diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ed87922..cf075fe 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,44 +7,34 @@ on:
     branches: [main]
 
 jobs:
-  lint:
+  test:
     runs-on: ubuntu-latest
-    
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
+
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
         with:
-          fetch-depth: 0
+          python-version: ${{ matrix.python-version }}
 
-      - name: Install uv
-        uses: astral-sh/setup-uv@v7
+      - name: Cache pip dependencies
+        uses: actions/cache@v4
         with:
-          version: "0.10.8"
-          enable-cache: true
-
-
-      - name: Set up Python
-        run: uv python install 3.10 && uv venv --python 3.10
-
-      - name: Install dependencies
-        run: uv sync --locked
-
-      - name: Run Ruff Check
-        run: |
-          if [ "${{ github.event_name }}" == "pull_request" ]; then
-            git fetch origin main
-            git diff --diff-filter=ACMR --name-only -z origin/main...HEAD -- '*.py' \
-              | xargs -0 -r uv run ruff check --
-          else
-            uv run ruff check .
-          fi
-
-      - name: Run Ruff Format
-        run: |
-          if [ "${{ github.event_name }}" == "pull_request" ]; then
-            git fetch origin main
-            git diff --diff-filter=ACMR --name-only -z origin/main...HEAD -- '*.py' \
-              | xargs -0 -r uv run ruff format --check --
-          else
-            uv run ruff format --check .
-          fi
\ No newline at end of file
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ matrix.python-version }}-${{ hashFiles('pyproject.toml') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-${{ matrix.python-version }}-
+
+      - name: Install package and dev dependencies
+        run: pip install -e ".[dev]"
+
+      - name: Run linter
+        run: ruff check openverifiablellm/
+
+      - name: Run tests
+        run: pytest tests/ -v --tb=short
diff --git a/pyproject.toml b/pyproject.toml
index 96523a0..21a38dd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,9 +17,19 @@ dependencies = [
     "tokenizers==0.15.2"
 ]
 
+# Intentionally duplicated from [dependency-groups] below.
+# pip uses this section; uv/PEP 735 uses [dependency-groups]. Keep both in sync.
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.0",
+    "ruff>=0.15.4",
+]
+
 [tool.setuptools.packages.find]
 include = ["openverifiablellm*"]
 
+# Intentionally duplicated from [project.optional-dependencies] above.
+# uv/PEP 735 uses this section; pip uses [project.optional-dependencies]. Keep both in sync.
 [dependency-groups]
 dev = [
     "pytest>=7.0",