Client library for secure key management and multi-blockchain communication
webmaster128 Merge pull request #532 from iov-one/cleanup-encode-fullsig
Move, cleanup and test encodeFullSignature()
Latest commit a8f645f Nov 14, 2018


Build Status

This repo is provides core functionality to all clients in a cross-platform typescript library. This can be used to build cli/gui clients, automated scripts, or help build bcp-proxy apps.

Main functionality provided:

  • Solid crypto library with HD support for ed25519 (following SLIP-0010, ledger compatible)
  • Secure private key management, including encrypted local storage for both browser and node
  • Generic, type-safe adaptor to read/write on tendermint rpc server (with http/s and ws/s support)
  • Adaptor to query / create transactions for IOV's testnet of the BNS blockchain
  • Adaptor for key management using IOV's BNS ledger app
  • High level controller for managing multiple user profiles and various key material
  • High level controller for managing read/write connections to multiple blockchains (CoreWriter)
  • Integration with REPL environment for quick prototyping for developers

This is still in pre-alpha state and will evolve quickly as we add support for multiple blockchains, more transactions types, and better extensibility. However, all attempts have been made that the foundational code is quite solid. A security audit and stable release will occur along with the timeline of IOV's mainnet launch, but developers looking for client-side libraries can do initial prototypes with the current state.

We are actively building out multiple clients on top of this library and shaking out usability issues in the API.


The compiled code from this package, which is published on npm, should work on any modern (2018) browser, and node 8+. The development environment has been tested on node 8.7.0 LTS and node 10.x.

Yarn not Npm Please npm install -g yarn and use yarn install, yarn build, etc. Developers who installed with npm i have reported problems in compiling, so wipe out node_modules and enjoy yarn.

CI Tests:

  • Linux: node 8, chrome, (electron manually)
  • OSX: node 8, chrome, firefox, safari, (electron manually)
  • Windows: node 8, (edge, electron manually)

(Node 10 tested on many dev machines)

Gettting Started

The best way to learn about code is to use it. You can read some examples in @iov/core. And you can use a REPL to interactively try the code.

Once you understand the basics, you can dig in deeper with the API documentation.

Api Docs

Documentation is published at

To build the documentation locally, run yarn install && yarn build && yarn docs in this repository. This will generate a ./docs directory in each package that you can browse locally to see API docs on the various packages.


We are more than happy to accept open source contributions. However, please try to work on existing issues or create an issue and get feedback from one of the main contributors before starting on a PR. If you don't know where to start, we try to tag "good first issues" that provide a nice way to get started with the iov-core repo.

Development Environment

If you go into a subpackage and try to yarn build or yarn test, chances are it will fail. The reason is that we only check in *.ts files, while we need the compiled *.js files to import other packages. We push these to npm but do not check them into git to avoid commit noise.

To get started, please go to the root directory and run:

yarn install
yarn build
yarn test

Once that passes, you have the code built and can go into any subdirectory, edit code and verify the changes with yarn test on that one package.

Integration Tests

There are a number of integration tests involving communication with tendermint (in iov-tendermint-rpc) and the bns blockchain (in iov-bns) that require a test server to run and are skipped by default. If you are working on those packages, please run those tests. (They require docker to be installed and executable by the current user)



cd packages/iov-tendermint-rpc
yarn test
cd ../..




cd packages/iov-bns
yarn test
cd ../..


If you are working on iov-lisk, you can run the tests against a local Lisk devnet. See scripts/lisk/ how to start the Lisk devnet.

cd packages/iov-lisk
yarn test

Browser tests

The CI runs all code not only under node, but also in various browsers

These work almost all of the time, but if you CI test fails in the browser, or if you are just curious to see this work, you can run the browser tests locally with any of the following, in any package you are working on:

yarn test-chrome
yarn test-firefox
yarn test-safari  # osx only
yarn test-edge    # windows only

Developing under Windows 10

Most of the developers working on this project in windows are also using Windows Subsystem for Linux (WSL), which should have maximum compatibility, as CI is linux and osx. However, we do attempt to ensure that this code also compiles on the normal windows shell, if you have set up git, node, yarn etc. correctly. (Note this has only be verified under windows 10, no guarantees for older versions).

Line endings (CRLF vs LF)

All the code in the repo should use LF not the windows-specific CRLF as a line ending. tsc is currently set up to output properly. However, you should also make sure your editor saves with LF line endings rather than CRLF.

A bigger issue is git changing the endings upon commit. Here is a short workaround, adapted from a stackoverflow discussion:

git config --global core.autocrlf false
git config --global core.eol lf

FAQ For Potential Issues

Libusb fails to build, why?

If you are running on linux, you may not have the proper dependencies installed. For ubuntu, try the following: sudo apt-get install libudev-dev libusb-1.0-0 libusb-1.0-0-dev. These are needed to compile the usb driver.

Currently, Libusb requires node-pre-gyp version 0.10.2 or lower to compile properly. If for some reason your dependency is 0.10.3 or higher, you may have issues. Its recommended to use only 0.10.2 until the compilation issues are fixed in the node-pre-gyp package. This package comes as a dependency of @ledger/hw-transport-node-hid and is not easily modifiable by our team. Once the issues are resolved, the hard requirement of this dependency will be removed to allow it to be synchronized with the packages that require it.

If node-pre-gyp keeps giving issues compiling this library, you may want to switch to node 8. There have been some reported issues on node 10.6.0 even after this, all around compiling node-usb for the ledger transport.

My PR works but the CI rejects it

Make sure you at least ran yarn test in all the directories where you modified code. The CI will reject any PR if type definitions change after compiling the code to ensure it was build and committed prior to pushing.


This repository is licensed under the Apache License 2.0 (see NOTICE and LICENSE).