diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 000000000..d9f4f2f80
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+pixi.lock filter=lfs diff=lfs merge=lfs -text
diff --git a/.github/workflows/basic.yml b/.github/workflows/basic.yml
index 406ccdf27..5f273a990 100644
--- a/.github/workflows/basic.yml
+++ b/.github/workflows/basic.yml
@@ -17,15 +17,15 @@ jobs:
             matrix:
                 os: [ubuntu-latest]
                 mpi-version: [mpich]
-                python-version: ["3.10", "3.11", "3.12", "3.13"]
+                python-version: ["py310", "py311", "py312", "py313", "py314"]
                 comms-type: [m, l]
                 include:
                     - os: macos-latest
-                      python-version: "3.11"
+                      python-version: "py311"
                       mpi-version: mpich
                       comms-type: m
                     - os: macos-latest
-                      python-version: "3.11"
+                      python-version: "py311"
                       mpi-version: mpich
                       comms-type: l
 
@@ -39,44 +39,24 @@ jobs:
                 shell: bash -l {0}
 
         steps:
-        - uses: actions/checkout@v6
-        - name: Setup conda - Python ${{ matrix.python-version }}
-          uses: conda-incubator/setup-miniconda@v3
+        - uses: actions/checkout@v4
           with:
-            activate-environment: condaenv
-            miniconda-version: "latest"
-            python-version: ${{ matrix.python-version }}
-            channels: conda-forge
-            channel-priority: strict
-            auto-update-conda: true
-
-        - name: Force-update certifi and pip
-          run: |
-            python --version
-            python -m pip install --upgrade pip
-            python -m pip install -I --upgrade certifi
-
-        - name: Install Ubuntu compilers
-          if: matrix.os == 'ubuntu-latest'
-          run: |
-              conda install -c conda-forge gcc_linux-64
+            lfs: true
 
-        # Roundabout solution on macos for proper linking with mpicc
-        - name: Install macOS compilers
-          if: matrix.os == 'macos-latest'
-          run: |
-            conda install clang_osx-64
+        - name: Checkout lockfile
+          run: git lfs checkout
 
-        - name: Install basic testing/feature dependencies
-          run: |
-            pip install -r install/testing_requirements.txt
-            pip install -r install/misc_feature_requirements.txt
-            source install/install_ibcdfo.sh
-            conda install numpy scipy
+        - uses: prefix-dev/setup-pixi@v0.9.2
+          with:
+            pixi-version: v0.55.0
+            cache: true
+            frozen: true
+            environments: ${{ matrix.python-version }}
+            activate-environment: ${{ matrix.python-version }}
 
-        - name: Install mpi4py and MPI from conda
+        - name: Install IBCDFO
           run: |
-            conda install mpi4py ${{ matrix.mpi-version }}
+            pixi run -e ${{ matrix.python-version }} ./install/install_ibcdfo.sh
 
         - name: Install libEnsemble, test flake8
           run: |
@@ -84,19 +64,19 @@ jobs:
             flake8 libensemble
 
         - name: Remove various tests on newer pythons
-          if: matrix.python-version >= '3.11'
+          if: matrix.python-version == 'py311' || matrix.python-version == 'py312' || matrix.python-version == 'py313' || matrix.python-version == 'py314'
           run: |
-            rm ./libensemble/tests/functionality_tests/test_local_sine_tutorial*.py # matplotlib errors on 3.12
+            rm ./libensemble/tests/functionality_tests/test_local_sine_tutorial*.py # matplotlib errors on py312
 
         - name: Run simple tests, Ubuntu
           if: matrix.os == 'ubuntu-latest'
           run: |
-           ./libensemble/tests/run_tests.py -A "-W error" -${{ matrix.comms-type }}
+            ./libensemble/tests/run_tests.py -A "-W error" -${{ matrix.comms-type }}
 
         - name: Run simple tests, macOS
           if: matrix.os == 'macos-latest'
           run: |
-            ./libensemble/tests/run_tests.py -A "-W error" -${{ matrix.comms-type }}
+            pixi run -e ${{ matrix.python-version }} ./libensemble/tests/run_tests.py -A "-W error" -${{ matrix.comms-type }}
 
         - name: Merge coverage
           run: |
diff --git a/docs/conf.py b/docs/conf.py
index 7686b741f..0b7e2b3dd 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -31,7 +31,7 @@ def __getattr__(cls, name):
         return MagicMock()
 
 
-autodoc_mock_imports = ["ax", "balsam", "gpcam", "IPython", "matplotlib", "pandas", "scipy", "surmise"]
+autodoc_mock_imports = ["ax", "gpcam", "IPython", "matplotlib", "pandas", "scipy", "surmise"]
 
 MOCK_MODULES = [
     "argparse",
diff --git a/pixi.lock b/pixi.lock
new file mode 100644
index 000000000..c7ebed04e
--- /dev/null
+++ b/pixi.lock
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:751e13cc32dc1d88c00f1e2e9c2b029d20a5884d43f86e1b67ced74b8015823b
+size 1089301
diff --git a/pyproject.toml b/pyproject.toml
index 80535d8cb..271c171b4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,34 +1,39 @@
 [project]
 
-authors = [{name = "Jeffrey Larson"}, {name = "Stephen Hudson"},
-            {name = "Stefan M. Wild"}, {name = "David Bindel"},
-            {name = "John-Luke Navarro"}]
+authors = [
+  { name = "Jeffrey Larson" },
+  { name = "Stephen Hudson" },
+  { name = "Stefan M. Wild" },
+  { name = "David Bindel" },
+  { name = "John-Luke Navarro" },
+]
 
-dependencies = [ "numpy", "psutil", "pydantic", "pyyaml", "tomli"]
+dependencies = ["numpy", "psutil", "pydantic", "pyyaml", "tomli"]
 
 description = "A Python toolkit for coordinating asynchronous and dynamic ensembles of calculations."
 name = "libensemble"
 requires-python = ">=3.10"
-license = {file = "LICENSE"}
+license = { file = "LICENSE" }
 readme = "README.rst"
 
 classifiers = [
-        "Development Status :: 5 - Production/Stable",
-        "Intended Audience :: Developers",
-        "Intended Audience :: Science/Research",
-        "License :: OSI Approved :: BSD License",
-        "Natural Language :: English",
-        "Operating System :: POSIX :: Linux",
-        "Operating System :: Unix",
-        "Operating System :: MacOS",
-        "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.10",
-        "Programming Language :: Python :: 3.11",
-        "Programming Language :: Python :: 3.12",
-        "Programming Language :: Python :: 3.13",
-        "Programming Language :: Python :: Implementation :: CPython",
-        "Topic :: Scientific/Engineering",
-        "Topic :: Software Development :: Libraries :: Python Modules",
+  "Development Status :: 5 - Production/Stable",
+  "Intended Audience :: Developers",
+  "Intended Audience :: Science/Research",
+  "License :: OSI Approved :: BSD License",
+  "Natural Language :: English",
+  "Operating System :: POSIX :: Linux",
+  "Operating System :: Unix",
+  "Operating System :: MacOS",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+  "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: 3.13",
+  "Programming Language :: Python :: 3.14",
+  "Programming Language :: Python :: Implementation :: CPython",
+  "Topic :: Scientific/Engineering",
+  "Topic :: Software Development :: Libraries :: Python Modules",
 ]
 dynamic = ["version"]
 
@@ -39,73 +44,175 @@ Issues = "https://github.com/Libensemble/libensemble/issues"
 
 [build-system]
 build-backend = "setuptools.build_meta"
-requires = ["setuptools", "wheel", "pip>=24.3.1,<26", "setuptools>=75.1.0,<81", ]
+requires = ["setuptools", "wheel", "pip>=24.3.1,<26", "setuptools>=75.1.0,<81"]
 
 [tool.setuptools.packages.find]
 where = ["."]
 include = ["libensemble*"]
 
 [tool.setuptools.dynamic]
-version = {attr = "libensemble.version.__version__"}
+version = { attr = "libensemble.version.__version__" }
 
-[tool.pixi.project]
+[tool.pixi.workspace]
 channels = ["conda-forge"]
-platforms = ["osx-arm64", "linux-64", "osx-64"]
+platforms = ["osx-arm64", "linux-64"]
 
 [tool.pixi.pypi-dependencies]
 libensemble = { path = ".", editable = true }
 
 [tool.pixi.environments]
 default = []
-dev = ["dev"]
+basic = ["basic"]
+extra = ["basic", "extra"]
+docs = ["docs", "basic"]
+
+dev = ["dev", "basic", "extra", "docs"]
+
+# CI environments
+py310 = ["py310", "basic"]
+py311 = ["py311", "basic"]
+py312 = ["py312", "basic"]
+py313 = ["py313", "basic"]
+py314 = ["py314", "basic"]
+
+py310e = ["py310", "py310e", "basic", "extra"]
+py311e = ["py311", "py311e", "basic", "extra"]
+py312e = ["py312", "py312e", "basic", "extra"]
+py313e = ["py313", "py313e", "basic", "extra"]
+py314e = ["py314", "py314e", "basic", "extra"]
 
+
+# Extra tools for dev environment
 [tool.pixi.feature.dev.dependencies]
+pre-commit = ">=4.5.1,<5"
+git-lfs = ">=3.7.1,<4"
+black = ">=25.12.0,<26"
+
+
+# Basic dependencies for basic CI
+[tool.pixi.feature.basic.dependencies]
 mpi = ">=1.0.1,<2"
-mpich = ">=4.3.0,<5"
-mpi4py = ">=4.0.3,<5"
-flake8 = ">=7.2.0,<8"
-coverage = ">=7.8.0,<8"
-pytest = ">=8.3.5,<9"
-pytest-cov = ">=6.1.1,<7"
-pytest-timeout = ">=2.3.1,<3"
+mpich = ">=4.3.2,<5"
+mpi4py = ">=4.1.1,<5"
+scipy = ">=1.15.2,<2"
+mpmath = ">=1.3.0,<2"
+
+# "dev" dependencies needed for basic CI
+flake8 = ">=7.3.0,<8"
+coverage = ">=7.13.0,<8"
+pytest = ">=9.0.2,<10"
+
+pytest-cov = ">=7.0.0,<8"
+pytest-timeout = ">=2.4.0,<3"
 mock = ">=5.2.0,<6"
 python-dateutil = ">=2.9.0.post0,<3"
-anyio = ">=4.9.0,<5"
-matplotlib = ">=3.10.1,<4"
-mpmath = ">=1.3.0,<2"
-rich = ">=14.0.0,<15"
+rich = ">=14.2.0,<15"
+matplotlib = ">=3.10.8,<4"
+
+# Extra dependencies for extra CI
+[tool.pixi.feature.extra.dependencies]
+superlu_dist = ">=9.1.0,<10"
+hypre = ">=2.32.0,<3"
+mumps-mpi = ">=5.8.1,<6"
+dfo-ls = ">=1.3.0,<2"
+petsc = ">=3.24.2,<4"
+petsc4py = ">=3.24.2,<4"
+ninja = ">=1.13.2,<2"        # for building Tasmanian from pypi
+nlopt = ">=2.10.0,<3"
+
+[tool.pixi.feature.docs.dependencies]
 sphinx = ">=8.2.3,<9"
-sphinxcontrib-bibtex = ">=2.6.3,<3"
+sphinxcontrib-bibtex = ">=2.6.5,<3"
 sphinx-design = ">=0.6.1,<0.7"
-sphinx_rtd_theme = ">=3.0.1,<4"
+sphinx_rtd_theme = ">=3.0.2,<4"
 sphinx-copybutton = ">=0.5.2,<0.6"
-pre-commit = ">=4.2.0,<5"
-nlopt = ">=2.10.0,<3"
+pre-commit = ">=4.5.1,<5"
 scipy = ">=1.15.2,<2"
-ax-platform = ">=0.5.0,<0.6"
-sphinxcontrib-spelling = ">=8.0.1,<9"
+ax-platform = ">=1.2.1,<2"
+sphinxcontrib-spelling = ">=8.0.2,<9"
 autodoc-pydantic = ">=2.1.0,<3"
 ipdb = ">=0.13.13,<0.14"
-mypy = ">=1.15.0,<2"
+mypy = ">=1.19.1,<2"
 types-psutil = ">=6.1.0.20241221,<7"
-types-pyyaml = ">=6.0.12.20250402,<7"
+types-pyyaml = ">=6.0.12.20250915,<7"
+
+# Linux dependencies, only for extra tests
+[tool.pixi.feature.extra.target.linux-64.dependencies]
+scikit-build = "*"
+packaging = "*"
+octave = ">=9.4.0,<11"
+pyzmq = ">=26.4.0,<28"
+
+# Python versions
+[tool.pixi.feature.py310.dependencies]
+python = "3.10.*"
+[tool.pixi.feature.py311.dependencies]
+python = "3.11.*"
+[tool.pixi.feature.py312.dependencies]
+python = "3.12.*"
+[tool.pixi.feature.py313.dependencies]
+python = "3.13.*"
+[tool.pixi.feature.py314.dependencies]
+python = "3.14.*"
+
+# ax-platform only works up to 3.13 on Linux
+[tool.pixi.feature.py310e.target.linux-64.dependencies]
+ax-platform = ">=1.2.1,<2"
+
+[tool.pixi.feature.py310e.dependencies]
+globus-compute-sdk = ">=4.3.0,<5"
+
+[tool.pixi.feature.py311e.target.linux-64.dependencies]
+ax-platform = ">=1.2.1,<2"
+
+[tool.pixi.feature.py311e.dependencies]
+globus-compute-sdk = ">=4.3.0,<5"
+
+[tool.pixi.feature.py312e.target.linux-64.dependencies]
+ax-platform = ">=1.2.1,<2"
+
+[tool.pixi.feature.py312e.dependencies]
+globus-compute-sdk = ">=4.3.0,<5"
+
+[tool.pixi.feature.py313e.target.linux-64.dependencies]
+ax-platform = ">=0.5.0,<0.6"
+
+[tool.pixi.feature.py314e]
 
+
+# Dependencies for libEnsemble
 [tool.pixi.dependencies]
-python = ">=3.10,<3.14"
-pip = ">=24.3.1,<25"
-setuptools = ">=75.6.0,<76"
-numpy = ">=1.21,<3"
-pydantic = ">=1.10,<3"
-pyyaml = ">=6.0,<7"
-tomli = ">=1.2.1,<3"
-psutil = ">=5.9.4,<7"
+python = ">=3.10,<3.15"
+pip = ">=25.2,<26"
+setuptools = ">=80.8.0,<81"
+numpy = ">=2.2.6,<3"
+pydantic = ">=2.12.4,<3"
+pyyaml = ">=6.0.2,<7"
+tomli = ">=2.2.1,<3"
+
 
+# macOS dependencies
 [tool.pixi.target.osx-arm64.dependencies]
-clang_osx-arm64 = ">=19.1.2,<20"
+clang_osx-arm64 = ">=21.1.7,<22"
+
+# Linux dependencies
+[tool.pixi.target.linux-64.dependencies]
+gxx_linux-64 = ">=15.2.0,<16"
 
+# Extra dependencies, from pypi
+[dependency-groups]
+extra = [
+  "pyenchant==3.2.2",
+  "enchant>=0.0.1,<0.0.2",
+  "proxystore>=0.8.3,<0.9",
+  "redis>=7.1.0,<8",
+]
+dev = ["wat>=0.7.0,<0.8"]
+
+# Various config from here onward
 [tool.black]
 line-length = 120
-target-version = ['py39', 'py310', 'py311', 'py312', 'py313']
+target-version = ['py310', 'py311', 'py312', 'py313', 'py314']
 force-exclude = '''
 (
   /(
@@ -117,10 +224,7 @@ force-exclude = '''
 '''
 
 [tool.typos.default]
-extend-ignore-identifiers-re = [
-    ".*NDArray.*",
-    "8ba9de56.*"
-]
+extend-ignore-identifiers-re = [".*NDArray.*", "8ba9de56.*"]
 
 [tool.typos.default.extend-words]
 als = "als"
@@ -141,6 +245,3 @@ extend-exclude = ["*.bib", "*.xml", "docs/nitpicky"]
 
 [tool.mypy]
 disable_error_code = ["import-not-found", "import-untyped"]
-
-[dependency-groups]
-dev = ["pyenchant", "enchant>=0.0.1,<0.0.2", "flake8-modern-annotations>=1.6.0,<2", "flake8-type-checking>=3.0.0,<4"]