OpenCode Go usage limits

It's $10 a month, not $10 per 5 hours. The 5-hour window is only a cap on how fast you can use the plan: each model gets a monthly allowance in dollars, and you can spend up to 20% of it in any 5 hours and 50% in a week. When a window resets you don't pay again, you just wait for it. If you hit a limit you can keep going on the free models, or turn on Extra Usage to fall back to pay-as-you-go credits. Details are on the Go docs page.

request counts won't tell you much; model and prompt size change the cost, so the usage history is the useful bit for estimating your pace