Behaviour activities implement to be dispatched by Hourglass.ActivityRunner.

Contract

An activity module's execute/1 callback receives the decoded input term and returns the output term directly. The runner handles encoding/decoding via Hourglass.Codec and the typed I/O accessors injected by use Hourglass.Activity.

Raises (programming bugs, e.g. FunctionClauseError, MatchError) flow through the runner's rescue clause and are classified via Hourglass.Activity.RetryClassifier.classify/1. The classifier marks programming-bug exceptions as :non_retryable (see RetryClassifier's @programming_bug_exceptions).

Authoring

Activity modules use Hourglass.Activity to inject the @behaviour declaration, the __activity_retry_policy__/0, __activity_input_type__/0, and __activity_output_type__/0 helpers that the runner reads at dispatch time. See Hourglass.Activity for the :input, :output, and :retry options.