diff --git a/Tools/pixi-packages/README.md b/Tools/pixi-packages/README.md
index 50c3315ac0e5fc..e096cd1ae9ff5f 100644
--- a/Tools/pixi-packages/README.md
+++ b/Tools/pixi-packages/README.md
@@ -1,18 +1,20 @@
 # CPython Pixi packages
 
-This directory contains definitions for [Pixi packages](https://pixi.sh/latest/reference/pixi_manifest/#the-package-section)
-which can be built from the CPython source code.
+This directory contains definitions for [Pixi
+packages](https://pixi.sh/latest/reference/pixi_manifest/#the-package-section) which can
+be built from the CPython source code.
 
-Downstream developers can make use of these packages by adding them as Git dependencies in a
-[Pixi workspace](https://pixi.sh/latest/first_workspace/), like:
+Downstream developers can make use of these packages by adding them as Git dependencies
+in a [Pixi workspace](https://pixi.sh/latest/first_workspace/), like:
 
 ```toml
 [dependencies]
-python = { git = "https://github.com/python/cpython", subdirectory = "Tools/pixi-packages/asan" }
+python.git = "https://github.com/python/cpython"
+python.subdirectory = "Tools/pixi-packages/asan"
 ```
 
 This is particularly useful when developers need to build CPython from source
-(for example, for an ASan-instrumented build), as it does not require any manual
+(for example, for an ASan or TSan-instrumented build), as it does not require any manual
 clone or build steps. Instead, Pixi will automatically handle both the build
 and installation of the package.
 
@@ -20,17 +22,38 @@ Each package definition is contained in a subdirectory, but they share the build
 `build.sh` in this directory. Currently defined package variants:
 
 - `default`
-- `asan`: ASan-instrumented build with `PYTHON_ASAN=1`
+- `freethreading`
+- `asan`: ASan-instrumented build
+- `tsan-freethreading`: TSan-instrumented free-threading build
 
 ## Maintenance
 
-- Keep the `version` fields in each `recipe.yaml` up to date with the Python version
-- Keep the dependency requirements up to date in each `recipe.yaml`
+- Keep the `abi_tag` and `version` fields in each `variants.yaml` up to date with the
+  Python version
 - Update `build.sh` for any breaking changes in the `configure` and `make` workflow
 
 ## Opportunities for future improvement
 
-- More package variants (such as TSan, UBSan)
+- More package variants (such as UBSan)
 - Support for Windows
-- Using a single `pixi.toml` and `recipe.yaml` for all package variants is blocked on https://github.com/prefix-dev/pixi/issues/4599
-- A workaround can be removed from the build script once https://github.com/prefix-dev/rattler-build/issues/2012 is resolved
+- Using a single `pixi.toml` and `recipe.yaml` for all package variants is blocked on
+  [pixi-build-backends#532](https://github.com/prefix-dev/pixi-build-backends/pull/532)
+  and [pixi#5248](https://github.com/prefix-dev/pixi/issues/5248)
+- A workaround can be removed from the build script once
+  [rattler-build#2012](https://github.com/prefix-dev/rattler-build/issues/2012) is
+  resolved
+
+## Troubleshooting
+
+TSan builds may crash on Linux with
+```
+FATAL: ThreadSanitizer: unexpected memory mapping 0x7977bd072000-0x7977bd500000
+```
+To fix it, try reducing `mmap_rnd_bits`:
+
+```bash
+$ sudo sysctl vm.mmap_rnd_bits
+vm.mmap_rnd_bits = 32  # too high for TSan
+$ sudo sysctl vm.mmap_rnd_bits=28  # reduce it
+vm.mmap_rnd_bits = 28
+```
diff --git a/Tools/pixi-packages/asan/pixi.toml b/Tools/pixi-packages/asan/pixi.toml
deleted file mode 100644
index 001ff78fa5d8cb..00000000000000
--- a/Tools/pixi-packages/asan/pixi.toml
+++ /dev/null
@@ -1,8 +0,0 @@
-[workspace]
-channels = ["https://prefix.dev/conda-forge"]
-platforms = ["osx-arm64", "linux-64"]
-preview = ["pixi-build"]
-
-[package.build.backend]
-name = "pixi-build-rattler-build"
-version = "*"
diff --git a/Tools/pixi-packages/asan/pixi.toml b/Tools/pixi-packages/asan/pixi.toml
new file mode 120000
index 00000000000000..3d713eb33ae811
--- /dev/null
+++ b/Tools/pixi-packages/asan/pixi.toml
@@ -0,0 +1 @@
+../default/pixi.toml
\ No newline at end of file
diff --git a/Tools/pixi-packages/asan/recipe.yaml b/Tools/pixi-packages/asan/recipe.yaml
deleted file mode 100644
index dea88394ad9fe2..00000000000000
--- a/Tools/pixi-packages/asan/recipe.yaml
+++ /dev/null
@@ -1,63 +0,0 @@
-context:
-  # Keep up to date
-  version: "3.15"
-
-package:
-  name: python
-  version: ${{ version }}
-
-source:
-  - path: ../../..
-
-build:
-  files:
-    exclude:
-      - "*.o"
-  script:
-    file: ../build.sh
-    env:
-      PYTHON_VARIANT: "asan"
-
-# derived from https://github.com/conda-forge/python-feedstock/blob/main/recipe/meta.yaml
-requirements:
-  build:
-    - ${{ compiler('c') }}
-    - ${{ compiler('cxx') }}
-    - make
-    - pkg-config
-    # configure script looks for llvm-ar for lto
-    - if: osx
-      then:
-        - llvm-tools
-    - if: linux
-      then:
-        - ld_impl_${{ target_platform }}
-        - binutils_impl_${{ target_platform }}
-    - clang-19
-    - llvm-tools-19
-
-  host:
-    - bzip2
-    - sqlite
-    - liblzma-devel
-    - zlib
-    - zstd
-    - openssl
-    - readline
-    - tk
-    # These two are just to get the headers needed for tk.h, but is unused
-    - xorg-libx11
-    - xorg-xorgproto
-    - ncurses
-    - libffi
-    - if: linux
-      then:
-        - ld_impl_${{ target_platform }}
-        - libuuid
-    - libmpdec-devel
-    - expat
-
-about:
-  homepage: https://www.python.org/
-  license: Python-2.0
-  license_file: LICENSE
diff --git a/Tools/pixi-packages/asan/recipe.yaml b/Tools/pixi-packages/asan/recipe.yaml
new file mode 120000
index 00000000000000..90c5c497965560
--- /dev/null
+++ b/Tools/pixi-packages/asan/recipe.yaml
@@ -0,0 +1 @@
+../default/recipe.yaml
\ No newline at end of file
diff --git a/Tools/pixi-packages/asan/variants.yaml b/Tools/pixi-packages/asan/variants.yaml
new file mode 100644
index 00000000000000..2404948457e6bb
--- /dev/null
+++ b/Tools/pixi-packages/asan/variants.yaml
@@ -0,0 +1,6 @@
+variant:
+  - asan
+abi_tag:
+  - asan_cp315
+version:
+  - 3.15
diff --git a/Tools/pixi-packages/build.sh b/Tools/pixi-packages/build.sh
index 120f1d6bb0088a..9d00afe311224e 100644
--- a/Tools/pixi-packages/build.sh
+++ b/Tools/pixi-packages/build.sh
@@ -1,17 +1,23 @@
 #!/bin/bash
 
-if [[ "${PYTHON_VARIANT}" == "asan" ]]; then
-    echo "BUILD TYPE: ASAN"
-    BUILD_DIR="../build_asan"
+echo "PYTHON_VARIANT: ${PYTHON_VARIANT}"
+
+if [[ "${PYTHON_VARIANT}" == "freethreading" ]]; then
+    CONFIGURE_EXTRA="--disable-gil"
+elif [[ "${PYTHON_VARIANT}" == "asan" ]]; then
     CONFIGURE_EXTRA="--with-address-sanitizer"
-    export PYTHON_ASAN="1"
     export ASAN_OPTIONS="strict_init_order=true"
-else
-    echo "BUILD TYPE: DEFAULT"
-    BUILD_DIR="../build"
+elif [[ "${PYTHON_VARIANT}" == "tsan-freethreading" ]]; then
+    CONFIGURE_EXTRA="--disable-gil --with-thread-sanitizer"
+    export TSAN_OPTIONS="suppressions=${SRC_DIR}/Tools/tsan/suppressions_free_threading.txt"
+elif [[ "${PYTHON_VARIANT}" == "default" ]]; then
     CONFIGURE_EXTRA=""
+else
+    echo "Unknown PYTHON_VARIANT: ${PYTHON_VARIANT}"
+    exit 1
 fi
 
+BUILD_DIR="../build_${PYTHON_VARIANT}"
 mkdir -p "${BUILD_DIR}"
 cd "${BUILD_DIR}"
 
@@ -23,6 +29,7 @@ else
         --oldincludedir="${BUILD_PREFIX}/${HOST}/sysroot/usr/include" \
         --enable-shared \
         --srcdir="${SRC_DIR}" \
+        --with-system-expat \
         ${CONFIGURE_EXTRA}
 fi
 
@@ -33,5 +40,6 @@ ln -sf "${PREFIX}/bin/python3" "${PREFIX}/bin/python"
 
 # https://github.com/prefix-dev/rattler-build/issues/2012
 if [[ ${OSTYPE} == "darwin"* ]]; then
-    cp "${BUILD_PREFIX}/lib/clang/21/lib/darwin/libclang_rt.asan_osx_dynamic.dylib" "${PREFIX}/lib/libclang_rt.asan_osx_dynamic.dylib"
+    cp "${BUILD_PREFIX}/lib/clang/21/lib/darwin/libclang_rt.asan_osx_dynamic.dylib" "${PREFIX}/lib/"
+    cp "${BUILD_PREFIX}/lib/clang/21/lib/darwin/libclang_rt.tsan_osx_dynamic.dylib" "${PREFIX}/lib/"
 fi
diff --git a/Tools/pixi-packages/default/recipe.yaml b/Tools/pixi-packages/default/recipe.yaml
index eeb4052ec3859c..a5609540ae7f68 100644
--- a/Tools/pixi-packages/default/recipe.yaml
+++ b/Tools/pixi-packages/default/recipe.yaml
@@ -1,59 +1,83 @@
 context:
   # Keep up to date
-  version: "3.15"
+  freethreading_tag: ${{ "t" if "freethreading" in variant else "" }}
 
-package:
+recipe:
   name: python
-  version: ${{ version }}
 
 source:
   - path: ../../..
 
-build:
-  files:
-    exclude:
-      - "*.o"
-  script:
-    file: ../build.sh
+outputs:
+- package:
+    name: python_abi
+    version: ${{ version }}
+  build:
+    string: "0_${{ abi_tag }}"
+  requirements:
+    run_constraints:
+      - python ${{ version }}.* *_${{ abi_tag }}
 
-# derived from https://github.com/conda-forge/python-feedstock/blob/main/recipe/meta.yaml
-requirements:
+- package:
+    name: python
+    version: ${{ version }}
   build:
-    - ${{ compiler('c') }}
-    - ${{ compiler('cxx') }}
-    - make
-    - pkg-config
-    # configure script looks for llvm-ar for lto
-    - if: osx
-      then:
-        - llvm-tools
-    - if: linux
-      then:
-        - ld_impl_${{ target_platform }}
-        - binutils_impl_${{ target_platform }}
-    - clang-19
-    - llvm-tools-19
-
-  host:
-    - bzip2
-    - sqlite
-    - liblzma-devel
-    - zlib
-    - zstd
-    - openssl
-    - readline
-    - tk
-    # These two are just to get the headers needed for tk.h, but is unused
-    - xorg-libx11
-    - xorg-xorgproto
-    - ncurses
-    - libffi
-    - if: linux
-      then:
-        - ld_impl_${{ target_platform }}
-        - libuuid
-    - libmpdec-devel
-    - expat
+    string: "0_${{ abi_tag }}"
+    files:
+      exclude:
+        - "*.o"
+    script:
+      file: ../build.sh
+      env:
+        PYTHON_VARIANT: ${{ variant }}
+    python:
+      site_packages_path: "lib/python${{ version }}${{ freethreading_tag }}/site-packages"
+
+  # derived from https://github.com/conda-forge/python-feedstock/blob/main/recipe/meta.yaml
+  requirements:
+    build:
+      - ${{ compiler('c') }}
+      - ${{ compiler('cxx') }}
+      - make
+      - pkg-config
+      # configure script looks for llvm-ar for lto
+      - if: osx
+        then:
+          - llvm-tools
+
+    host:
+      - bzip2
+      - sqlite
+      - liblzma-devel
+      - zlib
+      - zstd
+      - openssl
+      - readline
+      - tk
+      # These two are just to get the headers needed for tk.h, but is unused
+      - xorg-libx11
+      - xorg-xorgproto
+      - ncurses
+      - libffi
+      - if: linux
+        then:
+          - libuuid
+      - libmpdec-devel
+      - expat
+      - if: c_compiler == "gcc" and "san" in variant
+        then:
+          - libsanitizer
+
+    ignore_run_exports:
+      from_package:
+        - xorg-libx11
+        - xorg-xorgproto
+
+    run_exports:
+      noarch:
+        - python
+      weak:
+        - python_abi ${{ version }}.* *_${{ abi_tag }}
 
 about:
   homepage: https://www.python.org/
diff --git a/Tools/pixi-packages/default/variants.yaml b/Tools/pixi-packages/default/variants.yaml
new file mode 100644
index 00000000000000..f66e9e7a2226ba
--- /dev/null
+++ b/Tools/pixi-packages/default/variants.yaml
@@ -0,0 +1,6 @@
+variant:
+  - default
+abi_tag:
+  - cp315
+version:
+  - 3.15
diff --git a/Tools/pixi-packages/freethreading/pixi.toml b/Tools/pixi-packages/freethreading/pixi.toml
new file mode 120000
index 00000000000000..3d713eb33ae811
--- /dev/null
+++ b/Tools/pixi-packages/freethreading/pixi.toml
@@ -0,0 +1 @@
+../default/pixi.toml
\ No newline at end of file
diff --git a/Tools/pixi-packages/freethreading/recipe.yaml b/Tools/pixi-packages/freethreading/recipe.yaml
new file mode 120000
index 00000000000000..90c5c497965560
--- /dev/null
+++ b/Tools/pixi-packages/freethreading/recipe.yaml
@@ -0,0 +1 @@
+../default/recipe.yaml
\ No newline at end of file
diff --git a/Tools/pixi-packages/freethreading/variants.yaml b/Tools/pixi-packages/freethreading/variants.yaml
new file mode 100644
index 00000000000000..022833d04c3821
--- /dev/null
+++ b/Tools/pixi-packages/freethreading/variants.yaml
@@ -0,0 +1,6 @@
+variant:
+  - freethreading
+abi_tag:
+  - cp315t
+version:
+  - 3.15
diff --git a/Tools/pixi-packages/tsan-freethreading/pixi.toml b/Tools/pixi-packages/tsan-freethreading/pixi.toml
new file mode 120000
index 00000000000000..3d713eb33ae811
--- /dev/null
+++ b/Tools/pixi-packages/tsan-freethreading/pixi.toml
@@ -0,0 +1 @@
+../default/pixi.toml
\ No newline at end of file
diff --git a/Tools/pixi-packages/tsan-freethreading/recipe.yaml b/Tools/pixi-packages/tsan-freethreading/recipe.yaml
new file mode 120000
index 00000000000000..90c5c497965560
--- /dev/null
+++ b/Tools/pixi-packages/tsan-freethreading/recipe.yaml
@@ -0,0 +1 @@
+../default/recipe.yaml
\ No newline at end of file
diff --git a/Tools/pixi-packages/tsan-freethreading/variants.yaml b/Tools/pixi-packages/tsan-freethreading/variants.yaml
new file mode 100644
index 00000000000000..6ed09fcc9b656b
--- /dev/null
+++ b/Tools/pixi-packages/tsan-freethreading/variants.yaml
@@ -0,0 +1,6 @@
+variant:
+  - tsan-freethreading
+abi_tag:
+  - tsan_cp315t
+version:
+  - 3.15