FAQ

Why doesn't client.publish() throw on failure?

Every fallible operation returns a Result / AsyncResult (from unthrown) instead of throwing — await client.publish(...) gives you a Result that you .match() or chain. (unthrown 4 gates .unwrap() to infallible results, so to throw on failure you unwrap with .unwrapOrElse((e) => { throw e }) — see Getting the value out.) This makes failure handling explicit and type-checked rather than an invisible try/catch obligation. The Error Model guide explains the full Ok / Err / Defect model.

Which schema libraries can I use?

Any library implementing Standard Schema v1 — Zod, Valibot, and ArkType are all tested. See Schema Libraries.

Do I need to install amqplib myself?

No. amqplib (and amqp-connection-manager) ship as regular dependencies of the amqp-contract packages. Installing them yourself only risks version drift. You do need to install unthrown and your schema library directly, since both appear in the types you write against.

Why are queues quorum by default?

Quorum queues are RabbitMQ's recommended replicated queue type for data safety. amqp-contract defaults to them and only uses classic queues for features quorum queues don't support (exclusive, autoDelete, maxPriority, non-durable). See Defining Contracts.

Does it work with NestJS (or other frameworks)?

amqp-contract is framework-agnostic — it runs anywhere Node.js does, and you can wire the client/worker into any framework's lifecycle. There is no dedicated NestJS module today; if that would unblock you, open an issue.

Does it support Kafka, NATS, or SQS?

No — amqp-contract targets AMQP 0-9-1 (RabbitMQ) specifically, which is what allows it to model exchanges, queues, bindings, and routing keys in the type system.

Does it support request/reply (RPC)?

Yes — define an RPC in the contract and both the caller and the responder are typed, with timeout and cancellation handling. See Client Usage and Worker Usage.

How do I test my contracts?

@amqp-contract/testing provides Vitest fixtures that spin up a real RabbitMQ via testcontainers with per-test vhost isolation. See the Testing guide.