It's pretty simple. You need to negotiate a deal with your employer now, quit the company or keep working at the company with the knowledge that they will own i

It's pretty simple. You need to negotiate a deal with your employer now, quit the company or keep working at the company with the knowledge that they will own it. By doing nothing it will be regarded as a work-for-hire owned by the employer. How would this be done: If they are open to negotiating with you, then I'd keep the deal pretty simple. Incorporate a company, figure out the structure of the cap table, and figure out how you are going to handle any obvious possible future disputes that will affect the continuity of the business. Eg. they stop paying you, you stop working on it, etc. What type/amount of ownership should I request? In business you should try to be equitable and leave some money on the table. Don't forget about all the time they have spent testing and giving feedback on the product. Figure out how much time each side has invested in this product, and also figure out who is going to be a better custodian of the product if there is a dispute in the future. Change the cap table accordingly. You can if necessary separate these two concepts. For example, one side can have dominant voting power over the company, but distributions of shares could be (if deemed appropriate) payed out 50/50 between the parties. Any other next steps (eg. like getting a lawyer involved) would be a dumb idea.