ci: add ty as second blocking type-checker alongside mypy

.github/workflows/ci.yml

@@ -38,6 +38,8 @@ jobs:
         run: uv run ruff format --check src tests
       - name: Run mypy
         run: uv run mypy
+      - name: Run ty
+        run: uv run ty check
       - name: Run bandit
         run: uv run bandit -r src
       - name: Test with pytest

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 ci:
-  skip: [pytest]
+  skip: [pytest, ty]
 
 default_language_version:
   python: python3.14
@@ -30,6 +30,17 @@ repos:
       - id: mypy
         name: mypy
 
+  # ty - lint-like type checking (Astral, preview)
+  - repo: local
+    hooks:
+      - id: ty
+        name: ty
+        entry: uv run ty check
+        language: system
+        types: [python]
+        pass_filenames: false
+        require_serial: true
+
   # bandit - find common security issues
   - repo: https://github.com/pycqa/bandit
     rev: 1.9.4

README.md

@@ -113,6 +113,14 @@ Rules are defined in the [`pyproject.toml`](pyproject.toml).
 
 For more configuration options and details, see the [configuration docs](https://mypy.readthedocs.io/).
 
+### ty
+
+[ty](https://github.com/astral-sh/ty) is a fast type checker from Astral, written in Rust. It runs alongside mypy as a second blocking type-checker.
+
+Rules are defined in the [`pyproject.toml`](pyproject.toml).
+
+For more configuration options and details, see the [ty documentation](https://github.com/astral-sh/ty).
+
 ### bandit
 
 [bandit](https://bandit.readthedocs.io/) is a tool designed to find common security issues in Python code.

pyproject.toml

@@ -24,6 +24,7 @@ dev = [
   "mypy>=1.20.2",
   "bandit>=1.9.4",
   "ruff>=0.15.12",
+  "ty>=0.0.35",
 ]
 
 [tool.uv]
@@ -115,3 +116,35 @@ convention = "pep257"
 [tool.mypy]
 files = ["src", "tests"]
 strict = "true"
+
+[tool.ty.src]
+include = ["src", "tests"]
+
+[tool.ty.rules]
+# strict profile: every diagnostic ty exposes at "error" severity
+# Each rule whose default severity is "warn" or "ignore" is promoted to "error".
+ambiguous-protocol-member = "error"
+deprecated = "error"
+ignore-comment-unknown-rule = "error"
+ineffective-final = "error"
+invalid-enum-member-annotation = "error"
+invalid-ignore-comment = "error"
+invalid-legacy-positional-parameter = "error"
+invalid-named-tuple-override = "error"
+mismatched-type-name = "error"
+possibly-missing-implicit-call = "error"
+possibly-missing-submodule = "error"
+redundant-cast = "error"
+redundant-final-classvar = "error"
+undefined-reveal = "error"
+unresolved-global = "error"
+unsupported-base = "error"
+unused-awaitable = "error"
+unused-ignore-comment = "error"
+unused-type-ignore-comment = "error"
+useless-overload-body = "error"
+division-by-zero = "error"
+possibly-missing-attribute = "error"
+possibly-missing-import = "error"
+possibly-unresolved-reference = "error"
+unsupported-dynamic-base = "error"