[python] add typeddict `models-mode` for Python HTTP client emitter by iscai-msft · Pull Request #10439 · microsoft/typespec

iscai-msft · 2026-04-21T17:46:09Z

Add a new 'typeddict' value for the models-mode option that generates Python TypedDict classes instead of DPG model classes. Key features:

TypedDict classes with Required[T]/NotRequired[T] annotations
TypedDict inheritance for non-discriminated models
Discriminated models: Union of leaf TypedDicts, no abstract base class
Input-only: operations accept TypedDict input, return dict output
Wire names used as TypedDict keys
_model_base.py still generated for serialization utilities

Add a new 'typeddict' value for the models-mode option that generates Python TypedDict classes instead of DPG model classes. Key features: - TypedDict classes with Required[T]/NotRequired[T] annotations - TypedDict inheritance for non-discriminated models - Discriminated models: Union of leaf TypedDicts, no abstract base class - Input-only: operations accept TypedDict input, return dict output - Wire names used as TypedDict keys - _model_base.py still generated for serialization utilities Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

pkg-pr-new · 2026-04-21T17:48:01Z

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npm i https://pkg.pr.new/@typespec/http-client-python@10439

commit: 5777d0a

github-actions · 2026-04-21T17:49:06Z

All changed packages have been documented.

✅ @typespec/http-client-python

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`@typespec/http-client-python` - fix ✏️

Fix invalid lone @overload generated for body parameters in models-mode: typeddict. When the binary and JSON overloads are omitted, the single remaining body variant is now emitted as a plain parameter instead of a single @overload, which mypy rejects with "Single overload definition, multiple required".

`@typespec/http-client-python` - feature ✏️

[python] Always generate TypedDict typing hints for input models in the types.py file, and named union aliases in the _unions.py file

azure-sdk · 2026-04-21T18:00:13Z

You can try these changes here

🛝 Playground	🌐 Website	🛝 VSCode Extension

…ypespec into python/addTypedDict

…hon/addTypedDict

- TypedDictModelType returns 'JSON' for response type annotations - Response.type_annotation/docstring passes is_response=True - Typeddict deserialization uses response.json() directly - Removed NotRequired from TypedDictModelSerializer (total=False handles it) - Updated mock API tests to verify JSON dict responses Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Add client/naming typeddict variant to regenerate-common.ts - Create test_client_naming_typeddict.py with 11 tests verifying TypedDict uses wire names (defaultName, wireName) not client names - Tests cover: ClientNameModel, LanguageClientNameModel, ClientNameAndJsonEncodedNameModel, ClientModel, PythonModel Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

TypedDict is already JSON, so the MutableMapping[str, Any] overload is unnecessary. Only keep TypedDict model + IO[bytes] overloads. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Typeddict mode uses response.json() directly, so _deserialize is never called. Skip importing it to avoid W0611 unused-import lint warning. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Remove unused MutableMapping/Any imports from TypedDictModelType.imports() - Skip _deserialize import in paging_operation.py for typeddict mode Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…ypespec into python/addTypedDict

TypedDictModelType returns 'JSON' for response type annotations but never defined the JSON = MutableMapping[str, Any] type alias, causing NameError at runtime. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…ypespec into python/addTypedDict

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Replace is_operation_file with serialize_namespace_type to correctly determine when to add the typing.List import. Operation/client files only need it when has_operation_named_list is True, while model/types files need it when has_property_named_list is True. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…e conflicts Remove the 'from typing import List' import entirely from ListType. Types/model files now always use lowercase 'list' since a TypedDict field named 'list' doesn't shadow the builtin. Operation files still use the 'List = list' alias from define_mypy_type when there's an operation named 'list'. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

msyyc

Will take another review soon.

The response type rendering passes is_operation_file=True but not serialize_namespace_type, so we need to check both to correctly determine operation context. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

For models that are typeddict-only (either via models-mode=typeddict or individual models marked as typedDictOnly), skip the isinstance check against _models.X (which doesn't exist) and skip json.dumps serialization. TypedDict models are plain dicts and should be passed directly to the request as JSON. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Add tests passing TypedDicts to regular dpg operations (both sync and async) to verify model + typeddict combined overloads work - Add async test for typeddictonly variant Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…rate-common.ts Keep regenerate-common.ts as the synced, shared module instead of duplicating its helpers inline in regenerate.ts. Add the typeddict-specific emitter options and baseline changes there, and remove the now-supported response-as-bool skip entries. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

@overload

In models-mode: typeddict the binary/JSON overloads are omitted, leaving a single body variant that was still wrapped in a lone @overload (mypy: Single overload definition, multiple required). Collapse the one-member combined type back to a plain body type so no overload is emitted. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

l0lawrence · 2026-06-26T19:59:25Z

running into a mypy error because of: https://github.com/Azure/azure-sdk-for-python/pull/47346/changes#r3483777805

- Remove service/multiple-services from SKIP_SPECS (supported in main) - Restore by-design legacyCodePathNeededForTests baseline copy instead of whole-folder copy Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…crosoft#11161) fix microsoft#11149 ## Why PR microsoft#10439 enabled TypedDict body-overload generation in the default `dpg` mode. In real Azure mgmt libraries (e.g. `azure-mgmt-netapp`), this produced dangling `_types.CacheUpdate` references that were absent from `types.py`, causing an `AttributeError` at import time. ## Root cause Template-instantiated models all share the *template's* `crossLanguageDefinitionId`. For example, every `Azure.ResourceManager.Foundations.ResourceUpdateModel<T, P>` instantiation (`CacheUpdate`, `VolumeUpdate`, `ActiveDirectoryConfigUpdate`, ...) carries `clid = Azure.ResourceManager.Foundations.ResourceUpdateModel`. The `typeddict_models` dedup keyed the dpg-vs-copy pairing on that `clid`, so it treated genuinely distinct models as duplicates and skipped all but the first one. In netapp, `ActiveDirectoryConfigUpdate` was seen first, so `CacheUpdate` was dropped from `types.py` while still being referenced via `_types.CacheUpdate`. ## Fix - Key the dpg-vs-copy pairing on the model `name` instead of `crossLanguageDefinitionId`. The typeddict copy is a shallow copy of the source, so it shares the source's name; distinct template instantiations have distinct names, and model names are unique within a `types.py` module. - Harden `_find_existing_typeddict` in preprocess to also match on `name` (same root cause, tightly coupled). This keeps TypedDict generation on in `dpg` mode (intentional per microsoft#10439) and just corrects the rendering so referenced TypedDicts actually land in `types.py`. --------- Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Co-authored-by: Yuchao Yan <yuchaoyan@microsoft.com>

…1161) fix #11149 ## Why PR #10439 enabled TypedDict body-overload generation in the default `dpg` mode. In real Azure mgmt libraries (e.g. `azure-mgmt-netapp`), this produced dangling `_types.CacheUpdate` references that were absent from `types.py`, causing an `AttributeError` at import time. ## Root cause Template-instantiated models all share the *template's* `crossLanguageDefinitionId`. For example, every `Azure.ResourceManager.Foundations.ResourceUpdateModel<T, P>` instantiation (`CacheUpdate`, `VolumeUpdate`, `ActiveDirectoryConfigUpdate`, ...) carries `clid = Azure.ResourceManager.Foundations.ResourceUpdateModel`. The `typeddict_models` dedup keyed the dpg-vs-copy pairing on that `clid`, so it treated genuinely distinct models as duplicates and skipped all but the first one. In netapp, `ActiveDirectoryConfigUpdate` was seen first, so `CacheUpdate` was dropped from `types.py` while still being referenced via `_types.CacheUpdate`. ## Fix - Key the dpg-vs-copy pairing on the model `name` instead of `crossLanguageDefinitionId`. The typeddict copy is a shallow copy of the source, so it shares the source's name; distinct template instantiations have distinct names, and model names are unique within a `types.py` module. - Harden `_find_existing_typeddict` in preprocess to also match on `name` (same root cause, tightly coupled). This keeps TypedDict generation on in `dpg` mode (intentional per #10439) and just corrects the rendering so referenced TypedDicts actually land in `types.py`. --------- Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Co-authored-by: Yuchao Yan <yuchaoyan@microsoft.com>

iscai-msft requested review from ChenxiJiang333, catalinaperalta, laiapat, lmazuel, msyyc, swathipil, tadelesh and timotheeguerin as code owners April 21, 2026 17:46

microsoft-github-policy-service Bot added the emitter:client:python Issue for the Python client emitter: @typespec/http-client-python label Apr 21, 2026

Enhance Python HTTP client emitter with TypedDict support

27c8bfb

iscai-msft and others added 12 commits April 21, 2026 14:37

add discriminator

c1487f8

Merge branch 'python/addTypedDict' of https://github.com/iscai-msft/t…

02e6f35

…ypespec into python/addTypedDict

Merge branch 'main' of https://github.com/microsoft/typespec into pyt…

2647828

…hon/addTypedDict

fix: remove redundant JSON overload for typeddict mode

3e5c0ef

TypedDict is already JSON, so the MutableMapping[str, Any] overload is unnecessary. Only keep TypedDict model + IO[bytes] overloads. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

fix: remove unused _deserialize import in typeddict mode

f76c88d

Typeddict mode uses response.json() directly, so _deserialize is never called. Skip importing it to avoid W0611 unused-import lint warning. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

fix: remove all unused imports in typeddict generated code

2401b66

- Remove unused MutableMapping/Any imports from TypedDictModelType.imports() - Skip _deserialize import in paging_operation.py for typeddict mode Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Merge branch 'main' into python/addTypedDict

57bf76a

format and lint

47b5024

Merge branch 'python/addTypedDict' of https://github.com/iscai-msft/t…

87ea0a1

…ypespec into python/addTypedDict

fix: define JSON type alias in TypedDictModelType imports

95db199

TypedDictModelType returns 'JSON' for response type annotations but never defined the JSON = MutableMapping[str, Any] type alias, causing NameError at runtime. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

iscai-msft force-pushed the python/addTypedDict branch from 34e0cda to 95db199 Compare April 29, 2026 15:39

iscai-msft added 3 commits May 5, 2026 15:58

switch to always generating typeddicts as typing hints

37806df

switch to always generating typeddicts as typing hints

18786e3

Merge branch 'python/addTypedDict' of https://github.com/iscai-msft/t…

8d323ac

…ypespec into python/addTypedDict

iscai-msft and others added 3 commits June 24, 2026 16:31

refactor: extract typeddict helpers to fix too-many-statements lint

0a966b3

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

msyyc reviewed Jun 25, 2026

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msyyc self-requested a review June 25, 2026 00:18

msyyc approved these changes Jun 25, 2026

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msyyc self-requested a review June 25, 2026 00:19

iscai-msft and others added 5 commits June 25, 2026 12:56

format

b3380b9

fix: skip response-as-bool in README test (in SKIP_SPECS)

2b1291d

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Merge branch 'main' into python/addTypedDict

ceed358

msyyc reviewed Jun 26, 2026

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Comment thread packages/http-client-python/eng/scripts/ci/regenerate.ts

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Comment thread packages/http-client-python/tests/mock_api/shared/unittests/test_readme.py Outdated

l0lawrence and others added 2 commits June 26, 2026 10:54

msyyc reviewed Jun 29, 2026

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Comment thread packages/http-client-python/eng/scripts/ci/regenerate-common.ts Outdated

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Comment thread packages/http-client-python/eng/scripts/ci/regenerate-common.ts

msyyc approved these changes Jun 30, 2026

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msyyc added this pull request to the merge queue Jun 30, 2026

Merged via the queue into microsoft:main with commit 30d60f8 Jun 30, 2026
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This was referenced Jul 2, 2026

[python] gate TypedDict body overloads behind models-mode typeddict l0lawrence/typespec#6

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[python] fix TypedDict rendering for template-instantiated models #11161

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[python] add typeddict `models-mode` for Python HTTP client emitter - #10439

[python] add typeddict `models-mode` for Python HTTP client emitter#10439
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