Hey Xin - as Tom mentioned, if you want to do any schema validation or inspection that will have to be done on the recipient’s end. Whether that be using an AsyncAPI opensource community tooling for schema validation, or an IPaaS service (e.g. MuleSoft, Boomi), or writing your own custom payload inspection and validation microservice.
At the end of the day, Solace PubSub+ Event Broker is a “pipe” that streams data with no payload manipulation: whatever comes in goes out