Add LangGraph workflow streams sample#315
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Demonstrate the LangGraph plugin's Workflow Streams support: a node emits live tokens via get_stream_writer() (routed by the plugin's streaming_topic), and the workflow publishes coarse astream progress to its own topic. A single client subscribes to all topics and demultiplexes on item.topic. Bumps the langgraph group to temporalio>=1.28.0 (where workflow streams ship) and drops the now-obsolete langsmith<0.7.34 constraint, which was specific to the 1.27.2 langsmith patch. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
DABH
requested changes
Jul 7, 2026
Every other graph_api/ sample has a standalone README with run instructions and a "what this demonstrates" blurb; streaming was the only one without. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Streaming is at-least-once per activity attempt: a retried node re-runs and re-publishes its writes, so subscribers can see duplicate tokens. Tag each token chunk with a monotonic seq and dedupe on it in the client and test, demonstrating the documented idempotent-consumer pattern instead of implicitly assuming exactly-once delivery. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
set.add returns None, so the comprehension trick tripped mypy's func-returns-value. Rewrite as an explicit loop. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
DABH
approved these changes
Jul 11, 2026
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What
Adds a Graph-API sample demonstrating the LangGraph plugin's recently-added Workflow Streams support, under
langgraph_plugin/graph_api/streaming/.It combines both streaming patterns in one workflow:
write_storynode emits live tokens via LangGraph'sget_stream_writer(), routed onto thetokenstopic by the plugin'sstreaming_topic.astreampublish — the workflow drives the graph withapp.astream(...)and publishes each node-completion chunk onto aprogresstopic it owns viaWorkflowStream.topic().publish().A single client subscribes to all topics with
WorkflowStreamClientand demultiplexes onitem.topic. The workflow waits on anack_streamsignal before returning so the stream survives until the client finishes consuming it.Dependency changes
langgraphgroup totemporalio>=1.28.0(where workflow streams ship).langsmith<0.7.34uv constraint — 1.28.0 requireslangsmith>=0.7.34, and the pin was specific to the 1.27.2 langsmith patch. Existing langgraph tests still pass on the resulting langsmith 0.8.9.Also adds
langgraph_plugin/code owners.Testing
tests/langgraph_plugin/streaming_test.py; the fulltests/langgraph_plugin/suite passes (12 passed) on temporalio 1.28.0 / langsmith 0.8.9.ruffformat/import checks andmypyare clean for the new files.🤖 Generated with Claude Code