Modify the payload format?

[jooosh]

I'm working through building out actions with HTTP handlers.  I have a client with an existing RESTful api that I would like to interface with, but I'm running into issues.  Specifically, I am unable to have my client modify their API to be compatible with Hasura's request payload.  My question is, do I have any options on the Hasura side to modify the payload format?

Instead of a payload format of:

{"action"..., "input": {"arg1": "<value>"}, "session_variables"}

I would just like to have the payload be:

{"arg1": "<value>"}

I asked on Discord and tried a few different paths (i.e. Running NGINX Lua to rewrite the payload) but the answers didn't seem optimal. I've even started digging into Haskell to see if I can hack at it myself but don't want to go down that path if there's any easier option.

Thanks in advance for the support.