MAINT Migration from mypy to ty

.devcontainer/devcontainer.json

@@ -16,9 +16,6 @@
         "python.analysis.extraPaths": [
           "/workspace"
         ],
-        "python.linting.mypyArgs": [
-          "--cache-dir=.mypy_cache"
-        ],
         "python.analysis.typeCheckingMode": "basic",
         "python.analysis.diagnosticMode": "openFilesOnly",
         "python.analysis.autoSearchPaths": false,
@@ -52,7 +49,7 @@
           "**/dist/**": true,
           "**/pyrit/auxiliary_attacks/gcg/attack/**": true,
           "**/doc/**": true,
-          "**/.mypy_cache/**": true,
+          "**/.ty_cache/**": true,
           "**/frontend/node_modules/**": true,
           "**/frontend/dist/**": true,
           "**/dbdata/**": true

.devcontainer/devcontainer_setup.sh

@@ -1,31 +1,7 @@
 #!/bin/bash
 set -e
 
-MYPY_CACHE="/workspace/.mypy_cache"
 VIRTUAL_ENV="/opt/venv"
-# Create the mypy cache directory if it doesn't exist
-if [ ! -d "$MYPY_CACHE" ]; then
-    echo "Creating mypy cache directory..."
-    sudo mkdir -p $MYPY_CACHE
-    sudo chown vscode:vscode $MYPY_CACHE
-    sudo chmod 755 $MYPY_CACHE
-else
-    # Check ownership
-    OWNER=$(stat -c '%U:%G' $MYPY_CACHE)
-
-    if [ "$OWNER" != "vscode:vscode" ]; then
-        echo "Fixing mypy cache directory ownership..."
-        sudo chown -R vscode:vscode $MYPY_CACHE
-    fi
-
-    # Check permissions
-    PERMS=$(stat -c '%a' $MYPY_CACHE)
-
-    if [ "$PERMS" != "755" ]; then
-        echo "Fixing mypy cache directory permissions..."
-        sudo chmod -R 755 $MYPY_CACHE
-    fi
-fi
 
 # cleanup old extensions
 sudo rm -rf /vscode/vscode-server/extensionsCache/github.copilot-*

.devcontainer/docker-compose.yml

@@ -13,7 +13,7 @@ services:
       - pip-cache:/home/vscode/.cache/pip:cached
       - uv-cache:/home/vscode/.cache/uv:cached
       - precommit-cache:/home/vscode/.cache/pre-commit:cached
-      - mypy-cache:/workspace/.mypy_cache:cached
+      - ty-cache:/workspace/.ty_cache:cached
       - pylance-cache:/home/vscode/.cache/pylance:cached
       - node-modules:/workspace/frontend/node_modules:cached
       - ~/.pyrit:/home/vscode/.pyrit:cached
@@ -27,6 +27,6 @@ volumes:
   pip-cache:
   uv-cache:
   precommit-cache:
-  mypy-cache:
+  ty-cache:
   pylance-cache:
   node-modules:

.dockerignore

@@ -14,7 +14,7 @@ build/
 **/*.py[cod]
 **/*$py.class
 **/.pytest_cache/
-**/.mypy_cache/
+**/.ty_cache/
 
 # Environment files with secrets
 .env

.gitignore

@@ -149,11 +149,6 @@ env-test
 # mkdocs documentation
 /site
 
-# mypy
-.mypy_cache/
-.dmypy.json
-dmypy.json
-
 # Pyre type checker
 .pyre/
 

.pre-commit-config.yaml

@@ -79,14 +79,11 @@ repos:
       additional_dependencies: ['requests']
       exclude: (release_process.md|git.md|^doc/deployment/|tests|pyrit/prompt_converter/morse_converter.py|.github|pyrit/prompt_converter/emoji_converter.py|pyrit/score/markdown_injection.py|^pyrit/datasets/|^pyrit/auxiliary_attacks/gcg/)
 
-  - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: v1.15.0
+  - repo: https://github.com/allganize/ty-pre-commit
+    rev: v0.0.32
     hooks:
-      - id: mypy
-        name: mypy (strict)
-        files: &strict_modules ^pyrit/
+      - id: ty-check
+        name: ty (type check)
+        files: ^pyrit/
         exclude: ^pyrit/auxiliary_attacks/
-        args: [--install-types, --non-interactive, --ignore-missing-imports, --sqlite-cache, --cache-dir=.mypy_cache, --strict]
-        entry: mypy
-        language: system
-        types: [ python ]
+        types: [python]

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all pre-commit mypy unit-test unit-test-junit unit-test-cov-html unit-test-cov-xml diff-cover unit-test-diff-cover
+.PHONY: all pre-commit ty unit-test unit-test-junit unit-test-cov-html unit-test-cov-xml diff-cover unit-test-diff-cover
 
 CMD:=uv run -m
 PYMODULE:=pyrit
@@ -14,8 +14,8 @@ pre-commit:
 	$(CMD) isort --multi-line 3 --recursive $(PYMODULE) $(TESTS)
 	pre-commit run --all-files
 
-mypy:
-	$(CMD) mypy $(PYMODULE) $(UNIT_TESTS)
+ty:
+	$(CMD) ty check $(PYMODULE) $(UNIT_TESTS)
 
 # Build the full documentation site:
 # 1. Generate API reference JSON from Python source (griffe)

doc/getting_started/install_local_dev.md

@@ -172,7 +172,7 @@ uv run ruff check --fix .
 #### Running Type Checker
 
 ```bash
-uv run mypy pyrit/
+uv run ty check pyrit/
 ```
 
 #### Pre-commit Hooks
@@ -188,7 +188,7 @@ If you prefer conda for environment management, you can use it to create a Pytho
 
 ### Prerequisites
 
-1. **Conda or Miniconda**: Download from [https://docs.conda.io/en/latest/miniconda.html](https://docs.conda.io/en/latest/miniconda.html)
+1. **Conda or Miniconda**: Download from [https://docs.anaconda.com/free/miniconda/](https://docs.anaconda.com/free/miniconda/)
 
 2. **Git**: Clone the repository:
     ```bash

pyproject.toml

@@ -80,7 +80,7 @@ dev = [
     "jupyter-book>=2.0.0",
     "jupytext>=1.17.1",
     "matplotlib>=3.10.0",
-    "mypy>=1.16.0",
+    "ty>=0.0.32",
     "mock-alchemy>=0.2.6",
     "pandas>=2.2.0",
     "pre-commit>=4.2.0",
@@ -167,17 +167,33 @@ pythonpath = ["."]
 asyncio_default_fixture_loop_scope = "function"
 asyncio_mode = "auto"
 
-[tool.mypy]
-plugins = []
-ignore_missing_imports = true
-strict = true
-follow_imports = "silent"
-disable_error_code = ["empty-body"]
+[tool.ty]
+[tool.ty.rules]
+all = "error"
+# Suppress errors for missing third-party stubs
+unresolved-import = "ignore"
+# Tolerate None attribute access
+possibly-missing-attribute = "ignore"
+# Allow existing type: ignore comments without matching errors
+unused-ignore-comment = "warn"
+unused-type-ignore-comment = "warn"
+# Allow empty function bodies during development
+empty-body = "ignore"
+
+[tool.ty.analysis]
+respect-type-ignore-comments = true
+# Treat colorama as Any — it has no type stubs and uses a dynamic pattern
+# (class attrs are int, __init__ converts to str via setattr) that ty can't follow
+replace-imports-with-any = ["colorama.**"]
+
+[tool.ty.src]
 exclude = ["doc/code/", "pyrit/auxiliary_attacks/"]
 
-[[tool.mypy.overrides]]
-module = "pyrit.prompt_target.hugging_face.*"
-disallow_untyped_calls = false
+# Relax type checking for HuggingFace module
+[[tool.ty.overrides]]
+include = ["pyrit/prompt_target/hugging_face/**"]
+[tool.ty.overrides.rules]
+invalid-argument-type = "warn"
 
 [tool.uv]
 constraint-dependencies = [
@@ -297,8 +313,10 @@ select = [
     "UP",  # https://docs.astral.sh/ruff/rules/#pyupgrade-up
     "W",  # https://docs.astral.sh/ruff/rules/#pycodestyle-w
     "YTT",  # https://docs.astral.sh/ruff/rules/#flake8-2020-ytt
+    "ANN",  # https://docs.astral.sh/ruff/rules/#flake8-annotations-ann
 ]
 ignore = [
+    "ANN401",  # any-type (too strict — many legitimate uses of Any)
     "B903",  # class-as-data-structure (test helper classes use @apply_defaults pattern)
     "D100",  # Missing docstring in public module
     "D200",  # One-line docstring should fit on one line
@@ -331,12 +349,12 @@ notice-rgx = "Copyright \\(c\\) Microsoft Corporation\\.\\s*\\n.*Licensed under
 # Ignore copyright, import-location (E402), line length (E501), type-checking, and blanket type-ignore (PGH003) rules in doc/ directory
 # E402: notebooks have imports in code cells, not at top of file
 # E501: markdown comments in notebooks can exceed line length
-# PGH003: blanket type: ignore in notebooks (not mypy-checked)
+# PGH003: blanket type: ignore in notebooks (not type-checked)
 # A: notebook code commonly uses builtins like id, dir, display
 # ERA001: jupytext markdown cells look like commented-out code
 # LOG: notebooks use root logger for convenience
 # PLE1142: top-level await is valid in Jupyter notebooks
-"doc/**" = ["CPY001", "TCH", "E402", "E501", "PGH003", "A", "ERA001", "LOG", "PLE1142"]
+"doc/**" = ["ANN", "CPY001", "TCH", "E402", "E501", "PGH003", "A", "ERA001", "LOG", "PLE1142"]
 "pyrit/{auxiliary_attacks,ui}/**/*.py" = ["B905", "D101", "D102", "D103", "D104", "D105", "D106", "D107", "D401", "D404", "D417", "D418", "DOC102", "DOC201", "DOC202", "DOC402", "DOC501", "N", "PERF", "SIM101", "SIM108"]
 # Backend API routes raise HTTPException handled by FastAPI, not true exceptions
 "pyrit/backend/**/*.py" = ["DOC501", "B008"]
@@ -346,7 +364,11 @@ notice-rgx = "Copyright \\(c\\) Microsoft Corporation\\.\\s*\\n.*Licensed under
 "pyrit/ui/**/*.py" = ["D", "DOC201", "DOC501"]
 "pyrit/__init__.py" = ["D104"]
 # Allow broad pytest.raises(Exception) in tests
-"tests/**/*.py" = ["B017"]
+"tests/**/*.py" = ["ANN", "B017"]
+# Infrastructure/utility scripts — not part of the library API
+"build_scripts/**/*.py" = ["ANN"]
+"docker/**/*.py" = ["ANN"]
+"frontend/dev.py" = ["ANN"]
 
 [tool.ruff.lint.pydocstyle]
 convention = "google"

pyrightconfig.json

@@ -9,7 +9,6 @@
       "**/dist",
       ".venv",
       "pyrit.egg-info",
-      ".mypy_cache",
       ".pytest_cache"
     ],
     "reportMissingImports": true

pyrit/analytics/conversation_analytics.py

@@ -16,7 +16,7 @@ class ConversationAnalytics:
     based on conversation history or embedding similarity.
     """
 
-    def __init__(self, *, memory_interface: MemoryInterface):
+    def __init__(self, *, memory_interface: MemoryInterface) -> None:
         """
         Initialize the ConversationAnalytics with a memory interface for data access.
 
@@ -86,7 +86,7 @@ def get_similar_chat_messages_by_embedding(
         return similar_messages
 
 
-def cosine_similarity(a: np.ndarray, b: np.ndarray) -> float:  # type: ignore[type-arg, unused-ignore]
+def cosine_similarity(a: np.ndarray, b: np.ndarray) -> float:
     """
     Calculate the cosine similarity between two 1D vectors.
 

pyrit/auth/azure_auth.py

@@ -158,7 +158,7 @@ async def async_token_provider() -> str:
         """
         result = api_key()
         if inspect.isawaitable(result):
-            return await result
+            return await result  # type: ignore[ty:invalid-return-type]
         return result
 
     return async_token_provider
@@ -172,7 +172,7 @@ class AzureAuth(Authenticator):
     access_token: AccessToken
     _token_scope: str
 
-    def __init__(self, token_scope: str, tenant_id: str = ""):
+    def __init__(self, token_scope: str, tenant_id: str = "") -> None:
         """
         Initialize Azure authentication.
 
@@ -326,7 +326,7 @@ def get_azure_token_provider(scope: str) -> Callable[[], str]:
         raise
 
 
-def get_azure_async_token_provider(scope: str):  # type: ignore[no-untyped-def]
+def get_azure_async_token_provider(scope: str) -> Callable[[], Awaitable[str]]:
     """
     Get an asynchronous Azure token provider using AsyncDefaultAzureCredential.
 
@@ -370,7 +370,7 @@ def get_default_azure_scope(endpoint: str) -> str:
     return "https://cognitiveservices.azure.com/.default"
 
 
-def get_azure_openai_auth(endpoint: str):  # type: ignore[no-untyped-def]
+def get_azure_openai_auth(endpoint: str) -> Callable[[], Awaitable[str]]:
     """
     Get an async Azure token provider for OpenAI endpoints.
 

pyrit/auth/azure_storage_auth.py

@@ -86,11 +86,11 @@ async def get_sas_token(container_url: str) -> str:
                     account_name=storage_account_name,
                     container_name=container_name,
                     user_delegation_key=user_delegation_key,
-                    permission=ContainerSasPermissions(read=True, write=True, create=True, list=True, delete=True),  # type: ignore[no-untyped-call, unused-ignore]
+                    permission=ContainerSasPermissions(read=True, write=True, create=True, list=True, delete=True),
                     expiry=expiry_time,
                     start=start_time,
                 )
         finally:
             await credential.close()
 
-        return sas_token  # type: ignore[return-value, no-any-return, unused-ignore]
+        return sas_token

pyrit/auth/copilot_authenticator.py

@@ -56,7 +56,7 @@ def __init__(
         token_capture_timeout_seconds: int = DEFAULT_TOKEN_CAPTURE_TIMEOUT,
         network_retries: int = DEFAULT_NETWORK_RETRIES,
         fallback_to_plaintext: bool = False,
-    ):
+    ) -> None:
         """
         Initialize the CopilotAuthenticator.
 
@@ -233,7 +233,7 @@ async def _get_cached_token_if_available_and_valid(self) -> Optional[dict[str, A
                 minutes_left = (expiry_time - current_time).total_seconds() / 60
                 logger.info(f"Cached token is valid for another {minutes_left:.2f} minutes")
 
-            return token_data  # type: ignore[no-any-return]
+            return token_data
 
         except Exception as e:
             error_name = type(e).__name__
@@ -474,8 +474,8 @@ async def response_handler(response: Any) -> None:
             finally:
                 logger.info("Gracefully closing Playwright browser instance...")
 
-                if page:
-                    await page.close()
+                if page:  # type: ignore[ty:possibly-unresolved-reference]
+                    await page.close()  # type: ignore[ty:possibly-unresolved-reference]
                 if context:
                     await context.close()
                 if browser:

pyrit/backend/mappers/attack_mappers.py

@@ -108,7 +108,7 @@ async def _get_sas_for_container_async(*, container_url: str) -> str:
                 account_name=storage_account_name,
                 container_name=container_name,
                 user_delegation_key=delegation_key,
-                permission=ContainerSasPermissions(read=True),  # type: ignore[no-untyped-call,unused-ignore]
+                permission=ContainerSasPermissions(read=True),
                 expiry=expiry_time,
                 start=start_time,
             )