I am building an application using NestJS with RabbitMQ to enable communication between two services in a microservices architecture. I have a specific question regarding RabbitMQ's support for mixed acknowledgment modes:

Can RabbitMQ support a custom approach where I can switch between auto-ack and manual-ack for different scenarios?

For example:

Non-critical messages: I want to use auto-acknowledgment. Even if an error occurs, these messages can be processed and acknowledged automatically. Critical messages (e.g., POST, PATCH APIs): I need to ensure data consistency between the two services. If the consumer service is down, the message should remain in the queue. When the consumer service is back online, it should process the message to update the data and maintain consistency. For such cases, I prefer manual acknowledgment to ensure the message isn't lost until explicitly acknowledged. Is it possible to implement this custom behavior in RabbitMQ with NestJS? If so, what are the best practices to achieve this?

I have explored the RabbitMQ transport options in NestJS, including configuring acknowledgment modes. I tried using the default auto-ack behavior for handling non-critical messages, which worked as expected.

For critical messages, I attempted to use manual acknowledgment by disabling auto-ack and handling channel.ack() manually within the consumer logic. My expectation was that non-critical messages would be auto-acked seamlessly, while critical messages would stay in the queue if not explicitly acknowledged.

However, I’m unsure if this approach aligns with RabbitMQ's capabilities in NestJS or if there’s a better way to implement this hybrid acknowledgment strategy. Specifically, I want to confirm if I can dynamically switch between auto-ack and manual-ack based on message types or priorities.