# fintrapay

> fintrapay is a crypto payment gateway. Businesses use it to accept stablecoin
> payments, send payouts, and withdraw balances across 7 blockchains through a
> single HTTP API, with hosted checkout, webhooks and official SDKs in five
> languages.

Two integration modes. **Custodial**: fintrapay derives a deposit address per
invoice, holds the balance, and the merchant withdraws or pays out from it.
**Non-custodial**: the merchant supplies an XPUB, and each invoice is paid to a
fresh address derived from it, in the merchant's own wallet — fintrapay never
holds the funds.

## Networks and assets

- Chains (7): TRON, BSC, Ethereum, Solana, Base, Arbitrum, Polygon
- Stablecoins (6): USDT, USDC, DAI, FDUSD, TUSD, PYUSD
- 25 valid token/chain pairs. USDC on TRON is not supported — Circle
  discontinued it in February 2025.

## Pricing

- Invoice fee: 0.4% of the invoice amount
- Withdrawal fee: network fee only, no flat component
- Payout fee: $0.01 flat plus network fee, charged per payout — a batch charges
  it per recipient, not once per batch
- Network fee: charged at cost plus a per-chain margin, shown to merchants as
  one combined "Network Fee"

## API

- [Full API reference, plain text](https://fintrapay.io/llms-full.txt): every
  endpoint, parameter and auth detail in one file — the best starting point for
  an automated reader
- [OpenAPI 3.0 spec](https://fintrapay.io/openapi.json): machine-readable schema
- [API documentation](https://fintrapay.io/docs): the same reference for humans
- Base URL: `https://fintrapay.io/v1`
- Auth: HMAC-SHA256 request signing. Headers `X-API-Key`, `X-Timestamp`,
  `X-Signature`; the signature covers
  `timestamp + "\n" + METHOD + "\n" + path + "\n" + body`, with a ±30 second
  timestamp window. The API secret is never transmitted.

## SDKs

Official clients handle HMAC signing and webhook verification for you:
Python, PHP, Node.js, Go, Java.

## Pages

- [Home](https://fintrapay.io/)
- [Pricing](https://fintrapay.io/pricing)
- [For developers](https://fintrapay.io/developers)
- [Products](https://fintrapay.io/products)
- [Contact](https://fintrapay.io/contact)

## Optional

- [Payments](https://fintrapay.io/products/payments)
- [Payouts](https://fintrapay.io/products/payouts)
- [Earn](https://fintrapay.io/products/earn)
- [Smart contracts](https://fintrapay.io/products/contracts)