Pricing and fees
Prices are per million tokens, separately for input and output, in USDC. Each provider sets its own for each bundle it serves. GET /v1/models shows the lowest live price per model.
What you pay
Section titled “What you pay”A reply costs input tokens × input price + output tokens × output price at the price of the provider that served it. The number is on the reply and in your usage history. Two percent of every settled reply goes to Katara; it is included in the price you see.
How it is charged
Section titled “How it is charged”Replies are paid from a prepaid balance held in the settlement contract, not straight from your wallet. When that balance cannot cover a request’s maximum cost (the input estimate plus max_tokens at the offer price), Katara first moves a small chunk, one dollar at launch, from your wallet into it through the approval you gave. If your wallet cannot fund even the shortfall, the request is refused and nothing is charged.
When the reply is complete and the provider’s signed receipt checks out, the exact cost is debited from that balance. Debits are grouped into one transaction every few seconds, which is what keeps the fee at 2% instead of gas eating it.
If a provider fails mid-reply, nothing is charged for that attempt.
Paying per request from a wallet
Section titled “Paying per request from a wallet”Programs that pay with a wallet signature on each request, without an account, settle each reply in its own transaction. Those requests carry a minimum charge of 0.01 USDC so that a very short reply does not cost more to collect than it earns. Replies above the minimum are charged their settled cost as usual. Replies paid from an account balance have no minimum.
Spendable balance
Section titled “Spendable balance”Spendable is your prepaid balance plus what the approval can still move in from your wallet. The wallet panel shows both parts. When the budget follows your balance, spendable equals your balance.
Taking money out
Section titled “Taking money out”The prepaid balance is yours. Ask for a withdrawal in the wallet panel and it pays out after a one-hour delay, minus any replies that were still being settled when you asked. While a withdrawal is pending, new requests are refused so nothing can be served against money that is leaving.
The public test network
Section titled “The public test network”On the test network the token is test USDC with no value. The faucet gives 5 a day per account. Prices and fees work the same way so you can see real numbers before production.