feat: implement streaming support in to_a2a for issue #4240 by sanjeevamk1 · Pull Request #4230 · google/adk-python

sanjeevamk1 · 2026-01-21T21:56:02Z

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Link to Issue or Description of Change

1. Link to an existing issue (if applicable):

Closes: SSE Streaming providing to to_a2a #4240

Problem:
For token streaming when adk agent is exposed with to_a2a

Solution:
Added streaming_mode in to_a2a to select streaming while exposing the agent

gemini-code-assist · 2026-01-21T21:56:22Z

Summary of Changes

Hello @sanjeevamk1, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the to_a2a utility by integrating streaming support, allowing for more dynamic and efficient handling of agent responses. By introducing a StreamingMode and a configurable request converter, users can now specify how data is streamed when an ADK agent is converted into an A2A Starlette application, providing greater flexibility for interactive and real-time agent interactions.

Highlights

Streaming Mode Introduction: Introduced a new StreamingMode enum to control how agent responses are streamed.
Configurable Request Converter: Added a new experimental function create_request_converter that allows generating a request converter configured with a specific StreamingMode.
Streaming Support in to_a2a: The to_a2a utility function now accepts a streaming_mode parameter, enabling the configuration of streaming behavior when converting an ADK agent to an A2A Starlette application.
Executor Configuration Update: The A2aAgentExecutor within to_a2a is now initialized with an A2aAgentExecutorConfig, which incorporates the streaming-aware request converter.

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adk-bot · 2026-01-21T21:56:58Z

Response from ADK Triaging Agent

Hello @sanjeevamk1, thank you for creating this PR!

To help reviewers understand and evaluate your contribution, could you please fill out the pull request template in the description? Specifically, please provide the following:

Link to Issue or Description of Change: Please either link to the relevant issue or provide a description of the problem and your solution.
Testing Plan: Describe the tests you ran to verify your changes, including any unit tests or manual end-to-end tests.
Checklist: Please fill out the checklist to confirm you've followed the contribution guidelines.

This information is crucial for an efficient review process. You can find more details in our contribution guide.

Thanks!

gemini-code-assist

Code Review

This pull request introduces streaming support for the to_a2a function. The implementation approach is sound, but I've identified a critical issue with a shadowed import that will likely lead to runtime failures. Additionally, there's an opportunity to improve maintainability by addressing significant code duplication in the new request converter. I've also pointed out a minor typo. Please review my comments for details.

src/google/adk/a2a/converters/request_converter.py

src/google/adk/a2a/utils/agent_to_a2a.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

ryanaiagent · 2026-01-23T00:36:16Z

H @sanjeevamk1, Thank you for your contribution! We appreciate you taking the time to submit this pull request. Can you address the comment and also fix the formatting errors before we can proceed with the review. You can use autoformat.sh for formatting errors.

…adk-python into feature/a2a-token-streaming

ryanaiagent · 2026-01-28T06:19:28Z

/gemini review

gemini-code-assist · 2026-01-28T06:19:32Z

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zeroasterisk

Please remove all the "linter" artifacts from this PR.

Please implement a unit test and integration test.

I'm generally ok with this, though I am loathe to change the function signature unless I have to.

Challenge 1: Can you get the same functionality with a custom runner you pass into to_a2a()?

Challenge 2: Is this really sufficient for A2A, which I know supports many other types of transports or data bindings? It seems like you are solving for one more, but not all, and thus the interface would be fragile.

Please reduce the scope of this PR and answer my challenges to move forward.

zeroasterisk · 2026-02-07T23:26:10Z

contributing/samples/static_instruction/agent.py

 MOOD_INSTRUCTIONS = {
-    "full": """
+    "full": (
+        """


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:26:20Z

contributing/samples/cache_analysis/run_cache_experiments.py

          f" {cached_analysis['cache_utilization_ratio_percent']:.1f}%"
-          f" ({cached_analysis['requests_with_cache_hits']}/{cached_analysis['total_requests']} requests)"
+          f" ({cached_analysis['requests_with_cache_hits']}/{cached_analysis['total_requests']}"
+          " requests)"


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:26:26Z

contributing/dev/utils/build_llms_txt.py

                   – includes Python API reference from HTML files
                   – includes adk-python repository README
 """
+


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:26:32Z

contributing/samples/langchain_structured_tool_agent/agent.py

 """
 This agent aims to test the Langchain tool with Langchain's StructuredTool
 """
+


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:26:38Z

contributing/samples/session_state_agent/agent.py

 in session state.
 """

-


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:27:19Z

contributing/samples/token_usage/main.py

-            'Turn tokens:'
-            f' {event.usage_metadata.total_token_count} (prompt={event.usage_metadata.prompt_token_count},'
+            f'Turn tokens: {event.usage_metadata.total_token_count}'
+            f' (prompt={event.usage_metadata.prompt_token_count},'


i actually like this change, but it's unrelated to the focus of this PR

zeroasterisk · 2026-02-07T23:45:36Z

src/google/adk/tools/application_integration_tool/clients/connections_client.py

-                            "$ref": f"#/components/schemas/{action_display_name}_Request"
+                            "$ref": (
+                                f"#/components/schemas/{action_display_name}_Request"
+                            )


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:45:46Z

src/google/adk/cli/built_in_agents/tools/write_files.py

 # limitations under the License.

 """File writing tool for Agent Builder Assistant."""
+


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

zeroasterisk · 2026-02-07T23:46:01Z

src/google/adk/tools/application_integration_tool/clients/connections_client.py

            "summary": f"List {entity}",
-            "description": f"""Returns the list of {entity} data. If the page token was available in the response, let users know there are more records available. Ask if the user wants to fetch the next page of results. When passing filter use the
+            "description": (
+                f"""Returns the list of {entity} data. If the page token was available in the response, let users know there are more records available. Ask if the user wants to fetch the next page of results. When passing filter use the


these are a lot of what looks like unrelated linter changes.

please remove them, and only submit the PR with the lines that actually matter to this set of changes.

feat: implement streaming support in to_a2a for issue google#640

6ad8a2a

adk-bot added the live [Component] This issue is related to live, voice and video chat label Jan 21, 2026

gemini-code-assist bot reviewed Jan 21, 2026

View reviewed changes

src/google/adk/a2a/converters/request_converter.py Show resolved Hide resolved

src/google/adk/a2a/converters/request_converter.py Outdated Show resolved Hide resolved

src/google/adk/a2a/utils/agent_to_a2a.py Outdated Show resolved Hide resolved

Update src/google/adk/a2a/utils/agent_to_a2a.py

7597b75

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

sanjeevamk1 changed the title ~~feat: implement streaming support in to_a2a for issue #640~~ feat: implement streaming support in to_a2a for issue #4240 Jan 22, 2026

ryanaiagent self-assigned this Jan 23, 2026

ryanaiagent added the request clarification [Status] The maintainer need clarification or more information from the author label Jan 23, 2026

sanjeevamk1 and others added 4 commits January 27, 2026 20:08

feat: implement streaming support in to_a2a for issue google#640

71855c0

formatting update google#4240

2eab204

Merge branch 'feature/a2a-token-streaming' of github.com:sanjeevamk1/…

0e0db35

…adk-python into feature/a2a-token-streaming

Merge branch 'main' into feature/a2a-token-streaming

a6c90f4

zeroasterisk suggested changes Feb 7, 2026

View reviewed changes

		# limitations under the License.

		"""File writing tool for Agent Builder Assistant."""

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sanjeevamk1 commented Jan 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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sanjeevamk1 commented Jan 21, 2026 •

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