Is there an annual plan, and how much do I save by paying yearly?

Yes. Both plans can be paid yearly. The Pro plan is $970 a year and the Founders plan is $2,970 a year. Paying yearly works like paying for ten months and getting twelve, so two months are free.

You can switch from monthly to yearly at any time. Go to Settings, then Billing, choose the plan and pick yearly in the pop-up. When you switch, you pay a prorated amount.

On a yearly plan, the AI assistant credits included in the plan are still given month by month, not all at once, and unused credits do not carry over to the next month.