Differences with LedgerJS

Device management kit aims to replace LedgerJS libraries, mainly hw-app-XXX and hw-transport-XXX libraries

Current Problems

Ledger JS libraries where initially made for Ledger Live applications. As Ledger Live is a pretty old project (> 7 years), we have inevitably a big technical debt. Moreover time make that some part of the logic are today hard to understand and to maintain.

Some device behavior are not correctly handled by the libraries, for example opening an application on the device will cause unexpected disconnection. Another feedback we have learnt from partners (software wallets) is that we have a lack of simplicity in the libraries, it requires low level knowledge to use them (ex: APDU concept).

Target

LedgerJS was intended for Ledger Live. It was not designed to be used by third party developers. With the Device Management Kit we are targeting third party developers first.

Abstract complexity

As said above, we wanted to reduce the entry level to interact with Ledger devices. So we have tried as much as possible to abstract the complexity of the communication with the device and provide a simple and easy-to-use API.

Multiple Connected devices

With LedgerJS, it was impossible to be connected at the same time to two devices. With DMK, we have made it possible to connect to multiple devices at the same time and interact from one to another.

When prefer LedgerJS instead of DMK ?

As we are still missing some features in DMK, you may still need to use LedgerJS in some cases. For example, we are missing signer for some blockchains, so you may still need to use LedgerJS to sign transactions. Some solutions are studied at the moment to provide a better compatibility between DMK and LedgerJS.