Fees

There are several fee layers to consider in spanDEX, even though spanDEX itself does not impose fees:

• Provider fees: costs imposed by the upstream provider and included in the quote.
• Integrator fee capture: fee/surplus you choose to request because your product is sourcing order flow. This is activated by the provider on your behalf and included in the quote.
• LP fees: fees paid to market makers (AMM, RFQ, etc) and included in the quote.
• Network fees: gas costs, which scale with route complexity. They are not included in the quote output amount, but are estimated during simulation.

Provider Fees

These values represent default settings for each provider (new account or anonymous access) and are subject to negotiation.

Additionally, each swap has network fees, which are not included in outputTokens. Gas estimates can still be factored in when selecting quotes.

Integrator Fee Capture (Optional)

spanDEX supports two integrator fee-capture controls for applications that source order flow from end users:

• Fixed swap fee (integratorSwapFeeBps)
• Surplus share (integratorSurplusBps)

These requests are passed optimistically to providers. Each quote reports activatedFeatures so selection can prefer quotes that actually activated requested features.

Fixed Rate Swap Fees

Use a fixed bps fee when you want predictable revenue on eligible swaps.

import { createConfig, fabric, relay } from "@spandex/core";
 
const config = createConfig({
  providers: [fabric({ appId: "YOUR_FABRIC_APP_ID" }), relay({})],
  options: {
    integratorFeeAddress: "0xFee00000000000000000000000000000000000fee",
    integratorSwapFeeBps: 25, // 0.25%
  },
});

Surplus Capture

Surplus can be requested with integratorSurplusBps for providers that support it. If integratorSurplusAddress is omitted, the fallback is typically integratorFeeAddress.

import { createConfig, fabric, velora } from "@spandex/core";
 
const config = createConfig({
  providers: [fabric({ appId: "YOUR_FABRIC_APP_ID" }), velora({})],
  options: {
    integratorFeeAddress: "0xFee00000000000000000000000000000000000fee",
    integratorSwapFeeBps: 20,
    integratorSurplusBps: 1000, // 10%
  },
});

Integrator Fee Support by Provider

This table summarizes what a developer can control in the API today. Commercial enablement can still depend on provider plans/terms.

Swap fee requests are configured with integratorSwapFeeBps, and surplus requests are configured with integratorSurplusBps.

How Selection Uses Integrator Fee Requests

• Requested fees are optimistic; providers without support can still return valid quotes.
• activatedFeatures indicates which requested features were actually active.
• Selection strategies (other than fastest) prioritize higher feature activation count before the secondary criterion (best price, lowest gas, etc).