diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d12f5f9..91f587f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -10,9 +10,6 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
-env:
-  PIXI_VERSION: "v0.63.0"
-
 jobs:
   clear-cache:
     runs-on: ubuntu-slim
@@ -44,12 +41,48 @@ jobs:
           fi
           echo "Cache cleared"
 
-  cache-pixi-lock:
+  test-cache-restore-install:
     needs: clear-cache
-    runs-on: ubuntu-slim
-    outputs:
-      cache-key: ${{ steps.create-and-cache.outputs.cache-key }}
-      pixi-version: ${{ steps.create-and-cache.outputs.pixi-version }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # Test OS values with fixed test-folder and pixi-version
+          - os: ubuntu-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock__69110db0bf39d7ce64fd774c7078ccd56ebf8542d9a1e86f84e63011634dc43f_2026-02-24"
+            pixi-version: ""
+          - os: macos-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock__69110db0bf39d7ce64fd774c7078ccd56ebf8542d9a1e86f84e63011634dc43f_2026-02-24"
+            pixi-version: ""
+          - os: windows-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock__adbacdefe20c62f204989acf366ef09911f3af89f066088613341b946be131e8_2026-02-24"
+            pixi-version: ""
+          # Test test-folder values with fixed OS and pixi-version
+          - os: ubuntu-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock__69110db0bf39d7ce64fd774c7078ccd56ebf8542d9a1e86f84e63011634dc43f_2026-02-24"
+            pixi-version: ""
+          - os: ubuntu-latest
+            test-folder: just-pyproject-toml
+            expected-hash: "pixi-lock__4a057faded2062ff018955c0be1db1b9e1d2fb8d1fe4303d8b778af7fd9e411d_2026-02-24"
+            pixi-version: ""
+          - os: ubuntu-latest
+            test-folder: pyproject-and-pixi-toml
+            expected-hash: "pixi-lock__b5bae43771086cb1dd79c43dc06881f8b0e006ad8c54e7269dad1a4f8ce96522_2026-02-24"
+            pixi-version: ""
+          # Test pixi-version values with fixed OS and test-folder
+          - os: ubuntu-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock__69110db0bf39d7ce64fd774c7078ccd56ebf8542d9a1e86f84e63011634dc43f_2026-02-24"
+            pixi-version: ""
+          - os: ubuntu-latest
+            test-folder: just-pixi-toml
+            expected-hash: "pixi-lock_v0.63.2_69110db0bf39d7ce64fd774c7078ccd56ebf8542d9a1e86f84e63011634dc43f_2026-02-24"
+            pixi-version: "v0.63.2"
     steps:
       - name: Checkout repository
         uses: actions/checkout@v6
@@ -58,13 +91,27 @@ jobs:
 
       - name: Copy test files to working directory
         shell: bash
-        run: cp -r pixi-lock/ci/test/* .
+        run: cp -r pixi-lock/ci/test/${{ matrix.test-folder }}/* .
 
       - name: Run create-and-cache action
         id: create-and-cache
         uses: ./pixi-lock/create-and-cache
         with:
-          pixi-version: ${{ env.PIXI_VERSION }}
+          pixi-version: ${{ matrix.pixi-version }}
+
+      - name: Verify cache key hash matches expected
+        shell: bash
+        run: |
+          actual_hash="${{ steps.create-and-cache.outputs.cache-key }}"
+          expected_hash="${{ matrix.expected-hash }}"
+          echo "Expected hash: $expected_hash"
+          echo "Actual hash: $actual_hash"
+          if [ "$actual_hash" != "$expected_hash" ]; then
+            echo "ERROR: Hash mismatch!"
+            echo "Please update the expected-hash in the workflow matrix to: $actual_hash"
+            exit 1
+          fi
+          echo "Hash matches expected value"
 
       - name: Verify pixi.lock exists
         shell: bash
@@ -76,29 +123,20 @@ jobs:
             exit 1
           fi
 
-  restore-and-install:
-    needs: cache-pixi-lock
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-slim, macos-latest, windows-latest]
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v6
-        with:
-          path: pixi-lock
+      - name: Cleanup pixi.lock
+        shell: bash
+        run: rm pixi.lock
 
-      - name: Copy test files to working directory
+      - name: Cleanup pixi install
         shell: bash
-        run: cp -r pixi-lock/ci/test/* .
+        run: rm -rf ~/.pixi
 
       - name: Restore pixi.lock from cache
         uses: ./pixi-lock/restore
         with:
-          cache-key: ${{ needs.cache-pixi-lock.outputs.cache-key }}
+          cache-key: ${{ steps.create-and-cache.outputs.cache-key }}
 
-      - name: Verify pixi.lock exists
+      - name: Verify pixi.lock exists after restore
         shell: bash
         run: |
           if [ -f "pixi.lock" ]; then
@@ -111,7 +149,7 @@ jobs:
       - name: Setup pixi and install environment
         uses: prefix-dev/setup-pixi@v0.9.3
         with:
-          pixi-version:  ${{ needs.cache-pixi-lock.outputs.pixi-version }}
+          pixi-version: ${{ matrix.pixi-version }}
 
       - name: Verify environment installed
         shell: bash
diff --git a/README.md b/README.md
index 60303ca..ce44449 100644
--- a/README.md
+++ b/README.md
@@ -10,10 +10,9 @@ This repo provides two GitHub Actions for generating and caching `pixi.lock` fil
 
 This two-action pattern is so that the lockfile can be omitted from the git
 history, but still be generated in a performant manner (i.e., regenerated
-and cached with a key that depends on `pixi.toml` and the date - 
+and cached with a key that depends on `pixi.toml` and the date -
 then shared across jobs).
 
-
 ## Usage
 
 ```yaml
@@ -25,7 +24,7 @@ jobs:
       pixi-version: ${{ steps.pixi-lock.outputs.pixi-version }}
     steps:
       - uses: actions/checkout@v4
-      - uses: Parcels-code/pixi-lock/create-and-cache@... # TODO: Copy the hash for the rev you want to install from 
+      - uses: Parcels-code/pixi-lock/create-and-cache@... # TODO: Copy the hash for the rev you want to install from
         id: pixi-lock
         with:
           pixi-version: ... # TODO: update with your selected pixi version
@@ -45,7 +44,7 @@ jobs:
       - uses: Parcels-code/pixi-lock/restore@ # TODO: Copy the hash for the rev you want to install from (same as above)
         with:
           cache-key: ${{ needs.cache-pixi-lock.outputs.cache-key }}
-      - uses: prefix-dev/setup-pixi@v...  # TODO: update with your selected setup-pixi version
+      - uses: prefix-dev/setup-pixi@v... # TODO: update with your selected setup-pixi version
         with:
           pixi-version: ${{ needs.cache-pixi-lock.outputs.pixi-version }}
       # ... your CI steps
@@ -55,20 +54,21 @@ jobs:
 
 #### `create-and-cache`
 
-| Input | Description | Required | Default |
-|-------|-------------|----------|---------|
-| `pixi-version` | Version of pixi to use for generating the lock file | No | `latest` |
+| Input          | Description                                             | Required | Default                          |
+| -------------- | ------------------------------------------------------- | -------- | -------------------------------- |
+| `pixi-version` | Version of pixi to use for generating the lock file     | No       | `latest`                         |
+| `hash-files`   | Files to use to generate the hash key for the lock file | No       | `pixi.toml` and `pyproject.toml` |
 
-| Output | Description |
-|--------|-------------|
-| `pixi-version` | The pixi version used |
-| `cache-key` | The cache key (includes today's date) |
+| Output         | Description                           |
+| -------------- | ------------------------------------- |
+| `pixi-version` | The pixi version used                 |
+| `cache-key`    | The cache key (includes today's date) |
 
 #### `restore`
 
-| Input | Description | Required |
-|-------|-------------|----------|
-| `cache-key` | The cache key from `create-and-cache` | Yes |
+| Input       | Description                           | Required |
+| ----------- | ------------------------------------- | -------- |
+| `cache-key` | The cache key from `create-and-cache` | Yes      |
 
 > [!NOTE]
 > The cache key includes the current date, so the lock file is regenerated daily.
@@ -83,6 +83,7 @@ When developing and testing _library_ code, we don't want our environments to st
 The _easiest_ way to test against the latest versions of packages - and avoid the noisy commit history (and additional overhead) of regularly updating a lock file in git - is instead to ignore the lock file and rely on developers and CI to generate their own lock files. This much simpler setup forgoes perfect reprodubility between developer machines, and with CI machines - which may be a worthwhile tradeoff for your project.
 
 See the following threads for more detailed discussion:
+
 - [prefix.dev Discord: Should you commit the lockfile](https://discord.com/channels/1082332781146800168/1462778624212996209)
 - [Scientific Python Discord: lock files for libraries](https://discord.com/channels/786703927705862175/1450619697224487083)
 - https://github.com/prefix-dev/pixi/issues/5325
diff --git a/ci/test/pixi.toml b/ci/test/just-pixi-toml/pixi.toml
similarity index 100%
rename from ci/test/pixi.toml
rename to ci/test/just-pixi-toml/pixi.toml
diff --git a/ci/test/just-pyproject-toml/pyproject.toml b/ci/test/just-pyproject-toml/pyproject.toml
new file mode 100644
index 0000000..c0a0592
--- /dev/null
+++ b/ci/test/just-pyproject-toml/pyproject.toml
@@ -0,0 +1,22 @@
+[project]
+name = "just-pyproject-toml"
+version = "0.1.0"
+description = "Add your description here"
+readme = "README.md"
+requires-python = ">=3.12"
+dependencies = []
+
+[tool.pixi.workspace]
+authors = ["Vecko <36369090+VeckoTheGecko@users.noreply.github.com>"]
+channels = ["conda-forge"]
+name = "test"
+platforms = ["win-64", "linux-64", "osx-64", "osx-arm64", "linux-aarch64"]
+version = "0.1.0"
+
+[tool.pixi.tasks]
+
+[tool.pixi.dependencies]
+python = "*"
+numpy = "*"
+pandas = "*"
+xarray = "*"
diff --git a/ci/test/pyproject-and-pixi-toml/pixi.toml b/ci/test/pyproject-and-pixi-toml/pixi.toml
new file mode 100644
index 0000000..0dade70
--- /dev/null
+++ b/ci/test/pyproject-and-pixi-toml/pixi.toml
@@ -0,0 +1,14 @@
+[workspace]
+authors = ["Vecko <36369090+VeckoTheGecko@users.noreply.github.com>"]
+channels = ["conda-forge"]
+name = "test"
+platforms = ["win-64", "linux-64", "osx-64", "osx-arm64", "linux-aarch64"]
+version = "0.1.0"
+
+[tasks]
+
+[dependencies]
+python = "*"
+numpy = "*"
+pandas = "*"
+xarray = "*"
diff --git a/ci/test/pyproject-and-pixi-toml/pyproject.toml b/ci/test/pyproject-and-pixi-toml/pyproject.toml
new file mode 100644
index 0000000..e583bd4
--- /dev/null
+++ b/ci/test/pyproject-and-pixi-toml/pyproject.toml
@@ -0,0 +1,7 @@
+[project]
+name = "pyproject-and-pixi-toml"
+version = "0.1.0"
+description = "Add your description here"
+readme = "README.md"
+requires-python = ">=3.12"
+dependencies = []
diff --git a/create-and-cache/action.yml b/create-and-cache/action.yml
index 4c68b71..ff256a3 100644
--- a/create-and-cache/action.yml
+++ b/create-and-cache/action.yml
@@ -6,6 +6,12 @@ inputs:
     description: "Version of pixi to use for generating the lock file"
     required: false
     default: "latest"
+  hash-files:
+    description: "Files to use to generate the hash key for the lock file."
+    required: false
+    default: |
+      pixi.toml
+      pyproject.toml
 
 outputs:
   pixi-version:
@@ -23,7 +29,7 @@ runs:
       shell: bash
       run: |
         today=$(date +'%Y-%m-%d')
-        key="pixi-lock_${{ inputs.pixi-version }}_${{ hashFiles('pixi.toml') }}_${today}"
+        key="pixi-lock_${{ inputs.pixi-version }}_${{ hashFiles(inputs.hash-files) }}_${today}"
         echo "key=${key}" >> "$GITHUB_OUTPUT"
 
     - name: Restore pixi.lock from cache