You could create a Mycodo Input as a Listener and have it expose an endpoint that will receive the payload, parse it, and store the data in the Mycodo time series database.
I would recommend incorporating an API key set on the User Config page, so you can manage access to the endpoint you expose, otherwise it could be a security risk.
You can find example Inputs that are Listeners (don’t do anything periodically, but just wait for things to occur) and how to expose a new endpoint in several Widgets. Now that I think about it, you may not be able to create a new endpoint with an Input. I’ll have to think more about this and review the code later to have a better sense of what’s currently possible.