1.31.0

Notable Changes

Added

• Added the Worker max_eager_activity_reservations_per_workflow_task option for configuring
  the number of activity slots reserved for eager execution per workflow task. Configured values
  must be positive; use disable_eager_activity_execution to disable eager activity execution.

• Added experimental SDK payload converter support for values and type hints
  decorated with @transfer_type_convertible(...) using a TransferTypeConverter class.
  This lets types with transfer type converters delegate their wire representation to the
  configured payload converter, preserving SDK behavior such as serialization
  contexts.

• Added TLSConfig.verification_server_name to verify the server certificate against a fixed name
  instead of the connection's server name. Unlike domain, it does not change the TLS SNI or
  HTTP/2 authority values, which keep following the connected host, so it can be used when the
  server's certificate does not carry the dialed name but on-path infrastructure (e.g. an
  SNI-inspecting egress proxy) needs the SNI to remain resolvable. Requires
  server_root_ca_cert.

• Added the experimental Worker patch_activation_callback option, allowing workers
  to decide whether a first non-replay workflow.patched call should activate a patch
  during rolling deployments.

Changed

• Prepared replay-safe workflow activation scheduling that prevents cancellation
  from being lost when another event becomes ready in the same workflow task. The
  behavior is guarded by internal workflow logic flag 2 and remains disabled by
  default during its compatibility rollout.
  Maintainer reminder: keep flag 2 default-disabled for the first two published
  SDK releases that recognize it; enable it in the third release, remove the explicit
  overrides for this flag from tests/worker/test_workflow.py, and replace this rollout
  note with a Fixed entry announcing the behavior change.

💥 Breaking Changes

• Custom workflow runners that construct WorkflowInstanceDetails must now pass
  payload_converter_factory instead of payload_converter_class. The factory
  returns the already wrapped payload converter that workflow instances should
  use.
• System Nexus payload converter helpers added for generated bindings are now
  private implementation details, and the remaining public temporalio.nexus.system
  APIs are marked experimental and subject to change.
• Payload size limits have moved from DataConverter to Client.connect. Pass
  payload_limits=PayloadLimitsConfig(...) (now exported from
  temporalio.client) instead of setting payload_limits on DataConverter.
  Config fields were renamed to payloads_warn_size and memo_warn_size, and
  the deprecated PayloadSizeWarning was removed.

Fixed

• Marked system Nexus envelope payloads so nested payloads can be detected and
  visited after the envelope is already stored as a payload.

SDK Core

• db902171 cleanup changelog (#1374)
• 353fd3b8 chore: limit wasm test concurrency (#1375)
• 5df57f6d fix(otel): install subscriber on PeriodicReader thread (#1378)
• 467e871a Update api upstream (#1367)
• d96b1eb4 feat(sdk): switch to rich search attributes from all getters (#1373)
• 9b9325cd fix(client): correctly handle Node gRPC style unimplemented method message (#1379)
• 8e21d5bc chore(ci): use mise for installing protoc (#1382)
• afb5251f feat(schedules): provide typed accessor to schedule action (#1372)
• 2cf2c103 Test Cloud gzip support for GetSystemInfo and HealthCheck (#1362)
• 03a6d123 chore(sdk): reject #[workflow(name=...)] for overriding workflow name (#1390)
• 95e97686 fix: use worker hearbeat interval for heartbeat system info poller (#1393)
• 6f75de52 Fix workflow executor cooperative budget livelock (#1396)
• 6a0a5bc3 docs: update contributing guide (#1397)
• 208ca8bc chore: add dev tools to mise.toml, remove redundant CI installs (#1386)
• 207194c9 Fix task slots used metric (#1391)
• 16452094 feat(sdk): remove remaining raw protos in APIs (#1398)
• e72c031f feat(sdk): provide typed accessor for workflow count group (#1410)
• 1b6e4e38 Allow resource controllers to be shared across tuners (#1407)
• 3dac9013 feat: payload limit enforcement (#1363)
• 846ac2c5 chore: extract composite action for CI setup, add selective mise installs (#1387)
• 47d3a40e chore(ci): use github backend for temporal cli (#1414)
• a9bdead4 Add patch activation callback (#1394)
• 5f94631d Replace unmaintained backoff crate with backon (#1411)
• aeb102ef Only set worker control task queue field in polls when appropriate (#1418)
• 71f46055 feat(sdk): add random and uuid4 in workflow context (#1412)
• 52aa5ed7 fix(sdk): respect forced failure over completion in same poll (#1417)
• 19123894 chore(sdk): rename start_activity to execute_activity (#1416)
• 25de75e1 don't use versioning for internal nexus poller (#1420)
• eb004c78 Integrate Temporal API 1.63.4 (#1423)
• d2769368 Make eager activity reservation limit configurable (#1424)

What's Changed

• fix(activity): do not mutate caller-provided extra dict in LoggerAdapter by @1fanwang in #1513
• Update sdk-core to incorporate time-skipping api changes by @GregoryTravis in #1633
• Fix flaky TMPRL1104 duration-log assertions in test_extstore by @DABH in #1628
• Add dynamic node/task summaries to LangGraph plugin by @DABH in #1612
• Add First-Class Google Gen AI SDK Integration to Contrib by @JasonSteving99 in #1378
• fix: use functools.wraps in activity_tool to preserve annotations and module by @brucearctor in #1636
• Add musl/alpine support by @Sushisource in #1634
• Update extstore s3 driver key percent encoding to be consistent with other SDKs and S3's safe character guidelines. by @cconstable in #1637
• Update contributing guide by @tconley1428 in #1625
• Fix a few typos by @iampat in #1647
• Release the GIL during the activity heartbeat core call by @odedkedemdreeze in #1643
• Fix copy-paste error message in OpenTelemetryPlugin by @xumaple in #1649
• Clarify determinism of wait_condition with comment by @Sushisource in #1638
• Remove exclude-newer-package exemptions by @brianstrauch in #1653
• Add patch activation callback by @Sushisource in #1639
• Prevent post-return activity cancel from killing pool thread by @tconley1428 in #1654
• Fix stale workflow.tracer() references in OpenTelemetry contrib by @xumaple in #1662
• Fix type checking for google-genai 2.12.0 by @DABH in #1652
• 💥 refactor: payloads/memo size validation by @jmaeagle99 in #1640
• feat: expose histogram_bucket_overrides on OpenTelemetryConfig by @parth-wisdom in #1433
• Minor README update for Nexus operations and asyncio cancellation by @cretz in #1234
• fix: avoid spurious "exception in shielded future" logs on cancellation by @Bathula-Adiseshu in #1624
• Don't swallow stderr in gen_protos_docker by @dandavison in #1145
• Fixing indent issue with kwargs["extra"] by @MasonEgger in #789
• Fix minor typo by @tconley1428 in #1666
• Add TLSConfig.verification_server_name to decouple certificate verification from SNI by @kollektiv in #1651
• NEXUS-484: Support UpdateWorkflow as a Nexus Operation by @mavemuri in #1631
• fix: exclude sdk-core gitfile from wheels by @Sakshamm-Goyal in #1669
• 💥 Add transfer type payload conversion hooks by @tconley1428 in #1655
• Fix type checking for openai 2.45.0 by @xumaple in #1673
• Make eager activity reservation limit configurable by @Sushisource in #1674
• Unify Payload Visitation by @VegetarianOrc in #1684
• Add type_hint to TransferTypeConverter.from_transfer_type by @VegetarianOrc in #1685
• Fix cancellations being swallowed in some circumstances by @Sushisource in #1671
• Mark system Nexus envelope payloads by @tconley1428 in #1667
• AI-374: Warn against passing secrets through MCP factory_argument by @xumaple in #1688
• Prepare release 1.31.0 by @THardy98 in #1693

New Contributors

• @1fanwang made their first contribution in #1513
• @GregoryTravis made their first contribution in #1633
• @iampat made their first contribution in #1647
• @odedkedemdreeze made their first contribution in #1643
• @parth-wisdom made their first contribution in #1433
• @Bathula-Adiseshu made their first contribution in #1624
• @MasonEgger made their first contribution in #789
• @kollektiv made their first contribution in #1651
• @mavemuri made their first contribution in #1631
• @Sakshamm-Goyal made their first contribution in #1669

Full Changelog: 1.30.0...1.31.0