Temporal Interceptors are a mechanism for modifying inbound and outbound SDK calls. They are commonly used to add tracing and authorization to the scheduling and execution of Workflows and Activities. You can compare these to "middleware" in other frameworks.
The following types of Interceptors have been implemented:
WorkflowClientCallsInterceptor: Intercepts methods of the WorkflowClient, such as starting or signaling a Workflow.
WorkflowInboundCallsInterceptor: Intercepts inbound Workflow calls, including execution, Signals, and Queries.
WorkflowOutboundCallsInterceptor: Intercepts outbound Workflow calls to Temporal APIs, such as scheduling Activities and starting Timers.
ActivityInboundCallsInterceptor: Intercepts inbound calls to an Activity, such as execute.
GrpcClientInterceptor: Intercepts all service client gRPC calls (see
WorkflowOutboundRequestInterceptor: Intercepts all commands sent to the RoadRunner server (see
Please note that some interceptor interfaces will be expanded in the future. To avoid compatibility issues, always use the corresponding traits in your implementations. Traits will prevent implementations from breaking when new methods are added to the interfaces.
A reminder of this and a link to the corresponding trait are placed in the comments of the interceptor interfaces.
In this release, we have also added support for headers, which are an integral part of interceptors. Headers, being metadata, are intended for sharing context and auxiliary information. Headers sent at the start of a workflow will be propagated to all subsequent calls from the Workflow and can only be modified in interceptors.
Full Changelog: v2.6.2...v2.7.0-BETA1