Read the spending budget pay_service spends from: its cap, what has been spent, what remains, how many payments were made (and the limit, if any), and when it expires. Reading costs nothing and charges nothing. Use it whenever the human asks how much is left, or before a run of paid calls. Money is in CENTS: capCents is whole cents; spentCents and remainingCents can carry up to four decimals because the budget is charged per call at 1/10,000 of a cent (e.g. "1.632" = 1.632¢), and spentCents + remainingCents = capCents while the budget is within its cap. Tell the human message as it stands and never substitute a figure of your own: the budget includes routing fees and rounding, so adding up your calls will not match it. With no delegationId it reads the budget pay_service would use; that only includes budgets that can still pay, so {"status":"no_active_delegation"} also covers a budget that ran out or expired — pass the delegationId from an earlier pay_service result to read that one anyway. On a deployment that reports it, spentByDeliveryStatusCents splits the spend by what each payment delivered (delivered, charged_not_delivered, charged_unconfirmed, not_charged, not_delivered, pending, the deliveryStatus values list_payments uses), and unattributedSpentCents is spend no payment record itemizes; a non-zero charged_not_delivered is what was spent on calls that delivered nothing although the merchant charged (the merchant charge plus any routing fee not given back), so tell the human. not_delivered is held for calls the merchant answered with an error: not a confirmed charge; the reserve stays held until reconciliation decides whether the merchant charged after confirmed cancellation or authorization expiry (an older deployment reports it inside pending). lockedInChannels, when present, is money the wallet this budget pays from has deposited into payment channels with merchants that charge per call (per token, as in wallet_balance). It is that WALLET's total, shared by every budget paying from it, not a figure of this budget's own: it is NOT spent and NOT charged to this budget, it can pay further calls only to the merchant holding each channel, and what is unused comes back to that wallet when the channel closes, after 15 minutes without use; message then says so. An empty list means nothing is locked; null means it could not be read, and message then says that too. sessionChannels, when present, is the history behind that: each payment channel this budget used, newest first, with the merchant, its status, what was deposited (deposit, or depositAtomic in raw units when symbol is null), what came back (refund, null until the channel has closed and the refund is confirmed) and openedAt/closedAt. It is what explains money leaving the wallet and coming back when no payment shows it: a payment record carries one call's price, never the deposit. sharedWithOtherBudgets means the wallet's channel also served another budget, so its figures are not this budget's alone, and depositConfirmed: false means the open is not confirmed, so the deposit may not have landed. sessionChannelsTruncated: true means the list holds only the newest channels and older ones exist; message then says so. An empty list means none was used; null means it could not be read, and message then says so. Absent means this reader cannot see them: a budget owned by someone else, or an older deployment. Inventory fields creditsCoverage and creditsCoverageMessage describe public catalog eligibility, even when this caller has no subscription access or credit consent. Relay the message when present; absent means unavailable, never zero. A get_service endpoint carries subscription when credits can pay it. Its estimatedCreditsPerCall is an estimate from the last price seen, since credits follow the service’s live price; quote_service gives the exact credits of a request. When you have a Nevermined Subscription the result also carries subscription (creditsLeft, a digit string of every unexpired credit; resetsAt, when the allowance expires and, unless cancelAtPeriodEnd, the next period's is granted; status, suspended and plan) and subscriptionMessage to relay as it stands; subscription.subscribed: false means none. Whether or not you subscribe, it also carries credits (null: could not be read, which is not the same as none): total, spendable (what can pay a call now), parts (kind allowance | welcome | topup | sla, credits, expiresAt — null never expires — and frozen: null, renewal_overdue for allowance credits frozen until a renewal payment goes through, dispute for every credit while a card dispute holds them) and nextExpiry, with creditsMessage to relay as it stands. Every amount is a digit string. Never count credits yourself. Requires your Nevermined API key on the Authorization header.