refactor(dev): replace mypy with ty for type checking

- Remove mypy and types-requests from dev dependencies
- Update justfile to use ty check command
- Update CI workflow to run ty instead of mypy
- Update flake.nix pre-commit hook to use ty
- Update documentation references in CLAUDE.md, README.md and rules

Author: ryoppippi

.claude/rules/development-workflow.md

@@ -18,15 +18,15 @@ This rule provides code style guidelines and project conventions for the StackOn
 
 - Full type annotations required for all public APIs
 - Use Python 3.11+ typing features
-- Run `just mypy` to verify type correctness
-- Strict mypy configuration is enforced
+- Run `just ty` to verify type correctness
+- Strict ty configuration is enforced
 
 ## Pre-commit Hooks
 
 Pre-commit hooks are configured for:
 
 - ruff linting
-- mypy type checking
+- ty type checking
 
 Run `just install` to set up hooks.
 
@@ -36,7 +36,7 @@ Run `just install` to set up hooks.
 just install       # Install dependencies and pre-commit hooks
 just lint          # Run ruff linting
 just lint-fix      # Auto-fix linting issues
-just mypy          # Run type checking
+just ty            # Run type checking
 just test          # Run all tests
 just test-tools    # Run tool-specific tests
 just test-examples # Run example tests
@@ -48,7 +48,7 @@ just test-examples # Run example tests
 - Use `.yaml` extension instead of `.yml` for YAML files
 - Keep file names concise but meaningful
 
-## Import Organisation
+## Import Organization
 
 - Standard library imports first
 - Third-party imports second

.github/workflows/ci.yaml

@@ -54,8 +54,8 @@ jobs:
       - name: Run Lint
         run: nix develop --command just lint
 
-      - name: Run Mypy
-        run: nix develop --command just mypy
+      - name: Run Ty
+        run: nix develop --command just ty
 
       - name: Run Tests
         run: nix develop --command just test

CLAUDE.md

@@ -18,7 +18,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 | **no-relative-imports**      | `**/*.py`           | Enforce absolute imports in Python files           |
 | **package-installation**     | `**/pyproject.toml` | UV package management standards                    |
 | **uv-scripts**               | `scripts/**/*.py`   | Utility script standards with UV                   |
-| **examples-standards**       | `examples/**/*`     | Example requirements and organisation              |
+| **examples-standards**       | `examples/**/*`     | Example requirements and organization              |
 
 ## Project Overview
 
@@ -33,7 +33,7 @@ just install           # Install dependencies and pre-commit hooks
 # Code quality
 just lint             # Run ruff linting
 just lint-fix         # Auto-fix linting issues
-just mypy             # Run type checking
+just ty               # Run type checking
 
 # Testing
 just test             # Run all tests
@@ -88,7 +88,7 @@ toolset = StackOneToolSet(
 ### Type Safety
 
 - Full type annotations required (Python 3.11+)
-- Strict mypy configuration
+- Strict ty configuration
 - Use generics for better IDE support
 
 ### Testing
@@ -100,7 +100,7 @@ toolset = StackOneToolSet(
 ## Important Considerations
 
 1. **Dependencies**: See `package-installation` rule for uv dependency management
-2. **Pre-commit**: Hooks configured for ruff and mypy - run on all commits
+2. **Pre-commit**: Hooks configured for ruff and ty - run on all commits
 3. **Python Version**: Requires Python >=3.11
 4. **Error Handling**: Custom exceptions (`StackOneError`, `StackOneAPIError`)
 5. **File Uploads**: Binary parameters auto-detected from OpenAPI specs
@@ -114,7 +114,7 @@ toolset = StackOneToolSet(
 2. Parser automatically converts to tool definitions
 3. Test with `make test-tools`
 
-### Modifying Tool Behaviour
+### Modifying Tool Behavior
 
 - Core execution logic in `StackOneTool.execute()` method
 - HTTP configuration via `ExecuteConfig` class

README.md

@@ -47,7 +47,7 @@ The Nix development environment includes:
 
 - Python with uv package manager
 - Automatic dependency installation
-- Git hooks (treefmt + mypy) auto-configured
+- Git hooks (treefmt + ty) auto-configured
 - Consistent environment across all platforms
 
 ### Using pip/uv

flake.nix

@@ -60,16 +60,16 @@
 
           # Git hooks configuration
           pre-commit = {
-            check.enable = false; # Skip check in flake (mypy needs Python env)
+            check.enable = false; # Skip check in flake (ty needs Python env)
             settings.hooks = {
               treefmt = {
                 enable = true;
                 package = config.treefmt.build.wrapper;
               };
-              mypy = {
+              ty = {
                 enable = true;
-                name = "mypy";
-                entry = "${pkgs.uv}/bin/uv run mypy";
+                name = "ty";
+                entry = "${pkgs.uv}/bin/uv run ty check";
                 files = "^stackone_ai/";
                 language = "system";
                 types = [ "python" ];

justfile

@@ -23,8 +23,8 @@ test-examples:
 	uv run pytest examples
 
 # Run type checking
-mypy:
-	uv run mypy stackone_ai
+ty:
+	uv run ty check stackone_ai
 
 # Run typos spell checker
 typos:

pyproject.toml

@@ -57,15 +57,14 @@ examples = [
 
 [dependency-groups]
 dev = [
-    "mypy>=1.15.0",
     "pytest>=8.3.4",
     "pytest-asyncio>=0.25.3",
     "pytest-cov>=6.0.0",
     "pytest-snapshot>=0.9.0",
     "responses>=0.25.8",
     "ruff>=0.9.6",
     "stackone-ai",
-    "types-requests>=2.31.0.20240311",
+    "ty>=0.0.3",
 ]
 
 [tool.pytest.ini_options]
@@ -95,31 +94,3 @@ select = [
     "C4", # flake8-comprehensions
     "UP", # pyupgrade
 ]
-
-[tool.mypy]
-python_version = "3.10"
-disallow_untyped_defs = true
-disallow_incomplete_defs = true
-check_untyped_defs = true
-disallow_untyped_decorators = true
-no_implicit_optional = true
-warn_redundant_casts = true
-warn_unused_ignores = true
-warn_return_any = true
-warn_unreachable = true
-exclude = [
-    "^.venv/",
-]
-
-[[tool.mypy.overrides]]
-module = "bm25s"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "langgraph.*"
-ignore_missing_imports = true
-
-[[tool.mypy.overrides]]
-module = "mcp.*"
-ignore_missing_imports = true
-ignore_errors = true