So, you've been working for 9 months with no agreements with the company? Did you even assign the rights to the IP you are creating to the company? If not, we

So, you've been working for 9 months with no agreements with the company? Did you even assign the rights to the IP you are creating to the company? If not, well, you likely have plenty of leverage. smt88 is right that it's hard to come up with a number in this type of situation. I don't think you should expect less than the other 2 engineers - they'll be further along in vesting, which would account for the extra time they've been working with the company. But get this dealt with ASAP. You want your equity ironed out before the company gets funding.