Dead Letter Policy Protocol • AI Agent SDK

DeadLetterPolicyProtocol: Protocol for the durable-queue dead-letter decision.

DeadLetterPolicyProtocol

Defined in the protocols module.

Protocol for the durable-queue dead-letter decision.

Pure, import-free decision contract consumed by the outbound queue’s `drain and the inbound journal's redelivery/replay paths. The runtime supplies typed facts about a repeatedly-failing entry (its attempts, the first_seen_epoch it was first received, the current now_epoch, and a coarse error_class) and the policy returns a :class:DeadLetterDecision. Concrete queue state and side effects (SQLite rows, DLQ enqueue) stay in the implementation; this keeps the policy injectable and testable in isolation, symmetric with :class:SendPolicyProtocol / :class:RateLimitPolicyProtocol`.

A config-driven default (:class:AttemptAndAgeDeadLetterPolicy) is provided for the common “poison vs transient” case.

Methods

Source