Annual plans are ten times the monthly price, charged once a year: $1,490 for Operator, $3,990 for Command, $9,990 for Sovereign. That is two months free against paying monthly — $124.17, $332.50 and $832.50 a month respectively — and Stripe charges the yearly figure, not the monthly equivalent.
The trial works the same way on annual: 14 days with a card on file, first charge on day 15. AI action allowances are still counted per calendar month, so an annual Command plan gives you 1,500 actions each month, not 18,000 to spend whenever. Actions beyond the allowance are billed at the plan's per-action rate.
Switching from monthly to annual part-way through a month is prorated by Stripe, so you are credited for the unused part of the month you already paid for.