Drop support for PyTorch 2.1 and 2.2

.github/workflows/build-wheels.yml

@@ -29,25 +29,15 @@ jobs:
     name: ${{ matrix.name }} (torch v${{ matrix.torch-version }})
     strategy:
       matrix:
-        os: ['ubuntu-24.04', 'ubuntu-24.04-arm', 'macos-15-intel', 'macos-15', 'windows-2022']
+        os: ['ubuntu-24.04', 'ubuntu-24.04-arm', 'macos-15', 'windows-2022']
         arch: ['arm64', 'x86_64']
-        torch-version: ['2.1', '2.2', '2.3', '2.4', '2.5', '2.6', '2.7', '2.8', '2.9', '2.10']
+        torch-version: ['2.3', '2.4', '2.5', '2.6', '2.7', '2.8', '2.9', '2.10']
         exclude:
           # remove mismatched arch-os combinations
-          - {os: macos-15-intel, arch: arm64}
           - {os: windows-2022, arch: arm64}
           - {os: ubuntu-24.04, arch: arm64}
           - {os: macos-15, arch: x86_64}
           - {os: ubuntu-24.04-arm, arch: x86_64}
-          # arch x86_64 on macos is only supported for torch <2.3
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.3'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.4'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.5'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.6'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.7'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.8'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.9'}
-          - {os: macos-15-intel, arch: x86_64, torch-version: '2.10'}
         include:
           # add `cibw-arch` and `rust-target` to the different configurations
           - name: x86_64 Linux
@@ -60,11 +50,6 @@ jobs:
             arch: arm64
             rust-target: aarch64-unknown-linux-gnu
             cibw-arch: aarch64
-          - name: x86_64 macOS
-            os: macos-15-intel
-            arch: x86_64
-            rust-target: x86_64-apple-darwin
-            cibw-arch: x86_64
           - name: arm64 macOS
             os: macos-15
             arch: arm64
@@ -76,8 +61,6 @@ jobs:
             rust-target: x86_64-pc-windows-msvc
             cibw-arch: AMD64
           # add the right python version image for each torch version
-          - {torch-version: '2.1', cibw-python: 'cp311-*'}
-          - {torch-version: '2.2', cibw-python: 'cp312-*'}
           - {torch-version: '2.3', cibw-python: 'cp312-*'}
           - {torch-version: '2.4', cibw-python: 'cp312-*'}
           - {torch-version: '2.5', cibw-python: 'cp312-*'}
@@ -143,9 +126,6 @@ jobs:
           - name: arm64 Linux
             os: ubuntu-24.04-arm
             arch: arm64
-          - name: x86_64 macOS
-            os: macos-15-intel
-            arch: x86_64
           - name: arm64 macOS
             os: macos-15
             arch: arm64

.github/workflows/torch-tests.yml

@@ -19,7 +19,7 @@ jobs:
         include:
           - os: ubuntu-24.04
             python-version: "3.10"
-            torch-version: "2.1"
+            torch-version: "2.3"
             numpy-version-pin: "<2.0"
           - os: ubuntu-24.04
             python-version: "3.10"

docs/src/installation.rst

@@ -23,7 +23,7 @@ and use it will depend on the programming language you are using.
 
         We provide pre-compiled wheels on PyPI that are compatible with all the
         supported ``torch`` versions at the time of the ``metatomic-torch`` release.
-        Currently PyTorch version 2.1 and above is supported.
+        Currently PyTorch version 2.3 and above is supported.
 
         If you want to use the code with an unsupported PyTorch version, or a
         new release of PyTorch which did not exist yet when we released
@@ -105,7 +105,7 @@ and use it will depend on the programming language you are using.
           metatensor-torch.
         - the C++ part of PyTorch, which you can install `on its own
           <https://pytorch.org/get-started/locally/>`_. We are compatible with
-          ``libtorch`` version 2.1 or above. You can also use the same library as
+          ``libtorch`` version 2.3 or above. You can also use the same library as
           the Python version of torch by adding the output of the command below
           to ``CMAKE_PREFIX_PATH``:
 

metatomic-torch/CHANGELOG.md

@@ -17,6 +17,10 @@ a changelog](https://keepachangelog.com/en/1.1.0/) format. This project follows
 ### Removed
 -->
 
+### Changed
+
+- Removed support for torch 2.1 and 2.2
+
 ## [Version 0.1.8](https://github.com/metatensor/metatomic/releases/tag/metatomic-torch-v0.1.8) - 2026-02-02
 
 ### Added

metatomic-torch/CMakeLists.txt

@@ -91,7 +91,7 @@ endif()
 # fixed version in `cmake/FindCUDNN.cmake`
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake;${CMAKE_MODULE_PATH}")
 
-find_package(Torch 2.1 REQUIRED)
+find_package(Torch 2.3 REQUIRED)
 
 set(METATOMIC_TORCH_HEADERS
     "include/metatomic/torch/system.hpp"

python/metatomic_torch/build-backend/backend.py

@@ -11,7 +11,7 @@
 if FORCED_TORCH_VERSION is not None:
     TORCH_DEP = f"torch =={FORCED_TORCH_VERSION}"
 else:
-    TORCH_DEP = "torch >=2.1"
+    TORCH_DEP = "torch >=2.3"
 
 # ==================================================================================== #
 #                   Build backend functions definition                                 #

python/metatomic_torch/setup.py

@@ -312,7 +312,7 @@ def create_version_number(version):
         torch_version = f"== {torch_v_major}.{torch_v_minor}.*"
     except ImportError:
         # otherwise we are building a sdist
-        torch_version = ">= 2.1"
+        torch_version = ">= 2.3"
 
     install_requires = [
         f"torch {torch_version}",