Set up - Rhinestone

An app fee is a fee your application charges on top of transaction execution costs. Set a rate; the user sees the quoted fee before signing, in the embedded wallet’s review or in your own UI with a custom signer. App fees remain user-paid even when you sponsor gas and bridging. appFees.feeBps is an integer from 0 to 10000, where 10000 is 100%. A rate of 25 requests a 0.25% fee. The charged amount comes from the quote, not the rate alone: collection depends on the route.

Embedded wallet
Custom signer

Configure the fee

Start with the embedded-wallet example in Send a transaction. It defines wallet, the chains, tokens, amount, and transfer calls used here.Add appFees to that request. Keep the source and other options from the transaction guide when your flow needs them:

const result = await wallet.sendIntent({
  source: { chain: base.id, token: usdcOnBase },
  destination: {
    chain: arbitrum.id,
    token: usdcOnArbitrum,
    amount,
    calls: [...calls],
  },
  appFees: { feeBps: 25 },
});

To apply a default to every intent, add this option to your existing client initialization:

const wallet = new WalletClient({
  ...clientConfig,
  appFees: { feeBps: 25 },
});

clientConfig is the provider, client ID, and sponsorship configuration from the shared setup.Update your existing client rather than creating a second one. Its default applies to SDK intents, batch items, the EIP-1193 provider, and wagmi when they use that client.Override the default with appFees on an individual sendIntent request or sendBatchIntent item. Use { feeBps: 0 } to disable the fee for that intent; omitting appFees inherits the default. With neither a default nor an override, no fee is requested. Non-integer or out-of-range rates are rejected before signing.Keep application authentication configured even for user-paid intents. The app JWT identifies your Rhinestone project, which receives the fee; the rate is not configured in the developer portal.

Display the fee

The review dialog shows App fee as a separate charged line and includes it in the total. It is never labeled sponsored. An intent signed with a session key shows no review, so disclose the fee in your own UI before the user grants the session.

Validate the rate

The browser chooses the rate. For sponsored intents, add an assertion to the signer from Sponsorship setup:

import { createSponsorshipSigner } from "@rhinestone/wallet/server";

export const sponsorshipSigner = createSponsorshipSigner({
  shouldSponsor: {
    appFees: (fee) => fee?.feeBps === 25,
  },
});

Keep your other authorization checks alongside this filter. extensionToken() refuses to issue a grant if the requested rate differs from 25 or is missing. Use sponsorshipMode: "required" when sponsorship denial must stop the flow; disabled does not request a sponsorship grant.This check authorizes the requested rate, not the amount ultimately collected. It does not enforce a fee on self-funded transactions or guarantee that a route can carry one. See Policies and security for the authorization boundary.

Configure the fee

Pass appFees when you prepare the transaction. This example requests 100 USDC on Arbitrum and adds a 25 basis point (0.25%) app fee:

import { arbitrum, base } from "viem/chains";

const usdcOnBase = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913";
const usdcOnArbitrum = "0xaf88d065e77c8cC2239327C5EDb3A432268e5831";

const prepared = await account.prepareTransaction({
  source: { chain: base, token: usdcOnBase },
  destination: {
    chain: arbitrum,
    token: usdcOnArbitrum,
    amount: 100_000_000n,
  },
  appFees: { feeBps: 25 },
});

The same appFees object applies to supported Solana delivery requests; keep the Solana transaction shape and inspect the quoted fee. Solana instruction execution, authority changes, and deployment do not accept app fees.App fees are configured per transaction, at the top level of the SDK request. In the EVM example, fund the account with enough Base USDC for the delivery and user-paid fees. Keep the account initialization from your existing wallet setup rather than creating a separate client for monetization.

Display the fee

Read the app fee from the final selected quote:

const appFeeUsd = prepared.quotes.best.cost.fees.breakdown.app.usd;

showFeeToUser({
  label: "App fee",
  amount: appFeeUsd,
  currency: "USD",
});

Display the fee before the user signs. If you select or prepare a different quote, update the displayed amount because costs can change with the route.The full fee breakdown is available at prepared.quotes.best.cost.fees.breakdown. Each category includes usd and sponsored; the app fee itself is not sponsorable.

Next, follow Monetize the flow to understand how the fee is calculated, collected, and withdrawn.

​Configure the fee

​Display the fee

​Validate the rate

​Configure the fee

​Display the fee

Configure the fee

Display the fee

Validate the rate

Configure the fee

Display the fee