Self-serve billing now has four tiers. Starter covers a team putting its first paid routines to work. Scale sits above Pro for teams running many concurrent routines, and its API keys carry full write access — creating and updating routines from your own code no longer requires Pro specifically.
Plan changes project through Stripe's lifecycle events, so upgrades, downgrades, and cancellations all land in your billing settings with the timing Stripe reports. The pricing page has the current comparison.