Promise and RxJS APIs around Polkadot and any Substrate-based chain RPC calls. It is dynamically generated based on what the Substrate runtime provides in terms of metadata. Full documentation & examples available
Clone or download
Travis CI
Travis CI [CI Skip] 0.40.4
Latest commit 668ec1d Jan 16, 2019

polkadotjs license style npm travis maintainability coverage greenkeeper dependency devDependency


This library provides a clean wrapper around all the methods exposed by a Polkadot/Subtrate network client and defines all the types exposed by a node. For complete documentation around the classes, interfaces and their use, visit the documentation portal.


Looking for tutorials to get started? Look at examples for guides on how to use the API to make queries and submit transactions.


The API is split up into a number of internal packages -

Type definitions for interfaces as exposed by Polkadot & Substrate clients -


Contributions are welcome!

To start off, this repo (along with others in the @polkadot family) uses yarn workspaces to organise the code. As such, after cloning, its dependencies should be installed via yarn, not via npm; the latter will result in broken dependencies.

To get started -

  1. Clone the repo locally, via git clone <optional local path>
  2. Ensure that you have a recent version of Node.js, for development purposes Node 10 is recommended.
  3. Ensure that you have a recent version of Yarn, for development purposes Yarn >=1.10.1 is required.
  4. Install the dependencies by running yarn
  5. Build the API Docs, via yarn run build
  6. Ready! Now you can launch the API Docs, via yarn gitbook serve
  7. Access the API Docs via http://localhost:4000