Breaking changes

• client.StartActivityOptions.Builder.setStaticSummary was renamed to setSummary to align it with
  activity.ActivityOptions.

Highlights

Standalone Activities are stable

Standalone Activities feature is Generally Available. See feature guide at
https://docs.temporal.io/develop/java/activities/standalone-activities

Static Summary and Details are stable

setSummary/setStaticSummary and setStaticDetails for workflows and activities are stable. See feature guide at
https://docs.temporal.io/develop/java/platform/enriching-ui

External Storage (Public Preview)

This version adds experimental support for External Storage feature, allowing storing large payloads out-of-bounds,
effectively lifting usual payload size restrictions. Includes a storage driver for AWS S3. See feature guide at
https://docs.temporal.io/external-storage

What's Changed

2026-08-12 - cd2b543 - Upgrade temporal-api to v1.63.5 (#3003)
2026-08-12 - f973250 - Add @TemporalOperation annotation for Nexus operations (#2928)
2026-08-13 - 28619b8 - Add test verifying worker command polls omit versioning metadata (#3004)
2026-08-13 - 7cf3535 - 💥 Report Nexus input deserialization failures as non-retryable BAD_REQUEST (#3002)
2026-08-13 - 87a3c56 - Fix exception ser. in update validator (#3001)
2026-08-13 - ade44bc - 💥 Fix unbounded timeout failure chain in local activity (#3006)
2026-08-17 - af2f853 - Report non-retryable PayloadValidationError as BAD_REQUEST (#3009)
2026-08-20 - a0021f8 - Add payload validation failure factory (#3021)
2026-08-21 - ee9abf0 - Omit null payload validation details (#3027)
2026-08-24 - 12c2114 - Add SDK Sentinel PR responder (#3034)
2026-08-25 - 1b2ffb1 - [SDK Sentinel] Allow activity retry delay test to complete (#3010)
2026-08-26 - 3762754 - Default Nexus client activity task queue to the worker task queue (#3039)
2026-08-26 - 809e57c - Add failure_reason tag to activity execution failed metrics (#3036)
2026-08-26 - 867ecf0 - Remove Experimental annotation for user metadata from a few APIs (#3038)
2026-08-26 - c5f93b7 - Fix inconsistency in javadoc for WorkflowInterface (#2232) (#2233)
2026-08-26 - e10c8e6 - Fix NPE when a workflow implementation uses a composed @WorkflowImpl annotation (#3024)
2026-08-27 - 144ddea - Stabilize sticky cache metrics test (#3037)
2026-08-27 - 394d8ee - Fix setRetryOptions merging initialInterval into congestionInitialInterval (#2956)
2026-08-27 - 6d5ba59 - feat(#2790): Add ChildWorkflowOptions support to WorkflowImplementationOptions (#2887)
2026-08-27 - b7dd8c8 - Include WorkflowType in wrapFailure error message (#2960)
2026-08-27 - d730cff - Add GCP Cloud Run OpenTelemetry support (#3022)
2026-08-28 - 6c60097 - External Storage Integration: Lazy resolving references, general refactoring (#3016)
2026-08-31 - 4f5a107 - Fix custom slot supplier SlotInfo fields (#3014)
2026-09-02 - 496ddc0 - Add envconfig support to test harness (#2998)
2026-09-03 - 8d6c936 - Provision isolated Cloud namespaces for SDK tests (#3032)
2026-09-03 - dc0ad21 - Add workflow task completion pagination (#3051)
2026-09-04 - 015fdc1 - Pass a dedicated context to the driver selector (#3047)
2026-09-04 - 0817162 - External Storage Integration: NexusWorker (#3018)
2026-09-04 - 108462e - Bumping test CLI version (#3054)
2026-09-04 - 479ea76 - Fix WorkerFactory command-worker cleanup race (#2952)
2026-09-04 - b319d85 - Adding SDK Ergonomics Query link (#2988)
2026-09-08 - c73480f - Report runtime environment information in worker heartbeats (#3052)
2026-09-09 - a49045e - Implement operator commands for Standalone Activities (#3013)
2026-09-10 - 77b2db5 - External Storage Integration: Activity worker, client (#3020)
2026-09-10 - 895a65a - External Storage Integration: WorkflowWorker, replay, history (#3017)
2026-09-11 - afdfac2 - fix broken test that referenced InMemoryDriver (#3065)
2026-09-11 - dd28759 - Reject duplicates in SAA update options (#3061)
2026-09-14 - 0eade16 - Add extstore s3 driver (#2907)
2026-09-14 - c7f47b9 - Rename Standalone Activity StaticSummary to Summary (#3062)
2026-09-14 - f6968a4 - Removed @Experimental annotations from Standalone Activities API (#3071)