Highlights
Virtual Threads are stable
Support for virtual threads is now stable. The feature requires JVM version of 21 or higher.
Virtual threads can be used inside workflows by enabling WorkerFactoryOptions.setUsingVirtualWorkflowThreads.
Users can also use virtual threads for task processing in a worker by enabling WorkerOptions.setUsingVirtualThreads.
Workflow Streams (Public Preview)
This release adds Workflow Streams, a public preview contrib library that gives a workflow a durable, offset-addressed event channel
for keeping outside observers updated on workflow and activity progress. It's built on Temporal's existing signals, updates, and queries,
with batching, exactly-once deduplication, topic filtering, and continue-as-new helpers layered on top.
Intended uses are streaming UIs for long-running AI agents, status for in-flight payment or order processing, and progress for data pipelines.
It is not for not ultra-low-latency cases like real-time voice.
AWS Lambda Serverless Workers (experimental)
This release adds the temporal-aws-lambda contrib module for running Java Workers with Temporal Serverless Workers on AWS Lambda.
See online documentation and the module's README for more information.
Workflow preferred version provider (experimental)
Added worker.Options.PreferredVersionProvider, which can select the version recorded by a newly encountered workflow.GetVersion call.
This supports gradual rollout of a new GetVersion call before activating its new behavior.
What's Changed
2026-07-02 - ac9c7dd - Change references to master branch to main (#2938)
2026-07-06 - f86c766 - fix flakey WorkflowUpdateTest.duplicateRejectedUpdate logic where ADMITTED was reported for updates that were actually COMPLETED. (#2940)
2026-07-09 - 23590a1 - AWS Lambda (Java) (#2901)
2026-07-09 - b8ace30 - Add preferred version provider to worker options (#2942)
2026-07-10 - 2c5e662 - Fix misleading docstring in preferred version PR (#2944)
2026-07-13 - 0192576 - Stabilize Worker options to enable virtual threads (#2947)
2026-07-13 - c0c9132 - Add temporal-workflowstreams contrib module (#2912)
2026-07-13 - ed6a3f7 - fix: add @TemporalDsl receiver annotation to setRetryOptions extensions (#2915)
2026-07-13 - ff980d3 - Propagate memo on continue-as-new in the test server (#2943)