You should already have an NDA in place preferably including a non-solicitation clause, usually that comes first. After that you should have an LOI in place. Af

You should already have an NDA in place preferably including a non-solicitation clause, usually that comes first. After that you should have an LOI in place. After the LOI and before signing a purchase agreement, you'll go through DD. Even at that, you should hold back your IP until the Nth hour and you have a final version of the purchase agreement if you think that there's IP that they could steal and recreate to put you out of business. Obviously, you should speak to a transaction lawyer too.