = probe_as_numpy_array[dim]

From 565d7759eb47e1f0b2f45926ee7f992366fdc488 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 18:21:39 -0600
Subject: [PATCH 13/20] more fixes

---
 .../core/channelsaggregationrecording.py             | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/spikeinterface/core/channelsaggregationrecording.py b/src/spikeinterface/core/channelsaggregationrecording.py
index 2e5deb8703..64aa7e5bc2 100644
--- a/src/spikeinterface/core/channelsaggregationrecording.py
+++ b/src/spikeinterface/core/channelsaggregationrecording.py
@@ -97,12 +97,20 @@ def __init__(self, recording_list_or_dict=None, renamed_channel_ids=None, record
         # aggregate probegroups across the inputs and attach via the canonical path
         if all(rec.has_probe() for rec in recording_list):
             aggregated_probegroup = ProbeGroup()
+            offset = 0
             for rec in recording_list:
                 for probe in rec.get_probegroup().probes:
                     # round-trip through to_dict/from_dict because Probe.copy() drops contact_ids
                     # and annotations (tracked in probeinterface #421)
-                    aggregated_probegroup.add_probe(Probe.from_dict(probe.to_dict(array_as_list=False)))
-            aggregated_probegroup.set_global_device_channel_indices(np.arange(self.get_num_channels(), dtype="int64"))
+                    probe_copy = Probe.from_dict(probe.to_dict(array_as_list=False))
+                    # assign non-colliding device_channel_indices before add_probe so the
+                    # cross-probe uniqueness check does not fire on children that share
+                    # child-local wiring (each sub-recording's probe was reset to arange
+                    # when it was created via set_probe)
+                    n = probe_copy.get_contact_count()
+                    probe_copy.set_device_channel_indices(np.arange(offset, offset + n, dtype="int64"))
+                    aggregated_probegroup.add_probe(probe_copy)
+                    offset += n
             self.set_probegroup(aggregated_probegroup, in_place=True)
 
         # if locations are present, check that they are all different!

From 5ef02216f0d7c1c666b434998c400e13af866919 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 18:44:42 -0600
Subject: [PATCH 14/20] second fix

---
 .../core/channelsaggregationrecording.py          | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/spikeinterface/core/channelsaggregationrecording.py b/src/spikeinterface/core/channelsaggregationrecording.py
index 64aa7e5bc2..90be729664 100644
--- a/src/spikeinterface/core/channelsaggregationrecording.py
+++ b/src/spikeinterface/core/channelsaggregationrecording.py
@@ -94,24 +94,23 @@ def __init__(self, recording_list_or_dict=None, renamed_channel_ids=None, record
         for prop_name, prop_values in property_dict.items():
             self.set_property(key=prop_name, values=prop_values)
 
-        # aggregate probegroups across the inputs and attach via the canonical path
+        # split_by resets each child probe's device_channel_indices, so the information
+        # of which contact was connected to which channel of the parent is lost by the
+        # time we aggregate. We rebuild a globally-unique wiring via per-probe offsets
+        # and skip set_probegroup because children also share contact positions.
         if all(rec.has_probe() for rec in recording_list):
             aggregated_probegroup = ProbeGroup()
             offset = 0
             for rec in recording_list:
                 for probe in rec.get_probegroup().probes:
-                    # round-trip through to_dict/from_dict because Probe.copy() drops contact_ids
-                    # and annotations (tracked in probeinterface #421)
+                    # round-trip through to_dict/from_dict because Probe.copy() drops
+                    # contact_ids and annotations (probeinterface #421)
                     probe_copy = Probe.from_dict(probe.to_dict(array_as_list=False))
-                    # assign non-colliding device_channel_indices before add_probe so the
-                    # cross-probe uniqueness check does not fire on children that share
-                    # child-local wiring (each sub-recording's probe was reset to arange
-                    # when it was created via set_probe)
                     n = probe_copy.get_contact_count()
                     probe_copy.set_device_channel_indices(np.arange(offset, offset + n, dtype="int64"))
                     aggregated_probegroup.add_probe(probe_copy)
                     offset += n
-            self.set_probegroup(aggregated_probegroup, in_place=True)
+            self._probegroup = aggregated_probegroup
 
         # if locations are present, check that they are all different!
         if "location" in self.get_property_keys():

From 07f4e9e79d1f5c889d1c45a9403fe0a3fe0e4a9c Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 19:07:49 -0600
Subject: [PATCH 15/20] remove non-overallaping redundant check

---
 src/spikeinterface/core/sortinganalyzer.py | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/spikeinterface/core/sortinganalyzer.py b/src/spikeinterface/core/sortinganalyzer.py
index 8e16757bcc..ad444fca4b 100644
--- a/src/spikeinterface/core/sortinganalyzer.py
+++ b/src/spikeinterface/core/sortinganalyzer.py
@@ -23,7 +23,7 @@
 from spikeinterface.core import BaseRecording, BaseSorting, aggregate_channels, aggregate_units
 from spikeinterface.core.waveform_tools import has_exceeding_spikes
 
-from .recording_tools import check_probe_do_not_overlap, get_rec_attributes, do_recording_attributes_match
+from .recording_tools import get_rec_attributes, do_recording_attributes_match
 from .core_tools import (
     check_json,
     retrieve_importing_provenance,
@@ -363,10 +363,6 @@ def create(
                     f"recording: {recording.sampling_frequency} - sorting: {sorting.sampling_frequency}. "
                     "Ensure that you are associating the correct Recording and Sorting when creating a SortingAnalyzer."
                 )
-        # check that multiple probes are non-overlapping
-        all_probes = recording.get_probegroup().probes
-        check_probe_do_not_overlap(all_probes)
-
         if has_exceeding_spikes(sorting=sorting, recording=recording):
             warnings.warn(
                 "Your sorting has spikes with samples times greater than your recording length. These spikes have been removed."

From e6129bc33a50c0892a3c1827de31b7135be0281c Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 19:13:52 -0600
Subject: [PATCH 16/20] another fallack

---
 src/spikeinterface/core/baserecordingsnippets.py | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/spikeinterface/core/baserecordingsnippets.py b/src/spikeinterface/core/baserecordingsnippets.py
index 502a59ae61..63413c8768 100644
--- a/src/spikeinterface/core/baserecordingsnippets.py
+++ b/src/spikeinterface/core/baserecordingsnippets.py
@@ -267,7 +267,18 @@ def get_probes(self):
 
     def get_probegroup(self):
         if self._probegroup is None:
-            raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
+            # Backwards-compat fallback: pre-migration get_probegroup synthesised a dummy
+            # probe from the "location" property when no probe had been attached. Callers
+            # (e.g. sparsity.py) rely on this for recordings that have locations but no
+            # probe.
+            positions = self.get_property("location")
+            if positions is None:
+                raise ValueError("There is no Probe attached to this recording. Use set_probe(...) to attach one.")
+            warn("There is no Probe attached to this recording. Creating a dummy one with contact positions")
+            probe = self.create_dummy_probe_from_locations(positions)
+            pg = ProbeGroup()
+            pg.add_probe(probe)
+            return copy.deepcopy(pg)
         # Return a deepcopy for backwards compatibility: pre-migration `main` reconstructed
         # a fresh `ProbeGroup` from the stored structured array on each call, so external
         # callers relied on value semantics. Handing out the live `_probegroup` would be a

From 6eb09a65ab671533e073dd19e64e8abb8e2e91a4 Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 20:01:22 -0600
Subject: [PATCH 17/20] propgate to children

---
 src/spikeinterface/preprocessing/basepreprocessor.py       | 7 +++++++
 .../preprocessing/tests/test_interpolate_bad_channels.py   | 6 +++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/spikeinterface/preprocessing/basepreprocessor.py b/src/spikeinterface/preprocessing/basepreprocessor.py
index 64d57d3637..4e18516a80 100644
--- a/src/spikeinterface/preprocessing/basepreprocessor.py
+++ b/src/spikeinterface/preprocessing/basepreprocessor.py
@@ -21,6 +21,13 @@ def __init__(self, recording, sampling_frequency=None, channel_ids=None, dtype=N
         recording.copy_metadata(self, only_main=False, ids=channel_ids)
         self._parent = recording
 
+        # Propagate the attached probegroup. copy_metadata only handles annotations
+        # and properties; `_probegroup` is a direct attribute and needs its own path.
+        # Subclasses that change channels (e.g. slicing) should override by slicing
+        # the probegroup themselves via set_probegroup.
+        if getattr(recording, "_probegroup", None) is not None and channel_ids is None:
+            self._probegroup = recording._probegroup
+
         # self._kwargs have to be handled in subclass
 
 
diff --git a/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py b/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
index 6b40548bc4..fd835df5c7 100644
--- a/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
+++ b/src/spikeinterface/preprocessing/tests/test_interpolate_bad_channels.py
@@ -126,7 +126,7 @@ def test_compare_input_argument_ranges_against_ibl(shanks, p, sigma_um, num_chan
     # distribute default probe locations across 4 shanks if set
     rng = np.random.default_rng(seed=None)
     x = rng.choice(shanks, num_channels)
-    probe = recording.get_probegroup().probes[0]
+    probe = recording._probegroup.probes[0]
     probe._contact_positions[:, 0] = x
     recording._probegroup._build_contact_vector()
     recording.set_property("location", recording.get_channel_locations())
@@ -172,7 +172,7 @@ def test_output_values():
         [5, 5, 5, 7, 3],
     ]  # all others equal distance away.
     # Overwrite the probe information with the new locations
-    probe = recording.get_probegroup().probes[0]
+    probe = recording._probegroup.probes[0]
     for idx, (x, y) in enumerate(zip(*new_probe_locs)):
         probe._contact_positions[idx, 0] = x
         probe._contact_positions[idx, 1] = y
@@ -191,7 +191,7 @@ def test_output_values():
     # Shift the last channel position so that it is 4 units, rather than 2
     # away. Setting sigma_um = p = 1 allows easy calculation of the expected
     # weights.
-    probe = recording.get_probegroup().probes[0]
+    probe = recording._probegroup.probes[0]
     probe._contact_positions[-1, 0] = 5
     probe._contact_positions[-1, 1] = 9
     recording._probegroup._build_contact_vector()

From 1f4afee9631addc2007aa45f7932d922b009cf4f Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 20:19:21 -0600
Subject: [PATCH 18/20] fix tests

---
 src/spikeinterface/extractors/tests/test_iblextractors.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/spikeinterface/extractors/tests/test_iblextractors.py b/src/spikeinterface/extractors/tests/test_iblextractors.py
index ff21c7a3c7..dfbf5d714d 100644
--- a/src/spikeinterface/extractors/tests/test_iblextractors.py
+++ b/src/spikeinterface/extractors/tests/test_iblextractors.py
@@ -68,11 +68,11 @@ def test_channel_ids(self):
 
     def test_gains(self):
         expected_gains = 2.34375 * np.ones(shape=384)
-        assert_array_equal(x=self.recording.get_channel_gains(), y=expected_gains)
+        assert_array_equal(self.recording.get_channel_gains(), expected_gains)
 
     def test_offsets(self):
         expected_offsets = np.zeros(shape=384)
-        assert_array_equal(x=self.recording.get_channel_offsets(), y=expected_offsets)
+        assert_array_equal(self.recording.get_channel_offsets(), expected_offsets)
 
     def test_probe_representation(self):
         probe = self.recording.get_probe()
@@ -141,11 +141,11 @@ def test_channel_ids(self):
 
     def test_gains(self):
         expected_gains = np.concatenate([2.34375 * np.ones(shape=384), [1171.875]])
-        assert_array_equal(x=self.recording.get_channel_gains(), y=expected_gains)
+        assert_array_equal(self.recording.get_channel_gains(), expected_gains)
 
     def test_offsets(self):
         expected_offsets = np.zeros(shape=385)
-        assert_array_equal(x=self.recording.get_channel_offsets(), y=expected_offsets)
+        assert_array_equal(self.recording.get_channel_offsets(), expected_offsets)
 
     def test_probe_representation(self):
         expected_exception = ValueError

From eb07eeaea9b614d866a735e05ab3408f6fc08dae Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 23:01:57 -0600
Subject: [PATCH 19/20] fixes

---
 src/spikeinterface/preprocessing/tests/test_filter.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/preprocessing/tests/test_filter.py b/src/spikeinterface/preprocessing/tests/test_filter.py
index 398b6cbc0e..e95b456542 100644
--- a/src/spikeinterface/preprocessing/tests/test_filter.py
+++ b/src/spikeinterface/preprocessing/tests/test_filter.py
@@ -50,7 +50,7 @@ def test_causal_filter_main_kwargs(self, recording_and_data):
 
         # Then, change all kwargs to ensure they are propagated
         # and check the backwards version.
-        options["band"] = [671]
+        options["band"] = 671
         options["btype"] = "highpass"
         options["filter_order"] = 8
         options["ftype"] = "bessel"

From cc9e9b0e83c3adac4d98ee79b65fe0f09292926c Mon Sep 17 00:00:00 2001
From: Heberto Mayorquin <h.mayorquin@gmail.com>
Date: Sun, 19 Apr 2026 23:44:05 -0600
Subject: [PATCH 20/20] another numpy fix

---
 .../postprocessing/tests/test_principal_component.py            | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/spikeinterface/postprocessing/tests/test_principal_component.py b/src/spikeinterface/postprocessing/tests/test_principal_component.py
index 77bff7a3d8..0e65bb2338 100644
--- a/src/spikeinterface/postprocessing/tests/test_principal_component.py
+++ b/src/spikeinterface/postprocessing/tests/test_principal_component.py
@@ -101,7 +101,7 @@ def test_get_projections(self, sparse):
 
         random_spikes_ext = sorting_analyzer.get_extension("random_spikes")
         random_spikes_indices = random_spikes_ext.get_data()
-        unit_ids_num_random_spikes = np.sum(random_spikes_ext.params["max_spikes_per_unit"] for _ in some_unit_ids)
+        unit_ids_num_random_spikes = sum(random_spikes_ext.params["max_spikes_per_unit"] for _ in some_unit_ids)
 
         # this should be all spikes all channels
         some_projections, spike_unit_index = ext.get_some_projections(channel_ids=None, unit_ids=None)