CHANGELOG.md

Changelog

[Unreleased]

Added

• Added the Runtime(disable_environment_info=...) option to control whether runtime, hosting, and platform information is included in worker heartbeats.

• temporalio.workflow.uuid7() generates a determinism-safe, time-sortable UUIDv7 (RFC 9562) from workflow time and the workflow's deterministic random generator, complementing the existing workflow.uuid4() (#1450). The workflow sandbox now also restricts the non-deterministic uuid.uuid7() added to the standard library in Python 3.14, matching the existing uuid.uuid1()/uuid.uuid4() restrictions.

• Experimental: TemporalOperationHandler can now use Standalone Activities as asynchronous Nexus Operation backing executions through TemporalNexusClient.start_activity.

Changed

• temporalio.contrib.pydantic converters now reuse Pydantic type adapters for repeated type hints instead of rebuilding their schemas for every payload, greatly speeding up decode of non-model hints such as discriminated unions (#1695). Up to 1024 type adapters are cached per converter instance by default, with least-recently-used eviction. To change the bound, pass max_cached_type_adapters to PydanticPayloadConverter (or PydanticJSONPlainPayloadConverter) from a nullary subclass used as the DataConverter.payload_converter_class; None makes the cache unbounded and zero disables caching.

Deprecated

💥 Breaking Changes

Fixed

• The google-adk extra now depends on mcp, so fresh installs of temporalio[google-adk] can import temporalio.contrib.google_adk_agents without separately installing mcp. Previously the import failed with an ImportError because google.adk.tools.mcp_tool only exports McpToolset when mcp is installed.
• temporalio.contrib.openai_agents no longer crashes when a plain dict is passed for run_config. (openai-agents >= 0.19.0 accepts dict run configs at its public runner API)

Security

[1.31.0] - 2026-07-29

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.

• Added external storage support to Nexus task handling.

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.

[1.30.0] - 2026-07-01

Added

• Nexus operation link propagation for signals. When a Nexus operation handler signals a workflow (including signal-with-start), the inbound Nexus request links are now forwarded onto the signaled workflow so its history events link back to the caller, and the link the server returns for the signaled event is attached to the caller workflow's Nexus operation history event. This makes the caller and callee mutually navigable in the UI for signal-based Nexus operations.
• Exposed backoff_start_interval for continue-as-new, to allow the new workflow to start after a delay.

Changed

• AWS Lambda worker configure parameter supports sync, async, and async generator style functions. This callback is invoked on the asyncio event loop.
• Relaxed the protobuf dependency bounds to allow protobuf 7 where compatible with the selected optional dependencies.
• Standalone Nexus operation links are now forwarded on start workflow and signal requests.

💥 Breaking Changes

• AWS Lambda worker configure parameter has been changed to be invoked per-invocation of the worker instead of only at startup. It is advised that any shared, heavy-weight operations are performed outside of the callback before run_worker is invoked.

[1.29.0] - 2026-06-17

Added

• Added experimental temporalio.workflow.signal_with_start_workflow, backed by generated system Nexus bindings for WorkflowService.SignalWithStartWorkflowExecution.
• Added OpenAI Agents plugin support for CustomTool dispatch, including lazy tool discovery through defer_loading.

Changed

• Client connections now use gzip transport-level gRPC compression by default. Pass grpc_compression=GrpcCompression.NONE to Client.connect or CloudOperationsClient.connect to disable it.

💥 Breaking Changes

• StartWorkflowUpdateWithStartInput now owns the authoritative rpc_metadata and rpc_timeout fields for OutboundInterceptor.start_update_with_start_workflow. These fields were removed from the nested update-with-start input objects, so custom interceptors that accessed them there should read or update the top-level fields instead.

Fixed

• Fixed breakpoint() and pdb.set_trace() inside workflow code when a worker runs with debug_mode=True or TEMPORAL_DEBUG=1; sandboxed workflows without debug mode now get a clearer error pointing to debug_mode=True.
• Fixed start_update_with_start_workflow interceptor handling so RPC metadata and timeouts are forwarded to the underlying execute_multi_operation call.
• Fixed OpenAI Agents plugin streamed event serialization when pydantic had not yet built deferred schemas, and fixed terminal sandbox errors retrying forever.
• Removed the lazy-connect lock from the per-RPC hot path. It was previously acquired on every RPC, putting an event-loop-bound primitive on the hot path; it is now skipped once the client is connected. This reduces the client's coupling to the event loop it connected on, which can help when reusing a single long-lived Client across event loops or threads (e.g. the dedicated-loop pattern used with gevent/gunicorn and synchronous services). Note this does not make a Client fully thread- or loop-agnostic; reusing one long-lived loop is still the recommended pattern.