Consolidating StreamingResponse definitions and tweaking streaming entities' serialization

[rodrigobr-msft]

This pull request introduces and tests a new StreamInfo entity for streaming responses, refactors entity serialization to improve schema compliance, and removes some legacy citation utilities from the hosting layer. The most significant changes are the addition of the StreamInfo model for tracking streaming state in activities, improvements to entity serialization and schema handling, and comprehensive tests for streaming behavior.

Streaming response enhancements:

• Added the new StreamInfo entity (streaminfo) for tracking streaming response state in activities, including fields like stream_type, stream_sequence, and feedback loop support. ([[1]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-95569af9f3e8e01959838120d46dcc6fe53336c3d236c5b1780959b1937121a0R1-R20), [[2]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-c7c7dbca61cbea5cc83fa60accf177b402f886ec5b5a2cf554a3371068346f81R15), [[3]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-287a37a1619db573840fbc3f6b88a90bbe84d8623523a3e7225e05e7c03a5e7eR19), [[4]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-287a37a1619db573840fbc3f6b88a90bbe84d8623523a3e7225e05e7c03a5e7eR33), [[5]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-31cb72ea23ff32a2ccb5b68267163cf524218b1630beaa35e920da3b11b69eaaR47), [[6]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-31cb72ea23ff32a2ccb5b68267163cf524218b1630beaa35e920da3b11b69eaaR159))
• Updated the streaming response logic and tests to utilize the new StreamInfo entity, with thorough tests for both streaming and non-streaming channels. ([dev/tests/sdk/test_streaming_response.pyR1-R122](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-13cb0d27c7ad432613f8aa33b4a632d43b2da419e6d605569ae0ad85f95a2a4aR1-R122))

Entity model and serialization improvements:

• Introduced a _SchemaMixin to standardize and improve serialization of entities using @type and @context fields, and updated several AI-related entity classes (AIEntity, ClientCitation, ClientCitationAppearance, SensitivityUsageInfo, SensitivityPattern) to use this mixin and new serialization logic. ([[1]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-14b332fb65711770caf52d2645c1184b978f93d1248e85ce56d2c75355994c1aR1-R20), [[2]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-93896609025845dd511a2896088bf071689adf37d499090c6d5e689ec332c901L5-R9), [[3]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-93896609025845dd511a2896088bf071689adf37d499090c6d5e689ec332c901L45-R75), [[4]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-93896609025845dd511a2896088bf071689adf37d499090c6d5e689ec332c901L82-R94), [[5]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-93896609025845dd511a2896088bf071689adf37d499090c6d5e689ec332c901L98-L111), [[6]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-3762756c59905ea906e8e1cd5a022698d7635e5577cd5905777ebe1dda8b831eL6-R10), [[7]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-3762756c59905ea906e8e1cd5a022698d7635e5577cd5905777ebe1dda8b831eL19-R25), [[8]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-3762756c59905ea906e8e1cd5a022698d7635e5577cd5905777ebe1dda8b831eL28-R41))
• Updated AgentsModel and Entity configuration to improve alias and validation handling, ensuring better compatibility with Pydantic v2 and schema standards. ([[1]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-d93acfcec8f98f3d9e2be55d1bc902f9c9d566f422a3cf560a1d4991ca5deb4aL11-R13), [[2]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-3762756c59905ea906e8e1cd5a022698d7635e5577cd5905777ebe1dda8b831eL19-R25))

Cleanup and legacy code removal:

• Removed legacy citation and citation utility modules from the hosting layer, as citation handling is now managed by the activity models and core logic. ([[1]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-1d17672ed72428ef555add002149617dcec51f209c508c3e3dc11df75575e69aL1-L14), [[2]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-ecbbe00bcc36cf94f9fadb9296cce862b026ff1599538d4f836b426511f1c5f5L1-L12), [[3]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-81c34464ad26c732f0634a267e462489d292302326934dab5eda50808fd29127L1-L22), [[4]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-853458eaad9d1976df61be3554be7bb90b31b764c912a565685fe5f233d0d013L1-L85))

Other improvements:

• Added EntityTypes to the public API for easier referencing of entity types. ([libraries/microsoft-agents-activity/microsoft_agents/activity/__init__.pyR137](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-31cb72ea23ff32a2ccb5b68267163cf524218b1630beaa35e920da3b11b69eaaR137))
• Fixed minor schema and type consistency issues in ProductInfo and related models. ([[1]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-8a8c46cdb0cb99d41020f6a281cc0d2abd646c08641f48bb76819f67d2cd396eL19-R19), [[2]](https://github.com/microsoft/Agents-for-python/pull/327/files#diff-80288d3976c877f3a86d972b6d61bc36674e58550349c3ead0a4d45a2ba7463eL757-L759))

These changes collectively improve the streaming response infrastructure, ensure more robust and standards-compliant serialization for activities and entities, and clean up deprecated code paths.

[Copilot]

Pull request overview

This PR consolidates duplicated streaming-response helpers (StreamingResponse, Citation, CitationUtil) by removing the framework-specific copies (FastAPI + aiohttp) and centralizing the implementation under hosting-core, with minor behavioral tweaks to the core implementation.

Changes:

• Removed duplicate streaming/ implementations from microsoft-agents-hosting-fastapi and microsoft-agents-hosting-aiohttp.
• Updated TurnContext.streaming_response to construct a core StreamingResponse.
• Updated core StreamingResponse defaults/behavior (e.g., channel detection and stream-id initialization for some channels).

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
libraries/microsoft-agents-hosting-fastapi/microsoft_agents/hosting/fastapi/app/streaming/streaming_response.py	Removed duplicate StreamingResponse implementation (consolidation).
libraries/microsoft-agents-hosting-fastapi/microsoft_agents/hosting/fastapi/app/streaming/citation_util.py	Removed duplicate citation utilities (consolidation).
libraries/microsoft-agents-hosting-fastapi/microsoft_agents/hosting/fastapi/app/streaming/citation.py	Removed duplicate Citation model (consolidation).
libraries/microsoft-agents-hosting-fastapi/microsoft_agents/hosting/fastapi/app/streaming/init.py	Removed streaming re-export package (consolidation).
libraries/microsoft-agents-hosting-fastapi/microsoft_agents/hosting/fastapi/app/init.py	Removed app package re-exports (consolidation).
libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/turn_context.py	Switched TurnContext streaming_response wiring to core StreamingResponse (currently broken).
libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py	Centralized StreamingResponse implementation and adjusted defaults/IDs (currently introduces circular import).
libraries/microsoft-agents-hosting-aiohttp/microsoft_agents/hosting/aiohttp/app/streaming/streaming_response.py	Removed duplicate StreamingResponse implementation (consolidation).
libraries/microsoft-agents-hosting-aiohttp/microsoft_agents/hosting/aiohttp/app/streaming/citation_util.py	Removed duplicate citation utilities (consolidation).
libraries/microsoft-agents-hosting-aiohttp/microsoft_agents/hosting/aiohttp/app/streaming/citation.py	Removed duplicate Citation model (consolidation).
libraries/microsoft-agents-hosting-aiohttp/microsoft_agents/hosting/aiohttp/app/streaming/init.py	Removed streaming re-export package (consolidation).
libraries/microsoft-agents-hosting-aiohttp/microsoft_agents/hosting/aiohttp/app/init.py	Removed app package re-exports (consolidation).

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Copilot reviewed 13 out of 14 changed files in this pull request and generated 3 comments.

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Copilot reviewed 17 out of 21 changed files in this pull request and generated 4 comments.

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Copilot reviewed 27 out of 32 changed files in this pull request and generated 7 comments.

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Copilot reviewed 29 out of 34 changed files in this pull request and generated 6 comments.

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Copilot reviewed 29 out of 34 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (3)

libraries/microsoft-agents-activity/microsoft_agents/activity/activity.py:761

• AIEntity no longer inherits from Entity, and this constructor call no longer explicitly sets type. With model_dump(exclude_unset=True) (used elsewhere in the codebase), Pydantic can omit default-only fields like type, which would produce an entity missing its required top-level type (e.g., https://schema.org/Message). Mandatory: ensure type is always serialized for AIEntity—either by explicitly setting type here, or (preferably) adding an AIEntity-level serializer similar to Entity’s serialize_with_type, or making AIEntity inherit Entity again.

        if citations:
            ai_entity = AIEntity(
                id="",
                additional_type=["AIGeneratedContent"],
                citation=citations,
                usage_info=usage_info,
            )

tests/hosting_core/app/streaming/test_streaming_response.py:1

• This assertion is no longer checking the right shape after the schema refactor: the schema.org message entity now uses at_type/@type (and/or type == \"https://schema.org/Message\"), so filtering on schema_type will always produce an empty list and can mask regressions. Mandatory: update the predicate to match the new entity representation (e.g., check entity.type == \"https://schema.org/Message\" or getattr(entity, \"at_type\", None) == \"Message\").
  tests/hosting_core/app/streaming/test_streaming_response.py:1
• These tests rely on asyncio.sleep(...) timing to allow the internal queue to drain, which can be flaky under CI load. Optional but recommended: set response._interval = 0 and use await response.wait_for_queue() at deterministic points (as other tests already do) instead of fixed sleeps.

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Copilot reviewed 28 out of 33 changed files in this pull request and generated 6 comments.

Comments suppressed due to low confidence (2)

tests/hosting_core/app/streaming/test_streaming_response.py:1

• This assertion is likely ineffective after the serialization refactor: the schema.org entity path now uses AIEntity with at_type/@type, and schema_type is no longer present. As written, this test will pass even if a schema.org/AI entity is incorrectly included on the final activity. To actually validate the behavior, filter by entity.type == \"https://schema.org/Message\" (or getattr(entity, \"at_type\", None) == \"Message\") and assert the list is empty.
  tests/hosting_core/app/streaming/test_streaming_response.py:1
• These tests rely on real asyncio.sleep timing to allow the queue to drain. This can make CI flaky and increases runtime (especially as more scenarios get added). Prefer making the interval deterministic in tests (e.g., set response._interval = 0) and/or use await response.wait_for_queue() to synchronize on completion instead of sleeping.

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Copilot reviewed 28 out of 33 changed files in this pull request and generated 5 comments.

Comments suppressed due to low confidence (3)

tests/hosting_core/app/streaming/test_streaming_response.py:1

• This test filters on schema_type == \"Message\", but the updated schema entities use at_type/@type (and AIEntity no longer defines schema_type). As written, the filter will never match and the assertion can pass even if a schema.org Message entity is present. Update the predicate to check the new representation (e.g., entity.type == \"https://schema.org/Message\" and/or getattr(entity, \"at_type\", None) == \"Message\").
  libraries/microsoft-agents-hosting-core/microsoft_agents/hosting/core/app/streaming/streaming_response.py:388
• When generated_by_ai_label is disabled, the code still appends an AIEntity. AIEntity defaults additional_type to include AIGeneratedContent, which effectively marks content as AI-generated even when the feature flag is off. If the intent here is to attach citations without enabling the AI-generated label, consider using a citation-only schema entity (or explicitly overriding additional_type to an empty list / making it optional) so the flag semantics remain consistent.

        if (
            self._citations
            and not self._ended
            and not self._enable_generated_by_ai_label
        ):
            # Filter out the citations unused in content.
            curr_citations = CitationUtil.get_used_citations(
                self._message, self._citations
            )
            if curr_citations:
                activity.entities.append(
                    AIEntity(
                        type="https://schema.org/Message",
                        id="",
                        citation=curr_citations,
                    )
                )

tests/activity/test_activity.py:1

• Remove the extra blank line to keep test formatting consistent with the surrounding style.

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