The integration lets exchanges, fintechs and neobanks add bitcoin and stablecoin services for millions of users without holding customer keys or rebuilding server-based architecture.
Breez has partnered with Turnkey to let developers add non-custodial bitcoin to applications that run wallets from their own servers, targeting a long-standing trade-off between scale and self-custody. The setup is designed for mainstream apps that rely on a single backend to serve millions of users, where adding bitcoin has typically required companies to hold customer keys on their own servers and assume the legal, licensing and security burdens of custody. Under the new model, each user gets a wallet whose keys are created and stored in Turnkey’s secure enclaves (isolated hardware-protected environments). Breez and Turnkey said those keys remain inaccessible to the app’s servers, Breez and Turnkey, while the company backend holds only a credential defining which actions it can take. Control over moving funds stays with the user. The approval flow uses a user-held credential such as a passkey (passwordless login credential) registered with Turnkey at signup. A server prepares a transaction and shows the amount, fee and destination, then the user approves it before completion. The companies said the server cannot spend funds without that approval, allowing apps to preserve their existing user experience without requiring a seed phrase. The integration combines Turnkey’s support for Spark, the network the Breez SDK is built on, with Breez’s server mode so one backend can manage wallets for millions of users without storing keys. Breez said in a note to Bitcoin Magazine that the release is meant to help exchanges, fintechs and neobanks offer bitcoin and stablecoin services at scale while keeping custody with users. The launch builds on earlier Breez SDK features including Passkey Login, Stable Balance and support for sending USDT and USDC.