From db97b2f729960b98dfd35198f61420ff2d8757cf Mon Sep 17 00:00:00 2001
From: Teon L Brooks <teon.brooks@gmail.com>
Date: Thu, 17 Sep 2026 19:21:14 -0400
Subject: [PATCH 1/7] Lock JupyterLite's browser packages at build time

The package list moves to a single "jupyterlite" dependency group in
pyproject.toml instead of being duplicated in the setup cell.
---
 doc/changes/dev/14314.other.rst         |  1 +
 doc/conf.py                             |  2 +
 doc/jupyter_lite_config.py              | 38 ++++++++++++++
 doc/sphinxext/build_lite_wheel.py       | 19 ++++---
 doc/sphinxext/jupyterlite_data.py       | 13 ++---
 doc/sphinxext/jupyterlite_lock_specs.py | 66 +++++++++++++++++++++++++
 doc/sphinxext/jupyterlite_setup_cell.py | 43 ++++++++++------
 pyproject.toml                          | 13 +++++
 8 files changed, 168 insertions(+), 27 deletions(-)
 create mode 100644 doc/changes/dev/14314.other.rst
 create mode 100644 doc/jupyter_lite_config.py
 create mode 100644 doc/sphinxext/jupyterlite_lock_specs.py

diff --git a/doc/changes/dev/14314.other.rst b/doc/changes/dev/14314.other.rst
new file mode 100644
index 00000000000..43a577fb668
--- /dev/null
+++ b/doc/changes/dev/14314.other.rst
@@ -0,0 +1 @@
+Lock the JupyterLite browser kernel's extra packages at build time instead of installing them from the first notebook cell, by `Teon Brooks`_.
diff --git a/doc/conf.py b/doc/conf.py
index f28d499f539..e64423e5635 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -505,6 +505,8 @@
     # sphinx-gallery writes link to auto_*/... at the root
     jupyterlite_contents = ["jupyterlite_contents/auto_*"]
     jupyterlite_bind_ipynb_suffix = False
+    # bakes the browser's extra packages into the Pyodide lock at build time
+    jupyterlite_config = "jupyter_lite_config.py"
     # served at the docs root (/mne_data/...) through html_extra_path below
     stage_lite_data(curpath / "lite_extra" / "mne_data")
 
diff --git a/doc/jupyter_lite_config.py b/doc/jupyter_lite_config.py
new file mode 100644
index 00000000000..e9acc669c90
--- /dev/null
+++ b/doc/jupyter_lite_config.py
@@ -0,0 +1,38 @@
+"""Build-time config for the JupyterLite site's Pyodide lock.
+
+Adds packages to the lock so Pyodide loads them at kernel initialization.
+Packages Pyodide already curates keep their curated version.
+
+On a dev build, MNE is installed by jupyterlite_setup_cell instead.
+"""
+
+# Authors: The MNE-Python contributors.
+# License: BSD-3-Clause
+# Copyright the MNE-Python contributors.
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent / "sphinxext"))
+
+from jupyterlite_lock_specs import (  # noqa: E402
+    jupyterlite_package_names,
+    jupyterlite_specs_to_lock,
+    mne_pypi_spec,
+)
+
+c = get_config()  # noqa: F821
+
+specs = jupyterlite_specs_to_lock()
+prefetch = jupyterlite_package_names()
+
+# a stable/maint build locks the real PyPI release instead of the dev wheel
+# build_lite_wheel.py builds; see mne_pypi_spec for more info.
+mne_spec = mne_pypi_spec()
+if mne_spec is not None:
+    specs.append(mne_spec)
+    prefetch.append("mne")
+
+c.PyodideLockAddon.enabled = True
+c.PyodideLockAddon.specs = specs
+c.PyodideLockAddon.prefetch_extra = prefetch
diff --git a/doc/sphinxext/build_lite_wheel.py b/doc/sphinxext/build_lite_wheel.py
index 890e77c206c..3500b65f3a0 100644
--- a/doc/sphinxext/build_lite_wheel.py
+++ b/doc/sphinxext/build_lite_wheel.py
@@ -118,9 +118,16 @@ def build_wheel():
 
 
 if __name__ == "__main__":
-    # Reuse a wheel that is already there, so repeat `make html` runs do not
-    # rebuild it. Remove doc/pypi (or `make clean`) to force a fresh one.
-    existing = find_wheels()
-    wheels = ", ".join(str(wheel) for wheel in (existing or build_wheel()))
-    verb = "Reusing" if existing else "Built"
-    print(f"[JupyterLite] {verb} MNE wheel(s) for the browser kernel: {wheels}")
+    from jupyterlite_lock_specs import mne_pypi_spec
+
+    if mne_pypi_spec() is not None:
+        # a stable/maint build locks the real PyPI release instead
+        print("[JupyterLite] Stable build: no wheel needed, using the PyPI release")
+    else:
+        # Reuse a wheel that is already there, so repeat `make html` runs do
+        # not rebuild it. Remove doc/pypi (or `make clean`) to force a fresh
+        # one.
+        existing = find_wheels()
+        wheels = ", ".join(str(wheel) for wheel in (existing or build_wheel()))
+        verb = "Reusing" if existing else "Built"
+        print(f"[JupyterLite] {verb} MNE wheel(s) for the browser kernel: {wheels}")
diff --git a/doc/sphinxext/jupyterlite_data.py b/doc/sphinxext/jupyterlite_data.py
index 829380b4d3d..87ad21ee4f4 100644
--- a/doc/sphinxext/jupyterlite_data.py
+++ b/doc/sphinxext/jupyterlite_data.py
@@ -15,6 +15,7 @@
 from pathlib import Path
 
 from build_lite_wheel import build_wheel, find_wheels
+from jupyterlite_lock_specs import mne_pypi_spec
 from mne_doc_utils import sphinx_logger
 
 import mne
@@ -175,9 +176,9 @@ def stage_lite_data(dst_base):
     sphinx_logger.info(
         f"[JupyterLite] Served data: {n_copied} files copied, {n_missing} missing"
     )
-    # the development wheel, so the browser installs this MNE rather than the
-    # PyPI release: doc/sphinxext/build_lite_wheel.py puts it in doc/pypi, where
-    # the piplite addon indexes it; `make html` runs that first, so this is
-    # only a fallback for a bare sphinx-build
-    wheels = find_wheels() or build_wheel()
-    sphinx_logger.info(f"[JupyterLite] MNE wheel for the browser kernel: {wheels}")
+    # build the wheels for dev, default to pypi for release
+    if mne_pypi_spec() is None:
+        wheels = find_wheels() or build_wheel()
+        sphinx_logger.info(f"[JupyterLite] MNE wheel for the browser kernel: {wheels}")
+    else:
+        sphinx_logger.info("[JupyterLite] Stable build: locking the PyPI release")
diff --git a/doc/sphinxext/jupyterlite_lock_specs.py b/doc/sphinxext/jupyterlite_lock_specs.py
new file mode 100644
index 00000000000..fc66bb92852
--- /dev/null
+++ b/doc/sphinxext/jupyterlite_lock_specs.py
@@ -0,0 +1,66 @@
+"""Specs to add to Pyodide's lock for JupyterLite, versus what it already curates.
+
+Naming a package in ``PyodideLockAddon.specs`` drops its existing pin from
+the lock (see ``pyodide_lock.uv_pip_compile.constraints_txt``) and resolves
+it fresh from PyPI instead, a smaller and differently versioned set than
+Pyodide's own curated wheels. :func:`jupyterlite_specs_to_lock` avoids that
+by only including specs Pyodide's own lock does not already satisfy.
+
+:func:`mne_pypi_spec` is the same idea for MNE itself: a stable/maint build
+can lock the real PyPI release, but a dev build's version has no PyPI release
+to lock, so it needs the wheel ``build_lite_wheel.py`` builds instead.
+"""
+
+# Authors: The MNE-Python contributors.
+# License: BSD-3-Clause
+# Copyright the MNE-Python contributors.
+
+import json
+import tomllib
+import urllib.request
+from pathlib import Path
+
+from jupyterlite_pyodide_kernel.constants import PYODIDE_LOCK_DEFAULT_URL
+from packaging.requirements import Requirement
+from packaging.utils import canonicalize_name
+
+_PYPROJECT_TOML = Path(__file__).parents[2] / "pyproject.toml"
+
+
+def jupyterlite_specs():
+    """PEP-508 specs in the "jupyterlite" dependency group of pyproject.toml."""
+    with open(_PYPROJECT_TOML, "rb") as fid:
+        return tomllib.load(fid)["dependency-groups"]["jupyterlite"]
+
+
+def jupyterlite_package_names():
+    """Canonical package names in the "jupyterlite" dependency group."""
+    return [canonicalize_name(Requirement(spec).name) for spec in jupyterlite_specs()]
+
+
+def jupyterlite_specs_to_lock():
+    """PEP-508 specs from the "jupyterlite" group Pyodide does not already satisfy."""
+    with urllib.request.urlopen(PYODIDE_LOCK_DEFAULT_URL) as fid:
+        curated = json.load(fid)["packages"]
+
+    to_lock = []
+    for spec in jupyterlite_specs():
+        req = Requirement(spec)
+        pkg = curated.get(canonicalize_name(req.name))
+        if pkg is None or not req.specifier.contains(pkg["version"]):
+            to_lock.append(spec)
+    return to_lock
+
+
+def mne_pypi_spec():
+    """Return the ``mne==<version>`` spec for a stable/maint build, else None.
+
+    A ".dev" version (the docs building from ``main``) has no matching PyPI
+    release to lock against, so the browser kernel needs the wheel
+    ``build_lite_wheel.py`` builds from the working tree instead.
+    """
+    import mne
+
+    if ".dev" in mne.__version__:
+        return None
+    return f"mne=={mne.__version__}"
diff --git a/doc/sphinxext/jupyterlite_setup_cell.py b/doc/sphinxext/jupyterlite_setup_cell.py
index f0bd1b55c26..83faaa19a4c 100644
--- a/doc/sphinxext/jupyterlite_setup_cell.py
+++ b/doc/sphinxext/jupyterlite_setup_cell.py
@@ -1,35 +1,48 @@
 """The setup cell prepended to every JupyterLite notebook.
 
-It installs MNE into the browser kernel and hands over to
-``mne.viz.backends._jupyterlite.setup_notebook``, which patches what Pyodide
-does not provide. piplite (not micropip) prefers the development MNE wheel
-bundled with the docs over PyPI, and ``keep_going`` reports a dependency with
-no wheel instead of aborting. ``sys.platform`` is ``"emscripten"`` only inside
-Pyodide, so the cell is a no-op in a local kernel and a notebook downloaded
-from inside JupyterLite runs unchanged there.
+It hands over to ``mne.viz.backends._jupyterlite.setup_notebook``, which
+patches what Pyodide does not provide. ``sys.platform`` is ``"emscripten"``
+only inside Pyodide, so the cell is a no-op in a local kernel and a notebook
+downloaded from inside JupyterLite runs unchanged there.
 
 The docs build prepends it only to the notebooks copied into the JupyterLite
 contents, not through ``first_notebook_cell``, which would also put it in the
 ``.ipynb`` offered for download.
+
+The "jupyterlite" dependency group in pyproject.toml, and MNE itself on a
+stable/maint build, are already sitting in the browser kernel by the time
+this cell runs, loaded at kernel start per jupyter_lite_config.py. A dev
+build has no PyPI release of MNE to lock that way (see
+jupyterlite_lock_specs.mne_pypi_spec), so this cell installs the development
+wheel ``build_lite_wheel.py`` built instead.
 """
 
 # Authors: The MNE-Python contributors.
 # License: BSD-3-Clause
 # Copyright the MNE-Python contributors.
 
-# ruff: noqa: E501  # the install list stays on one line so the cell reads short
-
 import ast
 
-LITE_SETUP_CELL = """\
-# 💡 Added by the docs build: installs MNE into the browser kernel and adapts
-# it to Pyodide. Does nothing outside JupyterLite.
-import sys
+from jupyterlite_lock_specs import mne_pypi_spec
 
-if sys.platform == "emscripten":
+_INSTALL_MNE = """\
     import piplite
 
-    await piplite.install(["mne", "scikit-learn", "joblib", "pandas", "seaborn", "mne-connectivity", "nibabel", "pyvista-js", "pyxdf", "mffpy", "python-picard"], keep_going=True)  # noqa: E501
+    await piplite.install(["mne"], keep_going=True)
+"""
+
+# a raw newline or backslash inside an f-string's {} needs Python >= 3.12
+# (PEP 701), below MNE's floor, so the piplite block above is substituted in
+# by bare name; the \ right after it drops this template line's own newline,
+# so a blank line between "if" and "from" only appears when that block
+# (which ends with one) is substituted in
+LITE_SETUP_CELL = f"""\
+# 💡 Added by the docs build: adapts MNE to Pyodide. Does nothing outside
+# JupyterLite.
+import sys
+
+if sys.platform == "emscripten":
+{_INSTALL_MNE if mne_pypi_spec() is None else ""}\
     from mne.viz.backends._jupyterlite import setup_notebook
 
     setup_notebook()
diff --git a/pyproject.toml b/pyproject.toml
index 91ca7ed19a3..a46a83df435 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,6 +44,19 @@ doc = [
   "sphinxcontrib-youtube",
 ]
 doc-full = ["rpy2", { include-group = "doc" }]
+# Packages installed into the browser Pyodide kernel for JupyterLite notebooks
+jupyterlite = [
+  "joblib >= 0.8",
+  "mffpy >= 0.11.0",
+  "mne-connectivity",
+  "nibabel >= 5.2",
+  "pandas >= 2.2, != 3.0.4",
+  "python-picard >= 0.4",
+  "pyvista-js >= 0.16; python_version >= '3.12'",
+  "pyxdf",
+  "scikit-learn >= 1.5",
+  "seaborn >= 0.5, != 0.11.2",
+]
 # Dependencies in a separate group for uv lockfile generation, currently only used for
 # the 'old' environment CI test run
 lockfile_extras = [

From 3ffe162107f0a1ead07e55a80ae64c7f92354b54 Mon Sep 17 00:00:00 2001
From: Teon L Brooks <teon.brooks@gmail.com>
Date: Thu, 17 Sep 2026 19:43:48 -0400
Subject: [PATCH 2/7] cleanup

---
 doc/sphinxext/jupyterlite_lock_specs.py | 11 +++--------
 doc/sphinxext/jupyterlite_setup_cell.py | 11 -----------
 2 files changed, 3 insertions(+), 19 deletions(-)

diff --git a/doc/sphinxext/jupyterlite_lock_specs.py b/doc/sphinxext/jupyterlite_lock_specs.py
index fc66bb92852..45cc2a763bc 100644
--- a/doc/sphinxext/jupyterlite_lock_specs.py
+++ b/doc/sphinxext/jupyterlite_lock_specs.py
@@ -28,7 +28,7 @@
 
 
 def jupyterlite_specs():
-    """PEP-508 specs in the "jupyterlite" dependency group of pyproject.toml."""
+    """Retrieve the "jupyterlite" dependency group from pyproject.toml."""
     with open(_PYPROJECT_TOML, "rb") as fid:
         return tomllib.load(fid)["dependency-groups"]["jupyterlite"]
 
@@ -39,7 +39,7 @@ def jupyterlite_package_names():
 
 
 def jupyterlite_specs_to_lock():
-    """PEP-508 specs from the "jupyterlite" group Pyodide does not already satisfy."""
+    """Retrieve specs from "jupyterlite" group Pyodide does not already satisfy."""
     with urllib.request.urlopen(PYODIDE_LOCK_DEFAULT_URL) as fid:
         curated = json.load(fid)["packages"]
 
@@ -53,12 +53,7 @@ def jupyterlite_specs_to_lock():
 
 
 def mne_pypi_spec():
-    """Return the ``mne==<version>`` spec for a stable/maint build, else None.
-
-    A ".dev" version (the docs building from ``main``) has no matching PyPI
-    release to lock against, so the browser kernel needs the wheel
-    ``build_lite_wheel.py`` builds from the working tree instead.
-    """
+    """Return the ``mne==<version>`` spec for a stable/maint build, else None."""
     import mne
 
     if ".dev" in mne.__version__:
diff --git a/doc/sphinxext/jupyterlite_setup_cell.py b/doc/sphinxext/jupyterlite_setup_cell.py
index 83faaa19a4c..ddc19465661 100644
--- a/doc/sphinxext/jupyterlite_setup_cell.py
+++ b/doc/sphinxext/jupyterlite_setup_cell.py
@@ -8,13 +8,6 @@
 The docs build prepends it only to the notebooks copied into the JupyterLite
 contents, not through ``first_notebook_cell``, which would also put it in the
 ``.ipynb`` offered for download.
-
-The "jupyterlite" dependency group in pyproject.toml, and MNE itself on a
-stable/maint build, are already sitting in the browser kernel by the time
-this cell runs, loaded at kernel start per jupyter_lite_config.py. A dev
-build has no PyPI release of MNE to lock that way (see
-jupyterlite_lock_specs.mne_pypi_spec), so this cell installs the development
-wheel ``build_lite_wheel.py`` built instead.
 """
 
 # Authors: The MNE-Python contributors.
@@ -31,10 +24,6 @@
     await piplite.install(["mne"], keep_going=True)
 """
 
-# a raw newline or backslash inside an f-string's {} needs Python >= 3.12
-# (PEP 701), below MNE's floor, so the piplite block above is substituted in
-# by bare name; the \ right after it drops this template line's own newline,
-# so a blank line between "if" and "from" only appears when that block
 # (which ends with one) is substituted in
 LITE_SETUP_CELL = f"""\
 # 💡 Added by the docs build: adapts MNE to Pyodide. Does nothing outside

From b1d33ea1d37444ddc157a5d8c982a75aa5466fb5 Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Fri, 18 Sep 2026 11:08:27 -0400
Subject: [PATCH 3/7] Simplify [circle full]

---
 doc/jupyter_lite_config.py              | 26 +++++++++----------------
 doc/sphinxext/build_lite_wheel.py       | 19 ++++++------------
 doc/sphinxext/jupyterlite_data.py       | 11 ++++-------
 doc/sphinxext/jupyterlite_lock_specs.py | 13 -------------
 doc/sphinxext/jupyterlite_setup_cell.py | 26 +++++++------------------
 pyproject.toml                          | 23 +++++++++++++---------
 6 files changed, 40 insertions(+), 78 deletions(-)

diff --git a/doc/jupyter_lite_config.py b/doc/jupyter_lite_config.py
index e9acc669c90..07dd5b34af3 100644
--- a/doc/jupyter_lite_config.py
+++ b/doc/jupyter_lite_config.py
@@ -1,9 +1,8 @@
 """Build-time config for the JupyterLite site's Pyodide lock.
 
-Adds packages to the lock so Pyodide loads them at kernel initialization.
-Packages Pyodide already curates keep their curated version.
-
-On a dev build, MNE is installed by jupyterlite_setup_cell instead.
+Adds MNE and the packages the notebooks import to the lock, so Pyodide loads
+them at kernel initialization. Packages Pyodide already curates keep their
+curated version.
 """
 
 # Authors: The MNE-Python contributors.
@@ -18,21 +17,14 @@
 from jupyterlite_lock_specs import (  # noqa: E402
     jupyterlite_package_names,
     jupyterlite_specs_to_lock,
-    mne_pypi_spec,
 )
 
 c = get_config()  # noqa: F821
 
-specs = jupyterlite_specs_to_lock()
-prefetch = jupyterlite_package_names()
-
-# a stable/maint build locks the real PyPI release instead of the dev wheel
-# build_lite_wheel.py builds; see mne_pypi_spec for more info.
-mne_spec = mne_pypi_spec()
-if mne_spec is not None:
-    specs.append(mne_spec)
-    prefetch.append("mne")
-
 c.PyodideLockAddon.enabled = True
-c.PyodideLockAddon.specs = specs
-c.PyodideLockAddon.prefetch_extra = prefetch
+# the MNE wheel build_lite_wheel.py builds from this checkout (a tagged
+# checkout gives the release): the solve takes it over PyPI, which would
+# otherwise supply the latest release through mne-connectivity's mne>=1.6
+c.PyodideLockAddon.wheels = ["pypi"]
+c.PyodideLockAddon.specs = ["mne", *jupyterlite_specs_to_lock()]
+c.PyodideLockAddon.prefetch_extra = ["mne", *jupyterlite_package_names()]
diff --git a/doc/sphinxext/build_lite_wheel.py b/doc/sphinxext/build_lite_wheel.py
index 3500b65f3a0..890e77c206c 100644
--- a/doc/sphinxext/build_lite_wheel.py
+++ b/doc/sphinxext/build_lite_wheel.py
@@ -118,16 +118,9 @@ def build_wheel():
 
 
 if __name__ == "__main__":
-    from jupyterlite_lock_specs import mne_pypi_spec
-
-    if mne_pypi_spec() is not None:
-        # a stable/maint build locks the real PyPI release instead
-        print("[JupyterLite] Stable build: no wheel needed, using the PyPI release")
-    else:
-        # Reuse a wheel that is already there, so repeat `make html` runs do
-        # not rebuild it. Remove doc/pypi (or `make clean`) to force a fresh
-        # one.
-        existing = find_wheels()
-        wheels = ", ".join(str(wheel) for wheel in (existing or build_wheel()))
-        verb = "Reusing" if existing else "Built"
-        print(f"[JupyterLite] {verb} MNE wheel(s) for the browser kernel: {wheels}")
+    # Reuse a wheel that is already there, so repeat `make html` runs do not
+    # rebuild it. Remove doc/pypi (or `make clean`) to force a fresh one.
+    existing = find_wheels()
+    wheels = ", ".join(str(wheel) for wheel in (existing or build_wheel()))
+    verb = "Reusing" if existing else "Built"
+    print(f"[JupyterLite] {verb} MNE wheel(s) for the browser kernel: {wheels}")
diff --git a/doc/sphinxext/jupyterlite_data.py b/doc/sphinxext/jupyterlite_data.py
index 87ad21ee4f4..8fb06084220 100644
--- a/doc/sphinxext/jupyterlite_data.py
+++ b/doc/sphinxext/jupyterlite_data.py
@@ -15,7 +15,6 @@
 from pathlib import Path
 
 from build_lite_wheel import build_wheel, find_wheels
-from jupyterlite_lock_specs import mne_pypi_spec
 from mne_doc_utils import sphinx_logger
 
 import mne
@@ -176,9 +175,7 @@ def stage_lite_data(dst_base):
     sphinx_logger.info(
         f"[JupyterLite] Served data: {n_copied} files copied, {n_missing} missing"
     )
-    # build the wheels for dev, default to pypi for release
-    if mne_pypi_spec() is None:
-        wheels = find_wheels() or build_wheel()
-        sphinx_logger.info(f"[JupyterLite] MNE wheel for the browser kernel: {wheels}")
-    else:
-        sphinx_logger.info("[JupyterLite] Stable build: locking the PyPI release")
+    # the MNE wheel jupyter_lite_config.py locks for the browser: `make html`
+    # builds it first, so this is only a fallback for a bare sphinx-build
+    wheels = find_wheels() or build_wheel()
+    sphinx_logger.info(f"[JupyterLite] MNE wheel for the browser kernel: {wheels}")
diff --git a/doc/sphinxext/jupyterlite_lock_specs.py b/doc/sphinxext/jupyterlite_lock_specs.py
index 45cc2a763bc..ab795596d4b 100644
--- a/doc/sphinxext/jupyterlite_lock_specs.py
+++ b/doc/sphinxext/jupyterlite_lock_specs.py
@@ -5,10 +5,6 @@
 it fresh from PyPI instead, a smaller and differently versioned set than
 Pyodide's own curated wheels. :func:`jupyterlite_specs_to_lock` avoids that
 by only including specs Pyodide's own lock does not already satisfy.
-
-:func:`mne_pypi_spec` is the same idea for MNE itself: a stable/maint build
-can lock the real PyPI release, but a dev build's version has no PyPI release
-to lock, so it needs the wheel ``build_lite_wheel.py`` builds instead.
 """
 
 # Authors: The MNE-Python contributors.
@@ -50,12 +46,3 @@ def jupyterlite_specs_to_lock():
         if pkg is None or not req.specifier.contains(pkg["version"]):
             to_lock.append(spec)
     return to_lock
-
-
-def mne_pypi_spec():
-    """Return the ``mne==<version>`` spec for a stable/maint build, else None."""
-    import mne
-
-    if ".dev" in mne.__version__:
-        return None
-    return f"mne=={mne.__version__}"
diff --git a/doc/sphinxext/jupyterlite_setup_cell.py b/doc/sphinxext/jupyterlite_setup_cell.py
index ddc19465661..bfa631523fe 100644
--- a/doc/sphinxext/jupyterlite_setup_cell.py
+++ b/doc/sphinxext/jupyterlite_setup_cell.py
@@ -1,9 +1,11 @@
 """The setup cell prepended to every JupyterLite notebook.
 
 It hands over to ``mne.viz.backends._jupyterlite.setup_notebook``, which
-patches what Pyodide does not provide. ``sys.platform`` is ``"emscripten"``
-only inside Pyodide, so the cell is a no-op in a local kernel and a notebook
-downloaded from inside JupyterLite runs unchanged there.
+patches what Pyodide does not provide; MNE itself and the packages the
+notebooks import are in the Pyodide lock (see ``jupyter_lite_config.py``).
+``sys.platform`` is ``"emscripten"`` only inside Pyodide, so the cell is a
+no-op in a local kernel and a notebook downloaded from inside JupyterLite runs
+unchanged there.
 
 The docs build prepends it only to the notebooks copied into the JupyterLite
 contents, not through ``first_notebook_cell``, which would also put it in the
@@ -14,29 +16,15 @@
 # License: BSD-3-Clause
 # Copyright the MNE-Python contributors.
 
-import ast
-
-from jupyterlite_lock_specs import mne_pypi_spec
-
-_INSTALL_MNE = """\
-    import piplite
-
-    await piplite.install(["mne"], keep_going=True)
-"""
-
-# (which ends with one) is substituted in
-LITE_SETUP_CELL = f"""\
+LITE_SETUP_CELL = """\
 # 💡 Added by the docs build: adapts MNE to Pyodide. Does nothing outside
 # JupyterLite.
 import sys
 
 if sys.platform == "emscripten":
-{_INSTALL_MNE if mne_pypi_spec() is None else ""}\
     from mne.viz.backends._jupyterlite import setup_notebook
 
     setup_notebook()
 """
 # nothing else runs this before a reader does, so at least make sure it parses
-compile(
-    LITE_SETUP_CELL, "lite_setup_cell", "exec", flags=ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
-)
+compile(LITE_SETUP_CELL, "lite_setup_cell", "exec")
diff --git a/pyproject.toml b/pyproject.toml
index a46a83df435..2fd89b7d710 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,6 +16,9 @@ doc = [
   # the two resolve together. Below either, the browser drops to Pyodide 0.29
   # and its matplotlib 3.8.4, a minor under the 3.9 MNE declares.
   "jupyterlite-pyodide-kernel >= 0.8",
+  # [lock] brings pyodide-lock and uv for jupyter_lite_config.py; pyodide-lock
+  # needs 3.12, which every docs build has
+  "jupyterlite-pyodide-kernel[lock] >= 0.8; python_version >= '3.12'",
   "jupyterlite-sphinx >= 0.23",
   "memory_profiler >= 0.16",
   "mne-bids",
@@ -44,18 +47,20 @@ doc = [
   "sphinxcontrib-youtube",
 ]
 doc-full = ["rpy2", { include-group = "doc" }]
-# Packages installed into the browser Pyodide kernel for JupyterLite notebooks
+# Packages installed into the browser Pyodide kernel for JupyterLite notebooks;
+# unpinned, since Pyodide's curated version wins where it has one and the rest
+# resolve to the latest release (see doc/sphinxext/jupyterlite_lock_specs.py)
 jupyterlite = [
-  "joblib >= 0.8",
-  "mffpy >= 0.11.0",
+  "joblib",
+  "mffpy",
   "mne-connectivity",
-  "nibabel >= 5.2",
-  "pandas >= 2.2, != 3.0.4",
-  "python-picard >= 0.4",
-  "pyvista-js >= 0.16; python_version >= '3.12'",
+  "nibabel",
+  "pandas",
+  "python-picard",
+  "pyvista-js",
   "pyxdf",
-  "scikit-learn >= 1.5",
-  "seaborn >= 0.5, != 0.11.2",
+  "scikit-learn",
+  "seaborn",
 ]
 # Dependencies in a separate group for uv lockfile generation, currently only used for
 # the 'old' environment CI test run

From fef8fcf5b134ac321ad906907d6428aae43ee869 Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Fri, 18 Sep 2026 12:26:29 -0400
Subject: [PATCH 4/7] FIX: Stabilize [circle full]

---
 azure-pipelines.yml                     | 87 +++++--------------------
 mne/datasets/_fetch.py                  |  3 +-
 mne/datasets/_fsaverage/base.py         |  4 +-
 mne/datasets/_phantom/base.py           |  2 +-
 mne/datasets/config.py                  | 70 ++++++++++++--------
 mne/datasets/utils.py                   | 11 ++--
 mne/viz/backends/tests/test_renderer.py |  8 ++-
 7 files changed, 76 insertions(+), 109 deletions(-)

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index d85b5999387..320e73c9ddd 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -47,12 +47,6 @@ stages:
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           MNE_TEST_ALLOW_SKIP: '^$'  # nothing
           MNE_BROWSER_PRECOMPUTE: 'false'
-          # See tools/github_actions_env_vars.sh for why these are set (this job
-          # is on Python 3.14, so sys.monitoring can measure branches)
-          COVERAGE_CORE: 'sysmon'
-          UV_CACHE_DIR: '/home/vsts/.cache/uv'
-          UV_SYSTEM_PYTHON: 'true'  # UsePythonVersion gives us a bare interpreter, not a venv
-          UV_NO_PROGRESS: 'true'
         steps:
           - bash: |
               set -xeo pipefail
@@ -62,27 +56,21 @@ stages:
             displayName: Setup up Xvfb
           - task: Cache@2
             inputs:
-              key: '"minimal-cmds" | "$(Agent.OS)" | $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh'
+              key: minimal-cmds-1
               path: /home/vsts/minimal_cmds
             displayName: Cache minimal commands
-          - bash: $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh
+          - bash: ./tools/get_minimal_commands.sh
             displayName: Get minimal commands
           - task: UsePythonVersion@0
             inputs:
               versionSpec: '3.14'
               architecture: 'x64'
               addToPath: true
-          - task: Cache@2
-            inputs:
-              key: '"uv" | "$(Agent.OS)" | pyproject.toml'
-              restoreKeys: '"uv" | "$(Agent.OS)"'
-              path: $(UV_CACHE_DIR)
-            displayName: Cache uv
           - bash: |
               set -xeo pipefail
-              python -m pip install --progress-bar off --upgrade "uv>=0.9"
-              uv pip install --upgrade --only-binary=":all:" --no-binary=mne --no-binary=mne-qt-browser -e . --group=test "mne-qt-browser @ https://github.com/mne-tools/mne-qt-browser/archive/refs/heads/main.zip" pyvista scikit-learn python-picard qtpy nibabel sphinx-gallery "PySide6!=6.8.0,!=6.8.0.1,!=6.8.1.1,!=6.9.1" pandas neo pymatreader antio defusedxml curryreader pymef openmeeg
-            displayName: Install dependencies with uv
+              python -m pip install --progress-bar off --upgrade pip
+              python -m pip install --progress-bar off --upgrade --only-binary=":all:" -e . --group=test "mne-qt-browser @ https://github.com/mne-tools/mne-qt-browser/archive/refs/heads/main.zip" pyvista scikit-learn python-picard qtpy nibabel sphinx-gallery "PySide6!=6.8.0,!=6.8.0.1,!=6.8.1.1,!=6.9.1" pandas neo pymatreader antio defusedxml curryreader pymef openmeeg
+            displayName: Install dependencies with pip
           - bash: $(MNE_TOOLS_DIR)/tools/check_qt_import.sh PySide6
             displayName: Check Qt import
           - bash: |
@@ -94,7 +82,7 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
+              key: $(testing_version)
               path: /home/vsts/mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
@@ -117,8 +105,6 @@ stages:
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           TEST_OPTIONS: "--tb=short --cov=mne --cov-report=xml --cov-append -vv mne/gui mne/viz/_brain mne/viz/backends mne/viz/tests/test_evoked.py mne/report"
           MNE_TEST_ALLOW_SKIP: '^$'  # nothing (can be overridden below)
-          # See tools/github_actions_env_vars.sh; this job is on Python 3.14
-          COVERAGE_CORE: 'sysmon'
         steps:
           - bash: |
               set -xeo pipefail
@@ -147,7 +133,7 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
+              key: $(testing_version)
               path: /home/vsts/mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
@@ -180,22 +166,16 @@ stages:
         pool:
           vmImage: 'windows-latest'
         variables:
-          MNE_TOOLS_DIR: '$(Pipeline.Workspace)/mne-tools'
           MNE_LOGGING_LEVEL: 'warning'
           MNE_FORCE_SERIAL: 'true'
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           OMP_DYNAMIC: 'false'
           PYTHONUNBUFFERED: 1
-          # See tools/github_actions_env_vars.sh; both matrix legs are Python 3.14
-          COVERAGE_CORE: 'sysmon'
-          # See tools/github_actions_env_vars.sh for why these three are set
-          NUMBA_CACHE_DIR: 'C:\Users\VssAdministrator\.cache\mne-numba'
-          NUMBA_CPU_NAME: 'generic'
-          NUMBA_CPU_FEATURES: ''
-          UV_CACHE_DIR: 'C:\Users\VssAdministrator\.cache\uv'
-          UV_SYSTEM_PYTHON: 'true'  # UsePythonVersion gives us a bare interpreter, not a venv
-          UV_NO_PROGRESS: 'true'
           AZURE_CI_WINDOWS: 'true'
+          # Mesa's llvmpipe rasterizer threads can deadlock at process exit on
+          # Windows (pyvista/setup-headless-display-action#55); the action sets
+          # this itself on GHA, but here we only run its install script
+          LP_NUM_THREADS: '0'
           MNE_CI_KIND: $(TEST_MODE)
           MNE_TEST_ALLOW_SKIP: $(MNE_TEST_ALLOW_SKIP)
         timeoutInMinutes: 40
@@ -205,47 +185,25 @@ stages:
             3.14 pip:
               TEST_MODE: 'pip'
               PYTHON_VERSION: '3.14'
-              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires FreeSurfer|CUDA not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
+              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires MNE-C|Requires FreeSurfer|CUDA not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
             3.14 pip pre:
               TEST_MODE: 'pip-pre'
               PYTHON_VERSION: '3.14'
-              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires FreeSurfer|CUDA not|Numba not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
+              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires MNE-C|Requires FreeSurfer|CUDA not|Numba not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
         steps:
           - task: UsePythonVersion@0
             inputs:
               versionSpec: $(PYTHON_VERSION)
               architecture: 'x64'
               addToPath: true
-          - bash: |
-              set -xeo pipefail
-              git clone --depth 1 https://github.com/mne-tools/mne-tools.git "$MNE_TOOLS_DIR"
-            displayName: Clone mne-tools
-          - task: Cache@2
-            inputs:
-              key: '"minimal-cmds" | "$(Agent.OS)" | $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh'
-              path: C:\Users\VssAdministrator\minimal_cmds
-            displayName: Cache minimal commands
-          # MNE_TOOLS_DIR is a Windows path and these steps run under Git Bash, hence
-          # cygpath; backticks rather than $(...) so Azure does not read it as a macro
-          - bash: |
-              set -eo pipefail
-              MNE_TOOLS_UNIX=`cygpath -u "$MNE_TOOLS_DIR"`
-              bash "$MNE_TOOLS_UNIX/tools/get_minimal_commands.sh"
-            displayName: Get minimal commands
           - bash: |
               set -xeo pipefail
               git clone --depth 1 https://github.com/pyvista/setup-headless-display-action.git
               MESA3D_VERSION=24.3.0 bash setup-headless-display-action/windows/install_opengl.sh
             displayName: Install OpenGL
-          - task: Cache@2
-            inputs:
-              key: '"uv" | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(TEST_MODE)" | pyproject.toml'
-              restoreKeys: '"uv" | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(TEST_MODE)"'
-              path: $(UV_CACHE_DIR)
-            displayName: Cache uv
           - bash: ./tools/azure_dependencies.sh
             displayName: Install dependencies
-          - script: uv pip install --only-binary=":all:" --no-binary=mne -e .
+          - script: pip install --only-binary=":all:" -e .
             displayName: Install mne
           - script: mne sys_info -pd
             displayName: Print config
@@ -257,26 +215,11 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
+              key: $(testing_version)
               path: C:\Users\VssAdministrator\mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
             displayName: Download testing data
-          - bash: ./tools/get_numba_version.sh
-            displayName: Get numba version
-          - task: Cache@2
-            inputs:
-              key: 'mne_numba | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(numba_version)" | mne/**/*numba*.py'
-              path: C:\Users\VssAdministrator\.cache\mne-numba
-            displayName: Cache numba
-            # pip-pre has no numba when nightly wheels are missing; without it
-            # nothing creates the cache dir and the post-job save fails on tar
-            condition: ne(variables['numba_version'], 'none')
-          # Windows does not define HOME, and MNE-C dereferences it unconditionally:
-          # mne_forward_solution crashes with 0xC0000005 without it. Set after the
-          # steps above so that Git Bash keeps deriving its own MSYS-style HOME.
-          - script: 'echo ##vso[task.setvariable variable=HOME]%USERPROFILE%'
-            displayName: Set HOME for MNE-C
           - script: pytest -m "not (slowtest or pgtest)" -n $(PYTEST_XDIST_N) --dist loadscope --timeout=120 --timeout-method=thread -o faulthandler_timeout=110 --tb=short --cov=mne --cov-report=xml -vv mne
             displayName: Run tests
           - bash: bash <(curl -s https://codecov.io/bash)
diff --git a/mne/datasets/_fetch.py b/mne/datasets/_fetch.py
index 6ae66814dc4..0151e60dca8 100644
--- a/mne/datasets/_fetch.py
+++ b/mne/datasets/_fetch.py
@@ -126,7 +126,8 @@ def fetch_dataset(
         {'dataset_name': 'sample',
          'archive_name': 'MNE-sample-data-processed.tar.gz',
          'hash': 'md5:e8f30c4516abdc12a0c08e6bae57409c',
-         'url': 'https://osf.io/download/86qa2?version=6',
+         'url': 'https://github.com/mne-tools/mne-data/releases/download/'
+                'sample-6/MNE-sample-data-processed.tar.gz',
          'folder_name': 'MNE-sample-data',
          'config_key': 'MNE_DATASETS_SAMPLE_PATH'}
 
diff --git a/mne/datasets/_fsaverage/base.py b/mne/datasets/_fsaverage/base.py
index e6a1aa51ea5..2e83b20e870 100644
--- a/mne/datasets/_fsaverage/base.py
+++ b/mne/datasets/_fsaverage/base.py
@@ -73,13 +73,13 @@ def fetch_fsaverage(subjects_dir=None, *, verbose=None):
     _manifest_check_download(
         manifest_path=FSAVERAGE_MANIFEST_PATH / "root.txt",
         destination=subjects_dir,
-        url="https://osf.io/download/3bxqt?version=2",
+        url="https://github.com/mne-tools/mne-data/releases/download/fsaverage-1.0/fsaverage-root.zip",
         hash_="5133fe92b7b8f03ae19219d5f46e4177",
     )
     _manifest_check_download(
         manifest_path=FSAVERAGE_MANIFEST_PATH / "bem.txt",
         destination=subjects_dir / "fsaverage",
-        url="https://osf.io/download/7ve8g?version=4",
+        url="https://github.com/mne-tools/mne-data/releases/download/fsaverage-1.0/fsaverage-bem.zip",
         hash_="b31509cdcf7908af6a83dc5ee8f49fb1",
     )
     return fs_dir
diff --git a/mne/datasets/_phantom/base.py b/mne/datasets/_phantom/base.py
index 0cd54957192..c2c17243246 100644
--- a/mne/datasets/_phantom/base.py
+++ b/mne/datasets/_phantom/base.py
@@ -48,7 +48,7 @@ def fetch_phantom(kind="otaniemi", subjects_dir=None, *, verbose=None):
     """
     phantoms = dict(
         otaniemi=dict(
-            url="https://osf.io/download/j5czy?version=1",
+            url="https://github.com/mne-tools/mne-data/releases/download/phantom_otaniemi-1/phantom_otaniemi.zip",
             hash="42d17db5b1db3e30327ffb4cf2649de8",
         ),
     )
diff --git a/mne/datasets/config.py b/mne/datasets/config.py
index 0e2c581f450..8b7ade4e9ff 100644
--- a/mne/datasets/config.py
+++ b/mne/datasets/config.py
@@ -140,7 +140,7 @@
 MNE_DATASETS["fnirs_motor"] = dict(
     archive_name="MNE-fNIRS-motor-data.tgz",
     hash="md5:c4935d19ddab35422a69f3326a01fef8",
-    url="https://osf.io/download/dj3eh?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/fnirs_motor-1/MNE-fNIRS-motor-data.tgz",
     folder_name="MNE-fNIRS-motor-data",
     config_key="MNE_DATASETS_FNIRS_MOTOR_PATH",
 )
@@ -148,7 +148,8 @@
 MNE_DATASETS["ucl_opm_auditory"] = dict(
     archive_name="auditory_OPM_stationary.zip",
     hash="md5:b2d69aa2d656b960bd0c18968dc1a14d",
-    url="https://osf.io/download/tp324?version=1",  # original is mwrt3
+    # original is https://osf.io/mwrt3
+    url="https://github.com/mne-tools/mne-data/releases/download/ucl_opm_auditory-1/auditory_OPM_stationary.zip",
     folder_name="auditory_OPM_stationary",
     config_key="MNE_DATASETS_UCL_OPM_AUDITORY_PATH",
 )
@@ -156,7 +157,7 @@
 MNE_DATASETS["kiloword"] = dict(
     archive_name="MNE-kiloword-data.tar.gz",
     hash="md5:3a124170795abbd2e48aae8727e719a8",
-    url="https://osf.io/download/qkvf9?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/kiloword-1/MNE-kiloword-data.tar.gz",
     folder_name="MNE-kiloword-data",
     config_key="MNE_DATASETS_KILOWORD_PATH",
 )
@@ -172,7 +173,7 @@
 MNE_DATASETS["opm"] = dict(
     archive_name="MNE-OPM-data.tar.gz",
     hash="md5:370ad1dcfd5c47e029e692c85358a374",
-    url="https://osf.io/download/p6ae7?version=2",
+    url="https://github.com/mne-tools/mne-data/releases/download/opm-2/MNE-OPM-data.tar.gz",
     folder_name="MNE-OPM-data",
     config_key="MNE_DATASETS_OPM_PATH",
 )
@@ -180,7 +181,7 @@
 MNE_DATASETS["phantom_kit"] = dict(
     archive_name="MNE-phantom-KIT-data.tar.gz",
     hash="md5:7bfdf40bbeaf17a66c99c695640e0740",
-    url="https://osf.io/download/fb6ya?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/phantom_kit-1/MNE-phantom-KIT-data.tar.gz",
     folder_name="MNE-phantom-KIT-data",
     config_key="MNE_DATASETS_PHANTOM_KIT_PATH",
 )
@@ -188,7 +189,7 @@
 MNE_DATASETS["phantom_4dbti"] = dict(
     archive_name="MNE-phantom-4DBTi.zip",
     hash="md5:938a601440f3ffa780d20a17bae039ff",
-    url="https://osf.io/download/v2brw?version=2",
+    url="https://github.com/mne-tools/mne-data/releases/download/phantom_4dbti-2/MNE-phantom-4DBTi.zip",
     folder_name="MNE-phantom-4DBTi",
     config_key="MNE_DATASETS_PHANTOM_4DBTI_PATH",
 )
@@ -196,7 +197,7 @@
 MNE_DATASETS["phantom_kernel"] = dict(
     archive_name="MNE-phantom-kernel.tar.gz",
     hash="md5:4e2ad987dac1a20f95bae8ffeb2d41d6",
-    url="https://osf.io/download/dj7wz?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/phantom_kernel-1/MNE-phantom-kernel.tar.gz",
     folder_name="MNE-phantom-kernel-data",
     config_key="MNE_DATASETS_PHANTOM_KERNEL_PATH",
 )
@@ -204,7 +205,7 @@
 MNE_DATASETS["sample"] = dict(
     archive_name="MNE-sample-data-processed.tar.gz",
     hash="md5:e8f30c4516abdc12a0c08e6bae57409c",
-    url="https://osf.io/download/86qa2?version=6",
+    url="https://github.com/mne-tools/mne-data/releases/download/sample-6/MNE-sample-data-processed.tar.gz",
     folder_name="MNE-sample-data",
     config_key="MNE_DATASETS_SAMPLE_PATH",
 )
@@ -221,7 +222,7 @@
 MNE_DATASETS["somato"] = dict(
     archive_name="MNE-somato-data.tar.gz",
     hash="md5:9a191907b326b9402341ee7a0d1240d8",
-    url="https://osf.io/download/tp4sg?version=8",
+    url="https://github.com/mne-tools/mne-data/releases/download/somato-8/MNE-somato-data.tar.gz",
     folder_name="MNE-somato-data",
     config_key="MNE_DATASETS_SOMATO_PATH",
 )
@@ -229,7 +230,7 @@
 MNE_DATASETS["spm"] = dict(
     archive_name="MNE-spm-face.tar.gz",
     hash="md5:9f43f67150e3b694b523a21eb929ea75",
-    url="https://osf.io/download/je4s8?version=2",
+    url="https://github.com/mne-tools/mne-data/releases/download/spm-2/MNE-spm-face.tar.gz",
     folder_name="MNE-spm-face",
     config_key="MNE_DATASETS_SPM_FACE_PATH",
 )
@@ -241,17 +242,32 @@
     folder_name="MNE-visual_92_categories-data",
     config_key="MNE_DATASETS_VISUAL_92_CATEGORIES_PATH",
 )
+# four parts, each under GitHub's 2 GiB release-asset limit
 MNE_DATASETS["visual_92_categories_1"] = dict(
     archive_name="MNE-visual_92_categories-data-part1.tar.gz",
-    hash="md5:74f50bbeb65740903eadc229c9fa759f",
-    url="https://osf.io/download/8ejrs?version=1",
+    hash="md5:b7ee73c69c1c086354ae370c66b41f0b",
+    url="https://github.com/mne-tools/mne-data/releases/download/visual_92_categories-2/MNE-visual_92_categories-data-part1.tar.gz",
     folder_name="MNE-visual_92_categories-data",
     config_key="MNE_DATASETS_VISUAL_92_CATEGORIES_PATH",
 )
 MNE_DATASETS["visual_92_categories_2"] = dict(
     archive_name="MNE-visual_92_categories-data-part2.tar.gz",
-    hash="md5:203410a98afc9df9ae8ba9f933370e20",
-    url="https://osf.io/download/t4yjp?version=1",
+    hash="md5:f35b89c76a76f2341e68d60b46578621",
+    url="https://github.com/mne-tools/mne-data/releases/download/visual_92_categories-2/MNE-visual_92_categories-data-part2.tar.gz",
+    folder_name="MNE-visual_92_categories-data",
+    config_key="MNE_DATASETS_VISUAL_92_CATEGORIES_PATH",
+)
+MNE_DATASETS["visual_92_categories_3"] = dict(
+    archive_name="MNE-visual_92_categories-data-part3.tar.gz",
+    hash="md5:94b68c9c3ce267cc82106518129c6221",
+    url="https://github.com/mne-tools/mne-data/releases/download/visual_92_categories-2/MNE-visual_92_categories-data-part3.tar.gz",
+    folder_name="MNE-visual_92_categories-data",
+    config_key="MNE_DATASETS_VISUAL_92_CATEGORIES_PATH",
+)
+MNE_DATASETS["visual_92_categories_4"] = dict(
+    archive_name="MNE-visual_92_categories-data-part4.tar.gz",
+    hash="md5:59b0296b2ef1763481e6e5123b0ca207",
+    url="https://github.com/mne-tools/mne-data/releases/download/visual_92_categories-2/MNE-visual_92_categories-data-part4.tar.gz",
     folder_name="MNE-visual_92_categories-data",
     config_key="MNE_DATASETS_VISUAL_92_CATEGORIES_PATH",
 )
@@ -259,14 +275,14 @@
 MNE_DATASETS["mtrf"] = dict(
     archive_name="mTRF_1.5.zip",
     hash="md5:273a390ebbc48da2c3184b01a82e4636",
-    url="https://osf.io/download/h85s2?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/mtrf-1/mTRF_1.5.zip",
     folder_name="mTRF_1.5",
     config_key="MNE_DATASETS_MTRF_PATH",
 )
 MNE_DATASETS["refmeg_noise"] = dict(
     archive_name="sample_reference_MEG_noise-raw.zip",
     hash="md5:779fecd890d98b73a4832e717d7c7c45",
-    url="https://osf.io/download/drt6v?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/refmeg_noise-1/sample_reference_MEG_noise-raw.zip",
     folder_name="MNE-refmeg-noise-data",
     config_key="MNE_DATASETS_REFMEG_NOISE_PATH",
 )
@@ -274,7 +290,7 @@
 MNE_DATASETS["ssvep"] = dict(
     archive_name="ssvep_example_data.zip",
     hash="md5:af866bbc0f921114ac9d683494fe87d6",
-    url="https://osf.io/download/z8h6k?version=5",
+    url="https://github.com/mne-tools/mne-data/releases/download/ssvep-5/ssvep_example_data.zip",
     folder_name="ssvep-example-data",
     config_key="MNE_DATASETS_SSVEP_PATH",
 )
@@ -282,7 +298,7 @@
 MNE_DATASETS["erp_core"] = dict(
     archive_name="MNE-ERP-CORE-data.tar.gz",
     hash="md5:5866c0d6213bd7ac97f254c776f6c4b1",
-    url="https://osf.io/download/rzgba?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/erp_core-1/MNE-ERP-CORE-data.tar.gz",
     folder_name="MNE-ERP-CORE-data",
     config_key="MNE_DATASETS_ERP_CORE_PATH",
 )
@@ -290,7 +306,7 @@
 MNE_DATASETS["epilepsy_ecog"] = dict(
     archive_name="MNE-epilepsy-ecog-data.tar.gz",
     hash="md5:ffb139174afa0f71ec98adbbb1729dea",
-    url="https://osf.io/download/z4epq?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/epilepsy_ecog-1/MNE-epilepsy-ecog-data.tar.gz",
     folder_name="MNE-epilepsy-ecog-data",
     config_key="MNE_DATASETS_EPILEPSY_ECOG_PATH",
 )
@@ -299,7 +315,7 @@
 MNE_DATASETS["fieldtrip_cmc"] = dict(
     archive_name="SubjectCMC.zip",
     hash="md5:6f9fd6520f9a66e20994423808d2528c",
-    url="https://osf.io/download/j9b6s?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/fieldtrip_cmc-1/SubjectCMC.zip",
     folder_name="MNE-fieldtrip_cmc-data",
     config_key="MNE_DATASETS_FIELDTRIP_CMC_PATH",
 )
@@ -308,28 +324,28 @@
 MNE_DATASETS["bst_auditory"] = dict(
     archive_name="bst_auditory.tar.gz",
     hash="md5:fa371a889a5688258896bfa29dd1700b",
-    url="https://osf.io/download/5t9n8?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/bst_auditory-1/bst_auditory.tar.gz",
     folder_name="MNE-brainstorm-data",
     config_key="MNE_DATASETS_BRAINSTORM_PATH",
 )
 MNE_DATASETS["bst_phantom_ctf"] = dict(
     archive_name="bst_phantom_ctf.tar.gz",
     hash="md5:80819cb7f5b92d1a5289db3fb6acb33c",
-    url="https://osf.io/download/sxr8y?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/bst_phantom_ctf-1/bst_phantom_ctf.tar.gz",
     folder_name="MNE-brainstorm-data",
     config_key="MNE_DATASETS_BRAINSTORM_PATH",
 )
 MNE_DATASETS["bst_phantom_elekta"] = dict(
     archive_name="bst_phantom_elekta.tar.gz",
     hash="md5:1badccbe17998d18cc373526e86a7aaf",
-    url="https://osf.io/download/dpcku?version=1",
+    url="https://github.com/mne-tools/mne-data/releases/download/bst_phantom_elekta-1/bst_phantom_elekta.tar.gz",
     folder_name="MNE-brainstorm-data",
     config_key="MNE_DATASETS_BRAINSTORM_PATH",
 )
 MNE_DATASETS["bst_raw"] = dict(
     archive_name="bst_raw.tar.gz",
     hash="md5:fa2efaaec3f3d462b319bc24898f440c",
-    url="https://osf.io/download/9675n?version=2",
+    url="https://github.com/mne-tools/mne-data/releases/download/bst_raw-2/bst_raw.tar.gz",
     folder_name="MNE-brainstorm-data",
     config_key="MNE_DATASETS_BRAINSTORM_PATH",
 )
@@ -355,7 +371,7 @@
     # Zenodo can be slow, so we use the OSF mirror
     # url=('https://zenodo.org/record/3523071/files/'
     #      'hf_sef_evoked.tar.gz'),
-    url="https://osf.io/download/25f8d?version=2",
+    url="https://github.com/mne-tools/mne-data/releases/download/hf_sef_evoked-2/hf_sef_evoked.tar.gz",
     folder_name="hf_sef",
     config_key="MNE_DATASETS_HF_SEF_PATH",
 )
@@ -373,7 +389,9 @@
 MNE_DATASETS["eyelink"] = dict(
     archive_name="MNE-eyelink-data.zip",
     hash="md5:68a6323ef17d655f1a659c3290ee1c3f",
-    url=("https://osf.io/download/xsu4g?version=1"),
+    url=(
+        "https://github.com/mne-tools/mne-data/releases/download/eyelink-1/MNE-eyelink-data.zip"
+    ),
     folder_name="MNE-eyelink-data",
     config_key="MNE_DATASETS_EYELINK_PATH",
 )
diff --git a/mne/datasets/utils.py b/mne/datasets/utils.py
index bef7102ecad..a0dc490ca4d 100644
--- a/mne/datasets/utils.py
+++ b/mne/datasets/utils.py
@@ -250,9 +250,9 @@ def _download_mne_dataset(
     # handle case of multiple sub-datasets with different urls
     if name == "visual_92_categories":
         dataset_params = []
-        for name in ["visual_92_categories_1", "visual_92_categories_2"]:
-            this_dataset = MNE_DATASETS[name]
-            this_dataset["dataset_name"] = name
+        for part in sorted(key for key in MNE_DATASETS if key.startswith(f"{name}_")):
+            this_dataset = MNE_DATASETS[part]
+            this_dataset["dataset_name"] = part
             dataset_params.append(this_dataset)
 
     return cast(
@@ -435,7 +435,10 @@ def fetch_aparc_sub_parcellation(subjects_dir=None, verbose=None):
 
     subjects_dir = get_subjects_dir(subjects_dir, raise_error=True)
     destination = subjects_dir / "fsaverage" / "label"
-    urls = dict(lh="https://osf.io/download/p92yb", rh="https://osf.io/download/4kxny")
+    urls = dict(
+        lh="https://github.com/mne-tools/mne-data/releases/download/hcp_aparc_sub-1/lh.aparc_sub.annot",
+        rh="https://github.com/mne-tools/mne-data/releases/download/hcp_aparc_sub-1/rh.aparc_sub.annot",
+    )
     hashes = dict(
         lh="9e4d8d6b90242b7e4b0145353436ef77", rh="dd6464db8e7762d969fc1d8087cd211b"
     )
diff --git a/mne/viz/backends/tests/test_renderer.py b/mne/viz/backends/tests/test_renderer.py
index 75af51ee5e0..09072986fb7 100644
--- a/mne/viz/backends/tests/test_renderer.py
+++ b/mne/viz/backends/tests/test_renderer.py
@@ -4,6 +4,7 @@
 
 import os
 import platform
+import subprocess
 import sys
 from contextlib import nullcontext
 
@@ -15,7 +16,6 @@
 import mne
 from mne.datasets import testing
 from mne.transforms import quat_to_rot, rot_to_quat
-from mne.utils import run_subprocess
 from mne.viz import Figure3D, get_3d_backend, set_3d_backend
 from mne.viz.backends._utils import ALLOWED_QUIVER_MODES
 from mne.viz.backends.renderer import _get_renderer
@@ -299,7 +299,8 @@ def test_renderer(renderer, monkeypatch):
         f"assert backend != 'jupyterlite_notebook' or 'vtk' not in sys.modules",
     ]
     monkeypatch.setenv("MNE_3D_BACKEND", backend)
-    run_subprocess(cmd)
+    proc = subprocess.run(cmd, capture_output=True, text=True, timeout=60)
+    assert proc.returncode == 0, proc.stderr
 
 
 def test_set_3d_backend_bad(monkeypatch, tmp_path):
@@ -622,4 +623,5 @@ def test_lite_setup_notebook(renderer_lite, tmp_path):
         )
     )
     args = [sys.executable, str(script), str(tmp_path / "mne_data"), str(_data_path)]
-    run_subprocess(args, env=env)
+    proc = subprocess.run(args, capture_output=True, text=True, env=env, timeout=60)
+    assert proc.returncode == 0, proc.stderr

From 3b00c3d207f99275d901661844ac6f6cd326492b Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Fri, 18 Sep 2026 13:34:23 -0400
Subject: [PATCH 5/7] FIX: Better [circle full]

---
 Makefile            |  2 +-
 azure-pipelines.yml | 83 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 73 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index 3ce4eda956d..12f4f302a8b 100644
--- a/Makefile
+++ b/Makefile
@@ -41,7 +41,7 @@ test-no-testing-data: in
 	$(PYTESTS) mne
 
 test-doc: sample_data testing_data
-	$(PYTESTS) --tb=short --cov=mne --cov-report=xml --cov-branch --doctest-modules --doctest-ignore-import-errors --doctest-glob='*.rst' ./doc/ --ignore=./doc/auto_examples --ignore=./doc/auto_tutorials --ignore=./doc/_build --ignore=./doc/conf.py --ignore=doc/sphinxext --fulltrace
+	$(PYTESTS) --tb=short --cov=mne --cov-report=xml --cov-branch --doctest-modules --doctest-ignore-import-errors --doctest-glob='*.rst' ./doc/ --ignore=./doc/auto_examples --ignore=./doc/auto_tutorials --ignore=./doc/_build --ignore=./doc/conf.py --ignore=./doc/jupyter_lite_config.py --ignore=doc/sphinxext --fulltrace
 
 pre-commit:
 	@pre-commit run -a --show-diff-on-failure
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 320e73c9ddd..02df54ffd81 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -47,6 +47,12 @@ stages:
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           MNE_TEST_ALLOW_SKIP: '^$'  # nothing
           MNE_BROWSER_PRECOMPUTE: 'false'
+          # See tools/github_actions_env_vars.sh for why these are set (this job
+          # is on Python 3.14, so sys.monitoring can measure branches)
+          COVERAGE_CORE: 'sysmon'
+          UV_CACHE_DIR: '/home/vsts/.cache/uv'
+          UV_SYSTEM_PYTHON: 'true'  # UsePythonVersion gives us a bare interpreter, not a venv
+          UV_NO_PROGRESS: 'true'
         steps:
           - bash: |
               set -xeo pipefail
@@ -56,21 +62,27 @@ stages:
             displayName: Setup up Xvfb
           - task: Cache@2
             inputs:
-              key: minimal-cmds-1
+              key: '"minimal-cmds" | "$(Agent.OS)" | $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh'
               path: /home/vsts/minimal_cmds
             displayName: Cache minimal commands
-          - bash: ./tools/get_minimal_commands.sh
+          - bash: $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh
             displayName: Get minimal commands
           - task: UsePythonVersion@0
             inputs:
               versionSpec: '3.14'
               architecture: 'x64'
               addToPath: true
+          - task: Cache@2
+            inputs:
+              key: '"uv" | "$(Agent.OS)" | pyproject.toml'
+              restoreKeys: '"uv" | "$(Agent.OS)"'
+              path: $(UV_CACHE_DIR)
+            displayName: Cache uv
           - bash: |
               set -xeo pipefail
-              python -m pip install --progress-bar off --upgrade pip
-              python -m pip install --progress-bar off --upgrade --only-binary=":all:" -e . --group=test "mne-qt-browser @ https://github.com/mne-tools/mne-qt-browser/archive/refs/heads/main.zip" pyvista scikit-learn python-picard qtpy nibabel sphinx-gallery "PySide6!=6.8.0,!=6.8.0.1,!=6.8.1.1,!=6.9.1" pandas neo pymatreader antio defusedxml curryreader pymef openmeeg
-            displayName: Install dependencies with pip
+              python -m pip install --progress-bar off --upgrade "uv>=0.9"
+              uv pip install --upgrade --only-binary=":all:" --no-binary=mne --no-binary=mne-qt-browser -e . --group=test "mne-qt-browser @ https://github.com/mne-tools/mne-qt-browser/archive/refs/heads/main.zip" pyvista scikit-learn python-picard qtpy nibabel sphinx-gallery "PySide6!=6.8.0,!=6.8.0.1,!=6.8.1.1,!=6.9.1" pandas neo pymatreader antio defusedxml curryreader pymef openmeeg
+            displayName: Install dependencies with uv
           - bash: $(MNE_TOOLS_DIR)/tools/check_qt_import.sh PySide6
             displayName: Check Qt import
           - bash: |
@@ -82,7 +94,7 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: $(testing_version)
+              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
               path: /home/vsts/mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
@@ -105,6 +117,8 @@ stages:
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           TEST_OPTIONS: "--tb=short --cov=mne --cov-report=xml --cov-append -vv mne/gui mne/viz/_brain mne/viz/backends mne/viz/tests/test_evoked.py mne/report"
           MNE_TEST_ALLOW_SKIP: '^$'  # nothing (can be overridden below)
+          # See tools/github_actions_env_vars.sh; this job is on Python 3.14
+          COVERAGE_CORE: 'sysmon'
         steps:
           - bash: |
               set -xeo pipefail
@@ -133,7 +147,7 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: $(testing_version)
+              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
               path: /home/vsts/mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
@@ -166,11 +180,21 @@ stages:
         pool:
           vmImage: 'windows-latest'
         variables:
+          MNE_TOOLS_DIR: '$(Pipeline.Workspace)/mne-tools'
           MNE_LOGGING_LEVEL: 'warning'
           MNE_FORCE_SERIAL: 'true'
           PYTEST_XDIST_N: '2'  # Microsoft-hosted agents have 2 cores
           OMP_DYNAMIC: 'false'
           PYTHONUNBUFFERED: 1
+          # See tools/github_actions_env_vars.sh; both matrix legs are Python 3.14
+          COVERAGE_CORE: 'sysmon'
+          # See tools/github_actions_env_vars.sh for why these three are set
+          NUMBA_CACHE_DIR: 'C:\Users\VssAdministrator\.cache\mne-numba'
+          NUMBA_CPU_NAME: 'generic'
+          NUMBA_CPU_FEATURES: ''
+          UV_CACHE_DIR: 'C:\Users\VssAdministrator\.cache\uv'
+          UV_SYSTEM_PYTHON: 'true'  # UsePythonVersion gives us a bare interpreter, not a venv
+          UV_NO_PROGRESS: 'true'
           AZURE_CI_WINDOWS: 'true'
           # Mesa's llvmpipe rasterizer threads can deadlock at process exit on
           # Windows (pyvista/setup-headless-display-action#55); the action sets
@@ -185,25 +209,47 @@ stages:
             3.14 pip:
               TEST_MODE: 'pip'
               PYTHON_VERSION: '3.14'
-              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires MNE-C|Requires FreeSurfer|CUDA not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
+              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires FreeSurfer|CUDA not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
             3.14 pip pre:
               TEST_MODE: 'pip-pre'
               PYTHON_VERSION: '3.14'
-              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires MNE-C|Requires FreeSurfer|CUDA not|Numba not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
+              MNE_TEST_ALLOW_SKIP: "^.*(Requires (spm|brainstorm) dataset|Requires FreeSurfer|CUDA not|Numba not|on Windows|MNE_FORCE_SERIAL|PySide6 causes segfaults|SCIPY_ARRAY_API).*$"
         steps:
           - task: UsePythonVersion@0
             inputs:
               versionSpec: $(PYTHON_VERSION)
               architecture: 'x64'
               addToPath: true
+          - bash: |
+              set -xeo pipefail
+              git clone --depth 1 https://github.com/mne-tools/mne-tools.git "$MNE_TOOLS_DIR"
+            displayName: Clone mne-tools
+          - task: Cache@2
+            inputs:
+              key: '"minimal-cmds" | "$(Agent.OS)" | $(MNE_TOOLS_DIR)/tools/get_minimal_commands.sh'
+              path: C:\Users\VssAdministrator\minimal_cmds
+            displayName: Cache minimal commands
+          # MNE_TOOLS_DIR is a Windows path and these steps run under Git Bash, hence
+          # cygpath; backticks rather than $(...) so Azure does not read it as a macro
+          - bash: |
+              set -eo pipefail
+              MNE_TOOLS_UNIX=`cygpath -u "$MNE_TOOLS_DIR"`
+              bash "$MNE_TOOLS_UNIX/tools/get_minimal_commands.sh"
+            displayName: Get minimal commands
           - bash: |
               set -xeo pipefail
               git clone --depth 1 https://github.com/pyvista/setup-headless-display-action.git
               MESA3D_VERSION=24.3.0 bash setup-headless-display-action/windows/install_opengl.sh
             displayName: Install OpenGL
+          - task: Cache@2
+            inputs:
+              key: '"uv" | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(TEST_MODE)" | pyproject.toml'
+              restoreKeys: '"uv" | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(TEST_MODE)"'
+              path: $(UV_CACHE_DIR)
+            displayName: Cache uv
           - bash: ./tools/azure_dependencies.sh
             displayName: Install dependencies
-          - script: pip install --only-binary=":all:" -e .
+          - script: uv pip install --only-binary=":all:" --no-binary=mne -e .
             displayName: Install mne
           - script: mne sys_info -pd
             displayName: Print config
@@ -215,11 +261,26 @@ stages:
             displayName: Get testing version
           - task: Cache@2
             inputs:
-              key: $(testing_version)
+              key: mne_data-testing-$(testing_version)-misc-$(misc_version)
               path: C:\Users\VssAdministrator\mne_data
             displayName: Cache testing data
           - bash: ./tools/github_actions_download.sh
             displayName: Download testing data
+          - bash: ./tools/get_numba_version.sh
+            displayName: Get numba version
+          - task: Cache@2
+            inputs:
+              key: 'mne_numba | "$(Agent.OS)" | "$(PYTHON_VERSION)" | "$(numba_version)" | mne/**/*numba*.py'
+              path: C:\Users\VssAdministrator\.cache\mne-numba
+            displayName: Cache numba
+            # pip-pre has no numba when nightly wheels are missing; without it
+            # nothing creates the cache dir and the post-job save fails on tar
+            condition: ne(variables['numba_version'], 'none')
+          # Windows does not define HOME, and MNE-C dereferences it unconditionally:
+          # mne_forward_solution crashes with 0xC0000005 without it. Set after the
+          # steps above so that Git Bash keeps deriving its own MSYS-style HOME.
+          - script: 'echo ##vso[task.setvariable variable=HOME]%USERPROFILE%'
+            displayName: Set HOME for MNE-C
           - script: pytest -m "not (slowtest or pgtest)" -n $(PYTEST_XDIST_N) --dist loadscope --timeout=120 --timeout-method=thread -o faulthandler_timeout=110 --tb=short --cov=mne --cov-report=xml -vv mne
             displayName: Run tests
           - bash: bash <(curl -s https://codecov.io/bash)

From 38b552f88fa8aa58317667c888bb82369ce403ca Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Fri, 18 Sep 2026 13:35:01 -0400
Subject: [PATCH 6/7] TST [circle full]


From 66ceb17e2b8b46257f8751f77e80c85a0def1c69 Mon Sep 17 00:00:00 2001
From: Eric Larson <larson.eric.d@gmail.com>
Date: Fri, 18 Sep 2026 15:07:51 -0400
Subject: [PATCH 7/7] FIX: Dont double

---
 mne/viz/backends/_jupyterlite.py        | 2 ++
 mne/viz/backends/tests/test_renderer.py | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/mne/viz/backends/_jupyterlite.py b/mne/viz/backends/_jupyterlite.py
index 74aba331ff7..39651556525 100644
--- a/mne/viz/backends/_jupyterlite.py
+++ b/mne/viz/backends/_jupyterlite.py
@@ -40,6 +40,8 @@ def setup_notebook(data_path="/tmp/mne_data"):
         Where fetched data files are written; ``MNE_DATA`` is set to it.
     """
     global _base, _data_root
+    if _data_root is not None:  # the cell ran again: the wrappers below would
+        return  # otherwise wrap their own wrapped selves and recurse
     import js  # only exists inside Pyodide
 
     # The docs serve the data next to the pages (/mne_data/, via
diff --git a/mne/viz/backends/tests/test_renderer.py b/mne/viz/backends/tests/test_renderer.py
index 09072986fb7..61c846e62f9 100644
--- a/mne/viz/backends/tests/test_renderer.py
+++ b/mne/viz/backends/tests/test_renderer.py
@@ -589,6 +589,10 @@ def send(self):
 from mne.viz.backends._jupyterlite import setup_notebook
 
 setup_notebook(str(root))
+setup_notebook(str(root))  # running the cell twice must not wrap the wrappers
+from mne.viz.backends import _jupyterlite
+
+assert _jupyterlite._orig["read_raw_kit"] is not mne.io.read_raw_kit
 assert mne.viz.get_3d_backend() == "jupyterlite_notebook"
 assert mne.datasets.sample.data_path() == root / "MNE-sample-data"
 data = root / "MNE-testing-data"