How to design a service which can be exposed a file endpoint, REST endpoint and MQ endpoint?

I have a transaction processing service, which can consume transaction from MQ, File or web service.

• MQ - output goes back to MQ
• File - output wrtites into filesystem
• Web service - sends back realtime response

Again request/response can be in any format - csv,json or xml Request can be a list containing multiple transactions.

What is the best way to design for such requirement ?