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Interceptors

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Interceptors wrap inbound and outbound Temporal calls so you can apply shared behavior such as tracing, logging, or authorization. See Interceptors for the inbound vs outbound model.

Register them on the Client (client.Options.Interceptors), the Worker (worker.Options.Interceptors), or both. Full API: go.temporal.io/sdk/interceptor.

Implement a Client interceptor​

Embed ClientInterceptorBase on a type that implements InterceptClient, and embed ClientOutboundInterceptorBase on a type that overrides the calls you want to intercept. Forward every call you don't override to Next so the rest of the chain still runs.

type loggingClientInterceptor struct {
	interceptor.ClientInterceptorBase
}

func (loggingClientInterceptor) InterceptClient(
	next interceptor.ClientOutboundInterceptor,
) interceptor.ClientOutboundInterceptor {
	return &loggingClientOutboundInterceptor{
		ClientOutboundInterceptorBase: interceptor.ClientOutboundInterceptorBase{Next: next},
	}
}

type loggingClientOutboundInterceptor struct {
	interceptor.ClientOutboundInterceptorBase
}

func (l *loggingClientOutboundInterceptor) ExecuteWorkflow(
	ctx context.Context,
	in *interceptor.ClientExecuteWorkflowInput,
) (client.WorkflowRun, error) {
	log.Printf("starting workflow %q (%s)", in.Options.ID, in.WorkflowType)
	return l.Next.ExecuteWorkflow(ctx, in)
}

Register the interceptor when you create the Client:

c, err := client.Dial(client.Options{
	Interceptors: []interceptor.ClientInterceptor{&loggingClientInterceptor{}},
})

Worker interceptors follow the same pattern for WorkerInterceptorBase, WorkflowInboundInterceptorBase / WorkflowOutboundInterceptorBase, and ActivityInboundInterceptorBase / ActivityOutboundInterceptorBase. See the Logging Interceptor sample for a complete Worker interceptor and its registration.

Workflow interceptors and replay

Workflow interceptor methods also run during replay. Use replay-safe APIs for logging, randomness, and time.