Fix/typechecking

.github/workflows/ci.yml

@@ -53,7 +53,7 @@ jobs:
         run: uv run pytest --verbose --tb=short
 
   lint:
-    name: Code Quality
+    name: Code Quality & Type Checking
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -87,6 +87,22 @@ jobs:
 
       - name: Run Python linting
         run: uv run ruff check .
+
+      - name: Test type stub files exist
+        run: |
+          test -f python/cel/cel.pyi || (echo "❌ Type stub file missing" && exit 1)
+          test -f python/cel/py.typed || (echo "❌ PEP 561 marker missing" && exit 1)
+          echo "✅ Type stub files present"
+
+      - name: Run type checking tests
+        run: uv run pytest tests/test_type_stubs.py -v
+
+      - name: Test ty type checker integration
+        run: |
+          echo "from cel import evaluate, Context; evaluate('1+1')" > test_types.py
+          uvx ty check test_types.py
+          rm test_types.py
+          echo "✅ Type checker integration working"
   linux:
     runs-on: ${{ matrix.platform.runner }}
     needs: [test, lint]

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### ✨ Added
+
+- **Type checking support**: Added complete type stub files (`.pyi`) for PyO3 extension
+
+
 
 ## [0.5.0] - 2025-08-08
 

docs/contributing.md

@@ -246,6 +246,18 @@ def add_function(self, name: str, func: Callable) -> None:
     """
 ```
 
+### Type Checking Support
+
+This package includes manual type stub files (`.pyi`) for the PyO3 Rust extension to support static type checking.
+
+**Type checker verification:**
+```bash
+uvx ty check your_file.py      # ✅ Should pass without "no member" errors
+uvx mypy your_file.py          # ✅ Works with proper MYPYPATH setup
+```
+
+See https://pyo3.rs/main/type-stub to opt-in to the automated types when implemented in Maturin.
+
 ## Debugging & Troubleshooting
 
 ### Common Issues

python/cel/cel.pyi

@@ -0,0 +1,44 @@
+"""
+Type stubs for the CEL Rust extension module.
+"""
+
+from typing import Any, Callable, Dict, Optional, Union, overload
+
+class Context:
+    """CEL evaluation context for variables and functions."""
+
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, variables: Dict[str, Any]) -> None: ...
+    @overload
+    def __init__(
+        self,
+        variables: Optional[Dict[str, Any]] = None,
+        *,
+        functions: Optional[Dict[str, Callable[..., Any]]] = None,
+    ) -> None: ...
+    def add_variable(self, name: str, value: Any) -> None:
+        """Add a variable to the context."""
+        ...
+
+    def add_function(self, name: str, func: Callable[..., Any]) -> None:
+        """Add a function to the context."""
+        ...
+
+    def update(self, variables: Dict[str, Any]) -> None:
+        """Update context with variables from a dictionary."""
+        ...
+
+def evaluate(expression: str, context: Optional[Union[Dict[str, Any], Context]] = None) -> Any:
+    """
+    Evaluate a CEL expression.
+
+    Args:
+        expression: The CEL expression to evaluate
+        context: Optional context with variables and functions
+
+    Returns:
+        The result of evaluating the expression
+    """
+    ...