Breez today announces FiatLink, an open application programming interface (API) standard for integrating ingress and egress ramps directly within Lightning wallets and apps. There are currently several issues with seamless integration of Bitcoin with fiat exchanges within apps, the most important of which is the lack of Lightning support by many brokerages. In addition, each brokerage service on the market builds proprietary APIs to integrate with their services, which increases the burden of multiple options integration by app and wallet developers. Breez SDK support for the FiatLink API can facilitate a single solution to both problems.
FiatLink, as an open interface standard, will also allow for seamless integration of multiple brokerage options within a Lightning app or wallet. Instead of having to integrate the individual API for each option independently, any brokerage service that has integrated FiatLink will be usable within the application without any additional development costs. This can help foster an interoperable ecosystem of multiple brokers and multiple apps all seeking the optimal price point in order to match users who need to acquire fiat currencies or Bitcoin. Swiss Bitcoin operations, such as Relai and Pocket Bitcoin, were consulted in designing the API design to meet the needs of existing brokerage services.
Multiple payment options are supported (SEPA, credit cards, bank transfers). API providers allow users to request price and cost estimates and final quotes, then confirm and finalize a quote for a specific order by entering their payment information. In Switzerland, users can make transactions worth up to 1,000 Swiss Francs (CHF) per transaction between Swiss brokerages and non-Swiss regulated banks without requiring additional KYC outside of the payment method.
Withdrawals from the brokerage service to the users' wallet are processed through LNURL-Withdraw. This is a function in the LNURL protocol that allows the user to save a static QR code and scan it at their leisure, negotiating in the background via HTTP providing an actual Lighting invoice to receive their Bitcoin. It allows an optional on-chain address to be included to facilitate an on-chain withdrawal if it fails to process via Lightning for any reason.
The API supports the Address Proof of Ownership Protocol (AOPP) required by some jurisdictions under the Travel Rule, but in the case of Lightning wallets and apps, it can generate a random key for a Lightning node to use for a single withdrawal.
FiatLink, if widely adopted, could offer a competitive and streamlined solution for integrating fiat-to-Bitcoin conversions for wallet and app developers to integrate.