---
home: true
heroText:
tagline:
# Bringing JavaScript to the Polkadot world.
# actionText: Repository Overview
# actionLink: /REPOS.md
features:
- title: API
  details: A powerful dynamic API that allows chain interactions with transparent encoding and decoding.
- title: Substrate defaults
  details: An overview of the various default methods, state entries and RPCs for Substrate-based chains.
- title: Types
  details: Various type interfaces to make using returned values from API calls transparent in your code.

footer: Apache-2 Licensed | Copyright © 2017-2019 polkadot-js authors and contributors
---

## Welcome

The API provides application developers the ability to query a node and interact with the Polkadot or Substrate chains using Javascript. Here you will find documentation and examples to get you started.

::: tip Getting started & Examples
[Jump right in](/start/) and get an overview on using the API in your projects, from installation all the way through to making it do magic.  Already understand how things work and just want the examples? [The ApiPromise examples](/examples/promise/) provide some basic recipies.
:::

## Available packages

This repository split up into a number of internal packages, namely -

- [api](api/README.md) Promise and RxJS-based APIs
- [types](types/README.md) Type encoding and decoding wrappers

## The Polkadot Project

You can read more about the Polkadot Network at [https://polkadot.network/](https://polkadot.network/) and more about the polkadot-js projects at [https://polkadot.js.org](https://polkadot.js.org)

## Github repositories

You can find the Polkadot repositories at:

- [https://github.com/polkadot-js](https://github.com/polkadot-js)
- [https://github.com/paritytech/polkadot](https://github.com/paritytech/polkadot)
- [https://github.com/paritytech/substrate](https://github.com/paritytech/substrate)

This documentation is generated from [https://github.com/polkadot-js/api](https://github.com/polkadot-js/api)

## Contributing

Contribution to the Polkadot JS API are more than welcome. You can [report issues](https://github.com/polkadot-js/api/issues/new) and [log feature requests](https://github.com/polkadot-js/api/issues/new).