Zemu Testing Framework

Downloads in past


2960.37.0a day ago3 years agoMinified + gzip package size for @zondax/zemu in KB


License npm version GithubActions
We appreciate any contributions to this effort!
We recommend using the npmjs package in order to receive updates/fixes.

This project is under active development - API and usage guidelines are very likely to change


Integration and end-to-end testing of Ledger Apps is a manual and time consuming process. We believe that the Ledger apps ecosystem is lacking an adequate approach with respect to testing. The Zemu Framework is our solution for this problem. Under the hood, Zemu uses Ledger's project speculos. It's currently being used in every Ledger App built by Zondax, among many others (such as Ethereum one built by Ledger team).
Zemu is an emulation and testing framework for Ledger Nano S/S+/X devices.


  • Minimal configuration + Docker based
  • Speculos/Qemu based emulation
  • Easy JS API
- Mocha / Jest compatible - Parallelized testing - Abstracted device control (buttons, reset, etc.) - Navigate thru screens and take screenshots of them
  • Debugging (support for CLion and vscode, even mixed C/Rust)


Check our documentation and quickstart at https://docs.zondax.ch
Who we are?
We are Zondax, a company pioneering blockchain services. If you want to know more about us, please visit us at zondax.ch