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Fixed rates let a cross-chain transfer deliver its exact input amount, handling any slippage and bridging or swapping fees invisibly. A wallet that sends 100 USDC on Solana delivers 100 USDT on Arbitrum. This suits payouts, remittances, and any flow where a recipient expects an exact figure. Without fixed rates, bridging fees, swap fees, and slippage all come out of the transfer, so the amount that arrives is smaller than the amount sent.

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How it works

The app pays the routing cost so it does not reduce the amount delivered to the recipient. Prepaid accounts pay from their credit balance. Postpaid accounts pay through their monthly invoice. The prepaid balance must cover the sponsored fees before the transfer can proceed. Add credits if the balance is insufficient. View usage and billing for credit management and usage webhooks for charge events.

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Setup

Fee sponsorship supports prepaid and postpaid billing.
1

Set up billing

Open Fee sponsorship in the Privy Dashboard for the app. Select Add credits and complete the purchase. Credits are a balance purchased in advance. Privy deducts prepaid credits whenever it executes a sponsored action for the app, such as sponsoring gas or swap provider fees.
2

Enable gas sponsorship

Open the app’s Fee sponsorship page and turn on Sponsor gas fees to cover network gas. Under Supported chains, select the networks where the app will sponsor gas. See the gas sponsorship setup guide for details.
3

Enable swap provider fee sponsorship

Open the app’s Fee sponsorship page and turn on Sponsor swap provider fees. Sponsorship is supported for all routes.
The setting applies automatically to all supported routes for transfers, swaps, and crypto deposit addresses. No request parameter or integration change is required.

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Confirming the delivered amount

Use the quote endpoint and read estimated_output_amount to review the expected output. On non-fixed rate routes, the final amount received can differ due to slippage.
On a fixed-rate route, amount_type: 'exact_input' already delivers an exact figure to the recipient, so exact_output is rarely needed. See amount types for the difference between the two.

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Limitations

Fixed rates cover the cost of routing a transfer between chains or between assets. Same-chain, same-asset transfers have no routing cost to cover. Gas sponsorship covers network gas separately.
Fixed rates are a property of the app, so an app cannot turn them on for some transfers and not others.
Fixed rates change how routing costs are paid, not which routes exist. Available liquidity and supported asset pairs are unchanged. See the bridging limitations for supported routes.

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Next steps

Usage and billing

Manage prepaid credits or review postpaid billing.

Usage webhooks

Receive an event each time Privy records a charge.