I’m looking for the best approach as to how I can go about doing validation of a message as its enqueued in async messaging based systems.

Scenario:
Let’s say we have a two services A and B where they need to interact with each other asynchronously. And we have a queue between them lets say SQS which will receive the message from A, which will be then polled by service B.

Ask:
How can I validate the message like doing schema validation as its enqueued to SQS since currently SQS doesnt have any in-built schema validation functionality like we have for JMS

Couple of options I can think of:

1. Have a validation layer maybe a small service sitting between A and SQS queue but not sure how feasible this will be
2. Use some sort of MOM like AWS Eventbridge between A and SQS queue as it has functionalities to validate schemas as well as it could act as a central location to store all the schemas
3. Have a rest endpoint in B that’ll do the validation and have SQS sitting behind B but then this removes the async communication b/w A and B

Would appreciate any inputs on the above ask and how it could be resolved via best practices.