[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: 0feff61

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

# Conflicts: # packages/http-client-python/generator/pygen/preprocess/__init__.py

- Add crossLanguageDefinitionId-based dedup to dpg model TypedDict creation (prevents duplicate TypedDict classes when multiple operations share the same body model) - Dedup typeddict_models in TypesSerializer: prefer dpg model over typeddict copy when both exist with the same crossLanguageDefinitionId Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

iscai-msft · 2026-06-24T16:00:01Z

https://github.com/Azure/azure-sdk-for-python/pull/47346/changes#r3379640848

this is defined as a named union, that's why we generate it as one

…ct copies from _models.py - Only add 'from . import types' to sync __init__.py, not aio (types.py is generated at the sync level, aio doesn't have one) - Filter out base='typeddict' models from _models.py class list (typeddict copies should only appear in types.py, not as model classes) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Add 'List' import to ListType.imports() when property/operation named 'list' exists (fixes NameError in special-words types.py) - Use has_non_json_models() for has_models in ModelInitSerializer to avoid generating 'from . import _models' when _models.py doesn't exist - Remove 'from . import types' from __init__.py — each TypedDict type's imports() already handles adding the types import where needed (operations) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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>

msyyc · 2026-06-26T02:17:50Z

-  RegenerateContext,
-  RegenerateFlags,
-  runParallel,
-} from "./regenerate-common.js";


regenerate-common is very important since it makes sync easy for typespec-python repo about the regeneration and test cases.

Actually you just need add a few lines of new configuration in regenerate-common.ts instead of so many changes while most are duplicated in regenerate.ts.

msyyc · 2026-06-26T02:21:25Z

+const SKIP_SPECS: string[] = [
+  "type/file",
+  "service/multiple-services",
+  "azure/client-generator-core/response-as-bool",
+];


cases of line 56-line57 are already supported in https://github.com/microsoft/typespec/pull/10944/changes#diff-6d3a02078e3812a5ae4eb5b94e9f07952450932adb30a87dea6664ef8a270323.

msyyc · 2026-06-26T02:29:49Z

 SKIP_PACKAGES = {
    ("azure", "service-multiple-services"),
    ("azure", "azure-client-generator-core-client-initialization"),
+    ("azure", "azure-client-generator-core-response-as-bool"),


no need to add it since this folder has README.md: https://github.com/Azure/azure-sdk-for-python/blob/typespec-python-generated-tests/eng/tools/azure-sdk-tools/emitter/generated/azure/azure-client-generator-core-response-as-bool/README.md.

After my comments about regenerate.ts resolved, you could remove this line.

…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

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

fix calling polymorphic subtypes on combined type

f9f0f2f

iscai-msft requested a review from kashifkhan as a code owner June 22, 2026 17:47

iscai-msft and others added 4 commits June 22, 2026 15:28

Merge remote-tracking branch 'upstream/main' into python/addTypedDict

5226e44

# Conflicts: # packages/http-client-python/generator/pygen/preprocess/__init__.py

fix splatted body params method

73710dc

attempt to have correct typeddicts show for splatted models

48f1180

iscai-msft and others added 3 commits June 24, 2026 12:12

cspell

1ff2c23

iscai-msft force-pushed the python/addTypedDict branch from f77576c to 14b7d6c Compare June 24, 2026 20:20

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

View reviewed changes

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

msyyc approved these changes Jun 25, 2026

View reviewed changes

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

View reviewed changes

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

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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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