Installation

Packages

The @polkadot/api-contract packages is to be used alongside the @polkadot/api package. With that in mind, we can install from npm, so we are not going to waste too much time with the bare basics, just install the API & contracts extensions via

yarn add @polkadot/api @polkadot/api-contract

Generally you would want to keep the versions of the 2 in lock-step, which mean that if you upgrade one or the other, ensure that the versions continue to match.

Notes on use

Be aware that Substrate chains are different, which means that some chains will not have the FRAME contracts pallet installed. For instance, relay chains such as Polkadot do not have this functionality; however, many have parachains that do.

Additionally the contracts pallet and ink! are still evolving. With the upgrade from ink! v2 to v3 the ABI structure has changed completely. As of the polkadot-js API v2.2.1 only ink! v3.0-rc1 and later is supported. If you are using an earlier version, this guide will not be useful since the wrapper interfaces have changed in a major way to support the new formats.

So once we have it installed, let's take a brief tour through the base classes and interfaces before we get into using them.