The presented key's account: credits, scopes and per-call spending limit

Read-only; needs a key with the read scope and never returns the key. Check credits.available before a paid call, show the user the price first, and tell them what was spent afterwards. key.maxRequestPriceCredits null means the key has no per-call limit; each call's own maxPriceCredits still applies. Also available as the MCP tool get_daystruct_account. Charged responses report creditsRemaining. A low balance returns 402 insufficient_credits with requiredCredits, availableCredits and topUpUrl; a price above a limit returns 402 price_exceeds_limit with limitedBy (request or api_key).