system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] I'm the benevolent lifetime ruler of an independent planet. When the Empire shows up, can I just swear my planet's loyalty to them and avoid a painful annexation. Would I need to give them troops?, natural resources? military garrison? do I need to hand over my reign entirely?
gpt
A lot won't really change. Yes you would have to swear allegiance to the Empire and would have to accept some new laws and oversight. However the Empire is more than happy to leave the day to day running of the planetary government to the existing rulers, such as yourself.

They will leave a garrison on world to assist you with any problems you may encounter.

As for what you need to give to the Empire depends on the type of planet you govern. At the very least you will have to allow the recruiting of troops from your populous. You will also have to pay various Imperial taxes, and tributes. The Empire may also set some guidelines on natural resources or manufacturing that you will abide by.

All in all, should you cooperate, it will go well, and profitably for you and your people.