{"id":3159,"library":"mypy-boto3-transfer","title":"mypy-boto3-transfer","description":"mypy-boto3-transfer provides type annotations for the `boto3` Transfer service, generated with `mypy-boto3-builder`. It ensures `mypy` can correctly validate usage of the `boto3` Transfer client and associated data types. The library is actively maintained, with releases typically synchronized with `boto3` updates and `mypy-boto3-builder` enhancements, currently at version 1.42.84.","status":"active","version":"1.42.84","language":"en","source_language":"en","source_url":"https://github.com/youtype/mypy_boto3_builder","tags":["aws","boto3","mypy","type-hints","stubs","transfer","static-analysis"],"install":[{"cmd":"pip install mypy-boto3-transfer","lang":"bash","label":"Install service stubs"},{"cmd":"pip install boto3","lang":"bash","label":"Install runtime dependency"}],"dependencies":[{"reason":"Required at runtime for actual AWS API interaction; `mypy-boto3-transfer` only provides type stubs.","package":"boto3","optional":false},{"reason":"The type checker that consumes these stubs for static analysis.","package":"mypy","optional":true}],"imports":[{"symbol":"TransferClient","correct":"from mypy_boto3_transfer.client import TransferClient"},{"symbol":"ListServersResponseTypeDef","correct":"from mypy_boto3_transfer.type_defs import ListServersResponseTypeDef"}],"quickstart":{"code":"import boto3\nfrom mypy_boto3_transfer.client import TransferClient\nfrom mypy_boto3_transfer.type_defs import ListServersResponseTypeDef\nfrom typing import TYPE_CHECKING\n\nif TYPE_CHECKING:\n    # These imports are for type checking only and will not be executed at runtime\n    # They provide type hints for boto3 service clients and responses.\n    client: TransferClient = boto3.client(\"transfer\")\n    response: ListServersResponseTypeDef = client.list_servers()\n    print(f\"Found {len(response['Servers'])} Transfer servers.\")\n\n# Example of actual runtime usage (uncomment to run)\n# client = boto3.client(\"transfer\")\n# response = client.list_servers()\n# print(f\"Runtime: Found {len(response['Servers'])} Transfer servers.\")\n","lang":"python","description":"Demonstrates how to import and use the `TransferClient` type to annotate a `boto3` client, enabling static type checking with `mypy` for AWS Transfer service operations. It also shows a common response type definition."},"warnings":[{"fix":"Upgrade your Python environment to 3.9 or a later version.","message":"Support for Python 3.8 was removed in `mypy-boto3-builder` version 8.12.0. Users on Python 3.8 will need to upgrade to Python 3.9 or newer to use the latest `mypy-boto3-transfer` stubs.","severity":"breaking","affected_versions":"mypy-boto3-builder >= 8.12.0, mypy-boto3-transfer related versions"},{"fix":"Ensure `boto3` is installed alongside `mypy-boto3-transfer` in your project's dependencies.","message":"`mypy-boto3-transfer` provides type stubs only. You must also install the actual `boto3` library (`pip install boto3`) for your code to run at runtime. Without `boto3`, your application will encounter runtime import errors.","severity":"gotcha","affected_versions":"All versions"},{"fix":"Review your explicit `TypeDef` imports and update them to the new, often shorter, naming convention. Refer to the specific service's `type_defs.pyi` for correct names.","message":"`mypy-boto3-builder` version 8.9.0 introduced breaking changes to `TypeDef` naming conventions (e.g., `CreateDistributionRequestRequestTypeDef` became `CreateDistributionRequestTypeDef`). If you directly imported specific `TypeDef` classes by their full names, these imports may break.","severity":"breaking","affected_versions":"mypy-boto3-builder >= 8.9.0, mypy-boto3-transfer related versions"},{"fix":"Ensure your environment correctly handles PEP 561-compliant stub packages. Most modern `mypy` setups should work seamlessly, but verify if you have custom type-stub discovery configurations.","message":"`mypy-boto3-builder` version 8.12.0 migrated all packages, including `mypy-boto3-transfer`, to be PEP 561 compliant. While this improves standard type-checking workflows, custom build systems or specific tooling that relied on previous package structures might need adjustments.","severity":"breaking","affected_versions":"mypy-boto3-builder >= 8.12.0, mypy-boto3-transfer related versions"}],"env_vars":null,"last_verified":"2026-04-11T00:00:00.000Z","next_check":"2026-07-10T00:00:00.000Z"}