I have been working in what could be described as a niche marine sector for the last 12 years. Over the last 5 years, I taught myself how to code in python and a few other languages.
Once I became fairly competent at programming I started to see ways of developing a tool that would provide far greater news intelligence than was currently available in the market. I wrote the code during my spare time and after many refinements, it's working quite well on a standalone droplet paid for by myself and normally beats other news sources by a minimum of 6 hours which can provide a strong edge to major industry players.
Over the last 12 months, I have been forwarding alerts from the server to a company I have been freelancing for(Not as a programmer). The reception has been good but although undiscussed I was expecting them to make me some kind of offer or at least a financial contribution for the service I have been providing which has not materialised.
I made a few enquiries to other companies to see if they would be interested in my tool and have now been approached by one who has offered me a full-time contract albeit in a slightly different position than I am used to. They have asked under what terms I would bring my tool with me but I am uncertain as to how best to negotiate this.
Should I look at revealing the source code to them so that it can be further developed in-house as one of their own tools or keep the code private and just supply them with the service? Would it be best to safeguard my intellectual property?
Obviously, financial reward pays a large part in this but I have no idea how to value a piece of software like this. Even though the salary offer I received is good, it's slightly worse than what I am currently making as a freelancer and I am not sure if I should try to push for more at the risk of scaring them away from hiring me.